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