ON388 - TABLE 3

TYPE AND VALUE OF LEVEL
(PDS Octets 10, 11, & 12)


Revised 05/11/2009
Red text depicts changes made since 06/25/2007


VALUE
(Octet 10)
MEANING CONTENTS
(Octets 11 & 12)
ABBREV
0-99
special codes, See Table 3a
0
0
-
100
isobaric level
pressure in hectoPascals (hPa)
(2 octets)
ISBL
101
layer between two isobaric levels
pressure of top (kPa)
pressure of bottom (kPa)
ISBY
102
mean sea level
0
0
MSL
103
Specified altitude above MSL
altitude in meters
GPML
104
layer between two specified altitudes above MSL
altitude of top
(hm)
altitude of bottom
(hm)
GPMY
105
specified height level above ground
height in meters
(2 octets)
HTGL
106
layer between two specified height levels above ground
height of top
(hm)
height of bottom
(hm)
HTGY
107
sigma level
sigma value in 1/10000
(2 octets)
SIGL
108
layer between two sigma levels
sigma value at top in 1/100
sigma value at bottom in 1/100
SIGY
109
Hybrid level
level number
(2 octets)
HYBL
110
layer between two hybrid levels
level number at top
level number at bottom
HYBY
111
depth below land surface
centimeters
(2 octets)
DBLL
112
layer between two depths below land surface
depth of upper surface (cm)
depth of lower surface (cm)
DBLY
113
isentropic (theta) level
Potential Temperature (K)
(2 octets)
THEL
114
layer between two isentropic levels
475 K minus theta of top in K
475 K minus theta of bottom in K
THEY
115
level at specified pressure difference from ground to level
Pressure difference in hPa
(2 octets)
SPDL
116
layer between two levels at specified pressure difference from ground to level
pressure difference from ground to top level in hPa
pressure difference from ground to bottom level in hPa
SPDY
117
potential vorticity(pv) surface
pv value in units of 10-9Km2/kgs
(2 octets)
PVL
119
NAM level
NAM value in 1/10000
(2 octets)
NAML
120
layer between two NAM levels
NAM value at top of layer in 1/100
NAM value at bottom of layer in 1/100
NAMY
121
layer between two isobaric surfaces (high precision)
1100 hPa minus pressure of top, in hPa
1100 hPa minus pressure of bottom, in hPa
IBYH
125
specified height level above ground (high precision)
Height in centimeters
(2 octets)
HGLH
126
isobaric level
pressure in Pascals (Pa)
(2 octets)
ISBP
128
layer between two sigma levels (high precision)
1.1 minus sigma of top, in 1/1000 of sigma
1.1 minus sigma of bottom, in 1/1000 of sigma
SGYH
141
layer between two isobaric surfaces (mixed precision)
pressure of top, in hPa
1100hPa minus pressure of bottom, in hPa
IBYM
160
depth below sea level
Depth in meters
(2 octets)
DBSL
200
entire atmosphere (considered as a single layer)
0
(2 octets)
EATM
201
entire ocean (considered as a single layer)
0
(2 octets)
EOCN

Note: The numbering allows for additions within this framework:

100-119 normal precision
120-139 high precision
140-159 mixed precision





ON388 - TABLE 3a

SPECIAL LEVELS
(PDS Octet 10)


VALUE LEVEL ABBREV
00
Reserved
-
01
Ground or water surface
SFC
02
Cloud base level
CBL
03
Cloud top level
CTL
04
Level of 0 deg (C) isotherm
0DEG
05
Level of adiabatic condensation
lifted from the surface
ADCL
06
Maximum wind level
MWSL
07
Tropopause
TRO
08
Nominal top of atmosphere
NTAT
09
Sea bottom
SEAB
10-19
reserved
-
20
Isothermal level (temperature in 1/100 K in
octets 11 and 12)
TMPL
21-99
reserved
-
NCEP Special Levels & Layers:
204
Highest tropospheric freezing level
HTFL
206
Grid scale cloud bottom level
GCBL
207
Grid scale cloud top level
GCTL
209
Boundary layer cloud bottom level
BCBL
210
Boundary layer cloud top level
BCTL
211
Boundary layer cloud layer
BCY
212
Low cloud bottom level
LCBL
213
Low cloud top level
LCTL
214
Low cloud layer
LCY
215
Cloud ceiling
CEIL
216 Cumulonimbus Base (m) CBB
217 Cumulonimbus Top (m) CBT
220
Planetary Boundary Layer (derived from Richardson number) PBLRI
222
Middle cloud bottom level
MCBL
223
Middle cloud top level
MCTL
224
Middle cloud layer
MCY
232
High cloud bottom level
HCBL
233
High cloud top level
HCTL
234
High cloud layer
HCY
235
Ocean Isotherm Level (1/10 deg C) OITL
236
Layer between two depths below ocean surface
depth of upper surface (dam)   (octet 11)
depth of lower surface (dam)   (octet 12)
OLYR
237
Bottom of Ocean Mixed Layer (m) OBML
238
Bottom of Ocean Isothermal Layer (m) OBIL
239
Layer Ocean Surface and 26C Ocean Isothermal Level S26CY
240 Ocean Mixed Layer OMXL
241 Ordered Sequence of Data OSEQD
242
Convective cloud bottom level
CCBL
243
Convective cloud top level
CCTL
244
Convective cloud layer
CCY
245
Lowest level of the wet bulb zero
LLTW
246
Maximum equivalent potential temperature level
MTHE
247
Equilibrium level
EHLT
248
Shallow convective cloud bottom level
SCBL
249
Shallow convective cloud top level
SCTL
251
Deep convective cloud bottom level
DCBL
252
Deep convective cloud top level
DCTL
253
Lowest bottom level of supercooled liquid water layer LBLSW
254
Highest top level of supercooled liquid water layer HTLSW


Office Note 388 - GRIB