SUBROUTINE SFLX ( Clu.....add COUPLE C C FFROZP,ICE,DT,ZLVL,NSOIL,SLDPTH, C COUPLE,FFROZP,ICEIN,DT,ZLVL,NSOIL,SLDPTH, Clu.....pass in RADFLX instead of SOLDN and SOLNET Clu F LWDN,SOLDN,SOLNET,SFCPRS,PRCP,SFCTMP,Q2,SFCSPD, F LWDN,SWDN, RADFLX,SFCPRS,PRCP,SFCTMP,Q2,SFCSPD, I TH2,Q2SAT,DQSDT2, S VEGTYP,SOILTYP,SLOPETYP,SHDFAC,SHDMIN,PTU,ALB,SNOALB,TBOT, H CMC,T1,STC,SMC,SH2O,SNOWH,SNEQV,ALBEDO,CH,CM, O ETA,SHEAT, C ---------------------------------------------------------------------- C OUTPUTS, DIAGNOSTICS, PARAMETERS BELOW GENERALLY NOT NECESSARY WHEN C COUPLED WITH E.G. A NWP MODEL (SUCH AS THE NOAA/NWS/NCEP MESOSCALE ETA C MODEL). OTHER APPLICATIONS MAY REQUIRE DIFFERENT OUTPUT VARIABLES. C ---------------------------------------------------------------------- O EC,EDIR,ET,ETT,ESNOW,DRIP,DEW, O BETA,ETP,SSOIL, O FLX1,FLX2,FLX3, O SNOMLT,SNCOVR, O RUNOFF1,RUNOFF2,RUNOFF3, O RC,PC,RSMIN,XLAI,RCS,RCT,RCQ,RCSOIL, D SOILW,SOILM, P SMCWLT,SMCDRY,SMCREF,SMCMAX,NROOT) IMPLICIT NONE Clu --------------------------------------------------------------------- C (1) MODIFY CALLING ARGUMENT C 1. ADD 'COUPLE' (=1: COUPLED, =0: UNCOUPLED) C 2. REPLACE (SOLDN,SOLNET) BY (RADFLX) C (2) MODIFY SOURCE CODE C 1. INVOKE THE SECTION OF SFCDIF IF COUPLE=0 C 2. APPLY TIME FILTER TO STC AND TSKIN C 3. MODIFY HOW NAMELIST IS READ IN Clu --------------------------------------------------------------------- C ---------------------------------------------------------------------- C SUBROUTINE SFLX - VERSION 2.7 - June 2nd 2003 C ---------------------------------------------------------------------- C SUB-DRIVER FOR "NOAH/OSU LSM" FAMILY OF PHYSICS SUBROUTINES FOR A C SOIL/VEG/SNOWPACK LAND-SURFACE MODEL TO UPDATE SOIL MOISTURE, SOIL C ICE, SOIL TEMPERATURE, SKIN TEMPERATURE, SNOWPACK WATER CONTENT, C SNOWDEPTH, AND ALL TERMS OF THE SURFACE ENERGY BALANCE AND SURFACE C WATER BALANCE (EXCLUDING INPUT ATMOSPHERIC FORCINGS OF DOWNWARD C RADIATION AND PRECIP) C ---------------------------------------------------------------------- C SFLX ARGUMENT LIST KEY: C ---------------------------------------------------------------------- C C CONFIGURATION INFORMATION C F FORCING DATA C I OTHER (INPUT) FORCING DATA C S SURFACE CHARACTERISTICS C H HISTORY (STATE) VARIABLES C O OUTPUT VARIABLES C D DIAGNOSTIC OUTPUT C ---------------------------------------------------------------------- C 1. CONFIGURATION INFORMATION (C): C ---------------------------------------------------------------------- C COUPLE 0=UNCOUPLED (LAND MODEL ONLY) C 1=COUPLED ...WITH PARENT ATMOS MODEL C ICEIN SEA-ICE FLAG (= 1: SEA-ICE, = 0: LAND) C DT TIMESTEP (SEC) (DT SHOULD NOT EXCEED 3600 SECS, RECOMMEND C 1800 SECS OR LESS) C ZLVL HEIGHT (M) ABOVE GROUND OF ATMOSPHERIC FORCING VARIABLES C NSOIL NUMBER OF SOIL LAYERS (AT LEAST 2, AND NOT GREATER THAN C PARAMETER NSOLD SET BELOW) C SLDPTH THE THICKNESS OF EACH SOIL LAYER (M) C ---------------------------------------------------------------------- C 2. FORCING DATA (F): C ---------------------------------------------------------------------- C LWDN LW DOWNWARD RADIATION (W M-2; POSITIVE, NOT NET LONGWAVE) C SWDN SW DOWNWARD RADIATION (W M-2; POSITIVE, NOT NET SHORTWAVE) C RADFLX COUPLED MODE = NET SOLAR + DOWNWARD LONGWAVE C UNCOUPLED MODE = DOWNWARD (INCOMING) SOLAR, NOT NET SOLAR C SOLDN SOLAR DOWNWARD RADIATION (W M-2; POSITIVE, NOT NET SOLAR) C SOLNET NET SOLAR DOWNWARD RADIATION (W M-2; POSITIVE) C SFCPRS PRESSURE AT HEIGHT ZLVL ABOVE GROUND (PASCALS) C PRCP PRECIP RATE (KG M-2 S-1) (NOTE, THIS IS A RATE) C SFCTMP AIR TEMPERATURE (K) AT HEIGHT ZLVL ABOVE GROUND C TH2 AIR POTENTIAL TEMPERATURE (K) AT HEIGHT ZLVL ABOVE GROUND C Q2 MIXING RATIO AT HEIGHT ZLVL ABOVE GROUND (KG KG-1) C ---------------------------------------------------------------------- C 3. OTHER FORCING (INPUT) DATA (I): C ---------------------------------------------------------------------- C SFCSPD WIND SPEED (M S-1) AT HEIGHT ZLVL ABOVE GROUND C Q2SAT SAT MIXING RATIO AT HEIGHT ZLVL ABOVE GROUND (KG KG-1) C DQSDT2 SLOPE OF SAT SPECIFIC HUMIDITY CURVE AT T=SFCTMP C (KG KG-1 K-1) C ---------------------------------------------------------------------- C 4. CANOPY/SOIL CHARACTERISTICS (S): C ---------------------------------------------------------------------- C VEGTYP VEGETATION TYPE (INTEGER INDEX) C SOILTYP SOIL TYPE (INTEGER INDEX) C SLOPETYP CLASS OF SFC SLOPE (INTEGER INDEX) C SHDFAC AREAL FRACTIONAL COVERAGE OF GREEN VEGETATION C (FRACTION= 0.0-1.0) C SHDMIN MINIMUM AREAL FRACTIONAL COVERAGE OF GREEN VEGETATION C (FRACTION= 0.0-1.0) <= SHDFAC C PTU PHOTO THERMAL UNIT (PLANT PHENOLOGY FOR ANNUALS/CROPS) C (NOT YET USED, BUT PASSED TO REDPRM FOR FUTURE USE IN C VEG PARMS) C ALB BACKROUND SNOW-FREE SURFACE ALBEDO (FRACTION), FOR JULIAN C DAY OF YEAR (USUALLY FROM TEMPORAL INTERPOLATION OF C MONTHLY MEAN VALUES' CALLING PROG MAY OR MAY NOT C INCLUDE DIURNAL SUN ANGLE EFFECT) C SNOALB UPPER BOUND ON MAXIMUM ALBEDO OVER DEEP SNOW (E.G. FROM C ROBINSON AND KUKLA, 1985, J. CLIM. & APPL. METEOR.) C TBOT BOTTOM SOIL TEMPERATURE (LOCAL YEARLY-MEAN SFC AIR C TEMPERATURE) C ---------------------------------------------------------------------- C 5. HISTORY (STATE) VARIABLES (H): C ---------------------------------------------------------------------- C CMC CANOPY MOISTURE CONTENT (M) C T1 GROUND/CANOPY/SNOWPACK) EFFECTIVE SKIN TEMPERATURE (K) C STC(NSOIL) SOIL TEMP (K) C SMC(NSOIL) TOTAL SOIL MOISTURE CONTENT (VOLUMETRIC FRACTION) C SH2O(NSOIL) UNFROZEN SOIL MOISTURE CONTENT (VOLUMETRIC FRACTION) C NOTE: FROZEN SOIL MOISTURE = SMC - SH2O C SNOWH ACTUAL SNOW DEPTH (M) C SNEQV LIQUID WATER-EQUIVALENT SNOW DEPTH (M) C NOTE: SNOW DENSITY = SNEQV/SNOWH C ALBEDO SURFACE ALBEDO INCLUDING SNOW EFFECT (UNITLESS FRACTION) C =SNOW-FREE ALBEDO (ALB) WHEN SNEQV=0, OR C =FCT(MSNOALB,ALB,VEGTYP,SHDFAC,SHDMIN) WHEN SNEQV>0 C CH SURFACE EXCHANGE COEFFICIENT FOR HEAT AND MOISTURE C (M S-1); NOTE: CH IS TECHNICALLY A CONDUCTANCE SINCE C IT HAS BEEN MULTIPLIED BY WIND SPEED. C CM SURFACE EXCHANGE COEFFICIENT FOR MOMENTUM (M S-1); NOTE: C CM IS TECHNICALLY A CONDUCTANCE SINCE IT HAS BEEN C MULTIPLIED BY WIND SPEED. CM IS NOT NEEDED IN SFLX C ---------------------------------------------------------------------- C 6. OUTPUT (O): C ---------------------------------------------------------------------- C OUTPUT VARIABLES NECESSARY FOR A COUPLED NUMERICAL WEATHER PREDICTION C MODEL, E.G. NOAA/NWS/NCEP MESOSCALE ETA MODEL. FOR THIS APPLICATION, C THE REMAINING OUTPUT/DIAGNOSTIC/PARAMETER BLOCKS BELOW ARE NOT C NECESSARY. OTHER APPLICATIONS MAY REQUIRE DIFFERENT OUTPUT VARIABLES. C ETA ACTUAL LATENT HEAT FLUX (W M-2: NEGATIVE, IF UP FROM C SURFACE) C SHEAT SENSIBLE HEAT FLUX (W M-2: NEGATIVE, IF UPWARD FROM C SURFACE) C ---------------------------------------------------------------------- C EC CANOPY WATER EVAPORATION (W M-2) C EDIR DIRECT SOIL EVAPORATION (W M-2) C ET(NSOIL) PLANT TRANSPIRATION FROM A PARTICULAR ROOT (SOIL) LAYER C (W M-2) C ETT TOTAL PLANT TRANSPIRATION (W M-2) C ESNOW SUBLIMATION FROM SNOWPACK (W M-2) C DRIP THROUGH-FALL OF PRECIP AND/OR DEW IN EXCESS OF CANOPY C WATER-HOLDING CAPACITY (M) C DEW DEWFALL (OR FROSTFALL FOR T<273.15) (M) C ---------------------------------------------------------------------- C BETA RATIO OF ACTUAL/POTENTIAL EVAP (DIMENSIONLESS) C ETP POTENTIAL EVAPORATION (W M-2) C SSOIL SOIL HEAT FLUX (W M-2: NEGATIVE IF DOWNWARD FROM SURFACE) C ---------------------------------------------------------------------- C FLX1 PRECIP-SNOW SFC (W M-2) C FLX2 FREEZING RAIN LATENT HEAT FLUX (W M-2) C FLX3 PHASE-CHANGE HEAT FLUX FROM SNOWMELT (W M-2) C ---------------------------------------------------------------------- C SNOMLT SNOW MELT (M) (WATER EQUIVALENT) C SNCOVR FRACTIONAL SNOW COVER (UNITLESS FRACTION, 0-1) C ---------------------------------------------------------------------- C RUNOFF1 SURFACE RUNOFF (M S-1), NOT INFILTRATING THE SURFACE C RUNOFF2 SUBSURFACE RUNOFF (M S-1), DRAINAGE OUT BOTTOM OF LAST C SOIL LAYER, ALSO KNOWN AS BASEFLOW C RUNOFF3 NUMERICAL TRUNCTATION IN EXCESS OF POROSITY (SMCMAX) C FOR A GIVEN SOIL LAYER AT THE END OF A TIME STEP C ---------------------------------------------------------------------- C RC CANOPY RESISTANCE (S M-1) C PC PLANT COEFFICIENT (UNITLESS FRACTION, 0-1) WHERE PC*ETP C = ACTUAL TRANSPIRATION C XLAI LEAF AREA INDEX (DIMENSIONLESS) C RSMIN MINIMUM CANOPY RESISTANCE (S M-1) C RCS INCOMING SOLAR RC FACTOR (DIMENSIONLESS) C RCT AIR TEMPERATURE RC FACTOR (DIMENSIONLESS) C RCQ ATMOS VAPOR PRESSURE DEFICIT RC FACTOR (DIMENSIONLESS) C RCSOIL SOIL MOISTURE RC FACTOR (DIMENSIONLESS) C ---------------------------------------------------------------------- C 7. DIAGNOSTIC OUTPUT (D): C ---------------------------------------------------------------------- C SOILW AVAILABLE SOIL MOISTURE IN ROOT ZONE (UNITLESS FRACTION C BETWEEN SMCWLT AND SMCMAX) C SOILM TOTAL SOIL COLUMN MOISTURE CONTENT (FROZEN+UNFROZEN) (M) C ---------------------------------------------------------------------- C 8. PARAMETERS (P): C ---------------------------------------------------------------------- C SMCWLT WILTING POINT (VOLUMETRIC) C SMCDRY DRY SOIL MOISTURE THRESHOLD WHERE DIRECT EVAP FRM TOP C LAYER ENDS (VOLUMETRIC) C SMCREF SOIL MOISTURE THRESHOLD WHERE TRANSPIRATION BEGINS TO C STRESS (VOLUMETRIC) C SMCMAX POROSITY, I.E. SATURATED VALUE OF SOIL MOISTURE C (VOLUMETRIC) C NROOT NUMBER OF ROOT LAYERS, A FUNCTION OF VEG TYPE, DETERMINED C IN SUBROUTINE REDPRM. C ---------------------------------------------------------------------- INTEGER NSOLD PARAMETER(NSOLD = 4) C ---------------------------------------------------------------------- C DECLARATIONS - LOGICAL C ---------------------------------------------------------------------- LOGICAL FRZGRA LOGICAL SATURATED LOGICAL SNOWNG C ---------------------------------------------------------------------- C DECLARATIONS - INTEGER C ---------------------------------------------------------------------- INTEGER COUPLE !...***Clu*** INTEGER ICEIN INTEGER ICE INTEGER K INTEGER KZ INTEGER NSOIL INTEGER NROOT INTEGER SLOPETYP INTEGER SOILTYP INTEGER VEGTYP C ---------------------------------------------------------------------- C DECLARATIONS - REAL C ---------------------------------------------------------------------- REAL ALBEDO REAL ALB REAL BEXP REAL BETA REAL CFACTR REAL CH REAL CM REAL CMC REAL CMCMAX REAL CP REAL CSNOW REAL CSOIL REAL CZIL REAL DEW REAL DF1 REAL DF1H REAL DF1A REAL DKSAT REAL DT REAL DWSAT REAL DQSDT2 REAL DSOIL REAL DTOT REAL DRIP REAL EC REAL EDIR REAL ESNOW REAL ET(NSOIL) REAL ETT REAL FRCSNO REAL FRCSOI REAL EPSCA REAL ETA REAL ETP REAL FDOWN REAL F1 REAL FLX1 REAL FLX2 REAL FLX3 REAL FXEXP REAL FRZX REAL SHEAT REAL HS REAL KDT REAL LWDN REAL SWDN REAL LVH2O REAL PC REAL PRCP REAL PTU REAL PRCP1 REAL PSISAT REAL Q2 REAL Q2SAT REAL QUARTZ REAL R REAL RADFLX ! ... *** Clu *** REAL RCH REAL REFKDT REAL RR REAL RTDIS(NSOLD) REAL RUNOFF1 REAL RUNOFF2 REAL RGL REAL RUNOFF3 REAL RSMAX REAL RC REAL RSMIN REAL RCQ REAL RCS REAL RCSOIL REAL RCT REAL RSNOW REAL SNDENS REAL SNCOND REAL SSOIL REAL SBETA REAL SFCPRS REAL SFCSPD REAL SFCTMP REAL SHDFAC REAL SHDMIN REAL SH2O(NSOIL) REAL SLDPTH(NSOIL) REAL SMCDRY REAL SMCMAX REAL SMCREF REAL SMCWLT REAL SMC(NSOIL) REAL SNEQV REAL SNCOVR REAL SNOWH REAL SN_NEW REAL SLOPE REAL SNUP REAL SALP REAL SNOALB REAL STC(NSOIL) REAL SNOMLT REAL SOLDN REAL SOILM REAL SOILW REAL SOILWM REAL SOILWW REAL T1 REAL T1V REAL T24 REAL T2V REAL TBOT REAL TH2 REAL TH2V REAL TOPT REAL TFREEZ REAL TSNOW REAL XLAI REAL ZLVL REAL ZBOT REAL Z0 REAL ZSOIL(NSOLD) REAL FFROZP REAL SOLNET REAL LSUBS C ---------------------------------------------------------------------- C DECLARATIONS - PARAMETERS C ---------------------------------------------------------------------- PARAMETER(TFREEZ = 273.15) PARAMETER(LVH2O = 2.501E+6) PARAMETER(LSUBS = 2.83E+6) PARAMETER(R = 287.04) PARAMETER(CP = 1004.5) C ---------------------------------------------------------------------- C INITIALIZATION C ---------------------------------------------------------------------- RUNOFF1 = 0.0 RUNOFF2 = 0.0 RUNOFF3 = 0.0 SNOMLT = 0.0 C ---------------------------------------------------------------------- C DEFINE LOCAL VARIABLE ICE TO ACHIEVE: C SEA-ICE CASE, ICE = 1 C NON-GLACIAL LAND, ICE = 0 C GLACIAL-ICE LAND, ICE = -1 C IF VEGTYPE=13 (GLACIAL-ICE), RE-SET ICE FLAG = -1 (GLACIAL-ICE) C NOTE: FOR OPEN-SEA, SFLX SHOULD *NOT* HAVE BEEN CALLED. C SET GREEN VEGETATION FRACTION (SHDFAC) = 0. C ---------------------------------------------------------------------- ICE = ICEIN IF (VEGTYP .EQ. 13) THEN ICE = -1 SHDFAC = 0.0 ENDIF IF (ICE .EQ. 1) THEN SHDFAC = 0.0 C ---------------------------------------------------------------------- C SET GREEN VEGETATION FRACTION (SHDFAC) = 0. C SET SEA-ICE LAYERS OF EQUAL THICKNESS AND SUM TO 3 METERS C ---------------------------------------------------------------------- DO KZ = 1,NSOIL ZSOIL(KZ) = -3.*FLOAT(KZ)/FLOAT(NSOIL) END DO ELSE C ---------------------------------------------------------------------- C CALCULATE DEPTH (NEGATIVE) BELOW GROUND FROM TOP SKIN SFC TO BOTTOM OF C EACH SOIL LAYER. NOTE: SIGN OF ZSOIL IS NEGATIVE (DENOTING BELOW C GROUND) C ---------------------------------------------------------------------- ZSOIL(1) = -SLDPTH(1) DO KZ = 2,NSOIL ZSOIL(KZ) = -SLDPTH(KZ)+ZSOIL(KZ-1) END DO ENDIF C ---------------------------------------------------------------------- C NEXT IS CRUCIAL CALL TO SET THE LAND-SURFACE PARAMETERS, INCLUDING C SOIL-TYPE AND VEG-TYPE DEPENDENT PARAMETERS. C SET SHDFAC=0.0 FOR BARE SOIL SURFACES C ---------------------------------------------------------------------- CALL REDPRM (VEGTYP,SOILTYP,SLOPETYP, + CFACTR,CMCMAX,RSMAX,TOPT,REFKDT,KDT,SBETA, O SHDFAC,RSMIN,RGL,HS,ZBOT,FRZX,PSISAT,SLOPE, + SNUP,SALP,BEXP,DKSAT,DWSAT,SMCMAX,SMCWLT,SMCREF, O SMCDRY,F1,QUARTZ,FXEXP,RTDIS,SLDPTH,ZSOIL, + NROOT,NSOIL,Z0,CZIL,XLAI,CSOIL,PTU) C ---------------------------------------------------------------------- C INITIALIZE PRECIPITATION LOGICALS. C ---------------------------------------------------------------------- SNOWNG = .FALSE. FRZGRA = .FALSE. C ---------------------------------------------------------------------- C OVER SEA-ICE OR GLACIAL-ICE, IF S.W.E. (SNEQV) BELOW THRESHOLD LOWER C BOUND (0.01 M FOR SEA-ICE, 0.10 M FOR GLACIAL-ICE), THEN SET AT LOWER C BOUND AND STORE THE SOURCE INCREMENT IN SUBSURFACE RUNOFF/BASEFLOW C (RUNOFF2). NOTE: RUNOFF2 IS THEN A NEGATIVE VALUE (AS A FLAG) OVER C SEA-ICE OR GLACIAL-ICE, IN ORDER TO ACHIEVE WATER BALANCE. C ---------------------------------------------------------------------- IF (ICE .EQ. 1) THEN IF (SNEQV .LT. 0.01) THEN c SNDENS = SNEQV/SNOWH c RUNOFF2 = -(0.01-SNEQV)/DT SNEQV = 0.01 SNOWH = 0.10 c SNOWH = SNEQV/SNDENS ENDIF ELSEIF (ICE .EQ. -1) THEN IF (SNEQV .LT. 0.10) THEN c SNDENS = SNEQV/SNOWH c RUNOFF2 = -(0.10-SNEQV)/DT SNEQV = 0.10 SNOWH = 1.00 c SNOWH = SNEQV/SNDENS ENDIF ENDIF C ---------------------------------------------------------------------- C FOR SEA-ICE AND GLACIAL-ICE CASES, SET SMC AND SH20 VALUES = 1 AS A C FLAG FOR NON-SOIL MEDIUM C ---------------------------------------------------------------------- IF (ICE .NE. 0) THEN DO KZ = 1,NSOIL SMC(KZ) = 1.0 SH2O(KZ) = 1.0 END DO ENDIF C ---------------------------------------------------------------------- C IF INPUT SNOWPACK IS NONZERO, THEN COMPUTE SNOW DENSITY "SNDENS" AND C SNOW THERMAL CONDUCTIVITY "SNCOND" (NOTE THAT CSNOW IS A FUNCTION C SUBROUTINE) C ---------------------------------------------------------------------- IF (SNEQV .EQ. 0.0) THEN SNDENS = 0.0 SNOWH = 0.0 SNCOND = 1.0 ELSE SNDENS = SNEQV/SNOWH sndens = max(0.0, min(1.0, sndens)) ! Added by Moorthi SNCOND = CSNOW(SNDENS) ENDIF C ---------------------------------------------------------------------- C DETERMINE IF IT'S PRECIPITATING AND WHAT KIND OF PRECIP IT IS. C IF IT'S PRCPING AND THE AIR TEMP IS COLDER THAN 0 C, IT'S SNOWING! C IF IT'S PRCPING AND THE AIR TEMP IS WARMER THAN 0 C, BUT THE GRND C TEMP IS COLDER THAN 0 C, FREEZING RAIN IS PRESUMED TO BE FALLING. C ---------------------------------------------------------------------- IF (PRCP .GT. 0.0) THEN C IF (SFCTMP .LE. TFREEZ) THEN IF (FFROZP .GT. 0.5) THEN SNOWNG = .TRUE. ELSE IF (T1 .LE. TFREEZ) FRZGRA = .TRUE. ENDIF ENDIF C ---------------------------------------------------------------------- C IF EITHER PRCP FLAG IS SET, DETERMINE NEW SNOWFALL (CONVERTING PRCP C RATE FROM KG M-2 S-1 TO A LIQUID EQUIV SNOW DEPTH IN METERS) AND ADD C IT TO THE EXISTING SNOWPACK. C NOTE THAT SINCE ALL PRECIP IS ADDED TO SNOWPACK, NO PRECIP INFILTRATES C INTO THE SOIL SO THAT PRCP1 IS SET TO ZERO. C ---------------------------------------------------------------------- IF ( (SNOWNG) .OR. (FRZGRA) ) THEN SN_NEW = PRCP * DT * 0.001 SNEQV = SNEQV + SN_NEW PRCP1 = 0.0 C ---------------------------------------------------------------------- C UPDATE SNOW DENSITY BASED ON NEW SNOWFALL, USING OLD AND NEW SNOW. C UPDATE SNOW THERMAL CONDUCTIVITY C ---------------------------------------------------------------------- CALL SNOW_NEW (SFCTMP,SN_NEW,SNOWH,SNDENS) SNCOND = CSNOW (SNDENS) ELSE C ---------------------------------------------------------------------- C PRECIP IS LIQUID (RAIN), HENCE SAVE IN THE PRECIP VARIABLE THAT C LATER CAN WHOLELY OR PARTIALLY INFILTRATE THE SOIL (ALONG WITH C ANY CANOPY "DRIP" ADDED TO THIS LATER) C ---------------------------------------------------------------------- PRCP1 = PRCP ENDIF C ---------------------------------------------------------------------- C DETERMINE SNOWCOVER FRACTION AND ALBEDO FRACTION OVER LAND. C ---------------------------------------------------------------------- IF (ICE .NE. 0) THEN C ---------------------------------------------------------------------- C SNOW COVER, ALBEDO OVER SEA-ICE, GLACIAL-ICE C ---------------------------------------------------------------------- SNCOVR = 1.0 ALBEDO = 0.65 ELSE C ---------------------------------------------------------------------- C NON-GLACIAL LAND C IF SNOW DEPTH=0, SET SNOWCOVER FRACTION=0, ALBEDO=SNOW FREE ALBEDO. C ---------------------------------------------------------------------- IF (SNEQV .EQ. 0.0) THEN SNCOVR = 0.0 ALBEDO = ALB ELSE C ---------------------------------------------------------------------- C DETERMINE SNOW FRACTION COVER. C DETERMINE SURFACE ALBEDO MODIFICATION DUE TO SNOWDEPTH STATE. C ---------------------------------------------------------------------- CALL SNFRAC (SNEQV,SNUP,SALP,SNOWH,SNCOVR) CALL ALCALC (ALB,SNOALB,SHDFAC,SHDMIN,SNCOVR,TSNOW,ALBEDO) ENDIF ENDIF C ---------------------------------------------------------------------- C THERMAL CONDUCTIVITY FOR SEA-ICE CASE, GLACIAL-ICE CASE C ---------------------------------------------------------------------- IF (ICE .NE. 0) THEN DF1 = 2.2 ELSE C ---------------------------------------------------------------------- C NEXT CALCULATE THE SUBSURFACE HEAT FLUX, WHICH FIRST REQUIRES C CALCULATION OF THE THERMAL DIFFUSIVITY. TREATMENT OF THE C LATTER FOLLOWS THAT ON PAGES 148-149 FROM "HEAT TRANSFER IN C COLD CLIMATES", BY V. J. LUNARDINI (PUBLISHED IN 1981 C BY VAN NOSTRAND REINHOLD CO.) I.E. TREATMENT OF TWO CONTIGUOUS C "PLANE PARALLEL" MEDIUMS (NAMELY HERE THE FIRST SOIL LAYER C AND THE SNOWPACK LAYER, IF ANY). THIS DIFFUSIVITY TREATMENT C BEHAVES WELL FOR BOTH ZERO AND NONZERO SNOWPACK, INCLUDING THE C LIMIT OF VERY THIN SNOWPACK. THIS TREATMENT ALSO ELIMINATES C THE NEED TO IMPOSE AN ARBITRARY UPPER BOUND ON SUBSURFACE C HEAT FLUX WHEN THE SNOWPACK BECOMES EXTREMELY THIN. C ---------------------------------------------------------------------- C FIRST CALCULATE THERMAL DIFFUSIVITY OF TOP SOIL LAYER, USING C BOTH THE FROZEN AND LIQUID SOIL MOISTURE, FOLLOWING THE C SOIL THERMAL DIFFUSIVITY FUNCTION OF PETERS-LIDARD ET AL. C (1998,JAS, VOL 55, 1209-1224), WHICH REQUIRES THE SPECIFYING C THE QUARTZ CONTENT OF THE GIVEN SOIL CLASS (SEE ROUTINE REDPRM) C ---------------------------------------------------------------------- CALL TDFCND (DF1,SMC(1),QUARTZ,SMCMAX,SH2O(1)) C ---------------------------------------------------------------------- C NEXT ADD SUBSURFACE HEAT FLUX REDUCTION EFFECT FROM THE C OVERLYING GREEN CANOPY, ADAPTED FROM SECTION 2.1.2 OF C PETERS-LIDARD ET AL. (1997, JGR, VOL 102(D4)) C ---------------------------------------------------------------------- DF1 = DF1 * EXP(SBETA*SHDFAC) ENDIF C ---------------------------------------------------------------------- C FINALLY "PLANE PARALLEL" SNOWPACK EFFECT FOLLOWING C V.J. LINARDINI REFERENCE CITED ABOVE. NOTE THAT DTOT IS C COMBINED DEPTH OF SNOWDEPTH AND THICKNESS OF FIRST SOIL LAYER C ---------------------------------------------------------------------- DSOIL = -(0.5 * ZSOIL(1)) IF (SNEQV .EQ. 0.) THEN SSOIL = DF1 * (T1 - STC(1) ) / DSOIL ELSE DTOT = SNOWH + DSOIL FRCSNO = SNOWH/DTOT FRCSOI = DSOIL/DTOT C C 1. HARMONIC MEAN (SERIES FLOW) C DF1 = (SNCOND*DF1)/(FRCSOI*SNCOND+FRCSNO*DF1) DF1H = (SNCOND*DF1)/(FRCSOI*SNCOND+FRCSNO*DF1) C 2. ARITHMETIC MEAN (PARALLEL FLOW) C DF1 = FRCSNO*SNCOND + FRCSOI*DF1 DF1A = FRCSNO*SNCOND + FRCSOI*DF1 C C 3. GEOMETRIC MEAN (INTERMEDIATE BETWEEN HARMONIC AND ARITHMETIC MEAN) C DF1 = (SNCOND**FRCSNO)*(DF1**FRCSOI) C TEST - MBEK, 10 Jan 2002 C weigh DF by snow fraction c DF1 = DF1H*SNCOVR + DF1A*(1.0-SNCOVR) c DF1 = DF1H*SNCOVR + DF1*(1.0-SNCOVR) DF1 = DF1A*SNCOVR + DF1*(1.0-SNCOVR) C ---------------------------------------------------------------------- C CALCULATE SUBSURFACE HEAT FLUX, SSOIL, FROM FINAL THERMAL DIFFUSIVITY C OF SURFACE MEDIUMS, DF1 ABOVE, AND SKIN TEMPERATURE AND TOP C MID-LAYER SOIL TEMPERATURE C ---------------------------------------------------------------------- SSOIL = DF1 * (T1 - STC(1) ) / DTOT ENDIF C ---------------------------------------------------------------------- C DETERMINE SURFACE ROUGHNESS OVER SNOWPACK USING SNOW CONDITION FROM C THE PREVIOUS TIMESTEP. C ---------------------------------------------------------------------- IF (COUPLE .EQ. 0) THEN C UNCOUPLED MODE IF (SNCOVR .GT. 0.) THEN CALL SNOWZ0 (SNCOVR,Z0) ENDIF ENDIF C ---------------------------------------------------------------------- C NEXT CALL ROUTINE SFCDIF TO CALCULATE THE SFC EXCHANGE COEF (CH) FOR C HEAT AND MOISTURE. C C NOTE !!! C COMMENT OUT CALL SFCDIF, IF SFCDIF ALREADY CALLED IN CALLING PROGRAM C (SUCH AS IN COUPLED ATMOSPHERIC MODEL). C C NOTE !!! C DO NOT CALL SFCDIF UNTIL AFTER ABOVE CALL TO REDPRM, IN CASE C ALTERNATIVE VALUES OF ROUGHNESS LENGTH (Z0) AND ZILINTINKEVICH COEF C (CZIL) ARE SET THERE VIA NAMELIST I/O. C C NOTE !!! C ROUTINE SFCDIF RETURNS A CH THAT REPRESENTS THE WIND SPD TIMES THE C "ORIGINAL" NONDIMENSIONAL "Ch" TYPICAL IN LITERATURE. HENCE THE CH C RETURNED FROM SFCDIF HAS UNITS OF M/S. THE IMPORTANT COMPANION C COEFFICIENT OF CH, CARRIED HERE AS "RCH", IS THE CH FROM SFCDIF TIMES C AIR DENSITY AND PARAMETER "CP". "RCH" IS COMPUTED IN "CALL PENMAN". C RCH RATHER THAN CH IS THE COEFF USUALLY INVOKED LATER IN EQNS. C C NOTE !!! C SFCDIF ALSO RETURNS THE SURFACE EXCHANGE COEFFICIENT FOR MOMENTUM, CM, C ALSO KNOWN AS THE SURFACE DRAGE COEFFICIENT, BUT CM IS NOT USED HERE. C ---------------------------------------------------------------------- C CALC VIRTUAL TEMPS AND VIRTUAL POTENTIAL TEMPS NEEDED BY SUBROUTINES C SFCDIF AND PENMAN. C ---------------------------------------------------------------------- T2V = SFCTMP * (1.0 + 0.61 * Q2 ) C xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx C KEY REQUIRED RADIATION TERM IS THE TOTAL DOWNWARD RADIATION (FDOWN) = C NET SOLAR (SOLNET) + DOWNWARD LONGWAVE (LWDN), FOR USE IN PENMAN EP C CALCULATION (PENMAN) AND OTHER SURFACE ENERGY BUDGET CALCUATIONS. C C ALSO NEED DOWNWARD SOLAR (SOLDN) FOR CANOPY RESISTANCE ROUTINE C (CANRES). C C FDOWN, SOLDN ARE DERIVED DIFFERENTLY IN THE UNCOUPLED AND COUPLED C MODES. C xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx IF (COUPLE .EQ. 0) THEN !......uncoupled mode C ---------------------------------------------------------------------- C UNCOUPLED MODE: C C COMPUTE SURFACE EXCHANGE COEFFICIENTS C ---------------------------------------------------------------------- T1V = T1 * (1.0 + 0.61 * Q2) TH2V = TH2 * (1.0 + 0.61 * Q2) CALL SFCDIF (ZLVL,Z0,T1V,TH2V,SFCSPD,CZIL,CM,CH) C ---------------------------------------------------------------------- C RADFLX = DOWNWARD (INCOMING) SOLAR, NOT NET SOLAR C ---------------------------------------------------------------------- SOLDN = RADFLX SOLNET = SOLDN*(1.0-ALBEDO) FDOWN = SOLNET + LWDN ELSE !......coupled mode C ---------------------------------------------------------------------- C COUPLED MODE (COUPLE .NE. 0): c C SURFACE EXCHANGE COEFFICIENTS COMPUTED EXTERNALLY AND PASSED IN, HENCE C SUBROUTINE SFCDIF NOT CALLED. C C RADFLX = FDOWN = NET SOLAR + DOWNWARD LONGWAVE C ---------------------------------------------------------------------- FDOWN = RADFLX SOLNET = FDOWN - LWDN c SOLDN = SOLNET/(1.0-ALBEDO) SOLDN=SWDN ENDIF C ---------------------------------------------------------------------- C CALL PENMAN SUBROUTINE TO CALCULATE POTENTIAL EVAPORATION (ETP), AND C OTHER PARTIAL PRODUCTS AND SUMS SAVE IN COMMON/RITE FOR LATER C CALCULATIONS. C ---------------------------------------------------------------------- CALL PENMAN (SFCTMP,SFCPRS,CH,T2V,TH2,PRCP,FDOWN,T24,SSOIL, & Q2,Q2SAT,ETP,RCH,EPSCA,RR,SNOWNG,FRZGRA, & DQSDT2,FLX2) C ---------------------------------------------------------------------- C CALL CANRES TO CALCULATE THE CANOPY RESISTANCE AND CONVERT IT INTO PC C IF NONZERO GREENNESS FRACTION C ---------------------------------------------------------------------- IF (SHDFAC .GT. 0.) THEN C ---------------------------------------------------------------------- C FROZEN GROUND EXTENSION: TOTAL SOIL WATER "SMC" WAS REPLACED C BY UNFROZEN SOIL WATER "SH2O" IN CALL TO CANRES BELOW C ---------------------------------------------------------------------- CALL CANRES (SOLDN,CH,SFCTMP,Q2,SFCPRS,SH2O,ZSOIL,NSOIL, & SMCWLT,SMCREF,RSMIN,RC,PC,NROOT,Q2SAT,DQSDT2, & TOPT,RSMAX,RGL,HS,XLAI, & RCS,RCT,RCQ,RCSOIL) ENDIF C ---------------------------------------------------------------------- C NOW DECIDE MAJOR PATHWAY BRANCH TO TAKE DEPENDING ON WHETHER SNOWPACK C EXISTS OR NOT: C ---------------------------------------------------------------------- ESNOW = 0.0 IF (SNEQV .EQ. 0.0) THEN CALL NOPAC (ETP,ETA,PRCP,SMC,SMCMAX,SMCWLT, & SMCREF,SMCDRY,CMC,CMCMAX,NSOIL,DT,SHDFAC, & SBETA,Q2,T1,SFCTMP,T24,TH2,FDOWN,F1,SSOIL, & STC,EPSCA,BEXP,PC,RCH,RR,CFACTR, & SH2O,SLOPE,KDT,FRZX,PSISAT,ZSOIL, & DKSAT,DWSAT,TBOT,ZBOT,RUNOFF1,RUNOFF2, & RUNOFF3,EDIR,EC,ET,ETT,NROOT,ICE,RTDIS, & QUARTZ,FXEXP,CSOIL, & BETA,DRIP,DEW,FLX1,FLX2,FLX3) ELSE CALL SNOPAC (ETP,ETA,PRCP,PRCP1,SNOWNG,SMC,SMCMAX,SMCWLT, & SMCREF,SMCDRY,CMC,CMCMAX,NSOIL,DT, & SBETA,DF1, & Q2,T1,SFCTMP,T24,TH2,FDOWN,F1,SSOIL,STC,EPSCA, & SFCPRS,BEXP,PC,RCH,RR,CFACTR,SNCOVR,SNEQV,SNDENS, & SNOWH,SH2O,SLOPE,KDT,FRZX,PSISAT,SNUP, & ZSOIL,DWSAT,DKSAT,TBOT,ZBOT,SHDFAC,RUNOFF1, & RUNOFF2,RUNOFF3,EDIR,EC,ET,ETT,NROOT,SNOMLT, & ICE,RTDIS,QUARTZ,FXEXP,CSOIL, & BETA,DRIP,DEW,FLX1,FLX2,FLX3,ESNOW) ENDIF C ---------------------------------------------------------------------- C PREPARE SENSIBLE HEAT (H) FOR RETURN TO PARENT MODEL C ---------------------------------------------------------------------- SHEAT = -(CH * CP * SFCPRS)/(R * T2V) * ( TH2 - T1 ) C ---------------------------------------------------------------------- C CONVERT UNITS AND/OR SIGN OF TOTAL EVAP (ETA), POTENTIAL EVAP (ETP), C SUBSURFACE HEAT FLUX (S), AND RUNOFFS FOR WHAT PARENT MODEL EXPECTS C CONVERT ETA FROM KG M-2 S-1 TO W M-2 C ---------------------------------------------------------------------- c ETA = ETA*LVH2O c ETP = ETP*LVH2O C ---------------------------------------------------------------------- EDIR = EDIR * LVH2O EC = EC * LVH2O DO K=1,4 ET(K) = ET(K) * LVH2O ENDDO ETT = ETT * LVH2O ESNOW = ESNOW * LSUBS ETP = ETP*((1.-SNCOVR)*LVH2O + SNCOVR*LSUBS) IF (ETP .GT. 0.) THEN ETA = EDIR + EC + ETT + ESNOW ELSE ETA = ETP ENDIF BETA = ETA/ETP C ---------------------------------------------------------------------- C ---------------------------------------------------------------------- C CONVERT THE SIGN OF SOIL HEAT FLUX SO THAT: C SSOIL>0: WARM THE SURFACE (NIGHT TIME) C SSOIL<0: COOL THE SURFACE (DAY TIME) C ---------------------------------------------------------------------- SSOIL = -1.0*SSOIL IF (ICE .EQ. 0) THEN C ---------------------------------------------------------------------- C FOR THE CASE OF LAND (BUT NOT GLACIAL-ICE): C CONVERT RUNOFF3 (INTERNAL LAYER RUNOFF FROM SUPERSAT) FROM M TO M S-1 C AND ADD TO SUBSURFACE RUNOFF/BASEFLOW (RUNOFF2). RUNOFF2 IS ALREADY C A RATE AT THIS POINT. C ---------------------------------------------------------------------- RUNOFF3 = RUNOFF3/DT RUNOFF2 = RUNOFF2+RUNOFF3 ELSE C ---------------------------------------------------------------------- C FOR THE CASE OF SEA-ICE (ICE=1) OR GLACIAL-ICE (ICE=-1), ADD ANY C SNOWMELT DIRECTLY TO SURFACE RUNOFF (RUNOFF1) SINCE THERE IS NO C SOIL MEDIUM, AND THUS NO CALL TO SUBROUTINE SMFLX (FOR SOIL MOISTURE C TENDENCY). C ---------------------------------------------------------------------- RUNOFF1 = SNOMLT/DT ENDIF C ---------------------------------------------------------------------- C TOTAL COLUMN SOIL MOISTURE IN METERS (SOILM) AND ROOT-ZONE C SOIL MOISTURE AVAILABILITY (FRACTION) RELATIVE TO POROSITY/SATURATION C ---------------------------------------------------------------------- SOILM = -1.0*SMC(1)*ZSOIL(1) DO K = 2,NSOIL SOILM = SOILM+SMC(K)*(ZSOIL(K-1)-ZSOIL(K)) END DO SOILWM = -1.0*(SMCMAX-SMCWLT)*ZSOIL(1) SOILWW = -1.0*(SMC(1)-SMCWLT)*ZSOIL(1) DO K = 2,NROOT SOILWM = SOILWM+(SMCMAX-SMCWLT)*(ZSOIL(K-1)-ZSOIL(K)) SOILWW = SOILWW+(SMC(K)-SMCWLT)*(ZSOIL(K-1)-ZSOIL(K)) END DO SOILW = SOILWW/SOILWM C ---------------------------------------------------------------------- C END SUBROUTINE SFLX C ---------------------------------------------------------------------- RETURN END SUBROUTINE ALCALC (ALB,SNOALB,SHDFAC,SHDMIN,SNCOVR,TSNOW,ALBEDO) IMPLICIT NONE C ---------------------------------------------------------------------- C CALCULATE ALBEDO INCLUDING SNOW EFFECT (0 -> 1) C ALB SNOWFREE ALBEDO C SNOALB MAXIMUM (DEEP) SNOW ALBEDO C SHDFAC AREAL FRACTIONAL COVERAGE OF GREEN VEGETATION C SHDMIN MINIMUM AREAL FRACTIONAL COVERAGE OF GREEN VEGETATION C SNCOVR FRACTIONAL SNOW COVER C ALBEDO SURFACE ALBEDO INCLUDING SNOW EFFECT C TSNOW SNOW SURFACE TEMPERATURE (K) C ---------------------------------------------------------------------- REAL ALB, SNOALB, SHDFAC, SHDMIN, SNCOVR, ALBEDO, TSNOW C ---------------------------------------------------------------------- C SNOALB IS ARGUMENT REPRESENTING MAXIMUM ALBEDO OVER DEEP SNOW, C AS PASSED INTO SFLX, AND ADAPTED FROM THE SATELLITE-BASED MAXIMUM C SNOW ALBEDO FIELDS PROVIDED BY D. ROBINSON AND G. KUKLA C (1985, JCAM, VOL 24, 402-411) C ---------------------------------------------------------------------- C changed in version 2.6 on June 2nd 2003 C ALBEDO = ALB + (1.0-(SHDFAC-SHDMIN))*SNCOVR*(SNOALB-ALB) ALBEDO = ALB + SNCOVR*(SNOALB-ALB) IF (ALBEDO .GT. SNOALB) ALBEDO=SNOALB C BASE FORMULATION (DICKINSON ET AL., 1986, COGLEY ET AL., 1990) C IF (TSNOW.LE.263.16) THEN C ALBEDO=SNOALB C ELSE C IF (TSNOW.LT.273.16) THEN C TM=0.1*(TSNOW-263.16) C ALBEDO=0.5*((0.9-0.2*(TM**3))+(0.8-0.16*(TM**3))) C ELSE C ALBEDO=0.67 C ENDIF C ENDIF C ISBA FORMULATION (VERSEGHY, 1991; BAKER ET AL., 1990) C IF (TSNOW.LT.273.16) THEN C ALBEDO=SNOALB-0.008*DT/86400 C ELSE C ALBEDO=(SNOALB-0.5)*EXP(-0.24*DT/86400)+0.5 C ENDIF C ---------------------------------------------------------------------- C END SUBROUTINE ALCALC C ---------------------------------------------------------------------- RETURN END SUBROUTINE CANRES (SOLAR,CH,SFCTMP,Q2,SFCPRS,SMC,ZSOIL,NSOIL, & SMCWLT,SMCREF,RSMIN,RC,PC,NROOT,Q2SAT,DQSDT2, & TOPT,RSMAX,RGL,HS,XLAI, & RCS,RCT,RCQ,RCSOIL) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE CANRES C ---------------------------------------------------------------------- C CALCULATE CANOPY RESISTANCE WHICH DEPENDS ON INCOMING SOLAR RADIATION, C AIR TEMPERATURE, ATMOSPHERIC WATER VAPOR PRESSURE DEFICIT AT THE C LOWEST MODEL LEVEL, AND SOIL MOISTURE (PREFERABLY UNFROZEN SOIL C MOISTURE RATHER THAN TOTAL) C ---------------------------------------------------------------------- C SOURCE: JARVIS (1976), NOILHAN AND PLANTON (1989, MWR), JACQUEMIN AND C NOILHAN (1990, BLM) C SEE ALSO: CHEN ET AL (1996, JGR, VOL 101(D3), 7251-7268), EQNS 12-14 C AND TABLE 2 OF SEC. 3.1.2 C ---------------------------------------------------------------------- C INPUT: C SOLAR INCOMING SOLAR RADIATION C CH SURFACE EXCHANGE COEFFICIENT FOR HEAT AND MOISTURE C SFCTMP AIR TEMPERATURE AT 1ST LEVEL ABOVE GROUND C Q2 AIR HUMIDITY AT 1ST LEVEL ABOVE GROUND C Q2SAT SATURATION AIR HUMIDITY AT 1ST LEVEL ABOVE GROUND C DQSDT2 SLOPE OF SATURATION HUMIDITY FUNCTION WRT TEMP C SFCPRS SURFACE PRESSURE C SMC VOLUMETRIC SOIL MOISTURE C ZSOIL SOIL DEPTH (NEGATIVE SIGN, AS IT IS BELOW GROUND) C NSOIL NO. OF SOIL LAYERS C NROOT NO. OF SOIL LAYERS IN ROOT ZONE (1.LE.NROOT.LE.NSOIL) C XLAI LEAF AREA INDEX C SMCWLT WILTING POINT C SMCREF REFERENCE SOIL MOISTURE (WHERE SOIL WATER DEFICIT STRESS C SETS IN) C RSMIN, RSMAX, TOPT, RGL, HS ARE CANOPY STRESS PARAMETERS SET IN C SURBOUTINE REDPRM C OUTPUT: C PC PLANT COEFFICIENT C RC CANOPY RESISTANCE C ---------------------------------------------------------------------- INTEGER NSOLD PARAMETER(NSOLD = 4) INTEGER K INTEGER NROOT INTEGER NSOIL REAL CH REAL CP REAL DELTA REAL DQSDT2 REAL FF REAL GX REAL HS REAL P REAL PART(NSOLD) REAL PC REAL Q2 REAL Q2SAT REAL RC REAL RSMIN REAL RCQ REAL RCS REAL RCSOIL REAL RCT REAL RD REAL RGL REAL RR REAL RSMAX REAL SFCPRS REAL SFCTMP REAL SIGMA REAL SLV REAL SMC(NSOIL) REAL SMCREF REAL SMCWLT REAL SOLAR REAL TOPT REAL SLVCP REAL ST1 REAL TAIR4 REAL XLAI REAL ZSOIL(NSOIL) PARAMETER(CP = 1004.5) PARAMETER(RD = 287.04) PARAMETER(SIGMA = 5.67E-8) PARAMETER(SLV = 2.501000E6) C ---------------------------------------------------------------------- C INITIALIZE CANOPY RESISTANCE MULTIPLIER TERMS. C ---------------------------------------------------------------------- RCS = 0.0 RCT = 0.0 RCQ = 0.0 RCSOIL = 0.0 RC = 0.0 C ---------------------------------------------------------------------- C CONTRIBUTION DUE TO INCOMING SOLAR RADIATION C ---------------------------------------------------------------------- FF = 0.55*2.0*SOLAR/(RGL*XLAI) RCS = (FF + RSMIN/RSMAX) / (1.0 + FF) RCS = MAX(RCS,0.0001) C ---------------------------------------------------------------------- C CONTRIBUTION DUE TO AIR TEMPERATURE AT FIRST MODEL LEVEL ABOVE GROUND C RCT EXPRESSION FROM NOILHAN AND PLANTON (1989, MWR). C ---------------------------------------------------------------------- RCT = 1.0 - 0.0016*((TOPT-SFCTMP)**2.0) RCT = MAX(RCT,0.0001) C ---------------------------------------------------------------------- C CONTRIBUTION DUE TO VAPOR PRESSURE DEFICIT AT FIRST MODEL LEVEL. C RCQ EXPRESSION FROM SSIB C ---------------------------------------------------------------------- RCQ = 1.0/(1.0+HS*(Q2SAT-Q2)) RCQ = MAX(RCQ,0.01) C ---------------------------------------------------------------------- C CONTRIBUTION DUE TO SOIL MOISTURE AVAILABILITY. C DETERMINE CONTRIBUTION FROM EACH SOIL LAYER, THEN ADD THEM UP. C ---------------------------------------------------------------------- GX = (SMC(1) - SMCWLT) / (SMCREF - SMCWLT) IF (GX .GT. 1.) GX = 1. IF (GX .LT. 0.) GX = 0. C ---------------------------------------------------------------------- C USE SOIL DEPTH AS WEIGHTING FACTOR C ---------------------------------------------------------------------- PART(1) = (ZSOIL(1)/ZSOIL(NROOT)) * GX C ---------------------------------------------------------------------- C USE ROOT DISTRIBUTION AS WEIGHTING FACTOR C PART(1) = RTDIS(1) * GX C ---------------------------------------------------------------------- DO K = 2,NROOT GX = (SMC(K) - SMCWLT) / (SMCREF - SMCWLT) IF (GX .GT. 1.) GX = 1. IF (GX .LT. 0.) GX = 0. C ---------------------------------------------------------------------- C USE SOIL DEPTH AS WEIGHTING FACTOR C ---------------------------------------------------------------------- PART(K) = ((ZSOIL(K)-ZSOIL(K-1))/ZSOIL(NROOT)) * GX C ---------------------------------------------------------------------- C USE ROOT DISTRIBUTION AS WEIGHTING FACTOR C PART(K) = RTDIS(K) * GX C ---------------------------------------------------------------------- END DO DO K = 1,NROOT RCSOIL = RCSOIL+PART(K) END DO RCSOIL = MAX(RCSOIL,0.0001) C ---------------------------------------------------------------------- C DETERMINE CANOPY RESISTANCE DUE TO ALL FACTORS. CONVERT CANOPY C RESISTANCE (RC) TO PLANT COEFFICIENT (PC) TO BE USED WITH POTENTIAL C EVAP IN DETERMINING ACTUAL EVAP. PC IS DETERMINED BY: C PC * LINERIZED PENMAN POTENTIAL EVAP = C PENMAN-MONTEITH ACTUAL EVAPORATION (CONTAINING RC TERM). C ---------------------------------------------------------------------- RC = RSMIN/(XLAI*RCS*RCT*RCQ*RCSOIL) c TAIR4 = SFCTMP**4. c ST1 = (4.*SIGMA*RD)/CP c SLVCP = SLV/CP c RR = ST1*TAIR4/(SFCPRS*CH) + 1.0 RR = (4.*SIGMA*RD/CP)*(SFCTMP**4.)/(SFCPRS*CH) + 1.0 DELTA = (SLV/CP)*DQSDT2 PC = (RR+DELTA)/(RR*(1.+RC*CH)+DELTA) C ---------------------------------------------------------------------- C END SUBROUTINE CANRES C ---------------------------------------------------------------------- RETURN END FUNCTION CSNOW (DSNOW) IMPLICIT NONE C ---------------------------------------------------------------------- C FUNCTION CSNOW C ---------------------------------------------------------------------- C CALCULATE SNOW TERMAL CONDUCTIVITY C ---------------------------------------------------------------------- REAL C REAL DSNOW REAL CSNOW REAL UNIT PARAMETER(UNIT = 0.11631) C ---------------------------------------------------------------------- C CSNOW IN UNITS OF CAL/(CM*HR*C), RETURNED IN W/(M*C) C BASIC VERSION IS DYACHKOVA EQUATION (1960), FOR RANGE 0.1-0.4 C ---------------------------------------------------------------------- C=0.328*10**(2.25*DSNOW) CSNOW=UNIT*C C ---------------------------------------------------------------------- C DE VAUX EQUATION (1933), IN RANGE 0.1-0.6 C ---------------------------------------------------------------------- C CSNOW=0.0293*(1.+100.*DSNOW**2) C ---------------------------------------------------------------------- C E. ANDERSEN FROM FLERCHINGER C ---------------------------------------------------------------------- C CSNOW=0.021+2.51*DSNOW**2 C ---------------------------------------------------------------------- C END FUNCTION CSNOW C ---------------------------------------------------------------------- RETURN END SUBROUTINE DEVAP (EDIR1,ETP1,SMC,ZSOIL,SHDFAC,SMCMAX,BEXP, c FUNCTION DEVAP (ETP1,SMC,ZSOIL,SHDFAC,SMCMAX,BEXP, & DKSAT,DWSAT,SMCDRY,SMCREF,SMCWLT,FXEXP) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE DEVAP C FUNCTION DEVAP C ---------------------------------------------------------------------- C CALCULATE DIRECT SOIL EVAPORATION C ---------------------------------------------------------------------- REAL BEXP c REAL DEVAP REAL EDIR1 REAL DKSAT REAL DWSAT REAL ETP1 REAL FX REAL FXEXP REAL SHDFAC REAL SMC REAL SMCDRY REAL SMCMAX REAL ZSOIL REAL SMCREF REAL SMCWLT REAL SRATIO C ---------------------------------------------------------------------- C DIRECT EVAP A FUNCTION OF RELATIVE SOIL MOISTURE AVAILABILITY, LINEAR C WHEN FXEXP=1. C FX > 1 REPRESENTS DEMAND CONTROL C FX < 1 REPRESENTS FLUX CONTROL C ---------------------------------------------------------------------- SRATIO = (SMC - SMCDRY) / (SMCMAX - SMCDRY) IF (SRATIO .GT. 0.) THEN FX = SRATIO**FXEXP FX = MAX ( MIN ( FX, 1. ) ,0. ) ELSE FX = 0. ENDIF C ---------------------------------------------------------------------- C ALLOW FOR THE DIRECT-EVAP-REDUCING EFFECT OF SHADE C ---------------------------------------------------------------------- c DEVAP = FX * ( 1.0 - SHDFAC ) * ETP1 EDIR1 = FX * ( 1.0 - SHDFAC ) * ETP1 C ---------------------------------------------------------------------- C END SUBROUTINE DEVAP C END FUNCTION DEVAP C ---------------------------------------------------------------------- RETURN END SUBROUTINE EVAPO (ETA1,SMC,NSOIL,CMC,ETP1,DT,ZSOIL, & SH2O, & SMCMAX,BEXP,PC,SMCWLT,DKSAT,DWSAT, & SMCREF,SHDFAC,CMCMAX, & SMCDRY,CFACTR, & EDIR1,EC1,ET1,ETT1,SFCTMP,Q2,NROOT,RTDIS,FXEXP) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE EVAPO C ---------------------------------------------------------------------- C CALCULATE SOIL MOISTURE FLUX. THE SOIL MOISTURE CONTENT (SMC - A PER C UNIT VOLUME MEASUREMENT) IS A DEPENDENT VARIABLE THAT IS UPDATED WITH C PROGNOSTIC EQNS. THE CANOPY MOISTURE CONTENT (CMC) IS ALSO UPDATED. C FROZEN GROUND VERSION: NEW STATES ADDED: SH2O, AND FROZEN GROUND C CORRECTION FACTOR, FRZFACT AND PARAMETER SLOPE. C ---------------------------------------------------------------------- INTEGER NSOLD PARAMETER(NSOLD = 4) INTEGER I INTEGER K INTEGER NSOIL INTEGER NROOT REAL BEXP REAL CFACTR REAL CMC REAL CMC2MS REAL CMCMAX c REAL DEVAP REAL DKSAT REAL DT REAL DWSAT REAL EC1 REAL EDIR1 REAL ET1(NSOIL) REAL ETA1 REAL ETP1 REAL ETT1 REAL FXEXP REAL PC REAL Q2 REAL RTDIS(NSOIL) REAL SFCTMP REAL SHDFAC REAL SMC(NSOIL) REAL SH2O(NSOIL) REAL SMCDRY REAL SMCMAX REAL SMCREF REAL SMCWLT REAL ZSOIL(NSOIL) C ---------------------------------------------------------------------- C EXECUTABLE CODE BEGINS HERE IF THE POTENTIAL EVAPOTRANSPIRATION IS C GREATER THAN ZERO. C ---------------------------------------------------------------------- EDIR1 = 0. EC1 = 0. DO K = 1,NSOIL ET1(K) = 0. END DO ETT1 = 0. IF (ETP1 .GT. 0.0) THEN C ---------------------------------------------------------------------- C RETRIEVE DIRECT EVAPORATION FROM SOIL SURFACE. CALL THIS FUNCTION C ONLY IF VEG COVER NOT COMPLETE. C FROZEN GROUND VERSION: SH2O STATES REPLACE SMC STATES. C ---------------------------------------------------------------------- IF (SHDFAC .LT. 1.) THEN CALL DEVAP (EDIR1,ETP1,SH2O(1),ZSOIL(1),SHDFAC,SMCMAX, c EDIR = DEVAP(ETP1,SH2O(1),ZSOIL(1),SHDFAC,SMCMAX, & BEXP,DKSAT,DWSAT,SMCDRY,SMCREF,SMCWLT,FXEXP) ENDIF C ---------------------------------------------------------------------- C INITIALIZE PLANT TOTAL TRANSPIRATION, RETRIEVE PLANT TRANSPIRATION, C AND ACCUMULATE IT FOR ALL SOIL LAYERS. C ---------------------------------------------------------------------- IF (SHDFAC.GT.0.0) THEN CALL TRANSP (ET1,NSOIL,ETP1,SH2O,CMC,ZSOIL,SHDFAC,SMCWLT, & CMCMAX,PC,CFACTR,SMCREF,SFCTMP,Q2,NROOT,RTDIS) DO K = 1,NSOIL ETT1 = ETT1 + ET1(K) END DO C ---------------------------------------------------------------------- C CALCULATE CANOPY EVAPORATION. C IF STATEMENTS TO AVOID TANGENT LINEAR PROBLEMS NEAR CMC=0.0. C ---------------------------------------------------------------------- IF (CMC .GT. 0.0) THEN EC1 = SHDFAC * ( ( CMC / CMCMAX ) ** CFACTR ) * ETP1 ELSE EC1 = 0.0 ENDIF C ---------------------------------------------------------------------- C EC SHOULD BE LIMITED BY THE TOTAL AMOUNT OF AVAILABLE WATER ON THE C CANOPY. -F.CHEN, 18-OCT-1994 C ---------------------------------------------------------------------- CMC2MS = CMC / DT EC1 = MIN ( CMC2MS, EC1 ) ENDIF ENDIF C ---------------------------------------------------------------------- C TOTAL UP EVAP AND TRANSP TYPES TO OBTAIN ACTUAL EVAPOTRANSP C ---------------------------------------------------------------------- ETA1 = EDIR1 + ETT1 + EC1 C ---------------------------------------------------------------------- C END SUBROUTINE EVAPO C ---------------------------------------------------------------------- RETURN END FUNCTION FRH2O (TKELV,SMC,SH2O,SMCMAX,BEXP,PSIS) IMPLICIT NONE C ---------------------------------------------------------------------- C FUNCTION FRH2O C ---------------------------------------------------------------------- C CALCULATE AMOUNT OF SUPERCOOLED LIQUID SOIL WATER CONTENT IF C TEMPERATURE IS BELOW 273.15K (T0). REQUIRES NEWTON-TYPE ITERATION TO C SOLVE THE NONLINEAR IMPLICIT EQUATION GIVEN IN EQN 17 OF KOREN ET AL C (1999, JGR, VOL 104(D16), 19569-19585). C ---------------------------------------------------------------------- C NEW VERSION (JUNE 2001): MUCH FASTER AND MORE ACCURATE NEWTON C ITERATION ACHIEVED BY FIRST TAKING LOG OF EQN CITED ABOVE -- LESS THAN C 4 (TYPICALLY 1 OR 2) ITERATIONS ACHIEVES CONVERGENCE. ALSO, EXPLICIT C 1-STEP SOLUTION OPTION FOR SPECIAL CASE OF PARAMETER CK=0, WHICH C REDUCES THE ORIGINAL IMPLICIT EQUATION TO A SIMPLER EXPLICIT FORM, C KNOWN AS THE "FLERCHINGER EQN". IMPROVED HANDLING OF SOLUTION IN THE C LIMIT OF FREEZING POINT TEMPERATURE T0. C ---------------------------------------------------------------------- C INPUT: C C TKELV.........TEMPERATURE (Kelvin) C SMC...........TOTAL SOIL MOISTURE CONTENT (VOLUMETRIC) C SH2O..........LIQUID SOIL MOISTURE CONTENT (VOLUMETRIC) C SMCMAX........SATURATION SOIL MOISTURE CONTENT (FROM REDPRM) C B.............SOIL TYPE "B" PARAMETER (FROM REDPRM) C PSIS..........SATURATED SOIL MATRIC POTENTIAL (FROM REDPRM) C C OUTPUT: C FRH2O.........SUPERCOOLED LIQUID WATER CONTENT C ---------------------------------------------------------------------- REAL BEXP REAL BLIM REAL BX REAL CK REAL DENOM REAL DF REAL DH2O REAL DICE REAL DSWL REAL ERROR REAL FK REAL FRH2O REAL GS REAL HLICE REAL PSIS REAL SH2O REAL SMC REAL SMCMAX REAL SWL REAL SWLK REAL TKELV REAL T0 INTEGER NLOG INTEGER KCOUNT PARAMETER(CK = 8.0) C PARAMETER(CK = 0.0) PARAMETER(BLIM = 5.5) PARAMETER(ERROR = 0.005) PARAMETER(HLICE = 3.335E5) PARAMETER(GS = 9.81) PARAMETER(DICE = 920.0) PARAMETER(DH2O = 1000.0) PARAMETER(T0 = 273.15) C ---------------------------------------------------------------------- C LIMITS ON PARAMETER B: B < 5.5 (use parameter BLIM) C SIMULATIONS SHOWED IF B > 5.5 UNFROZEN WATER CONTENT IS C NON-REALISTICALLY HIGH AT VERY LOW TEMPERATURES. C ---------------------------------------------------------------------- BX = BEXP IF (BEXP .GT. BLIM) BX = BLIM C ---------------------------------------------------------------------- C INITIALIZING ITERATIONS COUNTER AND ITERATIVE SOLUTION FLAG. C ---------------------------------------------------------------------- NLOG=0 KCOUNT=0 C ---------------------------------------------------------------------- C IF TEMPERATURE NOT SIGNIFICANTLY BELOW FREEZING (T0), SH2O = SMC C ---------------------------------------------------------------------- IF (TKELV .GT. (T0 - 1.E-3)) THEN FRH2O = SMC ELSE IF (CK .NE. 0.0) THEN C ---------------------------------------------------------------------- C OPTION 1: ITERATED SOLUTION FOR NONZERO CK C IN KOREN ET AL, JGR, 1999, EQN 17 C ---------------------------------------------------------------------- C INITIAL GUESS FOR SWL (frozen content) C ---------------------------------------------------------------------- SWL = SMC-SH2O C ---------------------------------------------------------------------- C KEEP WITHIN BOUNDS. C ---------------------------------------------------------------------- IF (SWL .GT. (SMC-0.02)) SWL = SMC-0.02 IF (SWL .LT. 0.) SWL = 0. C ---------------------------------------------------------------------- C START OF ITERATIONS C ---------------------------------------------------------------------- DO WHILE ( (NLOG .LT. 10) .AND. (KCOUNT .EQ. 0) ) NLOG = NLOG+1 DF = ALOG(( PSIS*GS/HLICE ) * ( ( 1.+CK*SWL )**2. ) * & ( SMCMAX/(SMC-SWL) )**BX) - ALOG(-(TKELV-T0)/TKELV) DENOM = 2. * CK / ( 1.+CK*SWL ) + BX / ( SMC - SWL ) SWLK = SWL - DF/DENOM C ---------------------------------------------------------------------- C BOUNDS USEFUL FOR MATHEMATICAL SOLUTION. C ---------------------------------------------------------------------- IF (SWLK .GT. (SMC-0.02)) SWLK = SMC - 0.02 IF (SWLK .LT. 0.) SWLK = 0. C ---------------------------------------------------------------------- C MATHEMATICAL SOLUTION BOUNDS APPLIED. C ---------------------------------------------------------------------- DSWL = ABS(SWLK-SWL) SWL = SWLK C ---------------------------------------------------------------------- C IF MORE THAN 10 ITERATIONS, USE EXPLICIT METHOD (CK=0 APPROX.) C WHEN DSWL LESS OR EQ. ERROR, NO MORE ITERATIONS REQUIRED. C ---------------------------------------------------------------------- IF ( DSWL .LE. ERROR ) THEN KCOUNT = KCOUNT+1 ENDIF END DO C ---------------------------------------------------------------------- C END OF ITERATIONS C ---------------------------------------------------------------------- C BOUNDS APPLIED WITHIN DO-BLOCK ARE VALID FOR PHYSICAL SOLUTION. C ---------------------------------------------------------------------- FRH2O = SMC - SWL C ---------------------------------------------------------------------- C END OPTION 1 C ---------------------------------------------------------------------- ENDIF C ---------------------------------------------------------------------- C OPTION 2: EXPLICIT SOLUTION FOR FLERCHINGER EQ. i.e. CK=0 C IN KOREN ET AL., JGR, 1999, EQN 17 C APPLY PHYSICAL BOUNDS TO FLERCHINGER SOLUTION C ---------------------------------------------------------------------- IF (KCOUNT .EQ. 0) THEN !Clu........comment out the following line to shorten the standard output !* Print*,'Flerchinger used in NEW version. Iterations=',NLOG FK = (((HLICE/(GS*(-PSIS)))* & ((TKELV-T0)/TKELV))**(-1/BX))*SMCMAX IF (FK .LT. 0.02) FK = 0.02 FRH2O = MIN (FK, SMC) C ---------------------------------------------------------------------- C END OPTION 2 C ---------------------------------------------------------------------- ENDIF ENDIF C ---------------------------------------------------------------------- C END FUNCTION FRH2O C ---------------------------------------------------------------------- RETURN END SUBROUTINE HRT (RHSTS,STC,SMC,SMCMAX,NSOIL,ZSOIL,YY,ZZ1, & TBOT,ZBOT,PSISAT,SH2O,DT,BEXP, & F1,DF1,QUARTZ,CSOIL,AI,BI,CI) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE HRT C ---------------------------------------------------------------------- C CALCULATE THE RIGHT HAND SIDE OF THE TIME TENDENCY TERM OF THE SOIL C THERMAL DIFFUSION EQUATION. ALSO TO COMPUTE ( PREPARE ) THE MATRIX C COEFFICIENTS FOR THE TRI-DIAGONAL MATRIX OF THE IMPLICIT TIME SCHEME. C ---------------------------------------------------------------------- INTEGER NSOLD PARAMETER(NSOLD = 4) LOGICAL ITAVG INTEGER I INTEGER K INTEGER NSOIL C ---------------------------------------------------------------------- C DECLARE WORK ARRAYS NEEDED IN TRI-DIAGONAL IMPLICIT SOLVER C ---------------------------------------------------------------------- REAL AI(NSOLD) REAL BI(NSOLD) REAL CI(NSOLD) C ---------------------------------------------------------------------- C DECLARATIONS C ---------------------------------------------------------------------- REAL BEXP REAL CAIR REAL CH2O REAL CICE REAL CSOIL REAL DDZ REAL DDZ2 REAL DENOM REAL DF1 REAL DF1N REAL DF1K REAL DT REAL DTSDZ REAL DTSDZ2 REAL F1 REAL HCPCT REAL PSISAT REAL QUARTZ REAL QTOT REAL RHSTS(NSOIL) REAL SSOIL REAL SICE REAL SMC(NSOIL) REAL SH2O(NSOIL) REAL SMCMAX REAL SNKSRC REAL STC(NSOIL) REAL T0 REAL TAVG REAL TBK REAL TBK1 REAL TBOT REAL ZBOT REAL TSNSR REAL TSURF REAL YY REAL ZSOIL(NSOIL) REAL ZZ1 PARAMETER(T0 = 273.15) C ---------------------------------------------------------------------- C SET SPECIFIC HEAT CAPACITIES OF AIR, WATER, ICE, SOIL MINERAL C ---------------------------------------------------------------------- PARAMETER(CAIR = 1004.0) PARAMETER(CH2O = 4.2E6) PARAMETER(CICE = 2.106E6) C NOTE: CSOIL NOW SET IN ROUTINE REDPRM AND PASSED IN C PARAMETER(CSOIL = 1.26E6) C ---------------------------------------------------------------------- C INITIALIZE LOGICAL FOR SOIL LAYER TEMPERATURE AVERAGING. C ---------------------------------------------------------------------- ITAVG = .TRUE. C ITAVG = .FALSE. C ---------------------------------------------------------------------- C BEGIN SECTION FOR TOP SOIL LAYER C ---------------------------------------------------------------------- C CALC THE HEAT CAPACITY OF THE TOP SOIL LAYER C ---------------------------------------------------------------------- HCPCT = SH2O(1)*CH2O + (1.0-SMCMAX)*CSOIL + (SMCMAX-SMC(1))*CAIR & + ( SMC(1) - SH2O(1) )*CICE C ---------------------------------------------------------------------- C CALC THE MATRIX COEFFICIENTS AI, BI, AND CI FOR THE TOP LAYER C ---------------------------------------------------------------------- DDZ = 1.0 / ( -0.5 * ZSOIL(2) ) AI(1) = 0.0 CI(1) = (DF1 * DDZ) / (ZSOIL(1) * HCPCT) BI(1) = -CI(1) + DF1 / (0.5 * ZSOIL(1) * ZSOIL(1)*HCPCT*ZZ1) C ---------------------------------------------------------------------- C CALCULATE THE VERTICAL SOIL TEMP GRADIENT BTWN THE 1ST AND 2ND SOIL C LAYERS. THEN CALCULATE THE SUBSURFACE HEAT FLUX. USE THE TEMP C GRADIENT AND SUBSFC HEAT FLUX TO CALC "RIGHT-HAND SIDE TENDENCY C TERMS", OR "RHSTS", FOR TOP SOIL LAYER. C ---------------------------------------------------------------------- DTSDZ = (STC(1) - STC(2)) / (-0.5 * ZSOIL(2)) SSOIL = DF1 * (STC(1) - YY) / (0.5 * ZSOIL(1) * ZZ1) RHSTS(1) = (DF1 * DTSDZ - SSOIL) / (ZSOIL(1) * HCPCT) C ---------------------------------------------------------------------- C NEXT CAPTURE THE VERTICAL DIFFERENCE OF THE HEAT FLUX AT TOP AND C BOTTOM OF FIRST SOIL LAYER FOR USE IN HEAT FLUX CONSTRAINT APPLIED TO C POTENTIAL SOIL FREEZING/THAWING IN ROUTINE SNKSRC. C ---------------------------------------------------------------------- QTOT = SSOIL - DF1*DTSDZ C ---------------------------------------------------------------------- C IF TEMPERATURE AVERAGING INVOKED (ITAVG=TRUE; ELSE SKIP): C SET TEMP "TSURF" AT TOP OF SOIL COLUMN (FOR USE IN FREEZING SOIL C PHYSICS LATER IN FUNCTION SUBROUTINE SNKSRC). IF SNOWPACK CONTENT IS C ZERO, THEN TSURF EXPRESSION BELOW GIVES TSURF = SKIN TEMP. IF C SNOWPACK IS NONZERO (HENCE ARGUMENT ZZ1=1), THEN TSURF EXPRESSION C BELOW YIELDS SOIL COLUMN TOP TEMPERATURE UNDER SNOWPACK. THEN C CALCULATE TEMPERATURE AT BOTTOM INTERFACE OF 1ST SOIL LAYER FOR USE C LATER IN FUNCTION SUBROUTINE SNKSRC C ---------------------------------------------------------------------- IF (ITAVG) THEN TSURF = (YY + (ZZ1-1) * STC(1)) / ZZ1 CALL TBND (STC(1),STC(2),ZSOIL,ZBOT,1,NSOIL,TBK) ENDIF C ---------------------------------------------------------------------- C CALCULATE FROZEN WATER CONTENT IN 1ST SOIL LAYER. C ---------------------------------------------------------------------- SICE = SMC(1) - SH2O(1) C ---------------------------------------------------------------------- C IF FROZEN WATER PRESENT OR ANY OF LAYER-1 MID-POINT OR BOUNDING C INTERFACE TEMPERATURES BELOW FREEZING, THEN CALL SNKSRC TO C COMPUTE HEAT SOURCE/SINK (AND CHANGE IN FROZEN WATER CONTENT) C DUE TO POSSIBLE SOIL WATER PHASE CHANGE C ---------------------------------------------------------------------- IF ( (SICE .GT. 0.) .OR. (TSURF .LT. T0) .OR. & (STC(1) .LT. T0) .OR. (TBK .LT. T0) ) THEN IF (ITAVG) THEN CALL TMPAVG(TAVG,TSURF,STC(1),TBK,ZSOIL,NSOIL,1) ELSE TAVG = STC(1) ENDIF TSNSR = SNKSRC (TAVG,SMC(1),SH2O(1), & ZSOIL,NSOIL,SMCMAX,PSISAT,BEXP,DT,1,QTOT) RHSTS(1) = RHSTS(1) - TSNSR / ( ZSOIL(1) * HCPCT ) ENDIF C ---------------------------------------------------------------------- C THIS ENDS SECTION FOR TOP SOIL LAYER. C ---------------------------------------------------------------------- C INITIALIZE DDZ2 C ---------------------------------------------------------------------- DDZ2 = 0.0 C ---------------------------------------------------------------------- C LOOP THRU THE REMAINING SOIL LAYERS, REPEATING THE ABOVE PROCESS C (EXCEPT SUBSFC OR "GROUND" HEAT FLUX NOT REPEATED IN LOWER LAYERS) C ---------------------------------------------------------------------- DF1K = DF1 DO K = 2,NSOIL C ---------------------------------------------------------------------- C CALCULATE HEAT CAPACITY FOR THIS SOIL LAYER. C ---------------------------------------------------------------------- HCPCT = SH2O(K)*CH2O +(1.0-SMCMAX)*CSOIL +(SMCMAX-SMC(K))*CAIR & + ( SMC(K) - SH2O(K) )*CICE IF (K .NE. NSOIL) THEN C ---------------------------------------------------------------------- C THIS SECTION FOR LAYER 2 OR GREATER, BUT NOT LAST LAYER. C ---------------------------------------------------------------------- C CALCULATE THERMAL DIFFUSIVITY FOR THIS LAYER. C ---------------------------------------------------------------------- CALL TDFCND (DF1N,SMC(K),QUARTZ,SMCMAX,SH2O(K)) C ---------------------------------------------------------------------- C CALC THE VERTICAL SOIL TEMP GRADIENT THRU THIS LAYER C ---------------------------------------------------------------------- DENOM = 0.5 * ( ZSOIL(K-1) - ZSOIL(K+1) ) DTSDZ2 = ( STC(K) - STC(K+1) ) / DENOM C ---------------------------------------------------------------------- C CALC THE MATRIX COEF, CI, AFTER CALC'NG ITS PARTIAL PRODUCT C ---------------------------------------------------------------------- DDZ2 = 2. / (ZSOIL(K-1) - ZSOIL(K+1)) CI(K) = -DF1N * DDZ2 / ((ZSOIL(K-1) - ZSOIL(K)) * HCPCT) C ---------------------------------------------------------------------- C IF TEMPERATURE AVERAGING INVOKED (ITAVG=TRUE; ELSE SKIP): CALCULATE C TEMP AT BOTTOM OF LAYER. C ---------------------------------------------------------------------- IF (ITAVG) THEN CALL TBND (STC(K),STC(K+1),ZSOIL,ZBOT,K,NSOIL,TBK1) ENDIF ELSE C ---------------------------------------------------------------------- C SPECIAL CASE OF BOTTOM SOIL LAYER: CALCULATE THERMAL DIFFUSIVITY FOR C BOTTOM LAYER. C ---------------------------------------------------------------------- CALL TDFCND (DF1N,SMC(K),QUARTZ,SMCMAX,SH2O(K)) C ---------------------------------------------------------------------- C CALC THE VERTICAL SOIL TEMP GRADIENT THRU BOTTOM LAYER. C ---------------------------------------------------------------------- DENOM = .5 * (ZSOIL(K-1) + ZSOIL(K)) - ZBOT DTSDZ2 = (STC(K)-TBOT) / DENOM C ---------------------------------------------------------------------- C SET MATRIX COEF, CI TO ZERO IF BOTTOM LAYER. C ---------------------------------------------------------------------- CI(K) = 0. C ---------------------------------------------------------------------- C IF TEMPERATURE AVERAGING INVOKED (ITAVG=TRUE; ELSE SKIP): CALCULATE C TEMP AT BOTTOM OF LAST LAYER. C ---------------------------------------------------------------------- IF (ITAVG) THEN CALL TBND (STC(K),TBOT,ZSOIL,ZBOT,K,NSOIL,TBK1) ENDIF ENDIF C ---------------------------------------------------------------------- C THIS ENDS SPECIAL LOOP FOR BOTTOM LAYER. C ---------------------------------------------------------------------- C CALCULATE RHSTS FOR THIS LAYER AFTER CALC'NG A PARTIAL PRODUCT. C ---------------------------------------------------------------------- DENOM = ( ZSOIL(K) - ZSOIL(K-1) ) * HCPCT RHSTS(K) = ( DF1N * DTSDZ2 - DF1K * DTSDZ ) / DENOM QTOT = -1.0*DENOM*RHSTS(K) SICE = SMC(K) - SH2O(K) IF ( (SICE .GT. 0.) .OR. (TBK .LT. T0) .OR. & (STC(K) .LT. T0) .OR. (TBK1 .LT. T0) ) THEN IF (ITAVG) THEN CALL TMPAVG(TAVG,TBK,STC(K),TBK1,ZSOIL,NSOIL,K) ELSE TAVG = STC(K) ENDIF TSNSR = SNKSRC(TAVG,SMC(K),SH2O(K),ZSOIL,NSOIL, & SMCMAX,PSISAT,BEXP,DT,K,QTOT) RHSTS(K) = RHSTS(K) - TSNSR / DENOM ENDIF C ---------------------------------------------------------------------- C CALC MATRIX COEFS, AI, AND BI FOR THIS LAYER. C ---------------------------------------------------------------------- AI(K) = - DF1 * DDZ / ((ZSOIL(K-1) - ZSOIL(K)) * HCPCT) BI(K) = -(AI(K) + CI(K)) C ---------------------------------------------------------------------- C RESET VALUES OF DF1, DTSDZ, DDZ, AND TBK FOR LOOP TO NEXT SOIL LAYER. C ---------------------------------------------------------------------- TBK = TBK1 DF1K = DF1N DTSDZ = DTSDZ2 DDZ = DDZ2 END DO C ---------------------------------------------------------------------- C END SUBROUTINE HRT C ---------------------------------------------------------------------- RETURN END SUBROUTINE HRTICE (RHSTS,STC,NSOIL,ZSOIL,YY,ZZ1,DF1,AI,BI,CI, & ICE,TBOT) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE HRTICE C ---------------------------------------------------------------------- C CALCULATE THE RIGHT HAND SIDE OF THE TIME TENDENCY TERM OF THE SOIL C THERMAL DIFFUSION EQUATION FOR SEA-ICE (ICE = 1) OR GLACIAL-ICE (ICE). C COMPUTE (PREPARE) THE MATRIX COEFFICIENTS FOR THE TRI-DIAGONAL MATRIX C OF THE IMPLICIT TIME SCHEME. C C (NOTE: THIS SUBROUTINE ONLY CALLED FOR SEA-ICE OR GLACIAL ICE, BUT C NOT FOR NON-GLACIAL LAND (ICE = 0). C ---------------------------------------------------------------------- INTEGER NSOLD PARAMETER(NSOLD = 4) INTEGER ICE INTEGER K INTEGER NSOIL REAL AI(NSOLD) REAL BI(NSOLD) REAL CI(NSOLD) REAL DDZ REAL DDZ2 REAL DENOM REAL DF1 REAL DTSDZ REAL DTSDZ2 REAL HCPCT REAL RHSTS(NSOIL) REAL SSOIL REAL STC(NSOIL) REAL TBOT REAL YY REAL ZBOT REAL ZSOIL(NSOIL) REAL ZZ1 c DATA TBOT /271.16/ C ---------------------------------------------------------------------- C SET A NOMINAL UNIVERSAL VALUE OF THE SEA-ICE SPECIFIC HEAT CAPACITY, C HCPCT = 1880.0*917.0 = 1.72396E+6 (SOURCE: FEI CHEN, 1995) C SET BOTTOM OF SEA-ICE PACK TEMPERATURE C TBOT = 271.16 C SET A NOMINAL UNIVERSAL VALUE OF GLACIAL-ICE SPECIFIC HEAT CAPACITY, C HCPCT = 2100.0*900.0 = 1.89000E+6 (SOURCE: BOB GRUMBINE, 2005) C TBOT PASSED IN AS ARGUMENT, VALUE FROM GLOBAL DATA SET C ---------------------------------------------------------------------- c PARAMETER(HCPCT = 1.72396E+6) IF (ICE .EQ. 1) THEN C ---------------------------------------------------------------------- C SEA-ICE C ---------------------------------------------------------------------- HCPCT = 1.72396E+6 TBOT = 271.16 ELSE C ---------------------------------------------------------------------- C GLACIAL-ICE C ---------------------------------------------------------------------- HCPCT = 1.89000E+6 ENDIF C ---------------------------------------------------------------------- C THE INPUT ARGUMENT DF1 IS A UNIVERSALLY CONSTANT VALUE OF SEA-ICE C AND GLACIAL-ICE THERMAL DIFFUSIVITY, SET IN SFLX AS DF1 = 2.2. C ---------------------------------------------------------------------- C SET ICE PACK DEPTH. USE TBOT AS ICE PACK LOWER BOUNDARY TEMPERATURE C (THAT OF UNFROZEN SEA WATER AT BOTTOM OF SEA ICE PACK). ASSUME ICE C PACK IS OF N=NSOIL LAYERS SPANNING A UNIFORM CONSTANT ICE PACK C THICKNESS AS DEFINED BY ZSOIL(NSOIL) IN ROUTINE SFLX. C IF GLACIAL-ICE, SET ZBOT = -25 METERS C ---------------------------------------------------------------------- IF (ICE .EQ. 1) THEN C ---------------------------------------------------------------------- C SEA-ICE C ---------------------------------------------------------------------- ZBOT = ZSOIL(NSOIL) ELSE C ---------------------------------------------------------------------- C GLACIAL-ICE C ---------------------------------------------------------------------- ZBOT = -25.0 ENDIF C ---------------------------------------------------------------------- C CALC THE MATRIX COEFFICIENTS AI, BI, AND CI FOR THE TOP LAYER C ---------------------------------------------------------------------- DDZ = 1.0 / ( -0.5 * ZSOIL(2) ) AI(1) = 0.0 CI(1) = (DF1 * DDZ) / (ZSOIL(1) * HCPCT) BI(1) = -CI(1) + DF1/(0.5 * ZSOIL(1) * ZSOIL(1) * HCPCT * ZZ1) C ---------------------------------------------------------------------- C CALC THE VERTICAL SOIL TEMP GRADIENT BTWN THE TOP AND 2ND SOIL LAYERS. C RECALC/ADJUST THE SOIL HEAT FLUX. USE THE GRADIENT AND FLUX TO CALC C RHSTS FOR THE TOP SOIL LAYER. C ---------------------------------------------------------------------- DTSDZ = ( STC(1) - STC(2) ) / ( -0.5 * ZSOIL(2) ) SSOIL = DF1 * ( STC(1) - YY ) / ( 0.5 * ZSOIL(1) * ZZ1 ) RHSTS(1) = ( DF1 * DTSDZ - SSOIL ) / ( ZSOIL(1) * HCPCT ) C ---------------------------------------------------------------------- C INITIALIZE DDZ2 C ---------------------------------------------------------------------- DDZ2 = 0.0 C ---------------------------------------------------------------------- C LOOP THRU THE REMAINING SOIL LAYERS, REPEATING THE ABOVE PROCESS C ---------------------------------------------------------------------- DO K = 2,NSOIL IF (K .NE. NSOIL) THEN C ---------------------------------------------------------------------- C CALC THE VERTICAL SOIL TEMP GRADIENT THRU THIS LAYER. C ---------------------------------------------------------------------- DENOM = 0.5 * ( ZSOIL(K-1) - ZSOIL(K+1) ) DTSDZ2 = ( STC(K) - STC(K+1) ) / DENOM C ---------------------------------------------------------------------- C CALC THE MATRIX COEF, CI, AFTER CALC'NG ITS PARTIAL PRODUCT. C ---------------------------------------------------------------------- DDZ2 = 2. / (ZSOIL(K-1) - ZSOIL(K+1)) CI(K) = -DF1 * DDZ2 / ((ZSOIL(K-1) - ZSOIL(K)) * HCPCT) ELSE C ---------------------------------------------------------------------- C CALC THE VERTICAL SOIL TEMP GRADIENT THRU THE LOWEST LAYER. C ---------------------------------------------------------------------- DTSDZ2 = (STC(K)-TBOT)/(.5 * (ZSOIL(K-1) + ZSOIL(K))-ZBOT) C ---------------------------------------------------------------------- C SET MATRIX COEF, CI TO ZERO. C ---------------------------------------------------------------------- CI(K) = 0. ENDIF C ---------------------------------------------------------------------- C CALC RHSTS FOR THIS LAYER AFTER CALC'NG A PARTIAL PRODUCT. C ---------------------------------------------------------------------- DENOM = ( ZSOIL(K) - ZSOIL(K-1) ) * HCPCT RHSTS(K) = ( DF1 * DTSDZ2 - DF1 * DTSDZ ) / DENOM C ---------------------------------------------------------------------- C CALC MATRIX COEFS, AI, AND BI FOR THIS LAYER. C ---------------------------------------------------------------------- AI(K) = - DF1 * DDZ / ((ZSOIL(K-1) - ZSOIL(K)) * HCPCT) BI(K) = -(AI(K) + CI(K)) C ---------------------------------------------------------------------- C RESET VALUES OF DTSDZ AND DDZ FOR LOOP TO NEXT SOIL LYR. C ---------------------------------------------------------------------- DTSDZ = DTSDZ2 DDZ = DDZ2 END DO C ---------------------------------------------------------------------- C END SUBROUTINE HRTICE C ---------------------------------------------------------------------- RETURN END SUBROUTINE HSTEP (STCOUT,STCIN,RHSTS,DT,NSOIL,AI,BI,CI) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE HSTEP C ---------------------------------------------------------------------- C CALCULATE/UPDATE THE SOIL TEMPERATURE FIELD. C ---------------------------------------------------------------------- INTEGER NSOLD PARAMETER(NSOLD = 4) INTEGER K INTEGER NSOIL REAL AI(NSOLD) REAL BI(NSOLD) REAL CI(NSOLD) REAL CIin(NSOLD) REAL DT REAL RHSTS(NSOIL) REAL RHSTSin(NSOIL) REAL STCIN(NSOIL) REAL STCOUT(NSOIL) C ---------------------------------------------------------------------- C CREATE FINITE DIFFERENCE VALUES FOR USE IN ROSR12 ROUTINE C ---------------------------------------------------------------------- DO K = 1,NSOIL RHSTS(K) = RHSTS(K) * DT AI(K) = AI(K) * DT BI(K) = 1. + BI(K) * DT CI(K) = CI(K) * DT END DO C ---------------------------------------------------------------------- C COPY VALUES FOR INPUT VARIABLES BEFORE CALL TO ROSR12 C ---------------------------------------------------------------------- DO K = 1,NSOIL RHSTSin(K) = RHSTS(K) END DO DO K = 1,NSOLD CIin(K) = CI(K) END DO C ---------------------------------------------------------------------- C SOLVE THE TRI-DIAGONAL MATRIX EQUATION C ---------------------------------------------------------------------- CALL ROSR12(CI,AI,BI,CIin,RHSTSin,RHSTS,NSOIL) C ---------------------------------------------------------------------- C CALC/UPDATE THE SOIL TEMPS USING MATRIX SOLUTION C ---------------------------------------------------------------------- DO K = 1,NSOIL STCOUT(K) = STCIN(K) + CI(K) END DO C ---------------------------------------------------------------------- C END SUBROUTINE HSTEP C ---------------------------------------------------------------------- RETURN END SUBROUTINE NOPAC(ETP,ETA,PRCP,SMC,SMCMAX,SMCWLT, & SMCREF,SMCDRY,CMC,CMCMAX,NSOIL,DT,SHDFAC, & SBETA,Q2,T1,SFCTMP,T24,TH2,FDOWN,F1,SSOIL, & STC,EPSCA,BEXP,PC,RCH,RR,CFACTR, & SH2O,SLOPE,KDT,FRZFACT,PSISAT,ZSOIL, & DKSAT,DWSAT,TBOT,ZBOT,RUNOFF1,RUNOFF2, & RUNOFF3,EDIR,EC,ET,ETT,NROOT,ICE,RTDIS, & QUARTZ,FXEXP,CSOIL, & BETA,DRIP,DEW,FLX1,FLX2,FLX3) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE NOPAC C ---------------------------------------------------------------------- C CALCULATE SOIL MOISTURE AND HEAT FLUX VALUES AND UPDATE SOIL MOISTURE C CONTENT AND SOIL HEAT CONTENT VALUES FOR THE CASE WHEN NO SNOW PACK IS C PRESENT. C ---------------------------------------------------------------------- INTEGER ICE INTEGER NROOT INTEGER NSOIL REAL BEXP REAL BETA REAL CFACTR REAL CMC REAL CMCMAX REAL CP REAL CSOIL REAL DEW REAL DF1 REAL DKSAT REAL DRIP REAL DT REAL DWSAT REAL EC REAL EDIR REAL EPSCA REAL ETA REAL ETA1 REAL ETP REAL ETP1 REAL ET(NSOIL) REAL ETT REAL FDOWN REAL F1 REAL FXEXP REAL FLX1 REAL FLX2 REAL FLX3 REAL FRZFACT REAL KDT REAL PC REAL PRCP REAL PRCP1 REAL PSISAT REAL Q2 REAL QUARTZ REAL RCH REAL RR REAL RTDIS(NSOIL) REAL RUNOFF1 REAL RUNOFF2 REAL RUNOFF3 REAL SSOIL REAL SBETA REAL SFCTMP REAL SHDFAC REAL SH2O(NSOIL) REAL SIGMA REAL SLOPE REAL SMC(NSOIL) REAL SMCDRY REAL SMCMAX REAL SMCREF REAL SMCWLT REAL STC(NSOIL) REAL T1 REAL T24 REAL TBOT REAL TH2 REAL YY REAL YYNUM REAL ZBOT REAL ZSOIL(NSOIL) REAL ZZ1 REAL EC1 REAL EDIR1 REAL ET1(NSOIL) REAL ETT1 INTEGER K PARAMETER(CP = 1004.5) PARAMETER(SIGMA = 5.67E-8) C ---------------------------------------------------------------------- C EXECUTABLE CODE BEGINS HERE: C CONVERT ETP FROM KG M-2 S-1 TO MS-1 AND INITIALIZE DEW. C ---------------------------------------------------------------------- PRCP1 = PRCP * 0.001 ETP1 = ETP * 0.001 DEW = 0.0 EDIR = 0. EDIR1 = 0. EC = 0. EC1 = 0. DO K = 1,NSOIL ET(K) = 0. ET1(K) = 0. END DO ETT = 0. ETT1 = 0. IF (ETP .GT. 0.0) THEN C ---------------------------------------------------------------------- C CONVERT PRCP FROM 'KG M-2 S-1' TO 'M S-1'. C ---------------------------------------------------------------------- CALL EVAPO (ETA1,SMC,NSOIL,CMC,ETP1,DT,ZSOIL, & SH2O,SMCMAX,BEXP,PC,SMCWLT,DKSAT,DWSAT, & SMCREF,SHDFAC,CMCMAX, & SMCDRY,CFACTR, & EDIR1,EC1,ET1,ETT1,SFCTMP,Q2,NROOT,RTDIS,FXEXP) CALL SMFLX (SMC,NSOIL,CMC,DT,PRCP1,ZSOIL, & SH2O,SLOPE,KDT,FRZFACT, & SMCMAX,BEXP,SMCWLT,DKSAT,DWSAT, & SHDFAC,CMCMAX, & RUNOFF1,RUNOFF2,RUNOFF3, & EDIR1,EC1,ET1, & DRIP) C ---------------------------------------------------------------------- C CONVERT MODELED EVAPOTRANSPIRATION FM M S-1 TO KG M-2 S-1 C ---------------------------------------------------------------------- c ETA = ETA1 * 1000.0 C ---------------------------------------------------------------------- c EDIR = EDIR1 * 1000.0 c EC = EC1 * 1000.0 c ETT = ETT1 * 1000.0 c ET(1) = ET1(1) * 1000.0 c ET(2) = ET1(2) * 1000.0 c ET(3) = ET1(3) * 1000.0 c ET(4) = ET1(4) * 1000.0 C ---------------------------------------------------------------------- ELSE C ---------------------------------------------------------------------- C IF ETP < 0, ASSUME DEW FORMS (TRANSFORM ETP1 INTO DEW AND REINITIALIZE C ETP1 TO ZERO). C ---------------------------------------------------------------------- eta1 = 0.0 DEW = -ETP1 c ETP1 = 0.0 C ---------------------------------------------------------------------- C CONVERT PRCP FROM 'KG M-2 S-1' TO 'M S-1' AND ADD DEW AMOUNT. C ---------------------------------------------------------------------- PRCP1 = PRCP1 + DEW C c CALL EVAPO (ETA1,SMC,NSOIL,CMC,ETP1,DT,ZSOIL, c & SH2O,SMCMAX,BEXP,PC,SMCWLT,DKSAT,DWSAT, c & SMCREF,SHDFAC,CMCMAX, c & SMCDRY,CFACTR, c & EDIR1,EC1,ET1,ETT,SFCTMP,Q2,NROOT,RTDIS,FXEXP) CALL SMFLX (SMC,NSOIL,CMC,DT,PRCP1,ZSOIL, & SH2O,SLOPE,KDT,FRZFACT, & SMCMAX,BEXP,SMCWLT,DKSAT,DWSAT, & SHDFAC,CMCMAX, & RUNOFF1,RUNOFF2,RUNOFF3, & EDIR1,EC1,ET1, & DRIP) C ---------------------------------------------------------------------- C CONVERT MODELED EVAPOTRANSPIRATION FROM 'M S-1' TO 'KG M-2 S-1'. C ---------------------------------------------------------------------- c ETA = ETA1 * 1000.0 C ---------------------------------------------------------------------- c EDIR = EDIR1 * 1000.0 c EC = EC1 * 1000.0 c ETT = ETT1 * 1000.0 c ET(1) = ET1(1) * 1000.0 c ET(2) = ET1(2) * 1000.0 c ET(3) = ET1(3) * 1000.0 c ET(4) = ET1(4) * 1000.0 C ---------------------------------------------------------------------- ENDIF C ---------------------------------------------------------------------- C CONVERT MODELED EVAPOTRANSPIRATION FM M S-1 TO KG M-2 S-1 C ---------------------------------------------------------------------- ETA = ETA1 * 1000.0 C ---------------------------------------------------------------------- EDIR = EDIR1 * 1000.0 EC = EC1 * 1000.0 DO K = 1,NSOIL ET(K) = ET1(K) * 1000.0 c ET(1) = ET1(1) * 1000.0 c ET(2) = ET1(2) * 1000.0 c ET(3) = ET1(3) * 1000.0 c ET(4) = ET1(4) * 1000.0 ENDDO ETT = ETT1 * 1000.0 C ---------------------------------------------------------------------- C ---------------------------------------------------------------------- C BASED ON ETP AND E VALUES, DETERMINE BETA C ---------------------------------------------------------------------- IF ( ETP .LE. 0.0 ) THEN BETA = 0.0 IF ( ETP .LT. 0.0 ) THEN BETA = 1.0 c ETA = ETP ENDIF ELSE BETA = ETA / ETP ENDIF C ---------------------------------------------------------------------- C GET SOIL THERMAL DIFFUXIVITY/CONDUCTIVITY FOR TOP SOIL LYR, C CALC. ADJUSTED TOP LYR SOIL TEMP AND ADJUSTED SOIL FLUX, THEN C CALL SHFLX TO COMPUTE/UPDATE SOIL HEAT FLUX AND SOIL TEMPS. C ---------------------------------------------------------------------- CALL TDFCND (DF1,SMC(1),QUARTZ,SMCMAX,SH2O(1)) C ---------------------------------------------------------------------- C VEGETATION GREENNESS FRACTION REDUCTION IN SUBSURFACE HEAT FLUX C VIA REDUCTION FACTOR, WHICH IS CONVENIENT TO APPLY HERE TO THERMAL C DIFFUSIVITY THAT IS LATER USED IN HRT TO COMPUTE SUB SFC HEAT FLUX C (SEE ADDITIONAL COMMENTS ON VEG EFFECT SUB-SFC HEAT FLX IN C ROUTINE SFLX) C ---------------------------------------------------------------------- DF1 = DF1 * EXP(SBETA*SHDFAC) C ---------------------------------------------------------------------- C COMPUTE INTERMEDIATE TERMS PASSED TO ROUTINE HRT (VIA ROUTINE C SHFLX BELOW) FOR USE IN COMPUTING SUBSURFACE HEAT FLUX IN HRT C ---------------------------------------------------------------------- YYNUM = FDOWN - SIGMA * T24 YY = SFCTMP + (YYNUM/RCH+TH2-SFCTMP-BETA*EPSCA) / RR ZZ1 = DF1 / ( -0.5 * ZSOIL(1) * RCH * RR ) + 1.0 CALL SHFLX (SSOIL,STC,SMC,SMCMAX,NSOIL,T1,DT,YY,ZZ1,ZSOIL, & TBOT,ZBOT,SMCWLT,PSISAT,SH2O,BEXP,F1,DF1,ICE, & QUARTZ,CSOIL) C ---------------------------------------------------------------------- C SET FLX1 AND FLX3 (SNOPACK PHASE CHANGE HEAT FLUXES) TO ZERO SINCE C THEY ARE NOT USED HERE IN SNOPAC. FLX2 (FREEZING RAIN HEAT FLUX) WAS C SIMILARLY INITIALIZED IN THE PENMAN ROUTINE. C ---------------------------------------------------------------------- FLX1 = 0.0 FLX3 = 0.0 C ---------------------------------------------------------------------- C END SUBROUTINE NOPAC C ---------------------------------------------------------------------- RETURN END SUBROUTINE PENMAN (SFCTMP,SFCPRS,CH,T2V,TH2,PRCP,FDOWN,T24,SSOIL, & Q2,Q2SAT,ETP,RCH,EPSCA,RR,SNOWNG,FRZGRA, & DQSDT2,FLX2) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE PENMAN C ---------------------------------------------------------------------- C CALCULATE POTENTIAL EVAPORATION FOR THE CURRENT POINT. VARIOUS C PARTIAL SUMS/PRODUCTS ARE ALSO CALCULATED AND PASSED BACK TO THE C CALLING ROUTINE FOR LATER USE. C ---------------------------------------------------------------------- LOGICAL SNOWNG LOGICAL FRZGRA REAL A REAL BETA REAL CH REAL CP REAL CPH2O REAL CPICE REAL DELTA REAL DQSDT2 REAL ELCP REAL EPSCA REAL ETP REAL FDOWN REAL FLX2 REAL FNET REAL LSUBC REAL LSUBF REAL PRCP REAL Q2 REAL Q2SAT REAL R REAL RAD REAL RCH REAL RHO REAL RR REAL SSOIL REAL SFCPRS REAL SFCTMP REAL SIGMA REAL T24 REAL T2V REAL TH2 PARAMETER(CP = 1004.6) PARAMETER(CPH2O = 4.218E+3) PARAMETER(CPICE = 2.106E+3) PARAMETER(R = 287.04) PARAMETER(ELCP = 2.4888E+3) PARAMETER(LSUBF = 3.335E+5) PARAMETER(LSUBC = 2.501000E+6) PARAMETER(SIGMA = 5.67E-8) C ---------------------------------------------------------------------- C EXECUTABLE CODE BEGINS HERE: C ---------------------------------------------------------------------- FLX2 = 0.0 C ---------------------------------------------------------------------- C PREPARE PARTIAL QUANTITIES FOR PENMAN EQUATION. C ---------------------------------------------------------------------- DELTA = ELCP * DQSDT2 T24 = SFCTMP * SFCTMP * SFCTMP * SFCTMP RR = T24 * 6.48E-8 /(SFCPRS * CH) + 1.0 RHO = SFCPRS / (R * T2V) RCH = RHO * CP * CH C ---------------------------------------------------------------------- C ADJUST THE PARTIAL SUMS / PRODUCTS WITH THE LATENT HEAT C EFFECTS CAUSED BY FALLING PRECIPITATION. C ---------------------------------------------------------------------- IF (.NOT. SNOWNG) THEN IF (PRCP .GT. 0.0) RR = RR + CPH2O*PRCP/RCH ELSE RR = RR + CPICE*PRCP/RCH ENDIF FNET = FDOWN - SIGMA*T24 - SSOIL C ---------------------------------------------------------------------- C INCLUDE THE LATENT HEAT EFFECTS OF FRZNG RAIN CONVERTING TO ICE ON C IMPACT IN THE CALCULATION OF FLX2 AND FNET. C ---------------------------------------------------------------------- IF (FRZGRA) THEN FLX2 = -LSUBF * PRCP FNET = FNET - FLX2 ENDIF C ---------------------------------------------------------------------- C FINISH PENMAN EQUATION CALCULATIONS. C ---------------------------------------------------------------------- RAD = FNET/RCH + TH2 - SFCTMP A = ELCP * (Q2SAT - Q2) EPSCA = (A*RR + RAD*DELTA) / (DELTA + RR) ETP = EPSCA * RCH / LSUBC C ---------------------------------------------------------------------- C END SUBROUTINE PENMAN C ---------------------------------------------------------------------- RETURN END SUBROUTINE REDPRM ( & VEGTYP,SOILTYP,SLOPETYP, & CFACTR,CMCMAX,RSMAX,TOPT,REFKDT,KDT,SBETA, & SHDFAC,RSMIN,RGL,HS,ZBOT,FRZX,PSISAT,SLOPE, & SNUP,SALP,BEXP,DKSAT,DWSAT, & SMCMAX,SMCWLT,SMCREF, & SMCDRY,F1,QUARTZ,FXEXP,RTDIS,SLDPTH,ZSOIL, & NROOT,NSOIL,Z0,CZIL,LAI,CSOIL,PTU) C ---------------------------------------------------------------------- C SUBROUTINE REDPRM C ---------------------------------------------------------------------- C ALL SOIL, VEG, SLOPE, AND UNIVERSAL PARAMETERS VALUES ARE DEFINED C EXTERNALLY (IN SUBROUTINE "set_soilveg.f") AND THEN ACCESSED VIA "use C namelist_soilveg" (BELOW) AND THEN SET HERE. C ---------------------------------------------------------------------- use namelist_soilveg IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE REDPRM C ---------------------------------------------------------------------- C INTERNALLY SET (DEFAULT VALUESS), OR OPTIONALLY READ-IN VIA NAMELIST C I/O, ALL SOIL AND VEGETATION PARAMETERS REQUIRED FOR THE EXECUSION OF C THE NOAH LSM. C C OPTIONAL NON-DEFAULT PARAMETERS CAN BE READ IN, ACCOMMODATING UP TO 30 C SOIL, VEG, OR SLOPE CLASSES, IF THE DEFAULT MAX NUMBER OF SOIL, VEG, C AND/OR SLOPE TYPES IS RESET. C C FUTURE UPGRADES OF ROUTINE REDPRM MUST EXPAND TO INCORPORATE SOME OF C THE EMPIRICAL PARAMETERS OF THE FROZEN SOIL AND SNOWPACK PHYSICS (SUCH C AS IN ROUTINES FRH2O, SNOWPACK, AND SNOW_NEW) NOT YET SET IN THIS C REDPRM ROUTINE, BUT RATHER SET IN LOWER LEVEL SUBROUTINES. C C SET MAXIMUM NUMBER OF SOIL-, VEG-, AND SLOPETYP IN DATA STATEMENT. C ---------------------------------------------------------------------- C ---------------------------------------------------------------------- C SET-UP SOIL PARAMETERS FOR GIVEN SOIL TYPE C INPUT: SOLTYP: SOIL TYPE (INTEGER INDEX) C OUTPUT: SOIL PARAMETERS: C MAXSMC: MAX SOIL MOISTURE CONTENT (POROSITY) C REFSMC: REFERENCE SOIL MOISTURE (ONSET OF SOIL MOISTURE C STRESS IN TRANSPIRATION) C WLTSMC: WILTING PT SOIL MOISTURE CONTENTS C DRYSMC: AIR DRY SOIL MOIST CONTENT LIMITS C SATPSI: SATURATED SOIL POTENTIAL C SATDK: SATURATED SOIL HYDRAULIC CONDUCTIVITY C BB: THE 'B' PARAMETER C SATDW: SATURATED SOIL DIFFUSIVITY C F11: USED TO COMPUTE SOIL DIFFUSIVITY/CONDUCTIVITY C QUARTZ: SOIL QUARTZ CONTENT C ---------------------------------------------------------------------- C SOIL TYPES ZOBLER (1986) COSBY ET AL (1984) (quartz cont.(1)) C 1 COARSE LOAMY SAND (0.82) C 2 MEDIUM SILTY CLAY LOAM (0.10) C 3 FINE LIGHT CLAY (0.25) C 4 COARSE-MEDIUM SANDY LOAM (0.60) C 5 COARSE-FINE SANDY CLAY (0.52) C 6 MEDIUM-FINE CLAY LOAM (0.35) C 7 COARSE-MED-FINE SANDY CLAY LOAM (0.60) C 8 ORGANIC LOAM (0.40) C 9 GLACIAL LAND ICE LOAMY SAND (NA using 0.82) C 13: >>>OLD>>>GLACIAL LAND ICE<<>>OLD>>>GLACIAL (THE SAME PARAMETERS AS FOR TYPE 11)<< 30 C 4 0-30 C 5 0-8 & > 30 C 6 8-30 & > 30 C 7 0-8, 8-30, > 30 C 9 GLACIAL ICE C BLANK OCEAN/SEA C ---------------------------------------------------------------------- C NOTE: C CLASS 9 FROM 'ZOBLER' FILE SHOULD BE REPLACED BY 8 AND 'BLANK' 9 C ---------------------------------------------------------------------- REAL SLOPE C ---------------------------------------------------------------------- C SET NAMELIST FILE NAME C ---------------------------------------------------------------------- CHARACTER*50 NAMELIST_NAME C ** Clu: Retain definition status to quarantee 'one-time' execution SAVE LFIRST C ---------------------------------------------------------------------- C SET UNIVERSAL PARAMETERS (NOT DEPENDENT ON SOIL, VEG, SLOPE TYPE) C ---------------------------------------------------------------------- INTEGER I INTEGER NSOIL INTEGER SLOPETYP INTEGER SOILTYP INTEGER VEGTYP LOGICAL LFIRST DATA LFIRST /.TRUE./ C ---------------------------------------------------------------------- C PARAMETER USED TO CALCULATE ROUGHNESS LENGTH OF HEAT. C ---------------------------------------------------------------------- REAL CZIL C ---------------------------------------------------------------------- C PARAMETER USED TO CALUCULATE VEGETATION EFFECT ON SOIL HEAT FLUX. C ---------------------------------------------------------------------- REAL SBETA C ---------------------------------------------------------------------- C BARE SOIL EVAPORATION EXPONENT USED IN DEVAP. C ---------------------------------------------------------------------- REAL FXEXP C ---------------------------------------------------------------------- C SOIL HEAT CAPACITY [J M-3 K-1] C ---------------------------------------------------------------------- REAL CSOIL C ---------------------------------------------------------------------- C SPECIFY SNOW DISTRIBUTION SHAPE PARAMETER SALP - SHAPE PARAMETER OF C DISTRIBUTION FUNCTION OF SNOW COVER. FROM ANDERSON'S DATA (HYDRO-17) C BEST FIT IS WHEN SALP = 2.6 C ---------------------------------------------------------------------- REAL SALP C ---------------------------------------------------------------------- C KDT IS DEFINED BY REFERENCE REFKDT AND DKSAT; REFDK=2.E-6 IS THE SAT. C DK. VALUE FOR THE SOIL TYPE 2 C ---------------------------------------------------------------------- REAL REFDK REAL REFKDT REAL FRZX REAL KDT C ---------------------------------------------------------------------- C FROZEN GROUND PARAMETER, FRZK, DEFINITION: ICE CONTENT THRESHOLD ABOVE C WHICH FROZEN SOIL IS IMPERMEABLE REFERENCE VALUE OF THIS PARAMETER FOR C THE LIGHT CLAY SOIL (TYPE=3) FRZK = 0.15 M. C ---------------------------------------------------------------------- REAL FRZK REAL RTDIS(NSOIL) REAL SLDPTH(NSOIL) REAL ZSOIL(NSOIL) C ---------------------------------------------------------------------- C SET TWO CANOPY WATER PARAMETERS. C ---------------------------------------------------------------------- REAL CFACTR REAL CMCMAX C ---------------------------------------------------------------------- C SET MAX. STOMATAL RESISTANCE. C ---------------------------------------------------------------------- REAL RSMAX C ---------------------------------------------------------------------- C SET OPTIMUM TRANSPIRATION AIR TEMPERATURE. C ---------------------------------------------------------------------- REAL TOPT C ---------------------------------------------------------------------- C SPECIFY DEPTH[M] OF LOWER BOUNDARY SOIL TEMPERATURE. C ---------------------------------------------------------------------- REAL ZBOT C ---------------------------------------------------------------------- C NAMELIST DEFINITION: C ---------------------------------------------------------------------- c$$$ NAMELIST /SOIL_VEG/ SLOPE_DATA, RSMTBL, RGLTBL, HSTBL, SNUPX, c$$$ & BB, DRYSMC, F11, MAXSMC, REFSMC, SATPSI, SATDK, SATDW, c$$$ & WLTSMC, QTZ, LPARAM, ZBOT_DATA, SALP_DATA, CFACTR_DATA, c$$$ & CMCMAX_DATA, SBETA_DATA, RSMAX_DATA, TOPT_DATA, c$$$ & REFDK_DATA, FRZK_DATA, BARE, DEFINED_VEG, DEFINED_SOIL, c$$$ & DEFINED_SLOPE, FXEXP_DATA, NROOT_DATA, REFKDT_DATA, Z0_DATA, c$$$ & CZIL_DATA, LAI_DATA, CSOIL_DATA c cmy moved lfirst block to gfs_init c IF (SOILTYP .GT. DEFINED_SOIL) THEN WRITE(*,*) 'Warning: too many soil types' STOP 333 ENDIF IF (VEGTYP .GT. DEFINED_VEG) THEN WRITE(*,*) 'Warning: too many veg types' STOP 333 ENDIF IF (SLOPETYP .GT. DEFINED_SLOPE) THEN WRITE(*,*) 'Warning: too many slope types' STOP 333 ENDIF C ---------------------------------------------------------------------- C SET-UP UNIVERSAL PARAMETERS (NOT DEPENDENT ON SOILTYP, VEGTYP OR C SLOPETYP) C ---------------------------------------------------------------------- ZBOT = ZBOT_DATA SALP = SALP_DATA CFACTR = CFACTR_DATA CMCMAX = CMCMAX_DATA SBETA = SBETA_DATA RSMAX = RSMAX_DATA TOPT = TOPT_DATA REFDK = REFDK_DATA FRZK = FRZK_DATA FXEXP = FXEXP_DATA REFKDT = REFKDT_DATA CZIL = CZIL_DATA CSOIL = CSOIL_DATA C ---------------------------------------------------------------------- C SET-UP SOIL PARAMETERS C ---------------------------------------------------------------------- BEXP = BB(SOILTYP) DKSAT = SATDK(SOILTYP) DWSAT = SATDW(SOILTYP) F1 = F11(SOILTYP) KDT = REFKDT * DKSAT/REFDK PSISAT = SATPSI(SOILTYP) QUARTZ = QTZ(SOILTYP) SMCDRY = DRYSMC(SOILTYP) SMCMAX = MAXSMC(SOILTYP) SMCREF = REFSMC(SOILTYP) SMCWLT = WLTSMC(SOILTYP) FRZFACT = (SMCMAX / SMCREF) * (0.412 / 0.468) C ---------------------------------------------------------------------- C TO ADJUST FRZK PARAMETER TO ACTUAL SOIL TYPE: FRZK * FRZFACT C ---------------------------------------------------------------------- FRZX = FRZK * FRZFACT C ---------------------------------------------------------------------- C SET-UP VEGETATION PARAMETERS C ---------------------------------------------------------------------- NROOT = NROOT_DATA(VEGTYP) SNUP = SNUPX(VEGTYP) RSMIN = RSMTBL(VEGTYP) RGL = RGLTBL(VEGTYP) HS = HSTBL(VEGTYP) Z0 = Z0_DATA(VEGTYP) LAI = LAI_DATA(VEGTYP) IF (VEGTYP .EQ. BARE) SHDFAC = 0.0 IF (NROOT .GT. NSOIL) THEN WRITE(*,*) 'Warning: too many root layers' STOP 333 ENDIF C ---------------------------------------------------------------------- C CALCULATE ROOT DISTRIBUTION. PRESENT VERSION ASSUMES UNIFORM C DISTRIBUTION BASED ON SOIL LAYER DEPTHS. C ---------------------------------------------------------------------- DO I = 1,NROOT RTDIS(I) = -SLDPTH(I)/ZSOIL(NROOT) END DO C ---------------------------------------------------------------------- C SET-UP SLOPE PARAMETER C ---------------------------------------------------------------------- SLOPE = SLOPE_DATA(SLOPETYP) C ---------------------------------------------------------------------- C END SUBROUTINE REDPRM C ---------------------------------------------------------------------- RETURN END SUBROUTINE ROSR12 (P,A,B,C,D,DELTA,NSOIL) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE ROSR12 C ---------------------------------------------------------------------- C INVERT (SOLVE) THE TRI-DIAGONAL MATRIX PROBLEM SHOWN BELOW: C ### ### ### ### ### ### C #B(1), C(1), 0 , 0 , 0 , . . . , 0 # # # # # C #A(2), B(2), C(2), 0 , 0 , . . . , 0 # # # # # C # 0 , A(3), B(3), C(3), 0 , . . . , 0 # # # # D(3) # C # 0 , 0 , A(4), B(4), C(4), . . . , 0 # # P(4) # # D(4) # C # 0 , 0 , 0 , A(5), B(5), . . . , 0 # # P(5) # # D(5) # C # . . # # . # = # . # C # . . # # . # # . # C # . . # # . # # . # C # 0 , . . . , 0 , A(M-2), B(M-2), C(M-2), 0 # #P(M-2)# #D(M-2)# C # 0 , . . . , 0 , 0 , A(M-1), B(M-1), C(M-1)# #P(M-1)# #D(M-1)# C # 0 , . . . , 0 , 0 , 0 , A(M) , B(M) # # P(M) # # D(M) # C ### ### ### ### ### ### C ---------------------------------------------------------------------- INTEGER K INTEGER KK INTEGER NSOIL REAL A(NSOIL) REAL B(NSOIL) REAL C(NSOIL) REAL D(NSOIL) REAL DELTA(NSOIL) REAL P(NSOIL) C ---------------------------------------------------------------------- C INITIALIZE EQN COEF C FOR THE LOWEST SOIL LAYER C ---------------------------------------------------------------------- C(NSOIL) = 0.0 C ---------------------------------------------------------------------- C SOLVE THE COEFS FOR THE 1ST SOIL LAYER C ---------------------------------------------------------------------- P(1) = -C(1) / B(1) DELTA(1) = D(1) / B(1) C ---------------------------------------------------------------------- C SOLVE THE COEFS FOR SOIL LAYERS 2 THRU NSOIL C ---------------------------------------------------------------------- DO K = 2,NSOIL P(K) = -C(K) * ( 1.0 / (B(K) + A (K) * P(K-1)) ) DELTA(K) = (D(K)-A(K)*DELTA(K-1))*(1.0/(B(K)+A(K)*P(K-1))) END DO C ---------------------------------------------------------------------- C SET P TO DELTA FOR LOWEST SOIL LAYER C ---------------------------------------------------------------------- P(NSOIL) = DELTA(NSOIL) C ---------------------------------------------------------------------- C ADJUST P FOR SOIL LAYERS 2 THRU NSOIL C ---------------------------------------------------------------------- DO K = 2,NSOIL KK = NSOIL - K + 1 P(KK) = P(KK) * P(KK+1) + DELTA(KK) END DO C ---------------------------------------------------------------------- C END SUBROUTINE ROSR12 C ---------------------------------------------------------------------- RETURN END SUBROUTINE SFCDIF (ZLM,Z0,THZ0,THLM,SFCSPD,CZIL,AKMS,AKHS) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE SFCDIF C ---------------------------------------------------------------------- C CALCULATE SURFACE LAYER EXCHANGE COEFFICIENTS VIA ITERATIVE PROCESS. C SEE CHEN ET AL (1997, BLM) C ---------------------------------------------------------------------- REAL WWST, WWST2, G, VKRM, EXCM, BETA, BTG, ELFC, WOLD, WNEW REAL PIHF, EPSU2, EPSUST, EPSIT, EPSA, ZTMIN, ZTMAX, HPBL, SQVISC REAL RIC, RRIC, FHNEU, RFC, RFAC, ZZ, PSLMU, PSLMS, PSLHU, PSLHS REAL XX, PSPMU, YY, PSPMS, PSPHU, PSPHS, ZLM, Z0, THZ0, THLM REAL SFCSPD, CZIL, AKMS, AKHS, ZILFC, ZU, ZT, RDZ, CXCH REAL DTHV, DU2, BTGH, WSTAR2, USTAR, ZSLU, ZSLT, RLOGU, RLOGT REAL RLMO, ZETALT, ZETALU, ZETAU, ZETAT, XLU4, XLT4, XU4, XT4 REAL XLU, XLT, XU, XT, PSMZ, SIMM, PSHZ, SIMH, USTARK, RLMN, RLMA CCC ......REAL ZTFC INTEGER ITRMX, ILECH, ITR PARAMETER & (WWST=1.2,WWST2=WWST*WWST,G=9.8,VKRM=0.40,EXCM=0.001 & ,BETA=1./270.,BTG=BETA*G,ELFC=VKRM*BTG & ,WOLD=.15,WNEW=1.-WOLD,ITRMX=05,PIHF=3.14159265/2.) C ---------------------------------------------------------------------- PARAMETER & (EPSU2=1.E-4,EPSUST=0.07,EPSIT=1.E-4,EPSA=1.E-8 & ,ZTMIN=-5.,ZTMAX=1.,HPBL=1000.0 & ,SQVISC=258.2) C ---------------------------------------------------------------------- PARAMETER & (RIC=0.183,RRIC=1.0/RIC,FHNEU=0.8,RFC=0.191 & ,RFAC=RIC/(FHNEU*RFC*RFC)) C ---------------------------------------------------------------------- C NOTE: THE TWO CODE BLOCKS BELOW DEFINE FUNCTIONS C ---------------------------------------------------------------------- C LECH'S SURFACE FUNCTIONS C ---------------------------------------------------------------------- PSLMU(ZZ)=-0.96*log(1.0-4.5*ZZ) PSLMS(ZZ)=ZZ*RRIC-2.076*(1.-1./(ZZ+1.)) PSLHU(ZZ)=-0.96*log(1.0-4.5*ZZ) PSLHS(ZZ)=ZZ*RFAC-2.076*(1.-1./(ZZ+1.)) C ---------------------------------------------------------------------- C PAULSON'S SURFACE FUNCTIONS C ---------------------------------------------------------------------- PSPMU(XX)=-2.*log((XX+1.)*0.5)-log((XX*XX+1.)*0.5)+2.*ATAN(XX) & -PIHF PSPMS(YY)=5.*YY PSPHU(XX)=-2.*log((XX*XX+1.)*0.5) PSPHS(YY)=5.*YY C ---------------------------------------------------------------------- C THIS ROUTINE SFCDIF CAN HANDLE BOTH OVER OPEN WATER (SEA, OCEAN) AND C OVER SOLID SURFACE (LAND, SEA-ICE). C ---------------------------------------------------------------------- ILECH=0 C ---------------------------------------------------------------------- C ZTFC: RATIO OF ZOH/ZOM LESS OR EQUAL THAN 1 C C......ZTFC=0.1 C CZIL: CONSTANT C IN Zilitinkevich, S. S.1995,:NOTE ABOUT ZT C ---------------------------------------------------------------------- ZILFC=-CZIL*VKRM*SQVISC C ---------------------------------------------------------------------- ZU=Z0 C C.......ZT=Z0*ZTFC RDZ=1./ZLM CXCH=EXCM*RDZ DTHV=THLM-THZ0 DU2=MAX(SFCSPD*SFCSPD,EPSU2) C ---------------------------------------------------------------------- C BELJARS CORRECTION OF USTAR C ---------------------------------------------------------------------- BTGH=BTG*HPBL ccc If statements to avoid TANGENT LINEAR problems near zero IF (BTGH*AKHS*DTHV .NE. 0.0) THEN WSTAR2=WWST2*ABS(BTGH*AKHS*DTHV)**(2./3.) ELSE WSTAR2=0.0 ENDIF USTAR=MAX(SQRT(AKMS*SQRT(DU2+WSTAR2)),EPSUST) C ---------------------------------------------------------------------- C ZILITINKEVITCH APPROACH FOR ZT C ---------------------------------------------------------------------- ZT=EXP(ZILFC*SQRT(USTAR*Z0))*Z0 C ---------------------------------------------------------------------- ZSLU=ZLM+ZU ZSLT=ZLM+ZT C PRINT*,'ZSLT=',ZSLT C PRINT*,'ZLM=',ZLM C PRINT*,'ZT=',ZT C RLOGU=log(ZSLU/ZU) RLOGT=log(ZSLT/ZT) C RLMO=ELFC*AKHS*DTHV/USTAR**3 C PRINT*,'RLMO=',RLMO C PRINT*,'ELFC=',ELFC C PRINT*,'AKHS=',AKHS C PRINT*,'DTHV=',DTHV C PRINT*,'USTAR=',USTAR DO ITR=1,ITRMX C ---------------------------------------------------------------------- C 1./MONIN-OBUKKHOV LENGTH-SCALE C ---------------------------------------------------------------------- ZETALT=MAX(ZSLT*RLMO,ZTMIN) RLMO=ZETALT/ZSLT ZETALU=ZSLU*RLMO ZETAU=ZU*RLMO ZETAT=ZT*RLMO IF(ILECH.EQ.0) THEN IF(RLMO.LT.0.)THEN XLU4=1.-16.*ZETALU XLT4=1.-16.*ZETALT XU4 =1.-16.*ZETAU XT4 =1.-16.*ZETAT XLU=SQRT(SQRT(XLU4)) XLT=SQRT(SQRT(XLT4)) XU =SQRT(SQRT(XU4)) XT =SQRT(SQRT(XT4)) PSMZ=PSPMU(XU) C PRINT*,'-----------1------------' C PRINT*,'PSMZ=',PSMZ C PRINT*,'PSPMU(ZETAU)=',PSPMU(ZETAU) C PRINT*,'XU=',XU C PRINT*,'------------------------' SIMM=PSPMU(XLU)-PSMZ+RLOGU PSHZ=PSPHU(XT) SIMH=PSPHU(XLT)-PSHZ+RLOGT ELSE ZETALU=MIN(ZETALU,ZTMAX) ZETALT=MIN(ZETALT,ZTMAX) PSMZ=PSPMS(ZETAU) C PRINT*,'-----------2------------' C PRINT*,'PSMZ=',PSMZ C PRINT*,'PSPMS(ZETAU)=',PSPMS(ZETAU) C PRINT*,'ZETAU=',ZETAU C PRINT*,'------------------------' SIMM=PSPMS(ZETALU)-PSMZ+RLOGU PSHZ=PSPHS(ZETAT) SIMH=PSPHS(ZETALT)-PSHZ+RLOGT ENDIF ELSE C ---------------------------------------------------------------------- C LECH'S FUNCTIONS C ---------------------------------------------------------------------- IF(RLMO.LT.0.)THEN PSMZ=PSLMU(ZETAU) C PRINT*,'-----------3------------' C PRINT*,'PSMZ=',PSMZ C PRINT*,'PSLMU(ZETAU)=',PSLMU(ZETAU) C PRINT*,'ZETAU=',ZETAU C PRINT*,'------------------------' SIMM=PSLMU(ZETALU)-PSMZ+RLOGU PSHZ=PSLHU(ZETAT) SIMH=PSLHU(ZETALT)-PSHZ+RLOGT ELSE ZETALU=MIN(ZETALU,ZTMAX) ZETALT=MIN(ZETALT,ZTMAX) C PSMZ=PSLMS(ZETAU) C PRINT*,'-----------4------------' C PRINT*,'PSMZ=',PSMZ C PRINT*,'PSLMS(ZETAU)=',PSLMS(ZETAU) C PRINT*,'ZETAU=',ZETAU C PRINT*,'------------------------' SIMM=PSLMS(ZETALU)-PSMZ+RLOGU PSHZ=PSLHS(ZETAT) SIMH=PSLHS(ZETALT)-PSHZ+RLOGT ENDIF ENDIF C ---------------------------------------------------------------------- C BELJAARS CORRECTION FOR USTAR C ---------------------------------------------------------------------- USTAR=MAX(SQRT(AKMS*SQRT(DU2+WSTAR2)),EPSUST) C ---------------------------------------------------------------------- C ZILITINKEVITCH FIX FOR ZT C ---------------------------------------------------------------------- ZT=EXP(ZILFC*SQRT(USTAR*Z0))*Z0 ZSLT=ZLM+ZT RLOGT=log(ZSLT/ZT) C----------------------------------------------------------------------- USTARK=USTAR*VKRM AKMS=MAX(USTARK/SIMM,CXCH) AKHS=MAX(USTARK/SIMH,CXCH) C----------------------------------------------------------------------- C IF STATEMENTS TO AVOID TANGENT LINEAR PROBLEMS NEAR ZERO C----------------------------------------------------------------------- IF (BTGH*AKHS*DTHV .NE. 0.0) THEN WSTAR2=WWST2*ABS(BTGH*AKHS*DTHV)**(2./3.) ELSE WSTAR2=0.0 ENDIF RLMN=ELFC*AKHS*DTHV/USTAR**3 C----------------------------------------------------------------------- RLMA=RLMO*WOLD+RLMN*WNEW C----------------------------------------------------------------------- C IF(ABS((RLMN-RLMO)/RLMA).LT.EPSIT) GO TO 110 C----------------------------------------------------------------------- RLMO=RLMA C----------------------------------------------------------------------- END DO C PRINT*,'----------------------------' C PRINT*,'SFCDIF OUTPUT ! ! ! ! ! ! ! ! ! ! ! !' C C PRINT*,'ZLM=',ZLM C PRINT*,'Z0=',Z0 C PRINT*,'THZ0=',THZ0 C PRINT*,'THLM=',THLM C PRINT*,'SFCSPD=',SFCSPD C PRINT*,'CZIL=',CZIL C PRINT*,'AKMS=',AKMS C PRINT*,'AKHS=',AKHS C PRINT*,'----------------------------' C C ---------------------------------------------------------------------- C END SUBROUTINE SFCDIF C ---------------------------------------------------------------------- RETURN END SUBROUTINE SHFLX (SSOIL,STC,SMC,SMCMAX,NSOIL,T1,DT,YY,ZZ1,ZSOIL, & TBOT,ZBOT,SMCWLT,PSISAT,SH2O,BEXP,F1,DF1,ICE, & QUARTZ,CSOIL) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE SHFLX C ---------------------------------------------------------------------- C UPDATE THE TEMPERATURE STATE OF THE SOIL COLUMN BASED ON THE THERMAL C DIFFUSION EQUATION AND UPDATE THE FROZEN SOIL MOISTURE CONTENT BASED C ON THE TEMPERATURE. C ---------------------------------------------------------------------- INTEGER NSOLD PARAMETER(NSOLD = 4) INTEGER I INTEGER ICE INTEGER IFRZ INTEGER NSOIL REAL AI(NSOLD) REAL BI(NSOLD) REAL CI(NSOLD) REAL BEXP REAL CSOIL REAL DF1 REAL DT REAL F1 REAL PSISAT REAL QUARTZ REAL RHSTS(NSOLD) REAL SSOIL REAL SH2O(NSOIL) REAL SMC(NSOIL) REAL SMCMAX REAL SMCWLT REAL STC(NSOIL) REAL STCF(NSOLD) REAL T0 REAL T1 REAL TBOT REAL YY REAL ZBOT REAL ZSOIL(NSOIL) REAL ZZ1 Clu_timefilter REAL OLDT1 REAL STSOIL(NSOIL) REAL CTFIL1,CTFIL2 PARAMETER (CTFIL1=.5,CTFIL2=1.-CTFIL1) PARAMETER(T0 = 273.15) Clu_timefilter OLDT1 = T1 DO I = 1,NSOIL STSOIL(I) = STC(I) END DO C ---------------------------------------------------------------------- C HRT ROUTINE CALCS THE RIGHT HAND SIDE OF THE SOIL TEMP DIF EQN C ---------------------------------------------------------------------- IF (ICE.NE.0) THEN C ---------------------------------------------------------------------- C SEA-ICE CASE, GLACIAL-ICE CASE C ---------------------------------------------------------------------- CALL HRTICE (RHSTS,STC,NSOIL,ZSOIL,YY,ZZ1,DF1,AI,BI,CI, & ICE,TBOT) CALL HSTEP (STCF,STC,RHSTS,DT,NSOIL,AI,BI,CI) ELSE C ---------------------------------------------------------------------- C LAND-MASS CASE C ---------------------------------------------------------------------- CALL HRT (RHSTS,STC,SMC,SMCMAX,NSOIL,ZSOIL,YY,ZZ1,TBOT, & ZBOT,PSISAT,SH2O,DT, & BEXP,F1,DF1,QUARTZ,CSOIL,AI,BI,CI) CALL HSTEP (STCF,STC,RHSTS,DT,NSOIL,AI,BI,CI) ENDIF DO I = 1,NSOIL STC(I) = STCF(I) END DO C ---------------------------------------------------------------------- C IN THE NO SNOWPACK CASE (VIA ROUTINE NOPAC BRANCH,) UPDATE THE GRND C (SKIN) TEMPERATURE HERE IN RESPONSE TO THE UPDATED SOIL TEMPERATURE C PROFILE ABOVE. (NOTE: INSPECTION OF ROUTINE SNOPAC SHOWS THAT T1 C BELOW IS A DUMMY VARIABLE ONLY, AS SKIN TEMPERATURE IS UPDATED C DIFFERENTLY IN ROUTINE SNOPAC) C ---------------------------------------------------------------------- T1 = (YY + (ZZ1 - 1.0) * STC(1)) / ZZ1 Clu_timefilter T1 = CTFIL1 * T1 + CTFIL2 * OLDT1 DO I = 1, NSOIL STC(I) = CTFIL1 * STC(I) + CTFIL2 * STSOIL(I) ENDDO C ---------------------------------------------------------------------- C CALCULATE SURFACE SOIL HEAT FLUX C ---------------------------------------------------------------------- SSOIL = DF1 * (STC(1) - T1) / (0.5 * ZSOIL(1)) C ---------------------------------------------------------------------- C END SUBROUTINE SHFLX C ---------------------------------------------------------------------- RETURN END SUBROUTINE SMFLX (SMC,NSOIL,CMC,DT,PRCP1,ZSOIL, & SH2O,SLOPE,KDT,FRZFACT, & SMCMAX,BEXP,SMCWLT,DKSAT,DWSAT, & SHDFAC,CMCMAX, & RUNOFF1,RUNOFF2,RUNOFF3, & EDIR1,EC1,ET1, & DRIP) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE SMFLX C ---------------------------------------------------------------------- C CALCULATE SOIL MOISTURE FLUX. THE SOIL MOISTURE CONTENT (SMC - A PER C UNIT VOLUME MEASUREMENT) IS A DEPENDENT VARIABLE THAT IS UPDATED WITH C PROGNOSTIC EQNS. THE CANOPY MOISTURE CONTENT (CMC) IS ALSO UPDATED. C FROZEN GROUND VERSION: NEW STATES ADDED: SH2O, AND FROZEN GROUND C CORRECTION FACTOR, FRZFACT AND PARAMETER SLOPE. C ---------------------------------------------------------------------- INTEGER NSOLD PARAMETER(NSOLD = 4) INTEGER I INTEGER K INTEGER NSOIL REAL AI(NSOLD) REAL BI(NSOLD) REAL CI(NSOLD) REAL BEXP REAL CMC REAL CMCMAX REAL DKSAT REAL DRIP REAL DT REAL DUMMY REAL DWSAT REAL EC1 REAL EDIR1 REAL ET1(NSOIL) REAL EXCESS REAL FRZFACT REAL KDT REAL PCPDRP REAL PRCP1 REAL RHSCT REAL RHSTT(NSOLD) REAL RUNOFF1 REAL RUNOFF2 REAL RUNOFF3 REAL SHDFAC REAL SMC(NSOIL) REAL SH2O(NSOIL) REAL SICE(NSOLD) REAL SH2OA(NSOLD) REAL SH2OFG(NSOLD) REAL SLOPE REAL SMCMAX REAL SMCWLT REAL TRHSCT REAL ZSOIL(NSOIL) C ---------------------------------------------------------------------- C EXECUTABLE CODE BEGINS HERE. C ---------------------------------------------------------------------- DUMMY = 0. C ---------------------------------------------------------------------- C COMPUTE THE RIGHT HAND SIDE OF THE CANOPY EQN TERM ( RHSCT ) C ---------------------------------------------------------------------- RHSCT = SHDFAC * PRCP1 - EC1 C ---------------------------------------------------------------------- C CONVERT RHSCT (A RATE) TO TRHSCT (AN AMOUNT) AND ADD IT TO EXISTING C CMC. IF RESULTING AMT EXCEEDS MAX CAPACITY, IT BECOMES DRIP AND WILL C FALL TO THE GRND. C ---------------------------------------------------------------------- DRIP = 0. TRHSCT = DT * RHSCT EXCESS = CMC + TRHSCT IF (EXCESS .GT. CMCMAX) DRIP = EXCESS - CMCMAX C ---------------------------------------------------------------------- C PCPDRP IS THE COMBINED PRCP1 AND DRIP (FROM CMC) THAT GOES INTO THE C SOIL C ---------------------------------------------------------------------- PCPDRP = (1. - SHDFAC) * PRCP1 + DRIP / DT C ---------------------------------------------------------------------- C STORE ICE CONTENT AT EACH SOIL LAYER BEFORE CALLING SRT & SSTEP C ---------------------------------------------------------------------- DO I = 1,NSOIL SICE(I) = SMC(I) - SH2O(I) END DO C ---------------------------------------------------------------------- C CALL SUBROUTINES SRT AND SSTEP TO SOLVE THE SOIL MOISTURE C TENDENCY EQUATIONS. C C IF THE INFILTRATING PRECIP RATE IS NONTRIVIAL, C (WE CONSIDER NONTRIVIAL TO BE A PRECIP TOTAL OVER THE TIME STEP C EXCEEDING ONE ONE-THOUSANDTH OF THE WATER HOLDING CAPACITY OF C THE FIRST SOIL LAYER) C THEN CALL THE SRT/SSTEP SUBROUTINE PAIR TWICE IN THE MANNER OF C TIME SCHEME "F" (IMPLICIT STATE, AVERAGED COEFFICIENT) C OF SECTION 2 OF KALNAY AND KANAMITSU (1988, MWR, VOL 116, C PAGES 1945-1958)TO MINIMIZE 2-DELTA-T OSCILLATIONS IN THE C SOIL MOISTURE VALUE OF THE TOP SOIL LAYER THAT CAN ARISE BECAUSE C OF THE EXTREME NONLINEAR DEPENDENCE OF THE SOIL HYDRAULIC C DIFFUSIVITY COEFFICIENT AND THE HYDRAULIC CONDUCTIVITY ON THE C SOIL MOISTURE STATE C OTHERWISE CALL THE SRT/SSTEP SUBROUTINE PAIR ONCE IN THE MANNER OF C TIME SCHEME "D" (IMPLICIT STATE, EXPLICIT COEFFICIENT) C OF SECTION 2 OF KALNAY AND KANAMITSU C PCPDRP IS UNITS OF KG/M**2/S OR MM/S, ZSOIL IS NEGATIVE DEPTH IN M C ---------------------------------------------------------------------- C IF ( PCPDRP .GT. 0.0 ) THEN IF ( (PCPDRP*DT) .GT. (0.001*1000.0*(-ZSOIL(1))*SMCMAX) ) THEN C ---------------------------------------------------------------------- C FROZEN GROUND VERSION: C SMC STATES REPLACED BY SH2O STATES IN SRT SUBR. SH2O & SICE STATES C INCLUDED IN SSTEP SUBR. FROZEN GROUND CORRECTION FACTOR, FRZFACT C ADDED. ALL WATER BALANCE CALCULATIONS USING UNFROZEN WATER C ---------------------------------------------------------------------- CALL SRT (RHSTT,EDIR1,ET1,SH2O,SH2O,NSOIL,PCPDRP,ZSOIL, & DWSAT,DKSAT,SMCMAX,BEXP,RUNOFF1, & RUNOFF2,DT,SMCWLT,SLOPE,KDT,FRZFACT,SICE,AI,BI,CI) CALL SSTEP (SH2OFG,SH2O,DUMMY,RHSTT,RHSCT,DT,NSOIL,SMCMAX, & CMCMAX,RUNOFF3,ZSOIL,SMC,SICE,AI,BI,CI) DO K = 1,NSOIL SH2OA(K) = (SH2O(K) + SH2OFG(K)) * 0.5 END DO CALL SRT (RHSTT,EDIR1,ET1,SH2O,SH2OA,NSOIL,PCPDRP,ZSOIL, & DWSAT,DKSAT,SMCMAX,BEXP,RUNOFF1, & RUNOFF2,DT,SMCWLT,SLOPE,KDT,FRZFACT,SICE,AI,BI,CI) CALL SSTEP (SH2O,SH2O,CMC,RHSTT,RHSCT,DT,NSOIL,SMCMAX, & CMCMAX,RUNOFF3,ZSOIL,SMC,SICE,AI,BI,CI) ELSE CALL SRT (RHSTT,EDIR1,ET1,SH2O,SH2O,NSOIL,PCPDRP,ZSOIL, & DWSAT,DKSAT,SMCMAX,BEXP,RUNOFF1, & RUNOFF2,DT,SMCWLT,SLOPE,KDT,FRZFACT,SICE,AI,BI,CI) CALL SSTEP (SH2O,SH2O,CMC,RHSTT,RHSCT,DT,NSOIL,SMCMAX, & CMCMAX,RUNOFF3,ZSOIL,SMC,SICE,AI,BI,CI) ENDIF c RUNOF = RUNOFF C ---------------------------------------------------------------------- C END SUBROUTINE SMFLX C ---------------------------------------------------------------------- RETURN END SUBROUTINE SNFRAC (SNEQV,SNUP,SALP,SNOWH,SNCOVR) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE SNFRAC C ---------------------------------------------------------------------- C CALCULATE SNOW FRACTION (0 -> 1) C SNEQV SNOW WATER EQUIVALENT (M) C SNUP THRESHOLD SNEQV DEPTH ABOVE WHICH SNCOVR=1 C SALP TUNING PARAMETER C SNCOVR FRACTIONAL SNOW COVER C ---------------------------------------------------------------------- REAL SNEQV, SNUP, SALP, SNCOVR, RSNOW, Z0N, SNOWH C ---------------------------------------------------------------------- C SNUP IS VEG-CLASS DEPENDENT SNOWDEPTH THRESHHOLD (SET IN ROUTINE C REDPRM) ABOVE WHICH SNOCVR=1. C ---------------------------------------------------------------------- IF (SNEQV .LT. SNUP) THEN RSNOW = SNEQV/SNUP SNCOVR = 1. - ( EXP(-SALP*RSNOW) - RSNOW*EXP(-SALP)) ELSE SNCOVR = 1.0 ENDIF Z0N=0.035 C FORMULATION OF DICKINSON ET AL. 1986 C SNCOVR=SNOWH/(SNOWH + 5*Z0N) C FORMULATION OF MARSHALL ET AL. 1994 C SNCOVR=SNEQV/(SNEQV + 2*Z0N) C ---------------------------------------------------------------------- C END SUBROUTINE SNFRAC C ---------------------------------------------------------------------- RETURN END FUNCTION SNKSRC (TAVG,SMC,SH2O,ZSOIL,NSOIL, & SMCMAX,PSISAT,BEXP,DT,K,QTOT) IMPLICIT NONE C ---------------------------------------------------------------------- C FUNCTION SNKSRC C ---------------------------------------------------------------------- C CALCULATE SINK/SOURCE TERM OF THE TERMAL DIFFUSION EQUATION. (SH2O) IS C AVAILABLE LIQUED WATER. C ---------------------------------------------------------------------- INTEGER K INTEGER NSOIL REAL BEXP REAL DF REAL DH2O REAL DT REAL DZ REAL DZH REAL FREE REAL FRH2O REAL HLICE REAL PSISAT REAL QTOT REAL SH2O REAL SMC REAL SMCMAX REAL SNKSRC REAL T0 REAL TAVG REAL TDN REAL TM REAL TUP REAL TZ REAL X0 REAL XDN REAL XH2O REAL XUP REAL ZSOIL (NSOIL) PARAMETER(DH2O = 1.0000E3) PARAMETER(HLICE = 3.3350E5) PARAMETER(T0 = 2.7315E2) IF (K .EQ. 1) THEN DZ = -ZSOIL(1) ELSE DZ = ZSOIL(K-1)-ZSOIL(K) ENDIF C ---------------------------------------------------------------------- C VIA FUNCTION FRH2O, COMPUTE POTENTIAL OR 'EQUILIBRIUM' UNFROZEN C SUPERCOOLED FREE WATER FOR GIVEN SOIL TYPE AND SOIL LAYER TEMPERATURE. C FUNCTION FRH20 INVOKES EQN (17) FROM V. KOREN ET AL (1999, JGR, VOL. C 104, PG 19573). (ASIDE: LATTER EQN IN JOURNAL IN CENTIGRADE UNITS. C ROUTINE FRH2O USE FORM OF EQN IN KELVIN UNITS.) C ---------------------------------------------------------------------- FREE = FRH2O(TAVG,SMC,SH2O,SMCMAX,BEXP,PSISAT) C ---------------------------------------------------------------------- C IN NEXT BLOCK OF CODE, INVOKE EQN 18 OF V. KOREN ET AL (1999, JGR, C VOL. 104, PG 19573.) THAT IS, FIRST ESTIMATE THE NEW AMOUNTOF LIQUID C WATER, 'XH2O', IMPLIED BY THE SUM OF (1) THE LIQUID WATER AT THE BEGIN C OF CURRENT TIME STEP, AND (2) THE FREEZE OF THAW CHANGE IN LIQUID C WATER IMPLIED BY THE HEAT FLUX 'QTOT' PASSED IN FROM ROUTINE HRT. C SECOND, DETERMINE IF XH2O NEEDS TO BE BOUNDED BY 'FREE' (EQUIL AMT) OR C IF 'FREE' NEEDS TO BE BOUNDED BY XH2O. C ---------------------------------------------------------------------- XH2O = SH2O + QTOT*DT/(DH2O*HLICE*DZ) C ---------------------------------------------------------------------- C FIRST, IF FREEZING AND REMAINING LIQUID LESS THAN LOWER BOUND, THEN C REDUCE EXTENT OF FREEZING, THEREBY LETTING SOME OR ALL OF HEAT FLUX C QTOT COOL THE SOIL TEMP LATER IN ROUTINE HRT. C ---------------------------------------------------------------------- IF ( XH2O .LT. SH2O .AND. XH2O .LT. FREE) THEN IF ( FREE .GT. SH2O ) THEN XH2O = SH2O ELSE XH2O = FREE ENDIF ENDIF C ---------------------------------------------------------------------- C SECOND, IF THAWING AND THE INCREASE IN LIQUID WATER GREATER THAN UPPER C BOUND, THEN REDUCE EXTENT OF THAW, THEREBY LETTING SOME OR ALL OF HEAT C FLUX QTOT WARM THE SOIL TEMP LATER IN ROUTINE HRT. C ---------------------------------------------------------------------- IF ( XH2O .GT. SH2O .AND. XH2O .GT. FREE ) THEN IF ( FREE .LT. SH2O ) THEN XH2O = SH2O ELSE XH2O = FREE ENDIF ENDIF IF (XH2O .LT. 0.) XH2O = 0. IF (XH2O .GT. SMC) XH2O = SMC C ---------------------------------------------------------------------- C CALCULATE PHASE-CHANGE HEAT SOURCE/SINK TERM FOR USE IN ROUTINE HRT C AND UPDATE LIQUID WATER TO REFLCET FINAL FREEZE/THAW INCREMENT. C ---------------------------------------------------------------------- SNKSRC = -DH2O*HLICE*DZ*(XH2O-SH2O)/DT SH2O = XH2O C ---------------------------------------------------------------------- C END FUNCTION SNKSRC C ---------------------------------------------------------------------- 77 RETURN END SUBROUTINE SNOPAC (ETP,ETA,PRCP,PRCP1,SNOWNG,SMC,SMCMAX,SMCWLT, & SMCREF,SMCDRY,CMC,CMCMAX,NSOIL,DT, & SBETA,DF1, & Q2,T1,SFCTMP,T24,TH2,FDOWN,F1,SSOIL,STC,EPSCA, & SFCPRS,BEXP,PC,RCH,RR,CFACTR,SNCOVR,ESD,SNDENS, & SNOWH,SH2O,SLOPE,KDT,FRZFACT,PSISAT,SNUP, & ZSOIL,DWSAT,DKSAT,TBOT,ZBOT,SHDFAC,RUNOFF1, & RUNOFF2,RUNOFF3,EDIR,EC,ET,ETT,NROOT,SNOMLT, & ICE,RTDIS,QUARTZ,FXEXP,CSOIL, & BETA,DRIP,DEW,FLX1,FLX2,FLX3,ESNOW) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE SNOPAC C ---------------------------------------------------------------------- C CALCULATE SOIL MOISTURE AND HEAT FLUX VALUES & UPDATE SOIL MOISTURE C CONTENT AND SOIL HEAT CONTENT VALUES FOR THE CASE WHEN A SNOW PACK IS C PRESENT. C ---------------------------------------------------------------------- INTEGER ICE INTEGER NROOT INTEGER NSOIL LOGICAL SNOWNG REAL BEXP REAL BETA REAL CFACTR REAL CMC REAL CMCMAX REAL CP REAL CPH2O REAL CPICE REAL CSOIL REAL DENOM REAL DEW REAL DF1 REAL DKSAT REAL DRIP REAL DSOIL REAL DTOT REAL DT REAL DWSAT REAL EC REAL EDIR REAL EPSCA REAL ESD REAL ESDMIN REAL EXPSNO REAL EXPSOI REAL ETA REAL ETA1 REAL ETP REAL ETP1 REAL ETP2 REAL ET(NSOIL) REAL ETT REAL EX REAL EXPFAC REAL FDOWN REAL FXEXP REAL FLX1 REAL FLX2 REAL FLX3 REAL F1 REAL KDT REAL LSUBF REAL LSUBC REAL LSUBS REAL PC REAL PRCP REAL PRCP1 REAL Q2 REAL RCH REAL RR REAL RTDIS(NSOIL) REAL SSOIL REAL SBETA REAL SSOIL1 REAL SFCTMP REAL SHDFAC REAL SIGMA REAL SMC(NSOIL) REAL SH2O(NSOIL) REAL SMCDRY REAL SMCMAX REAL SMCREF REAL SMCWLT REAL SNOMLT REAL SNOEXP !!!!!<-------- for Noah V2.7.1 REAL SNOWH REAL STC(NSOIL) REAL T1 REAL T11 REAL T12 REAL T12A REAL T12B REAL T24 REAL TBOT REAL ZBOT REAL TH2 REAL YY REAL ZSOIL(NSOIL) REAL ZZ1 REAL TFREEZ REAL SALP REAL SFCPRS REAL SLOPE REAL FRZFACT REAL PSISAT REAL SNUP REAL RUNOFF1 REAL RUNOFF2 REAL RUNOFF3 REAL QUARTZ REAL SNDENS REAL SNCOND REAL RSNOW REAL SNCOVR REAL QSAT REAL ETP3 REAL SEH REAL T14 REAL CSNOW REAL EC1 REAL EDIR1 REAL ET1(NSOIL) REAL ETT1 REAL ETNS REAL ETNS1 REAL ESNOW REAL ESNOW1 REAL ESNOW2 REAL ETANRG INTEGER K PARAMETER(CP = 1004.5) PARAMETER(CPH2O = 4.218E+3) PARAMETER(CPICE = 2.106E+3) PARAMETER(ESDMIN = 1.E-6) PARAMETER(LSUBF = 3.335E+5) PARAMETER(LSUBC = 2.501000E+6) PARAMETER(LSUBS = 2.83E+6) PARAMETER(SIGMA = 5.67E-8) PARAMETER(TFREEZ = 273.15) ! DATA SNOEXP /1.0/ !!! <----- for Noah V2.7 DATA SNOEXP /2.0/ !!! <----- for Noah V2.7.1 C ---------------------------------------------------------------------- C EXECUTABLE CODE BEGINS HERE: C CONVERT POTENTIAL EVAP (ETP) FROM KG M-2 S-1 TO M S-1 AND THEN TO AN C AMOUNT (M) GIVEN TIMESTEP (DT) AND CALL IT AN EFFECTIVE SNOWPACK C REDUCTION AMOUNT, ESNOW2 (M) FOR A SNOWCOVER FRACTION = 1.0. THIS IS c THE AMOUNT THE SNOWPACK WOULD BE REDUCED DUE TO SUBLIMATION FROM THE C SNOW SFC DURING THE TIMESTEP. SUBLIMATION WILL PROCEED AT THE C POTENTIAL RATE UNLESS THE SNOW DEPTH IS LESS THAN THE EXPECTED C SNOWPACK REDUCTION. FOR SNOWCOVER FRACTION = 1.0, 0=EDIR=ET=EC, AND C HENCE TOTAL EVAP = ESNOW = SUBLIMATION (POTENTIAL EVAP RATE) C ---------------------------------------------------------------------- C IF SEA-ICE (ICE=1) OR GLACIAL-ICE (ICE=-1), SNOWCOVER FRACTION = 1.0, C AND SUBLIMATION IS AT THE POTENTIAL RATE. C FOR NON-GLACIAL LAND (ICE=0), IF SNOWCOVER FRACTION < 1.0, TOTAL C EVAPORATION < POTENTIAL DUE TO NON-POTENTIAL CONTRIBUTION FROM C NON-SNOW COVERED FRACTION. C ---------------------------------------------------------------------- PRCP1 = PRCP1*0.001 C ---------------------------------------------------------------------- EDIR = 0.0 EDIR1 = 0.0 EC = 0.0 EC1 = 0.0 DO K = 1,NSOIL ET(K) = 0.0 ET1(K) = 0.0 ENDDO ETT = 0.0 ETT1 = 0.0 ETNS = 0.0 ETNS1 = 0.0 ESNOW = 0.0 ESNOW1 = 0.0 ESNOW2 = 0.0 C ---------------------------------------------------------------------- DEW = 0.0 ETP1 = ETP*0.001 IF (ETP .LT. 0.0) THEN C ---------------------------------------------------------------------- C IF ETP<0 (DOWNWARD) THEN DEWFALL (=FROSTFALL IN THIS CASE). C ---------------------------------------------------------------------- DEW = -ETP1 ESNOW2 = ETP1 * DT ETANRG = ETP*((1.-SNCOVR)*LSUBC + SNCOVR*LSUBS) ELSE C ---------------------------------------------------------------------- C ETP >= 0, UPWARD MOISTURE FLUX C ---------------------------------------------------------------------- IF (ICE .NE. 0) THEN C ---------------------------------------------------------------------- C SEA-ICE AND GLACIAL-ICE CASE C ---------------------------------------------------------------------- ESNOW = ETP ESNOW1 = ESNOW*0.001 ESNOW2 = ESNOW1*DT ETANRG = ESNOW*LSUBS ELSE C ---------------------------------------------------------------------- C NON-GLACIAL LAND CASE C ---------------------------------------------------------------------- IF (SNCOVR .LT. 1.) THEN CALL EVAPO (ETNS1,SMC,NSOIL,CMC,ETP1,DT,ZSOIL, & SH2O,SMCMAX,BEXP,PC,SMCWLT,DKSAT,DWSAT, & SMCREF,SHDFAC,CMCMAX, & SMCDRY,CFACTR, & EDIR1,EC1,ET1,ETT1,SFCTMP,Q2,NROOT,RTDIS,FXEXP) C ---------------------------------------------------------------------- EDIR1 = EDIR1*(1.-SNCOVR) EC1 = EC1*(1.-SNCOVR) DO K = 1,NSOIL ET1(K) = ET1(K)*(1.-SNCOVR) END DO ETT1 = ETT1*(1.-SNCOVR) ETNS1 = ETNS1*(1.-SNCOVR) C ---------------------------------------------------------------------- EDIR = EDIR1 * 1000.0 EC = EC1 * 1000.0 DO K = 1,NSOIL ET(K) = ET1(K) * 1000.0 END DO ETT = ETT1 * 1000.0 ETNS = ETNS1 * 1000.0 C ---------------------------------------------------------------------- ENDIF ESNOW = ETP*SNCOVR c ESNOW1 = ETP*0.001 ESNOW1 = ESNOW*0.001 ESNOW2 = ESNOW1*DT ETANRG = ESNOW*LSUBS + ETNS*LSUBC ENDIF ENDIF C ---------------------------------------------------------------------- C IF PRECIP IS FALLING, CALCULATE HEAT FLUX FROM SNOW SFC TO NEWLY C ACCUMULATING PRECIP. NOTE THAT THIS REFLECTS THE FLUX APPROPRIATE FOR C THE NOT-YET-UPDATED SKIN TEMPERATURE (T1). ASSUMES TEMPERATURE OF THE C SNOWFALL STRIKING THE GOUND IS =SFCTMP (LOWEST MODEL LEVEL AIR TEMP). C ---------------------------------------------------------------------- FLX1 = 0.0 IF (SNOWNG) THEN FLX1 = CPICE * PRCP * (T1 - SFCTMP) ELSE IF (PRCP .GT. 0.0) FLX1 = CPH2O * PRCP * (T1 - SFCTMP) ENDIF C ---------------------------------------------------------------------- C CALCULATE AN 'EFFECTIVE SNOW-GRND SFC TEMP' (T12) BASED ON HEAT FLUXES C BETWEEN THE SNOW PACK AND THE SOIL AND ON NET RADIATION. C INCLUDE FLX1 (PRECIP-SNOW SFC) AND FLX2 (FREEZING RAIN LATENT HEAT) C FLUXES. C FLX2 REFLECTS FREEZING RAIN LATENT HEAT FLUX USING T1 CALCULATED IN C PENMAN. C ---------------------------------------------------------------------- DSOIL = -(0.5 * ZSOIL(1)) DTOT = SNOWH + DSOIL DENOM = 1.0 + DF1 / (DTOT * RR * RCH) c T12A = ( (FDOWN-FLX1-FLX2-SIGMA*T24)/RCH c & + TH2 - SFCTMP - BETA*EPSCA ) / RR T12A = ( (FDOWN-FLX1-FLX2-SIGMA*T24)/RCH & + TH2 - SFCTMP - ETANRG/RCH ) / RR T12B = DF1 * STC(1) / (DTOT * RR * RCH) T12 = (SFCTMP + T12A + T12B) / DENOM C ---------------------------------------------------------------------- C IF THE 'EFFECTIVE SNOW-GRND SFC TEMP' IS AT OR BELOW FREEZING, NO SNOW C MELT WILL OCCUR. SET THE SKIN TEMP TO THIS EFFECTIVE TEMP. REDUCE C (BY SUBLIMINATION ) OR INCREASE (BY FROST) THE DEPTH OF THE SNOWPACK, C DEPENDING ON SIGN OF ETP. C UPDATE SOIL HEAT FLUX (SSOIL) USING NEW SKIN TEMPERATURE (T1) C SINCE NO SNOWMELT, SET ACCUMULATED SNOWMELT TO ZERO, SET 'EFFECTIVE' C PRECIP FROM SNOWMELT TO ZERO, SET PHASE-CHANGE HEAT FLUX FROM SNOWMELT C TO ZERO. C ---------------------------------------------------------------------- IF (T12 .LE. TFREEZ) THEN T1 = T12 SSOIL = DF1 * (T1 - STC(1)) / DTOT c ESD = MAX(0.0, ESD-ETP2) ESD = MAX(0.0, ESD-ESNOW2) FLX3 = 0.0 EX = 0.0 SNOMLT = 0.0 ELSE C ---------------------------------------------------------------------- C IF THE 'EFFECTIVE SNOW-GRND SFC TEMP' IS ABOVE FREEZING, SNOW MELT C WILL OCCUR. CALL THE SNOW MELT RATE,EX AND AMT, SNOMLT. REVISE THE C EFFECTIVE SNOW DEPTH. REVISE THE SKIN TEMP BECAUSE IT WOULD HAVE CHGD C DUE TO THE LATENT HEAT RELEASED BY THE MELTING. CALC THE LATENT HEAT C RELEASED, FLX3. SET THE EFFECTIVE PRECIP, PRCP1 TO THE SNOW MELT RATE, C EX FOR USE IN SMFLX. ADJUSTMENT TO T1 TO ACCOUNT FOR SNOW PATCHES. C CALCULATE QSAT VALID AT FREEZING POINT. NOTE THAT ESAT (SATURATION C VAPOR PRESSURE) VALUE OF 6.11E+2 USED HERE IS THAT VALID AT FRZZING C POINT. NOTE THAT ETP FROM CALL PENMAN IN SFLX IS IGNORED HERE IN C FAVOR OF BULK ETP OVER 'OPEN WATER' AT FREEZING TEMP. C UPDATE SOIL HEAT FLUX (S) USING NEW SKIN TEMPERATURE (T1) C ---------------------------------------------------------------------- c....Noah V2.7.1 c mek Feb2004 c non-linear weighting of snow vs non-snow covered portions of gridbox c so with SNOEXP = 2.0 (>1), surface skin temperature is higher than for c the linear case (SNOEXP = 1). !! T1 = TFREEZ * SNCOVR + T12 * (1.0 - SNCOVR) T1=TFREEZ * SNCOVR**SNOEXP+T12*(1.0 - SNCOVR**SNOEXP) c QSAT = (0.622*6.11E2)/(SFCPRS-0.378*6.11E2) c ETP = RCH*(QSAT-Q2)/CP c ETP2 = ETP*0.001*DT BETA = 1.0 SSOIL = DF1 * (T1 - STC(1)) / DTOT C ---------------------------------------------------------------------- C IF POTENTIAL EVAP (SUBLIMATION) GREATER THAN DEPTH OF SNOWPACK. C BETA<1 C SNOWPACK HAS SUBLIMATED AWAY, SET DEPTH TO ZERO. C ---------------------------------------------------------------------- c IF (ESD .LE. ETP2) THEN c IF (ESD .LE. ESNOW2) THEN IF (ESD-ESNOW2 .LE. ESDMIN) THEN c BETA = ESD / ETP2 ESD = 0.0 EX = 0.0 SNOMLT = 0.0 FLX3 = 0.0 ELSE C ---------------------------------------------------------------------- C POTENTIAL EVAP (SUBLIMATION) LESS THAN DEPTH OF SNOWPACK, RETAIN C BETA=1. C SNOWPACK (ESD) REDUCED BY POTENTIAL EVAP RATE C ETP3 (CONVERT TO FLUX) C ---------------------------------------------------------------------- c ESD = ESD-ETP2 ESD = ESD-ESNOW2 c ETP3 = ETP*LSUBC SEH = RCH*(T1-TH2) T14 = T1*T1 T14 = T14*T14 c FLX3 = FDOWN - FLX1 - FLX2 - SIGMA*T14 - SSOIL - SEH - ETP3 FLX3 = FDOWN - FLX1 - FLX2 - SIGMA*T14 - SSOIL - SEH - ETANRG IF (FLX3 .LE .0.0) FLX3 = 0.0 EX = FLX3*0.001/LSUBF C ---------------------------------------------------------------------- C SNOWMELT REDUCTION DEPENDING ON SNOW COVER C IF SNOW COVER LESS THAN 5% NO SNOWMELT REDUCTION C ***NOTE: DOES 'IF' BELOW FAIL TO MATCH THE MELT WATER WITH THE MELT C ENERGY? C ---------------------------------------------------------------------- c IF (SNCOVR .GT. 0.05) EX = EX * SNCOVR SNOMLT = EX * DT C ---------------------------------------------------------------------- C ESDMIN REPRESENTS A SNOWPACK DEPTH THRESHOLD VALUE BELOW WHICH WE C CHOOSE NOT TO RETAIN ANY SNOWPACK, AND INSTEAD INCLUDE IT IN SNOWMELT. C ---------------------------------------------------------------------- IF (ESD-SNOMLT .GE. ESDMIN) THEN ESD = ESD - SNOMLT ELSE C ---------------------------------------------------------------------- C SNOWMELT EXCEEDS SNOW DEPTH C ---------------------------------------------------------------------- EX = ESD/DT FLX3 = EX*1000.0*LSUBF SNOMLT = ESD ESD = 0.0 ENDIF C ---------------------------------------------------------------------- C END OF 'ESD .LE. ETP2' IF-BLOCK C ---------------------------------------------------------------------- ENDIF c PRCP1 = PRCP1 + EX C ---------------------------------------------------------------------- C IF NON-GLACIAL LAND, ADD SNOWMELT RATE (EX) TO PRECIP RATE TO BE USED C IN SUBROUTINE SMFLX (SOIL MOISTURE EVOLUTION) VIA INFILTRATION. C C FOR SEA-ICE AND GLACIAL-ICE, THE SNOWMELT WILL BE ADDED TO SUBSURFACE C RUNOFF/BASEFLOW LATER NEAR THE END OF SFLX (AFTER RETURN FROM CALL TO C SUBROUTINE SNOPAC) C ---------------------------------------------------------------------- IF (ICE .EQ. 0) PRCP1 = PRCP1 + EX C ---------------------------------------------------------------------- C END OF 'T12 .LE. TFREEZ' IF-BLOCK C ---------------------------------------------------------------------- ENDIF C ---------------------------------------------------------------------- C FINAL BETA NOW IN HAND, SO COMPUTE EVAPORATION. EVAP EQUALS ETP C UNLESS BETA<1. C ---------------------------------------------------------------------- c ETA = BETA*ETP C ---------------------------------------------------------------------- C SMFLX RETURNS UPDATED SOIL MOISTURE VALUES FOR NON-GLACIAL LAND. C IF SEA-ICE (ICE=1) OR GLACIAL-ICE (ICE=-1), SKIP CALL TO SMFLX, SINCE C NO SOIL MEDIUM FOR SEA-ICE OR GLACIAL-ICE C ---------------------------------------------------------------------- IF (ICE .EQ. 0) THEN CALL SMFLX (SMC,NSOIL,CMC,DT,PRCP1,ZSOIL, & SH2O,SLOPE,KDT,FRZFACT, & SMCMAX,BEXP,SMCWLT,DKSAT,DWSAT, & SHDFAC,CMCMAX, & RUNOFF1,RUNOFF2,RUNOFF3, & EDIR1,EC1,ET1, & DRIP) ENDIF C ---------------------------------------------------------------------- C BEFORE CALL SHFLX IN THIS SNOWPACK CASE, SET ZZ1 AND YY ARGUMENTS TO C SPECIAL VALUES THAT ENSURE THAT GROUND HEAT FLUX CALCULATED IN SHFLX C MATCHES THAT ALREADY COMPUTER FOR BELOW THE SNOWPACK, THUS THE SFC C HEAT FLUX TO BE COMPUTED IN SHFLX WILL EFFECTIVELY BE THE FLUX AT THE C SNOW TOP SURFACE. T11 IS A DUMMY ARGUEMENT SO WE WILL NOT USE THE C SKIN TEMP VALUE AS REVISED BY SHFLX. C ---------------------------------------------------------------------- ZZ1 = 1.0 YY = STC(1)-0.5*SSOIL*ZSOIL(1)*ZZ1/DF1 T11 = T1 C ---------------------------------------------------------------------- C SHFLX WILL CALC/UPDATE THE SOIL TEMPS. NOTE: THE SUB-SFC HEAT FLUX C (SSOIL1) AND THE SKIN TEMP (T11) OUTPUT FROM THIS SHFLX CALL ARE NOT C USED IN ANY SUBSEQUENT CALCULATIONS. RATHER, THEY ARE DUMMY VARIABLES C HERE IN THE SNOPAC CASE, SINCE THE SKIN TEMP AND SUB-SFC HEAT FLUX ARE C UPDATED INSTEAD NEAR THE BEGINNING OF THE CALL TO SNOPAC. C ---------------------------------------------------------------------- CALL SHFLX (SSOIL1,STC,SMC,SMCMAX,NSOIL,T11,DT,YY,ZZ1,ZSOIL, & TBOT,ZBOT,SMCWLT,PSISAT,SH2O,BEXP,F1,DF1,ICE, & QUARTZ,CSOIL) C ---------------------------------------------------------------------- C SNOW DEPTH AND DENSITY ADJUSTMENT BASED ON SNOW COMPACTION. YY IS C ASSUMED TO BE THE SOIL TEMPERTURE AT THE TOP OF THE SOIL COLUMN. C ---------------------------------------------------------------------- IF (ICE .EQ. 0) THEN C NON-GLACIAL LAND IF (ESD .GT. 0.) THEN CALL SNOWPACK (ESD,DT,SNOWH,SNDENS,T1,YY) ELSE ESD = 0. SNOWH = 0. SNDENS = 0. SNCOND = 1. SNCOVR = 0. ENDIF C ---------------------------------------------------------------------- C OVER SEA-ICE OR GLACIAL-ICE, IF S.W.E. (ESD) BELOW THRESHOLD LOWER C BOUND (0.01 M FOR SEA-ICE, 0.10 M FOR GLACIAL-ICE), THEN SET AT LOWER C BOUND AND STORE THE SOURCE INCREMENT IN SUBSURFACE RUNOFF/BASEFLOW C (RUNOFF2). NOTE: RUNOFF2 IS THEN A NEGATIVE VALUE (AS A FLAG) OVER C SEA-ICE OR GLACIAL-ICE, IN ORDER TO ACHIEVE WATER BALANCE. C ---------------------------------------------------------------------- ELSEIF (ICE .EQ. 1) THEN C SEA-ICE IF (ESD .GE. 0.01) THEN CALL SNOWPACK (ESD,DT,SNOWH,SNDENS,T1,YY) ELSE c SNDENS = ESD/SNOWH c RUNOFF2 = -(0.01-ESD)/DT ESD = 0.01 SNOWH = 0.05 SNCOVR = 1.0 c SNOWH = ESD/SNDENS ENDIF ELSE C GLACIAL-ICE IF (ESD .GE. 0.10) THEN CALL SNOWPACK (ESD,DT,SNOWH,SNDENS,T1,YY) ELSE c SNDENS = ESD/SNOWH c RUNOFF2 = -(0.10-ESD)/DT ESD = 0.10 SNOWH = 0.50 SNCOVR = 1.0 c SNOWH = ESD/SNDENS ENDIF ENDIF C ---------------------------------------------------------------------- C END SUBROUTINE SNOPAC C ---------------------------------------------------------------------- RETURN END SUBROUTINE SNOWPACK (ESD,DTSEC,SNOWH,SNDENS,TSNOW,TSOIL) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE SNOWPACK C ---------------------------------------------------------------------- C CALCULATE COMPACTION OF SNOWPACK UNDER CONDITIONS OF INCREASING SNOW C DENSITY, AS OBTAINED FROM AN APPROXIMATE SOLUTION OF E. ANDERSON'S C DIFFERENTIAL EQUATION (3.29), NOAA TECHNICAL REPORT NWS 19, BY VICTOR C KOREN, 03/25/95. C ---------------------------------------------------------------------- C ESD WATER EQUIVALENT OF SNOW (M) C DTSEC TIME STEP (SEC) C SNOWH SNOW DEPTH (M) C SNDENS SNOW DENSITY (G/CM3=DIMENSIONLESS FRACTION OF H2O DENSITY) C TSNOW SNOW SURFACE TEMPERATURE (K) C TSOIL SOIL SURFACE TEMPERATURE (K) C C SUBROUTINE WILL RETURN NEW VALUES OF SNOWH AND SNDENS C ---------------------------------------------------------------------- INTEGER IPOL, J REAL BFAC,C1,C2,SNDENS,DSX,DTHR,DTSEC,DW,SNOWHC,SNOWH,PEXP,TAVGC, & TSNOW,TSNOWC,TSOIL,TSOILC,ESD,ESDC,ESDCX,G,KN PARAMETER(C1 = 0.01, C2=21.0, G=9.81, KN=4000.0) C ---------------------------------------------------------------------- C CONVERSION INTO SIMULATION UNITS C ---------------------------------------------------------------------- SNOWHC = SNOWH*100. ESDC = ESD*100. DTHR = DTSEC/3600. TSNOWC = TSNOW-273.15 TSOILC = TSOIL-273.15 C ---------------------------------------------------------------------- C CALCULATING OF AVERAGE TEMPERATURE OF SNOW PACK C ---------------------------------------------------------------------- TAVGC = 0.5*(TSNOWC+TSOILC) C ---------------------------------------------------------------------- C CALCULATING OF SNOW DEPTH AND DENSITY AS A RESULT OF COMPACTION C SNDENS=DS0*(EXP(BFAC*ESD)-1.)/(BFAC*ESD) C BFAC=DTHR*C1*EXP(0.08*TAVGC-C2*DS0) C NOTE: BFAC*ESD IN SNDENS EQN ABOVE HAS TO BE CAREFULLY TREATED C NUMERICALLY BELOW: C C1 IS THE FRACTIONAL INCREASE IN DENSITY (1/(CM*HR)) C C2 IS A CONSTANT (CM3/G) KOJIMA ESTIMATED AS 21 CMS/G C ---------------------------------------------------------------------- IF (ESDC .GT. 1.E-2) THEN ESDCX = ESDC ELSE ESDCX = 1.E-2 ENDIF BFAC = DTHR*C1*EXP(0.08*TAVGC-C2*SNDENS) C DSX = SNDENS*((DEXP(BFAC*ESDC)-1.)/(BFAC*ESDC)) C ---------------------------------------------------------------------- C THE FUNCTION OF THE FORM (e**x-1)/x IMBEDDED IN ABOVE EXPRESSION C FOR DSX WAS CAUSING NUMERICAL DIFFICULTIES WHEN THE DENOMINATOR "x" C (I.E. BFAC*ESDC) BECAME ZERO OR APPROACHED ZERO (DESPITE THE FACT THAT C THE ANALYTICAL FUNCTION (e**x-1)/x HAS A WELL DEFINED LIMIT AS C "x" APPROACHES ZERO), HENCE BELOW WE REPLACE THE (e**x-1)/x C EXPRESSION WITH AN EQUIVALENT, NUMERICALLY WELL-BEHAVED C POLYNOMIAL EXPANSION. C C NUMBER OF TERMS OF POLYNOMIAL EXPANSION, AND HENCE ITS ACCURACY, C IS GOVERNED BY ITERATION LIMIT "IPOL". C IPOL GREATER THAN 9 ONLY MAKES A DIFFERENCE ON DOUBLE C PRECISION (RELATIVE ERRORS GIVEN IN PERCENT %). C IPOL=9, FOR REL.ERROR <~ 1.6 E-6 % (8 SIGNIFICANT DIGITS) C IPOL=8, FOR REL.ERROR <~ 1.8 E-5 % (7 SIGNIFICANT DIGITS) C IPOL=7, FOR REL.ERROR <~ 1.8 E-4 % ... C ---------------------------------------------------------------------- IPOL = 4 PEXP = 0. DO J = IPOL,1,-1 C PEXP = (1. + PEXP)*BFAC*ESDC/REAL(J+1) PEXP = (1. + PEXP)*BFAC*ESDCX/REAL(J+1) END DO PEXP = PEXP + 1. DSX = SNDENS*(PEXP) C ---------------------------------------------------------------------- C ABOVE LINE ENDS POLYNOMIAL SUBSTITUTION C ---------------------------------------------------------------------- C END OF KOREAN FORMULATION C BASE FORMULATION (COGLEY ET AL., 1990) C CONVERT DENSITY FROM G/CM3 TO KG/M3 C DSM=SNDENS*1000.0 C DSX=DSM+DTSEC*0.5*DSM*G*ESD/ C & (1E7*EXP(-0.02*DSM+KN/(TAVGC+273.16)-14.643)) C CONVERT DENSITY FROM KG/M3 TO G/CM3 C DSX=DSX/1000.0 C END OF COGLEY ET AL. FORMULATION C ---------------------------------------------------------------------- C SET UPPER/LOWER LIMIT ON SNOW DENSITY C ---------------------------------------------------------------------- IF (DSX .GT. 0.40) DSX = 0.40 IF (DSX .LT. 0.05) DSX = 0.05 SNDENS = DSX C ---------------------------------------------------------------------- C UPDATE OF SNOW DEPTH AND DENSITY DEPENDING ON LIQUID WATER DURING C SNOWMELT. ASSUMED THAT 13% OF LIQUID WATER CAN BE STORED IN SNOW PER C DAY DURING SNOWMELT TILL SNOW DENSITY 0.40. C ---------------------------------------------------------------------- IF (TSNOWC .GE. 0.) THEN DW = 0.13*DTHR/24. SNDENS = SNDENS*(1.-DW)+DW IF (SNDENS .GT. 0.40) SNDENS = 0.40 ENDIF C ---------------------------------------------------------------------- C CALCULATE SNOW DEPTH (CM) FROM SNOW WATER EQUIVALENT AND SNOW DENSITY. C CHANGE SNOW DEPTH UNITS TO METERS C ---------------------------------------------------------------------- SNOWHC = ESDC/SNDENS SNOWH = SNOWHC*0.01 C ---------------------------------------------------------------------- C END SUBROUTINE SNOWPACK C ---------------------------------------------------------------------- RETURN END SUBROUTINE SNOWZ0 (SNCOVR,Z0) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE SNOWZ0 C ---------------------------------------------------------------------- C CALCULATE TOTAL ROUGHNESS LENGTH OVER SNOW C SNCOVR FRACTIONAL SNOW COVER C Z0 ROUGHNESS LENGTH (m) C Z0S SNOW ROUGHNESS LENGTH:=0.001 (m) C ---------------------------------------------------------------------- REAL SNCOVR, Z0, Z0S c PARAMETER (Z0S=0.001) C CURRENT NOAH LSM CONDITION - MBEK, 09-OCT-2001 Z0S = Z0 C Z0 = (1-SNCOVR)*Z0 + SNCOVR*Z0S C ---------------------------------------------------------------------- C END SUBROUTINE SNOWZ0 C ---------------------------------------------------------------------- RETURN END SUBROUTINE SNOW_NEW (TEMP,NEWSN,SNOWH,SNDENS) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE SNOW_NEW C ---------------------------------------------------------------------- C CALCULATE SNOW DEPTH AND DENSITITY TO ACCOUNT FOR THE NEW SNOWFALL. C NEW VALUES OF SNOW DEPTH & DENSITY RETURNED. C C TEMP AIR TEMPERATURE (K) C NEWSN NEW SNOWFALL (M) C SNOWH SNOW DEPTH (M) C SNDENS SNOW DENSITY (G/CM3=DIMENSIONLESS FRACTION OF H2O DENSITY) C ---------------------------------------------------------------------- REAL SNDENS REAL DSNEW REAL SNOWHC REAL HNEWC REAL SNOWH REAL NEWSN REAL NEWSNC REAL TEMP REAL TEMPC C ---------------------------------------------------------------------- C CONVERSION INTO SIMULATION UNITS C ---------------------------------------------------------------------- SNOWHC = SNOWH*100. NEWSNC = NEWSN*100. TEMPC = TEMP-273.15 C ---------------------------------------------------------------------- C CALCULATING NEW SNOWFALL DENSITY DEPENDING ON TEMPERATURE C EQUATION FROM GOTTLIB L. 'A GENERAL RUNOFF MODEL FOR SNOWCOVERED C AND GLACIERIZED BASIN', 6TH NORDIC HYDROLOGICAL CONFERENCE, C VEMADOLEN, SWEDEN, 1980, 172-177PP. C----------------------------------------------------------------------- IF (TEMPC .LE. -15.) THEN DSNEW = 0.05 ELSE DSNEW = 0.05+0.0017*(TEMPC+15.)**1.5 ENDIF C ---------------------------------------------------------------------- C ADJUSTMENT OF SNOW DENSITY DEPENDING ON NEW SNOWFALL C ---------------------------------------------------------------------- HNEWC = NEWSNC/DSNEW SNDENS = (SNOWHC*SNDENS+HNEWC*DSNEW)/(SNOWHC+HNEWC) SNOWHC = SNOWHC+HNEWC SNOWH = SNOWHC*0.01 C ---------------------------------------------------------------------- C END SUBROUTINE SNOW_NEW C ---------------------------------------------------------------------- RETURN END SUBROUTINE SRT (RHSTT,EDIR,ET,SH2O,SH2OA,NSOIL,PCPDRP, & ZSOIL,DWSAT,DKSAT,SMCMAX,BEXP,RUNOFF1, & RUNOFF2,DT,SMCWLT,SLOPE,KDT,FRZX,SICE,AI,BI,CI) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE SRT C ---------------------------------------------------------------------- C CALCULATE THE RIGHT HAND SIDE OF THE TIME TENDENCY TERM OF THE SOIL C WATER DIFFUSION EQUATION. ALSO TO COMPUTE ( PREPARE ) THE MATRIX C COEFFICIENTS FOR THE TRI-DIAGONAL MATRIX OF THE IMPLICIT TIME SCHEME. C ---------------------------------------------------------------------- INTEGER NSOLD PARAMETER(NSOLD = 4) INTEGER CVFRZ INTEGER IALP1 INTEGER IOHINF INTEGER J INTEGER JJ INTEGER K INTEGER KS INTEGER NSOIL REAL ACRT REAL AI(NSOLD) REAL BEXP REAL BI(NSOLD) REAL CI(NSOLD) REAL DD REAL DDT REAL DDZ REAL DDZ2 REAL DENOM REAL DENOM2 REAL DICE REAL DKSAT REAL DMAX(NSOLD) REAL DSMDZ REAL DSMDZ2 REAL DT REAL DT1 REAL DWSAT REAL EDIR REAL ET(NSOIL) REAL FCR REAL FRZX REAL INFMAX REAL KDT REAL MXSMC REAL MXSMC2 REAL NUMER REAL PCPDRP REAL PDDUM REAL PX REAL RHSTT(NSOIL) REAL RUNOFF1 REAL RUNOFF2 REAL SH2O(NSOIL) REAL SH2OA(NSOIL) REAL SICE(NSOIL) REAL SICEMAX REAL SLOPE REAL SLOPX REAL SMCAV REAL SMCMAX REAL SMCWLT REAL SSTT REAL SUM REAL VAL REAL WCND REAL WCND2 REAL WDF REAL WDF2 REAL ZSOIL(NSOIL) C ---------------------------------------------------------------------- C FROZEN GROUND VERSION: C REFERENCE FROZEN GROUND PARAMETER, CVFRZ, IS A SHAPE PARAMETER OF C AREAL DISTRIBUTION FUNCTION OF SOIL ICE CONTENT WHICH EQUALS 1/CV. C CV IS A COEFFICIENT OF SPATIAL VARIATION OF SOIL ICE CONTENT. BASED C ON FIELD DATA CV DEPENDS ON AREAL MEAN OF FROZEN DEPTH, AND IT CLOSE C TO CONSTANT = 0.6 IF AREAL MEAN FROZEN DEPTH IS ABOVE 20 CM. THAT IS C WHY PARAMETER CVFRZ = 3 (INT{1/0.6*0.6}). C CURRENT LOGIC DOESN'T ALLOW CVFRZ BE BIGGER THAN 3 C ---------------------------------------------------------------------- PARAMETER(CVFRZ = 3) C ---------------------------------------------------------------------- C DETERMINE RAINFALL INFILTRATION RATE AND RUNOFF. INCLUDE THE C INFILTRATION FORMULE FROM SCHAAKE AND KOREN MODEL. C MODIFIED BY Q DUAN C ---------------------------------------------------------------------- IOHINF=1 C ---------------------------------------------------------------------- C LET SICEMAX BE THE GREATEST, IF ANY, FROZEN WATER CONTENT WITHIN SOIL C LAYERS. C ---------------------------------------------------------------------- SICEMAX = 0.0 DO KS=1,NSOIL IF (SICE(KS) .GT. SICEMAX) SICEMAX = SICE(KS) END DO C ---------------------------------------------------------------------- C DETERMINE RAINFALL INFILTRATION RATE AND RUNOFF C ---------------------------------------------------------------------- PDDUM = PCPDRP RUNOFF1 = 0.0 IF (PCPDRP .NE. 0.0) THEN C ---------------------------------------------------------------------- C MODIFIED BY Q. DUAN, 5/16/94 C ---------------------------------------------------------------------- C IF (IOHINF .EQ. 1) THEN DT1 = DT/86400. SMCAV = SMCMAX - SMCWLT DMAX(1)=-ZSOIL(1)*SMCAV C ---------------------------------------------------------------------- C FROZEN GROUND VERSION: C ---------------------------------------------------------------------- DICE = -ZSOIL(1) * SICE(1) DMAX(1)=DMAX(1)*(1.0 - (SH2OA(1)+SICE(1)-SMCWLT)/SMCAV) DD=DMAX(1) DO KS=2,NSOIL C ---------------------------------------------------------------------- C FROZEN GROUND VERSION: C ---------------------------------------------------------------------- DICE = DICE + ( ZSOIL(KS-1) - ZSOIL(KS) ) * SICE(KS) DMAX(KS) = (ZSOIL(KS-1)-ZSOIL(KS))*SMCAV DMAX(KS) = DMAX(KS)*(1.0 - (SH2OA(KS)+SICE(KS)-SMCWLT)/SMCAV) DD = DD+DMAX(KS) END DO C ---------------------------------------------------------------------- C VAL = (1.-EXP(-KDT*SQRT(DT1))) C IN BELOW, REMOVE THE SQRT IN ABOVE C ---------------------------------------------------------------------- VAL = (1.-EXP(-KDT*DT1)) DDT = DD*VAL PX = PCPDRP*DT IF (PX .LT. 0.0) PX = 0.0 INFMAX = (PX*(DDT/(PX+DDT)))/DT C ---------------------------------------------------------------------- C FROZEN GROUND VERSION: C REDUCTION OF INFILTRATION BASED ON FROZEN GROUND PARAMETERS C ---------------------------------------------------------------------- FCR = 1. IF (DICE .GT. 1.E-2) THEN ACRT = CVFRZ * FRZX / DICE SUM = 1. IALP1 = CVFRZ - 1 DO J = 1,IALP1 K = 1 DO JJ = J+1,IALP1 K = K * JJ END DO SUM = SUM + (ACRT ** ( CVFRZ-J)) / FLOAT (K) END DO FCR = 1. - EXP(-ACRT) * SUM ENDIF INFMAX = INFMAX * FCR C ---------------------------------------------------------------------- C CORRECTION OF INFILTRATION LIMITATION: C IF INFMAX .LE. HYDROLIC CONDUCTIVITY ASSIGN INFMAX THE VALUE OF C HYDROLIC CONDUCTIVITY C ---------------------------------------------------------------------- C MXSMC = MAX ( SH2OA(1), SH2OA(2) ) MXSMC = SH2OA(1) CALL WDFCND (WDF,WCND,MXSMC,SMCMAX,BEXP,DKSAT,DWSAT, & SICEMAX) INFMAX = MAX(INFMAX,WCND) INFMAX = MIN(INFMAX,PX) IF (PCPDRP .GT. INFMAX) THEN RUNOFF1 = PCPDRP - INFMAX PDDUM = INFMAX ENDIF ENDIF C ---------------------------------------------------------------------- C TO AVOID SPURIOUS DRAINAGE BEHAVIOR, 'UPSTREAM DIFFERENCING' IN LINE C BELOW REPLACED WITH NEW APPROACH IN 2ND LINE: C 'MXSMC = MAX(SH2OA(1), SH2OA(2))' C ---------------------------------------------------------------------- MXSMC = SH2OA(1) CALL WDFCND (WDF,WCND,MXSMC,SMCMAX,BEXP,DKSAT,DWSAT, & SICEMAX) C ---------------------------------------------------------------------- C CALC THE MATRIX COEFFICIENTS AI, BI, AND CI FOR THE TOP LAYER C ---------------------------------------------------------------------- DDZ = 1. / ( -.5 * ZSOIL(2) ) AI(1) = 0.0 BI(1) = WDF * DDZ / ( -ZSOIL(1) ) CI(1) = -BI(1) C ---------------------------------------------------------------------- C CALC RHSTT FOR THE TOP LAYER AFTER CALC'NG THE VERTICAL SOIL MOISTURE C GRADIENT BTWN THE TOP AND NEXT TO TOP LAYERS. C ---------------------------------------------------------------------- DSMDZ = ( SH2O(1) - SH2O(2) ) / ( -.5 * ZSOIL(2) ) RHSTT(1) = (WDF * DSMDZ + WCND - PDDUM + EDIR + ET(1))/ZSOIL(1) SSTT = WDF * DSMDZ + WCND + EDIR + ET(1) C ---------------------------------------------------------------------- C INITIALIZE DDZ2 C ---------------------------------------------------------------------- DDZ2 = 0.0 C ---------------------------------------------------------------------- C LOOP THRU THE REMAINING SOIL LAYERS, REPEATING THE ABV PROCESS C ---------------------------------------------------------------------- DO K = 2,NSOIL DENOM2 = (ZSOIL(K-1) - ZSOIL(K)) IF (K .NE. NSOIL) THEN SLOPX = 1. C ---------------------------------------------------------------------- C AGAIN, TO AVOID SPURIOUS DRAINAGE BEHAVIOR, 'UPSTREAM DIFFERENCING' IN C LINE BELOW REPLACED WITH NEW APPROACH IN 2ND LINE: C 'MXSMC2 = MAX (SH2OA(K), SH2OA(K+1))' C ---------------------------------------------------------------------- MXSMC2 = SH2OA(K) CALL WDFCND (WDF2,WCND2,MXSMC2,SMCMAX,BEXP,DKSAT,DWSAT, & SICEMAX) C ---------------------------------------------------------------------- C CALC SOME PARTIAL PRODUCTS FOR LATER USE IN CALC'NG RHSTT C ---------------------------------------------------------------------- DENOM = (ZSOIL(K-1) - ZSOIL(K+1)) DSMDZ2 = (SH2O(K) - SH2O(K+1)) / (DENOM * 0.5) C ---------------------------------------------------------------------- C CALC THE MATRIX COEF, CI, AFTER CALC'NG ITS PARTIAL PRODUCT C ---------------------------------------------------------------------- DDZ2 = 2.0 / DENOM CI(K) = -WDF2 * DDZ2 / DENOM2 ELSE C ---------------------------------------------------------------------- C SLOPE OF BOTTOM LAYER IS INTRODUCED C ---------------------------------------------------------------------- SLOPX = SLOPE C ---------------------------------------------------------------------- C RETRIEVE THE SOIL WATER DIFFUSIVITY AND HYDRAULIC CONDUCTIVITY FOR C THIS LAYER C ---------------------------------------------------------------------- CALL WDFCND (WDF2,WCND2,SH2OA(NSOIL),SMCMAX,BEXP,DKSAT,DWSAT, & SICEMAX) C ---------------------------------------------------------------------- C CALC A PARTIAL PRODUCT FOR LATER USE IN CALC'NG RHSTT C ---------------------------------------------------------------------- DSMDZ2 = 0.0 C ---------------------------------------------------------------------- C SET MATRIX COEF CI TO ZERO C ---------------------------------------------------------------------- CI(K) = 0.0 ENDIF C ---------------------------------------------------------------------- C CALC RHSTT FOR THIS LAYER AFTER CALC'NG ITS NUMERATOR C ---------------------------------------------------------------------- NUMER = (WDF2 * DSMDZ2) + SLOPX * WCND2 - (WDF * DSMDZ) & - WCND + ET(K) RHSTT(K) = NUMER / (-DENOM2) C ---------------------------------------------------------------------- C CALC MATRIX COEFS, AI, AND BI FOR THIS LAYER C ---------------------------------------------------------------------- AI(K) = -WDF * DDZ / DENOM2 BI(K) = -( AI(K) + CI(K) ) C ---------------------------------------------------------------------- C RESET VALUES OF WDF, WCND, DSMDZ, AND DDZ FOR LOOP TO NEXT LYR C RUNOFF2: SUB-SURFACE OR BASEFLOW RUNOFF C ---------------------------------------------------------------------- IF (K .EQ. NSOIL) THEN RUNOFF2 = SLOPX * WCND2 ENDIF IF (K .NE. NSOIL) THEN WDF = WDF2 WCND = WCND2 DSMDZ = DSMDZ2 DDZ = DDZ2 ENDIF END DO C ---------------------------------------------------------------------- C END SUBROUTINE SRT C ---------------------------------------------------------------------- RETURN END SUBROUTINE SSTEP (SH2OOUT,SH2OIN,CMC,RHSTT,RHSCT,DT, & NSOIL,SMCMAX,CMCMAX,RUNOFF3,ZSOIL,SMC,SICE, & AI,BI,CI) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE SSTEP C ---------------------------------------------------------------------- C CALCULATE/UPDATE SOIL MOISTURE CONTENT VALUES AND CANOPY MOISTURE C CONTENT VALUES. C ---------------------------------------------------------------------- INTEGER NSOLD PARAMETER(NSOLD = 4) INTEGER I INTEGER K INTEGER KK11 INTEGER NSOIL REAL AI(NSOLD) REAL BI(NSOLD) REAL CI(NSOLD) REAL CIin(NSOLD) REAL CMC REAL CMCMAX REAL DDZ REAL DT REAL RHSCT REAL RHSTT(NSOIL) REAL RHSTTin(NSOIL) REAL RUNOFF3 REAL SH2OIN(NSOIL) REAL SH2OOUT(NSOIL) REAL SICE(NSOIL) REAL SMC(NSOIL) REAL SMCMAX REAL STOT REAL WPLUS REAL ZSOIL(NSOIL) C ---------------------------------------------------------------------- C CREATE 'AMOUNT' VALUES OF VARIABLES TO BE INPUT TO THE C TRI-DIAGONAL MATRIX ROUTINE. C ---------------------------------------------------------------------- DO K = 1,NSOIL RHSTT(K) = RHSTT(K) * DT AI(K) = AI(K) * DT BI(K) = 1. + BI(K) * DT CI(K) = CI(K) * DT END DO C ---------------------------------------------------------------------- C COPY VALUES FOR INPUT VARIABLES BEFORE CALL TO ROSR12 C ---------------------------------------------------------------------- DO K = 1,NSOIL RHSTTin(K) = RHSTT(K) END DO DO K = 1,NSOLD CIin(K) = CI(K) END DO C ---------------------------------------------------------------------- C CALL ROSR12 TO SOLVE THE TRI-DIAGONAL MATRIX C ---------------------------------------------------------------------- CALL ROSR12 (CI,AI,BI,CIin,RHSTTin,RHSTT,NSOIL) C ---------------------------------------------------------------------- C SUM THE PREVIOUS SMC VALUE AND THE MATRIX SOLUTION TO GET A C NEW VALUE. MIN ALLOWABLE VALUE OF SMC WILL BE 0.02. C RUNOFF3: RUNOFF WITHIN SOIL LAYERS C ---------------------------------------------------------------------- WPLUS = 0.0 RUNOFF3 = 0. DDZ = -ZSOIL(1) DO K = 1,NSOIL IF (K .NE. 1) DDZ = ZSOIL(K - 1) - ZSOIL(K) SH2OOUT(K) = SH2OIN(K) + CI(K) + WPLUS / DDZ STOT = SH2OOUT(K) + SICE(K) IF (STOT .GT. SMCMAX) THEN IF (K .EQ. 1) THEN DDZ = -ZSOIL(1) ELSE KK11 = K - 1 DDZ = -ZSOIL(K) + ZSOIL(KK11) ENDIF WPLUS = (STOT-SMCMAX) * DDZ ELSE WPLUS = 0. ENDIF SMC(K) = MAX ( MIN(STOT,SMCMAX),0.02 ) SH2OOUT(K) = MAX((SMC(K)-SICE(K)),0.0) END DO RUNOFF3 = WPLUS C ---------------------------------------------------------------------- C UPDATE CANOPY WATER CONTENT/INTERCEPTION (CMC). CONVERT RHSCT TO C AN 'AMOUNT' VALUE AND ADD TO PREVIOUS CMC VALUE TO GET NEW CMC. C ---------------------------------------------------------------------- CMC = CMC + DT * RHSCT IF (CMC .LT. 1.E-20) CMC=0.0 CMC = MIN(CMC,CMCMAX) C ---------------------------------------------------------------------- C END SUBROUTINE SSTEP C ---------------------------------------------------------------------- RETURN END SUBROUTINE TBND (TU,TB,ZSOIL,ZBOT,K,NSOIL,TBND1) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE TBND C ---------------------------------------------------------------------- C CALCULATE TEMPERATURE ON THE BOUNDARY OF THE LAYER BY INTERPOLATION OF C THE MIDDLE LAYER TEMPERATURES C ---------------------------------------------------------------------- INTEGER NSOIL INTEGER K REAL TBND1 REAL T0 REAL TU REAL TB REAL ZB REAL ZBOT REAL ZUP REAL ZSOIL (NSOIL) PARAMETER(T0 = 273.15) C ---------------------------------------------------------------------- C USE SURFACE TEMPERATURE ON THE TOP OF THE FIRST LAYER C ---------------------------------------------------------------------- IF (K .EQ. 1) THEN ZUP = 0. ELSE ZUP = ZSOIL(K-1) ENDIF C ---------------------------------------------------------------------- C USE DEPTH OF THE CONSTANT BOTTOM TEMPERATURE WHEN INTERPOLATE C TEMPERATURE INTO THE LAST LAYER BOUNDARY C ---------------------------------------------------------------------- IF (K .EQ. NSOIL) THEN ZB = 2.*ZBOT-ZSOIL(K) ELSE ZB = ZSOIL(K+1) ENDIF C ---------------------------------------------------------------------- C LINEAR INTERPOLATION BETWEEN THE AVERAGE LAYER TEMPERATURES C ---------------------------------------------------------------------- TBND1 = TU+(TB-TU)*(ZUP-ZSOIL(K))/(ZUP-ZB) C ---------------------------------------------------------------------- C END SUBROUTINE TBND C ---------------------------------------------------------------------- RETURN END SUBROUTINE TDFCND ( DF, SMC, QZ, SMCMAX, SH2O) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE TDFCND C ---------------------------------------------------------------------- C CALCULATE THERMAL DIFFUSIVITY AND CONDUCTIVITY OF THE SOIL FOR A GIVEN C POINT AND TIME. C ---------------------------------------------------------------------- C PETERS-LIDARD APPROACH (PETERS-LIDARD et al., 1998) C June 2001 CHANGES: FROZEN SOIL CONDITION. C ---------------------------------------------------------------------- REAL DF REAL GAMMD REAL THKDRY REAL AKE REAL THKICE REAL THKO REAL THKQTZ REAL THKSAT REAL THKS REAL THKW REAL QZ REAL SATRATIO REAL SH2O REAL SMC REAL SMCMAX REAL XU REAL XUNFROZ C ---------------------------------------------------------------------- C WE NOW GET QUARTZ AS AN INPUT ARGUMENT (SET IN ROUTINE REDPRM): C DATA QUARTZ /0.82, 0.10, 0.25, 0.60, 0.52, C & 0.35, 0.60, 0.40, 0.82/ C ---------------------------------------------------------------------- C IF THE SOIL HAS ANY MOISTURE CONTENT COMPUTE A PARTIAL SUM/PRODUCT C OTHERWISE USE A CONSTANT VALUE WHICH WORKS WELL WITH MOST SOILS C ---------------------------------------------------------------------- C THKW ......WATER THERMAL CONDUCTIVITY C THKQTZ ....THERMAL CONDUCTIVITY FOR QUARTZ C THKO ......THERMAL CONDUCTIVITY FOR OTHER SOIL COMPONENTS C THKS ......THERMAL CONDUCTIVITY FOR THE SOLIDS COMBINED(QUARTZ+OTHER) C THKICE ....ICE THERMAL CONDUCTIVITY C SMCMAX ....POROSITY (= SMCMAX) C QZ .........QUARTZ CONTENT (SOIL TYPE DEPENDENT) C ---------------------------------------------------------------------- C USE AS IN PETERS-LIDARD, 1998 (MODIF. FROM JOHANSEN, 1975). C C PABLO GRUNMANN, 08/17/98 C REFS.: C FAROUKI, O.T.,1986: THERMAL PROPERTIES OF SOILS. SERIES ON ROCK C AND SOIL MECHANICS, VOL. 11, TRANS TECH, 136 PP. C JOHANSEN, O., 1975: THERMAL CONDUCTIVITY OF SOILS. PH.D. THESIS, C UNIVERSITY OF TRONDHEIM, C PETERS-LIDARD, C. D., ET AL., 1998: THE EFFECT OF SOIL THERMAL C CONDUCTIVITY PARAMETERIZATION ON SURFACE ENERGY FLUXES C AND TEMPERATURES. JOURNAL OF THE ATMOSPHERIC SCIENCES, C VOL. 55, PP. 1209-1224. C ---------------------------------------------------------------------- C NEEDS PARAMETERS C POROSITY(SOIL TYPE): C POROS = SMCMAX C SATURATION RATIO: SATRATIO = SMC/SMCMAX C PARAMETERS W/(M.K) THKICE = 2.2 THKW = 0.57 THKO = 2.0 C IF (QZ .LE. 0.2) THKO = 3.0 THKQTZ = 7.7 C SOLIDS' CONDUCTIVITY THKS = (THKQTZ**QZ)*(THKO**(1.- QZ)) C UNFROZEN FRACTION (FROM 1., i.e., 100%LIQUID, TO 0. (100% FROZEN)) XUNFROZ = (SH2O + 1.E-9) / (SMC + 1.E-9) C UNFROZEN VOLUME FOR SATURATION (POROSITY*XUNFROZ) XU=XUNFROZ*SMCMAX C SATURATED THERMAL CONDUCTIVITY THKSAT = THKS**(1.-SMCMAX)*THKICE**(SMCMAX-XU)*THKW**(XU) C DRY DENSITY IN KG/M3 GAMMD = (1. - SMCMAX)*2700. C DRY THERMAL CONDUCTIVITY IN W.M-1.K-1 THKDRY = (0.135*GAMMD + 64.7)/(2700. - 0.947*GAMMD) IF ( (SH2O + 0.0005) .LT. SMC ) THEN C FROZEN AKE = SATRATIO ELSE C UNFROZEN C RANGE OF VALIDITY FOR THE KERSTEN NUMBER (AKE) IF ( SATRATIO .GT. 0.1 ) THEN C KERSTEN NUMBER (USING "FINE" FORMULA, VALID FOR SOILS CONTAINING AT C LEAST 5% OF PARTICLES WITH DIAMETER LESS THAN 2.E-6 METERS.) C (FOR "COARSE" FORMULA, SEE PETERS-LIDARD ET AL., 1998). AKE = LOG10(SATRATIO) + 1.0 ELSE C USE K = KDRY AKE = 0.0 ENDIF ENDIF C THERMAL CONDUCTIVITY DF = AKE*(THKSAT - THKDRY) + THKDRY C ---------------------------------------------------------------------- C END SUBROUTINE TDFCND C ---------------------------------------------------------------------- RETURN END SUBROUTINE TMPAVG (TAVG,TUP,TM,TDN,ZSOIL,NSOIL,K) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE TMPAVG C ---------------------------------------------------------------------- C CALCULATE SOIL LAYER AVERAGE TEMPERATURE (TAVG) IN FREEZING/THAWING C LAYER USING UP, DOWN, AND MIDDLE LAYER TEMPERATURES (TUP, TDN, TM), C WHERE TUP IS AT TOP BOUNDARY OF LAYER, TDN IS AT BOTTOM BOUNDARY OF C LAYER. TM IS LAYER PROGNOSTIC STATE TEMPERATURE. C ---------------------------------------------------------------------- INTEGER K INTEGER NSOIL REAL DZ REAL DZH REAL T0 REAL TAVG REAL TDN REAL TM REAL TUP REAL X0 REAL XDN REAL XUP REAL ZSOIL (NSOIL) PARAMETER(T0 = 2.7315E2) C ---------------------------------------------------------------------- IF (K .EQ. 1) THEN DZ = -ZSOIL(1) ELSE DZ = ZSOIL(K-1)-ZSOIL(K) ENDIF DZH=DZ*0.5 IF (TUP .LT. T0) THEN IF (TM .LT. T0) THEN IF (TDN .LT. T0) THEN C ---------------------------------------------------------------------- C TUP, TM, TDN < T0 C ---------------------------------------------------------------------- TAVG = (TUP + 2.0*TM + TDN)/ 4.0 ELSE C ---------------------------------------------------------------------- C TUP & TM < T0, TDN >= T0 C ---------------------------------------------------------------------- X0 = (T0 - TM) * DZH / (TDN - TM) TAVG = 0.5 * (TUP*DZH+TM*(DZH+X0)+T0*(2.*DZH-X0)) / DZ ENDIF ELSE IF (TDN .LT. T0) THEN C ---------------------------------------------------------------------- C TUP < T0, TM >= T0, TDN < T0 C ---------------------------------------------------------------------- XUP = (T0-TUP) * DZH / (TM-TUP) XDN = DZH - (T0-TM) * DZH / (TDN-TM) TAVG = 0.5 * (TUP*XUP+T0*(2.*DZ-XUP-XDN)+TDN*XDN) / DZ ELSE C ---------------------------------------------------------------------- C TUP < T0, TM >= T0, TDN >= T0 C ---------------------------------------------------------------------- XUP = (T0-TUP) * DZH / (TM-TUP) TAVG = 0.5 * (TUP*XUP+T0*(2.*DZ-XUP)) / DZ ENDIF ENDIF ELSE IF (TM .LT. T0) THEN IF (TDN .LT. T0) THEN C ---------------------------------------------------------------------- C TUP >= T0, TM < T0, TDN < T0 C ---------------------------------------------------------------------- XUP = DZH - (T0-TUP) * DZH / (TM-TUP) TAVG = 0.5 * (T0*(DZ-XUP)+TM*(DZH+XUP)+TDN*DZH) / DZ ELSE C ---------------------------------------------------------------------- C TUP >= T0, TM < T0, TDN >= T0 C ---------------------------------------------------------------------- XUP = DZH - (T0-TUP) * DZH / (TM-TUP) XDN = (T0-TM) * DZH / (TDN-TM) TAVG = 0.5 * (T0*(2.*DZ-XUP-XDN)+TM*(XUP+XDN)) / DZ ENDIF ELSE IF (TDN .LT. T0) THEN C ---------------------------------------------------------------------- C TUP >= T0, TM >= T0, TDN < T0 C ---------------------------------------------------------------------- XDN = DZH - (T0-TM) * DZH / (TDN-TM) TAVG = (T0*(DZ-XDN)+0.5*(T0+TDN)*XDN) / DZ ELSE C ---------------------------------------------------------------------- C TUP >= T0, TM >= T0, TDN >= T0 C ---------------------------------------------------------------------- TAVG = (TUP + 2.0*TM + TDN) / 4.0 ENDIF ENDIF ENDIF C ---------------------------------------------------------------------- C END SUBROUTINE TMPAVG C ---------------------------------------------------------------------- RETURN END SUBROUTINE TRANSP (ET1,NSOIL,ETP1,SMC,CMC,ZSOIL,SHDFAC,SMCWLT, & CMCMAX,PC,CFACTR,SMCREF,SFCTMP,Q2,NROOT,RTDIS) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE TRANSP C ---------------------------------------------------------------------- C CALCULATE TRANSPIRATION FOR THE VEG CLASS. C ---------------------------------------------------------------------- INTEGER I INTEGER K INTEGER NSOIL INTEGER NROOT REAL CFACTR REAL CMC REAL CMCMAX REAL DENOM REAL ET1(NSOIL) REAL ETP1 REAL ETP1A REAL GX (7) C.....REAL PART(NSOIL) REAL PC REAL Q2 REAL RTDIS(NSOIL) REAL RTX REAL SFCTMP REAL SGX REAL SHDFAC REAL SMC(NSOIL) REAL SMCREF REAL SMCWLT REAL ZSOIL(NSOIL) C ---------------------------------------------------------------------- C INITIALIZE PLANT TRANSP TO ZERO FOR ALL SOIL LAYERS. C ---------------------------------------------------------------------- DO K = 1,NSOIL ET1(K) = 0. END DO C ---------------------------------------------------------------------- C CALCULATE AN 'ADJUSTED' POTENTIAL TRANSPIRATION C IF STATEMENT BELOW TO AVOID TANGENT LINEAR PROBLEMS NEAR ZERO C NOTE: GX AND OTHER TERMS BELOW REDISTRIBUTE TRANSPIRATION BY LAYER, C ET(K), AS A FUNCTION OF SOIL MOISTURE AVAILABILITY, WHILE PRESERVING C TOTAL ETP1A. C ---------------------------------------------------------------------- IF (CMC .NE. 0.0) THEN ETP1A = SHDFAC * PC * ETP1 * (1.0 - (CMC /CMCMAX) ** CFACTR) ELSE ETP1A = SHDFAC * PC * ETP1 ENDIF SGX = 0.0 DO I = 1,NROOT GX(I) = ( SMC(I) - SMCWLT ) / ( SMCREF - SMCWLT ) GX(I) = MAX ( MIN ( GX(I), 1. ), 0. ) SGX = SGX + GX (I) END DO SGX = SGX / NROOT DENOM = 0. DO I = 1,NROOT RTX = RTDIS(I) + GX(I) - SGX GX(I) = GX(I) * MAX ( RTX, 0. ) DENOM = DENOM + GX(I) END DO IF (DENOM .LE. 0.0) DENOM = 1. DO I = 1,NROOT ET1(I) = ETP1A * GX(I) / DENOM END DO C ---------------------------------------------------------------------- C ABOVE CODE ASSUMES A VERTICALLY UNIFORM ROOT DISTRIBUTION C CODE BELOW TESTS A VARIABLE ROOT DISTRIBUTION C ---------------------------------------------------------------------- C ET(1) = ( ZSOIL(1) / ZSOIL(NROOT) ) * GX * ETP1A C ET(1) = ( ZSOIL(1) / ZSOIL(NROOT) ) * ETP1A C ---------------------------------------------------------------------- C USING ROOT DISTRIBUTION AS WEIGHTING FACTOR C ---------------------------------------------------------------------- C ET(1) = RTDIS(1) * ETP1A C ET(1) = ETP1A * PART(1) C ---------------------------------------------------------------------- C LOOP DOWN THRU THE SOIL LAYERS REPEATING THE OPERATION ABOVE, C BUT USING THE THICKNESS OF THE SOIL LAYER (RATHER THAN THE C ABSOLUTE DEPTH OF EACH LAYER) IN THE FINAL CALCULATION. C ---------------------------------------------------------------------- C DO K = 2,NROOT C GX = ( SMC(K) - SMCWLT ) / ( SMCREF - SMCWLT ) C GX = MAX ( MIN ( GX, 1. ), 0. ) C TEST CANOPY RESISTANCE C GX = 1.0 C ET(K) = ((ZSOIL(K)-ZSOIL(K-1))/ZSOIL(NROOT))*GX*ETP1A C ET(K) = ((ZSOIL(K)-ZSOIL(K-1))/ZSOIL(NROOT))*ETP1A C ---------------------------------------------------------------------- C USING ROOT DISTRIBUTION AS WEIGHTING FACTOR C ---------------------------------------------------------------------- C ET(K) = RTDIS(K) * ETP1A C ET(K) = ETP1A*PART(K) C END DO C ---------------------------------------------------------------------- C END SUBROUTINE TRANSP C ---------------------------------------------------------------------- RETURN END SUBROUTINE WDFCND (WDF,WCND,SMC,SMCMAX,BEXP,DKSAT,DWSAT, & SICEMAX) IMPLICIT NONE C ---------------------------------------------------------------------- C SUBROUTINE WDFCND C ---------------------------------------------------------------------- C CALCULATE SOIL WATER DIFFUSIVITY AND SOIL HYDRAULIC CONDUCTIVITY. C ---------------------------------------------------------------------- REAL BEXP REAL DKSAT REAL DWSAT REAL EXPON REAL FACTR1 REAL FACTR2 REAL SICEMAX REAL SMC REAL SMCMAX REAL VKwgt REAL WCND REAL WDF C ---------------------------------------------------------------------- C CALC THE RATIO OF THE ACTUAL TO THE MAX PSBL SOIL H2O CONTENT C ---------------------------------------------------------------------- SMC = SMC SMCMAX = SMCMAX FACTR1 = 0.2 / SMCMAX FACTR2 = SMC / SMCMAX C ---------------------------------------------------------------------- C PREP AN EXPNTL COEF AND CALC THE SOIL WATER DIFFUSIVITY C ---------------------------------------------------------------------- EXPON = BEXP + 2.0 WDF = DWSAT * FACTR2 ** EXPON C ---------------------------------------------------------------------- C FROZEN SOIL HYDRAULIC DIFFUSIVITY. VERY SENSITIVE TO THE VERTICAL C GRADIENT OF UNFROZEN WATER. THE LATTER GRADIENT CAN BECOME VERY C EXTREME IN FREEZING/THAWING SITUATIONS, AND GIVEN THE RELATIVELY C FEW AND THICK SOIL LAYERS, THIS GRADIENT SUFFERES SERIOUS C TRUNCTION ERRORS YIELDING ERRONEOUSLY HIGH VERTICAL TRANSPORTS OF C UNFROZEN WATER IN BOTH DIRECTIONS FROM HUGE HYDRAULIC DIFFUSIVITY. C THEREFORE, WE FOUND WE HAD TO ARBITRARILY CONSTRAIN WDF C -- C VERSION D_10CM: ........ FACTR1 = 0.2/SMCMAX C WEIGHTED APPROACH...................... PABLO GRUNMANN, 28_SEP_1999. C ---------------------------------------------------------------------- IF (SICEMAX .GT. 0.0) THEN VKWGT = 1./(1.+(500.*SICEMAX)**3.) WDF = VKWGT*WDF + (1.- VKWGT)*DWSAT*FACTR1**EXPON ENDIF C ---------------------------------------------------------------------- C RESET THE EXPNTL COEF AND CALC THE HYDRAULIC CONDUCTIVITY C ---------------------------------------------------------------------- EXPON = (2.0 * BEXP) + 3.0 WCND = DKSAT * FACTR2 ** EXPON C ---------------------------------------------------------------------- C END SUBROUTINE WDFCND C ---------------------------------------------------------------------- RETURN END