| Bit No. |
Flag Value |
Description |
Unit |
Status |
| 0 |
|
Reserved |
|
Operational |
| 1 |
|
Ground or water surface |
- |
Operational |
| 2 |
|
Cloud base level |
- |
Operational |
| 3 |
|
Level of cloud tops |
- |
Operational |
| 4 |
|
Level of 0 °C isotherm |
- |
Operational |
| 5 |
|
Level of adiabatic condensation lifted from the surface |
- |
Operational |
| 6 |
|
Maximum wind level |
- |
Operational |
| 7 |
|
Tropopause |
- |
Operational |
| 8 |
|
Nominal top of the atmosphere |
- |
Operational |
| 9 |
|
Sea bottom |
- |
Operational |
| 10 |
|
Entire atmosphere |
- |
Operational |
| 11 |
|
Cumulonimbus (CB) base |
m |
Operational |
| 12 |
|
Cumulonimbus (CB) top |
m |
Operational |
| 13 |
|
Lowest level where vertically integrated cloud cover exceeds the specified percentage (cloud base for a given percentage cloud cover) |
% |
Operational |
| 14 |
|
Level of free convection (LFC) |
- |
Operational |
| 15 |
|
Convective condensation level (CCL) |
- |
Operational |
| 16 |
|
Level of neutral buoyancy or equilibrium level (LNB) |
- |
Operational |
| 17 |
|
Departure level of the most unstable parcel of air (MUDL) |
- |
Operational |
| 18 |
|
Departure level of a mixed layer parcel of air with specified layer depth |
Pa |
Operational |
| 19 |
|
Reserved |
|
Operational |
| 20 |
|
Isothermal level |
K |
Operational |
| 21 |
|
Lowest level where mass density exceeds the specified value (base for a given threshold of mass density) |
kg m-3 |
Operational |
| 22 |
|
Highest level where mass density exceeds the specified value (top for a given threshold of mass density) |
kg m-3 |
Operational |
| 23 |
|
Lowest level where air concentration exceeds the specified value (base for a given threshold of air concentration) |
Bq m-3 |
Operational |
| 24 |
|
Highest level where air concentration exceeds the specified value (top for a given threshold of air concentration) |
Bq m-3 |
Operational |
| 25 |
|
Highest level where radar reflectivity exceeds the specified value (echo top for a given threshold of reflectivity) |
dBZ |
Operational |
| 26-29 |
|
Reserved |
|
Operational |
| 30 |
|
Specified radius from the center of the Sun |
m |
Operational |
| 31 |
|
Solar photosphere |
|
Operational |
| 32 |
|
Ionospheric D-region level |
|
Operational |
| 33 |
|
Ionospheric E-region level |
|
Operational |
| 34 |
|
Ionospheric F1-region level |
|
Operational |
| 35 |
|
Ionospheric F2-region level |
|
Operational |
| 36-99 |
|
Reserved |
|
Operational |
| 100 |
|
Isobaric surface |
Pa |
Operational |
| 101 |
|
Mean sea level |
|
Operational |
| 102 |
|
Specific altitude above mean sea level |
m |
Operational |
| 103 |
|
Specified height level above ground |
m |
Operational |
| 104 |
|
Sigma level |
"sigma" value |
Operational |
| 105 |
|
Hybrid level |
- |
Operational |
| 106 |
|
Depth below land surface |
m |
Operational |
| 107 |
|
Isentropic (theta) level |
K |
Operational |
| 108 |
|
Level at specified pressure difference from ground to level |
Pa |
Operational |
| 109 |
|
Potential vorticity surface |
K m2 kg-1 s-1 |
Operational |
| 110 |
|
Reserved |
|
Operational |
| 111 |
|
Eta level |
- |
Operational |
| 112 |
|
Reserved |
|
Operational |
| 113 |
|
Logarithmic hybrid level |
|
Operational |
| 114 |
|
Snow level |
Numeric |
Operational |
| 115 |
|
Sigma height level |
- |
Operational |
| 116 |
|
Reserved |
|
Operational |
| 117 |
|
Mixed layer depth |
m |
Operational |
| 118 |
|
Hybrid height level |
- |
Operational |
| 119 |
|
Hybrid pressure level |
- |
Operational |
| 120-149 |
|
Reserved |
|
Operational |
| 150 |
|
Generalized vertical height coordinate |
|
Operational |
| 151 |
|
Soil level |
Numeric |
Operational |
| 152 |
|
Sea-ice level |
Numeric |
Operational |
| 153-159 |
|
Reserved |
|
Operational |
| 160 |
|
Depth below sea level |
m |
Operational |
| 161 |
|
Depth below water surface |
m |
Operational |
| 162 |
|
Lake or river bottom |
- |
Operational |
| 163 |
|
Bottom of sediment layer |
- |
Operational |
| 164 |
|
Bottom of thermally active sediment layer |
- |
Operational |
| 165 |
|
Bottom of sediment layer penetrated by thermal wave |
- |
Operational |
| 166 |
|
Mixing layer |
- |
Operational |
| 167 |
|
Bottom of root zone |
- |
Operational |
| 168 |
|
Ocean model level |
Numeric |
Operational |
| 169 |
|
Ocean level defined by water density (sigma-theta) difference from near-surface to level |
kg m-3 |
Operational |
| 170 |
|
Ocean level defined by water potential temperature difference from near-surface to level |
K |
Operational |
| 171-173 |
|
Reserved |
|
Operational |
| 174 |
|
Top surface of ice on sea, lake or river |
- |
Operational |
| 175 |
|
Top surface of ice, under snow cover, on sea, lake or river |
- |
Operational |
| 176 |
|
Bottom surface (underside) ice on sea, lake or river |
- |
Operational |
| 177 |
|
Deep soil (of indefinite depth) |
- |
Operational |
| 178 |
|
Reserved |
- |
Operational |
| 179 |
|
Top surface of glacier ice and inland ice |
- |
Operational |
| 180 |
|
Deep inland or glacier ice (of indefinite depth) |
- |
Operational |
| 181 |
|
Grid tile land fraction as a model surface |
- |
Operational |
| 182 |
|
Grid tile water fraction as a model surface |
- |
Operational |
| 183 |
|
Grid tile ice fraction on sea, lake or river as a model surface |
- |
Operational |
| 184 |
|
Grid tile glacier ice and inland ice fraction as a model surface |
- |
Operational |
| 185-191 |
|
Reserved |
|
Operational |
| 192-254 |
|
Reserved for local use |
|
Operational |
| 255 |
|
Missing |
|
Operational |