Level type Description L1 value L2 value
0 Reserved
1 Ground or water surface
2 Cloud base level
3 Level of cloud tops
4 Level of 0$^o$C isotherm
5 Level of adiabatic condensation lifted
from the surface
6 Maximum wind level
7 Tropopause
8 Nominal top of atmosphere
9 Sea bottom
10-19 Reserved
20 Isothermal level Temperature in 1/100 K
21-99 Reserved
100 Isobaric surface Pressure in hPa
101 Layer between two isobaric surfaces Pressure of top in kPa Pressure of bottom in kPa
102 Mean sea level
103 Specified altitude above mean sea Altitude in meters
level
104 Layer between two specified altitudes Altitude of top in hm Altitude of bottom in hm
above mean sea level
105 Specified height above ground Height in meters
106 Layer between two specified height Height of top in hm Height of bottom in hm
levels above ground
107 Sigma level Sigma value in 1/10000
108 Layer between two sigma levels Sigma value of top in 1/100 Sigma value of bottom in
1/100
109 Hybrid level Level number
110 Layer between two hybrid levels Level number of top Level number of bottom
111 Depth below land surface Depth in centimeters
112 Layer between two depths below land Depth of upper surface in Depth of lower surface in
surface cm cm
Level type Description L1 value L2 value
113 Isentropic (theta) level Potential temperature in K
114 Layer between two isentropic levels 475 K minus theta of top in 475 K minus theta of bottom
K in K
115 Level at specified pressure difference Pressure difference in hPa
from ground to level
116 Layer between two levels at specified Pressure difference from Pressure difference from
pressure differences from ground to ground to top level in hPa ground to bottom level in
level hPa
117 Potential vorticity surface 10-9 K m2 kg-1 s-1
118 Reserved
119 ETA* level ETA value in 1/10000
120 Layer between two ETA* levels ETA value at top of layer ETA value at bottom of
in 1/100 layer in 1/100
121 Layer between two isobaric surfaces 1100 hPa minus pressure of 1100 hPa minus pressure of
(high precision) top in hPa bottom in hPa
122-124 Reserved
125 Specified height level above ground Height in centimeters
(high precision)
126-127 Reserved
128 Layer between two sigma levels (high 1.1 minus sigma of top in 1.1 minus sigma of bottom
precision) 1/1000 of sigma in 1/1000 of sigma
129-140 Reserved
141 Layer between two isobaric surfaces Pressure of top in kPa 1100 hPa minus pressure of
(mixed precision) bottom in hPa
142-159 Reserved
160 Depth below sea level Depth in meters
161-199 Reserved
200 Entire atmosphere (considered as a
single layer)
201 Entire ocean (considered as a single
layer)
202-254 Reserved
256 Cloud levels 0 0=General Cloud Group,
1=CL, 2=CM, 3=CH
256 Synop cloud group 1 1
Level type Description L1 value L2 value
256 Synop cloud group 2 2
256 Synop cloud group 3 3
256 Synop cloud group 4 4
257 Extra anagraphical informations
