Assimilation and analysis (current status)
| Model parameters | ALADIN | COSMO | HIRLAM/HARMONIE | UM/JULES | ECMWF |
|---|---|---|---|---|---|
| Soil temperature and water content | Optimum interpolation based on screen-level analysis increments of T and RH | 2-dimensional (vertical and temporal) variational technique using 2-m temperature analyses at 12 and 15 UTC Analysed variables : soil moisture of the top 5 soil layers (0-81 cm) at 00 UTC |
Optimum interpolation based on screen-level analysis increments of T and RH | Errors in forecasts of screen T and RH used to calculate increments to soil moisture. NAE and M4 use UKPP over UK and interpolated global SMC elsewhere Level 1 T atmospheric increments applied to top soil level in absence of snow |
EKF for soil moisture and OI for soil/snow temperatures based on screen-level analysis increments of T and RH |
| Sea surface temperature | Optimum interpolation using surface observations with a relaxation towards OSTIA SST analysis | Correction method. Background field from GME SST analysis using NCEP 0.5°x0.5° SST analysis that includes satellite data. Observations from SYNOP-SHIP and BUOY. | OI (HIRLAM) - interpolation from OSTIA (HARMONIE) | Interpolated from OSTIA analysis | Aggregation of OSTIA SST products based on surface observations and satellite products |
| Sea-ice extent | Derived from sea-ice concentration (used only to update sea-ice temperature) | Sea ice cover analysis from BSH (German Institute for shipping and hydrology) for the Baltic sea. Resolution lon/lat : 0.167x0.1 degrees, NCEP analysis in other areas | Taken from OSISAF | Interpolated from OSTIA analysis | Aggregation of OSTIA and NCEP sea-ice products which are the OSI-SAF products (from SSM/I data) |
| Sea-ice temperature | From BSH and NECP analyses | Interpolated from ECMWF analyses | |||
| Snow depth | Background values with relaxation towards climatology from the global model ARPEGE | Correction method. Used data : background values from COSMO model, snow depth observations from SYNOP stations, present and past SYNOP weather, precipitation amount, 2-m temperature analysis (+model prediction). Monthly snow depth, climatology from ECMWF for permanently glacial covered areas | OI based on in-situ measurements | Model values corrected using IMS mask and use of background info | OI analysis using surface observations (SYNOP+national networks)+ use of 4km NOAA/NESDIS snow cover extent to correct snow depth observations |
| Lake | Closest point from SST analysis (using NCEP 0.5° for large lakes) | Flake values from last forecast | FLake + OI from LST observations (Finland, SYKE) | Climatology or nearest SST | Great lakes : interpolation of the NCEP SST products. Other lakes: SST derived from T2m climatology from Legates and Wilmott (1990) |
| Vegetation | None | None | None | Seasonal LAI climatology derived from MODIS data | LAI climatology derived from MODIS data |