Assimilation experiments for radar and lidar. Support-to-Science-Element (STSE) Study EarthCARE Assimilation

Title
Assimilation experiments for radar and lidar. Support-to-Science-Element (STSE) Study EarthCARE Assimilation
Report
Date Published
01/2014
Series/Collection
WP-3200 Report: ESA ESTEC Contract AO/I-6441/10/NL/CB
Document Number
2014:WP-3200
Author
Marta Janiskova
Event Series/Collection
ESA Contract Report
Abstract 1D-Var assimilation experiments have been performed using observations of cloud radar reflectivity and lidar backscatter, either separately or in combination. Information on temperature and specific humidity retrieved from 1D-Var was used as pseudo-observations in the 4D-Var system. Obtained results indicate that 1D-Var analyses get closer to assimilated and also independent observations. However, impact of the cloud radar reflectivity is larger than that of the lidar backscatter. 1D+4D-Var analysis reduces analysis departures for q pseudo-observations and provides analysis departures closer to T pseudo-observations than would be obtained if temperature pseudo-observations were not assimilated. Impact on the first-guess and analysis departure statistics when verified against other observation types assimilated in 4D-Var is small. The performed 1D+4D-Var assimilation experiments also suggest a positive impact of the new observations on the subsequent forecast.
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