Generating a polar wind vector data set from METOP-AVHRR observations

In the context of the European Union Framework Program 7 EUMETSAT participates in the ERA-CLIM project. One of EUMETST´s contributions is the reprocessing of all METOP-A AVHRR polar winds back to the year 2007. At EUMETSAT two algorithms for the retrieval of Atmospheric Motion Vectors (AMVs) are available. Both algorithms will be used and the two data sets will give a unique opportunity to investigate into the differences of the two algorithms. The paper presents the two algorithms and discusses some first results obtained with the above mentioned two algorithms, including validation results against radiosondes and numerical weather prediction (NWP) data for a small test data set.