Assimilation of ATOVS data in the HIRLAM 3D-VAR System

Harald Schyberg, Tomas Landelius, Sigurdur Thorsteinsson, Frank Thomas Tveter, Ole Vignes, Bjarne Amstrup, Nils Gustafsson, Heikki Järvinen, Magnus Lindskog

Abstract

Abstract

With the implementation of the HIRLAM 3D-VAR system and the new generation of instruments in the ATOVS system, there were expectations of obtaining significant positive effects from the assimilation of ATOVS, even in the limited-area setups in HIRLAM. Development projects started at the Norwegian Meteorological Institute (DNMI) and at the Swedish Meteorological and Hydrological Institute (SMHI) at the time when ATOVS was ready for launch. This formed part of a coordinated effort in the HIRLAM community to provide preprocessing and assimilation of AMSU-A data in HIRLAM 3D-VAR. There have also been important contributions from the Danish and Finnish Meteorological Institutes (DMI and FMI). The development had benefit from some of the work that had already taken place at other forecasting centers. For instance, several processing modules developed elsewhere were made available through EUMETSAT.

In this report we describe the developments that have taken place in HIRLAM towards use of AMSU-A data. In the next chapters we give an overview of the preprocessing and the implementation in 3D-VAR. Then we describe various impact studies undertaken in several of the HIRLAM countries. Finally we give an overview of ongoing work and future developments, before concluding.

download report