You are viewing an old version of this page. View the current version.

Compare with Current View Page History

Version 1 Next »

Yes, in most cases the forecast fields at time 0 are the same as the analysis fields. The exceptions are:

  • Soil temperature lev2
  • Soil temperature lev3
  • Soil temperature lev4
  • Sea-ice cover
  • Skin temperature
  • 2m temperature
  • 2m dew-point temperature

Soil temperature lev2, 3 and 4 and skin temperature are identical over land; however, over sea there are differences due to the re-computation of the sea-ice mixed temperature, using the new SST and ice fraction provided by the analysis.

Sea-ice cover differs because a threshold is imposed for minimum sea-ice cover (>0.2) which resets the values along the edge of the sea-ice.

The difference between the 2m temperature and the 2m dewpoint temperature is due to the nature of these two fields: they are diagnostic fields, computed at each forecast step (including step =0) as an interpolated value between the lowest level and the surface, whereas the analysed values are the result of a separate computation of the 2m analysis.

  • No labels