Experimental assimilation of radar measurements

Title
Experimental assimilation of radar measurements
Report
Date Published
08/2010
Series/Collection
WP-3200 Report for ESA contract 1-5576/07/NL/CB: Project QuARL - Quantitative Assessment of the Operational Value of Space-Borne Radar and Lidar Measurements of Cloud and Aerosol Profiles
Document Number
2010:WP-3200 contract 1-5576/07/NL/CB
Author
Event Series/Collection
ESA Contract Report
Abstract Observations providing three-dimensional information on clouds from spaceborne active instruments on board of CloudSat and CALIPSO are already available and new ones, such as EarthCARE, should appear in the near future. This opens new possibilities to explore the usefulness of this data sources not only directly for model parametrization improvements, but also to investigate their usage in the assimilation process which could transform a possible extracted information from the data through the model into an improvement of the initial atmospheric state. In this study, a 1D+4D-Var technique has been selected to study the impact of observations related to clouds on 4D-Var (four-dimensional variational) analyses and subsequent forecasts. Using this two step approach, temperature and specific humidity profiles retrieved from 1D-Var assimilation of CloudSat observations have been included in the 4D-Var system. Several experiments have been run for a couple of selected meteorological situations and the statistical evaluation of the results has been carried out.