LDAS Output File The LDAS project output file format is designed to output a limited number of variables into the most compressed file format available. Most of the output variables are stored as short int values in a binary file. Short int values require only 2 bytes for storage but do not allow the range of values normally stored so most variables are modified by a constant before storage. Details of the file storage format are discussed on this page.
Each output file contains model output from one grid cell. The files use the naming convention "fluxes_xx.xx_yy.yy", where xx.xx is the latitude, and yy.yy is the longitude. The number of decimal places in the output file is determined by GRID_DECIMAL in the model control file, while the latitude and longitude values come from the soil parameter file.
Data is in an Binary column format:
| Column | Variable Name | Units | Type | Multiplier | Description |
|---|---|---|---|---|---|
| 1 | year | year | unsigned short int | 1 | Year of current record |
| 2 | month | month | char | 1 | Month of current record |
| 3 | day | day | char | 1 | Day of current record |
| 4 | hour | hour | char | 1 | Hour of current record. Hour is present only if model is run at a sub-daily time step. |
| 5 | prec | mm | unsigned short int | 100 | Precipitation |
| 6 | evap | mm | short int | 100 | Evaporation |
| 7 | runoff | mm | float | 1 | Runoff |
| 8 | baseflow | mm | float | 1 | Baseflow |
| 9:(8+Nlayer) | moist | mm | unsigned short int | 10 | Layer moisture content (unfrozen) |
| (9+Nlayer) | swq | mm | unsigned short int | 100 | Snowpack water equivalence |
| (10+Nlayer) | net_short | W/m2 | short int | 10 | Net shortwave radiation |
| (11+Nlayer) | in_long | W/m2 | short int | 10 | Incoming longwave radiation |
| (12+Nlayer) | r_net | W/m2 | short int | 10 | Net surface radiation |
| (13+Nlayer) | latent | W/m2 | short int | 10 | Latent heat flux |
| (14+Nlayer) | sensible | W/m2 | short int | 10 | Sensible heat flux |
| (15+Nlayer) | grnd_flux | W/m2 | short int | 10 | Ground heat flux |
| (16+Nlayer) | albedo | fraction | unsigned short int | 10000 | Surface albedo |
| (17+Nlayer) | surf_temp | C | short int | 100 | Surface temperature |
| (18+Nlayer) | rel_humid | % | unsigned short int | 100 | Relative humidity |
| (19+Nlayer) | air_temp | C | short int | 100 | Air temperature |
| (20+Nlayer) | wind | m/s | unsigned short int | 100 | Wind speed |
| (21+Nlayer):(20+2*Nlayer) | ice | mm | unsigned short int | 10 | Ice content. Present only if FROZEN_SOIL is TRUE |
| (21+2*Nlayer),(23+2*Nlayer),...,((19+MAX_FRONTS*2)+2*Nlayer) | fdepth | m | unsigned short int | 100 | Depth of frost ( < 0C above this depth ). Frost depth values alternate with thaw depth values for all defined fronts. Present only if FROZEN_SOIL is TRUE |
| (22+2*Nlayer),(24+2*Nlayer),...,((20+MAX_FRONTS*2)+2*Nlayer) | tdepth | m | unsigned short int | 100 | Depth of thaw ( > 0C above this depth ). Thaw depth values alternate with frost depth values for all defined fronts. Present only if FROZEN_SOIL is TRUE |
Example File: (3hr WB simulation, converted to daily ASCII)
1994 12 26 0.000000 0.170000 0.145896 0.407349 27.062500 68.900002 178.062500 0.780000 35.662502 283.274994 6.124999 6.625000 3.500000 0.000000 0.423200 -0.731250 63.405003 -0.792500 4.200000 1994 12 27 0.000000 0.000000 0.000000 0.409438 25.100000 70.162506 179.024994 0.000000 47.099998 245.875015 -20.925001 0.825000 5.200000 0.000000 0.180000 -0.427500 68.949997 -0.427500 4.650000 1994 12 28 0.000000 0.000000 0.000000 0.411777 23.787500 70.025002 180.037491 0.000000 39.399998 251.625015 -18.362501 0.487500 5.200000 0.000000 0.180000 -1.372500 77.154999 -1.372500 5.119999 1994 12 29 0.000000 0.000000 0.000000 0.413973 22.962500 69.474998 180.987503 0.000000 45.037502 230.350006 -16.887501 0.537500 5.200000 0.000000 0.180000 -5.227500 67.962509 -5.227500 3.400000 1994 12 30 1.120000 0.260000 0.000000 0.415916 22.337500 68.812500 181.849991 0.472500 3.587500 293.699982 3.637500 3.650000 0.100000 0.000000 0.850000 -4.893750 85.953751 -4.873750 2.690000 1994 12 31 0.800000 0.650000 0.000000 0.417613 21.862499 68.150002 182.550003 0.990000 7.250000 276.649994 8.062500 8.400000 0.175000 0.000000 0.850000 -9.165000 62.501251 -8.983749 3.820000
