SUBROUTINE W3FC05(U, V, DIR, SPD) 11260000 C$$$ SUBPROGRAM DOCUMENTATION BLOCK 11270000 C . . . . 11280000 C SUBPROGRAM: W3FC05 EARTH U,V WIND COMPONENTS TO DIR AND SPD 11290000 C PRGMMR: KEYSER ORG: W/NMC22 DATE: 92-10-21 11300000 C 11310000 C ABSTRACT: GIVEN THE TRUE (EARTH ORIENTED) WIND COMPONENTS 11320000 C COMPUTE THE WIND DIRECTION AND SPEED. 11330000 C INPUT WINDS AT THE POLE ARE ASSUMED TO FOLLOW THE WMO 11340000 C CONVENTIONS, WITH THE OUTPUT DIRECTION COMPUTED IN ACCORDANCE 11350000 C WITH WMO STANDARDS FOR REPORTING WINDS AT THE POLE. 11360000 C (SEE OFFICE NOTE 241 FOR WMO DEFINITION.) 11370000 C 11380000 C PROGRAM HISTORY LOG: 11390000 C 92-10-21 D.A.KEYSER ADDED 1.E-3 TO DIRECTION TO ALLOW TRUNCATION 11391000 C TO NEAREST WHOLE DEGREE TO BE CORRECT 11391100 C (KEEPS AGREEMENT BETWEEN CRAY & NAS VERSIONS) 11391200 C 91-03-05 R.E.JONES CHANGES FOR CRAY CFT77 FORTRAN 11391300 C 88-10-19 CHASE, P. ALLOW OUTPUT VALUES TO OVERLAY INPUT 11392000 C 81-12-30 STACKPOLE, JOHN 11400000 C 11430000 C USAGE: CALL W3FC05 (U, V, DIR, SPD) 11440000 C 11450000 C INPUT ARGUMENT LIST: 11460000 C U - REAL EARTH-ORIENTED U-COMPONENT 11470001 C V - REAL EARTH-ORIENTED V-COMPONENT 11480001 C 11490000 C OUTPUT ARGUMENT LIST: (INCLUDING WORK ARRAYS) 11500000 C DIR - REAL WIND DIRECTION, DEGREES. VALUES WILL 11510001 C BE FROM 0 TO 360 INCLUSIVE. 11520000 C SPD - REAL WIND SPEED IN SAME UNITS AS INPUT 11530001 C 11540000 C INPUT FILES: NONE 11550000 C 11560000 C OUTPUT FILES: NONE 11570000 C 11580000 C SUBPROGRAMS CALLED: 11590000 C LIBRARY: 11600000 C COMMON - SQRT, ATAN2 11610000 C 11620000 C REMARKS: IF SPEED IS LESS THAN 1E-10 THEN DIRECTION WILL BE SET 11630000 C TO ZERO. 11640000 C 11650000 C ATTRIBUTES: 11660000 C LANGUAGE: CRAY CFT77 FORTRAN 11670000 C MACHINE: CRAY Y-MP8/832 11680000 C 11690000 C$$$ 11700000 C 11710000 C VARIABLES..... 11720000 C 11730000 REAL U, V, DIR, SPD, XSPD 11740000 C 11750000 C CONSTANTS..... 11760000 C 11770000 DATA SPDTST/1.0E-10/ 11780000 DATA RTOD /57.2957795/ 11790000 DATA DCHALF/180.0/ 11800000 C 11810000 XSPD = SQRT(U * U + V * V) 11820000 IF (XSPD .LT. SPDTST) THEN 11830000 DIR = 0.0 11840000 ELSE 11850000 DIR = ATAN2(U,V) * RTOD + DCHALF + 1.E-3 11860000 ENDIF 11870000 SPD = XSPD 11880000 RETURN 11890000 END 11900000