IMPLEMENTATION OF A NEW ASSIMILATION SCHEME FOR
SOIL AND SURFACE VARIABLES IN A GLOBAL NWP MODEL
by D. Giard and E. Bazile
Major changes have been introduced in the description of the
soil-atmosphere-vegetation interactions in the global Numerical Weather
Prediction model ARPEGE and the embedded Limited Area Model
ALADIN used at Météo-France. The ISBA parameterization is now used to
describe exchanges between the atmosphere and the land surface.
The analysis scheme for soil moisture has been changed accordingly and is
now based on an optimal interpolation type using two meter
observations of temperature and relative humidity. Additionally, the
description of land surface and vegetation characteristics has been improved
by the use of new datasets.
The overall impact of these modifications is a clear improvement in the
forecast of low-level fields and of the global hydrological cycle.
Reference