Level type valuesΒΆ

This table lists the possible values for leveltype1 or leveltype2 and the interpretation of the corresponding numerical value l1 or l2. Leveltype values in the range 0-255 can be used for defining either a single level (leveltype1) or a surface delimiting a layer (leveltype1 and leveltype2) with any meaningful combination of leveltypes; values of leveltype >255 have a special use for encoding cloud values in SYNOP reports and they do not strictly define physical surfaces.

The idea is borrowed from the GRIB edition 2 fixed surface concept and the values for leveltype coincide with the GRIB standard where possible.

Level type Meaning Unit/contents of l1/l2
0 Reserved  
1 Ground or Water Surface  
2 Cloud Base Level  
3 Level of Cloud Tops  
4 Level of 0C Isotherm  
5 Level of Adiabatic Condensation Lifted from the Surface  
6 Maximum Wind Level  
7 Tropopause  
8 Nominal Top of the Atmosphere DB-All.e encodes the channel number of polar satellites in L1
9 Sea Bottom  
10-19 Reserved  
20 Isothermal Level K/10
21-99 Reserved  
100 Isobaric Surface Pa
101 Mean Sea Level  
102 Specific Altitude Above Mean Sea Level mm
103 Specified Height Level Above Ground mm
104 Sigma Level 1/10000
105 Hybrid Level  
106 Depth Below Land Surface mm
107 Isentropic (theta) Level K/10
108 Level at Specified Pressure Difference from Ground to Level Pa
109 Potential Vorticity Surface 10-9 K m2 kg-1 s-1
110 Reserved  
111 Eta (NAM) Level (see note below) 1/10000
112 116 Reserved  
117 Mixed Layer Depth mm
118-159 Reserved    
160 Depth Below Mean Sea Level mm
161 Depth Below Water Surface mm
162-191 Reserved    
200 Entire atmosphere (considered as a single layer)  
201 Entire ocean (considered as a single layer)  
204 Highest tropospheric freezing level  
206 Grid scale cloud bottom level  
207 Grid scale cloud top level  
209 Boundary layer cloud bottom level  
210 Boundary layer cloud top level  
211 Boundary layer cloud layer  
212 Low cloud bottom level  
213 Low cloud top level  
214 Low cloud layer  
215 Cloud ceiling  
220 Planetary Boundary Layer  
222 Middle cloud bottom level  
223 Middle cloud top level  
224 Middle cloud layer  
232 High cloud bottom level  
233 High cloud top level  
234 High cloud layer  
235 Ocean Isotherm Level K/10
240 Ocean Mixed Layer  
241 Ordered Sequence of Data  
242 Convective cloud bottom level  
243 Convective cloud top level  
244 Convective cloud layer  
245 Lowest level of the wet bulb zero  
246 Maximum equivalent potential temperature level  
247 Equilibrium level  
248 Shallow convective cloud bottom level  
249 Shallow convective cloud top level  
251 Deep convective cloud bottom level  
252 Deep convective cloud top level  
253 Lowest bottom level of supercooled liquid water layer  
254 Highest top level of supercooled liquid water layer  
256 Clouds  
257 Information about the station that generated the data  
258 (use when ltype1=256) Cloud Data group, L2 = 1 low clouds, 2 middle clouds, 3 high clouds, 0 others  
259 (use when ltype1=256) Individual cloud groups, L2 = group number  
260 (use when ltype1=256) Cloud drift, L2 = group number  
261 (use when ltype1=256) Cloud elevation, L2 = group number; (use when ltype1=264) L2 = swell wave group number  
262 (use when ltype1=256) Direction and elevation of clouds, L2 is ignored  
263 (use when ltype1=256) Cloud groups with bases below station level, L2 = group number  
264 Waves  
265 Non-physical data level