Showing papers by "Gianpaolo Balsamo published in 2005"

A simplified variational analysis scheme for soil moisture: Developments at Meteo-France and MSC

Abstract: A simplified variational data assimilation technique, developed for the land surface initialization of a numerical weather prediction (NWP) model, is considered in the frame of the ELDAS project at Météo-France, for the production of a daily soil moisture over Europe. The assimilation of indirect data of screen-level temperature and relative humidity is combined with a complementary correction based on precipitation error. The simplified variational approach obtains the linearized observation operator from perturbed integration(s) of the NWP model. The linearity of the observation operator and the horizontal decoupling between grid points allow the simplified 2D-VAR formalism, applied on each grid point separately. The corrections applied to the soil moisture field are adapted to the current meteorological conditions and the grid point characteristics (texture and vegetation), as well as to the previous soil state. The complementary correction based on precipitation error is applied with an optimum interpolation (OI) approach. The results obtained within ELDAS at MétéoFrance are presented and discussed. The assimilation of other sources of data is investigated, with an Observing System Simulated Experiment (OSSE) conducted at the Meteorological Service of Canada. The assimilation of current available satellite observations provided by AQUA satellite (microwave C-band), GOES (infrared), and the potential of observations provided in the future by SMOS and HYDROS satellite missions (microwave L-band) is investigated. The results of this study are presented and perspectives are provided.

Towards the inclusion of hydros soil moisture measurements in forecasting systems of the meteorological service of Canada

Abstract: In this paper we present the efforts that are currently undertaken at the Meteorological Service of Canada (MSC) to include Hydros soil moisture measurements in operational forecasting systems. Accurate representation of land surface processes, and more particularly of soil moisture, is shown to have a significant impact on short and medium-range weather forecasts. A new land data assimilation system is currently being developed to take full advantage of future L-band missions (SMOS and Hydros) and produce better soil moisture initial conditions for MSC’s environmental forecasting systems. A diagnostic study reveals the relative information content of Lband radiances for the assimilation of soil moisture, relative to other types of data such as screen-level air characteristics and Cband radiances. Weather forecasting systems; soil moisture; Hydros; land data assimilation; relative information content