TABLE 3: VERTICAL LEVELS

VALUE | DESCRIPTION | REQUIRED PARAMETERS | ABBREV.
0-99 | Special Codes | (See Table 3a below) |
100 | Isobaric level | Pressure in hPa (2 octets) | ISBL
101 | Layer between two isobaric levels | Pressure of top in kPa | Pressure of bottom in kPa |
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 in hm | Altitude of bottom in hm | GPMY
105 | Specified height level above ground | Height in meters | TGL
106 | Layer between two specified height levels above ground | Height of top in hm | Height of bottom in 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 of top | Level number of bottom | HYBY
111 | depth below land surface | Depth in cm (2 octets) | DBLL
112 | Layer between two depths below land surface | Depth of upper surface in cm | Depth of lower surface in cm | DBLY
113 | Isentropic (theta) level | Potential temperature in K | 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 | Pressure difference in hPa (2 octets) | SPDL
116 | Layer between two levels at specified pressure difference from ground | Pressure difference from ground to top in hPa | Pressure difference from ground to bottom in hPa | SPDY
117 | Potential vorticity surface | Potential vorticity value in units of 10-6 K m2/kg s | PVL
119 | ETA level | ETA value in 1/1000 (2 octets) | ETAL
120 | Layer between two ETA levels | ETA value at top in 1/100 | ETA value at bottom in 1/100 | ETAY
121 | Layer between two isobaric surfaces (high precision) | 1100 minus pressure of top in hPa | 1100 minus pressure of bottom in hPa | IBYH
125 | Specified height level above ground (high precision) | Height in cm (2 octets) | HGLH
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 | 1100 minus pressure of bottom in hPa | IBYM
160 | Depth below sea level | Depth in m (2 octets) | DBSL
200 | Entire atmosphere | 0 (2 octets) | EATM
201 | Entire ocean | 0 (2 octets) | EOCN
204-244 | NCEP Special Levels & Layers | See Table 3a |

TABLE 3a: SPECIAL VERTICAL LEVELS

VALUE | DESCRIPTION | 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 |
204 | Highest tropospheric freezing level | HTFL
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
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
242 | Convective cloud bottom level | CCBL
243 | Convective cloud top level | CCTL
244 | Convective cloud layer | CCY