Use of radar information for assimilation into atmospheric models: a review—part II: assimilation of radar data

Within the framework of the European Cooperation in the field of Science and Technical research (COST) program, action 717, entitled 'use of radar observations in hydrological and NWP models' is currently running (1999-2004). Working group three (WG3) of this action focusses on the assimilation of radar data into atmospheric models. One of WG3's first activities has been to compile a review of the state-of-the-art in assimilation of radar data into atmospheric models, including pre-processing of the data.

The review has been divided into three sections: one on the pre-processing of radar reflectivity and Doppler data, one on the assimilation of radar reflectivity data into NWP models, and a final one on the assimilation of Doppler data into NWP models.

The first section will be presented in part I of this contribution. In part II three main approaches for assimilation of radar reflectivity data are discussed, i.e. physical initialisation, latent heat nudging, and 4DVAR. In the final section assimilation of Doppler data, both of wind profiles and radial winds, is presented using amongst others the techniques optimal interpolation, variational assimilation (3D and 4D), and nudging.

The content of the second and third section of the review will be highlighted in the presentation at the conference, while the complete review and corresponding bibliography will be made available.