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 |