A Feasibility Study of Assimilating European Wind Profiler Data Using the HIRLAM 3D-VAR System

Xiang-Yu Huang¹¹ and Magnus Lindskog²

¹Danish Meteorological Institute, Denmark

²Swedish Meteorological and Hydrological Institute, Sweden

Sep 16, 2003

Abstract.

The HIRLAM 3-dimensional variational data assimilation system has been prepared to handle the data from the European wind profiler (EWP) network. A number of data assimilation experiments have been performed.

In the selected period the amount of the EWP data is rather minor compared with the total data volume. However, if we only take wind profiles into account the EWP data are significant, and on asynoptic hours (0300, 0900, 1500, 2100 UTC) even the major data source.

High data rejection ratios have been found for a few stations, indicating possible problems with the data. Large differences between the observations and the background have been found for a few stations, also indicating a need for bias correction or blacklisting.

Data assimilation experiments are performed for February 2002 without any bias correction or blacklisting. The experiments with 3 h assimilation cycles have shown a marginal positive impact from the EWP data on the analyses and forecasts over the whole month.

Footnotes:

¹Corresponding address: Danish Meteorological Institute, Lyngbyvej 100, DK-2100 Copenhagen Ø, DENMARK. Email: xyh@dmi.dk