Assimilation of Multinational Radar Reflectivity Data in a Mesoscale Model: A Proof of Concept

Source abstract

Abstract Radar reflectivity observations have proven to be beneficial for improving the skill of numerical weather prediction (NWP) models. A few countries around the world use radar reflectivity observations in their operational runs. The majority of experiments and usage are still only including the local radar observations from the country in which the forecasts are made. The model domains, on the other hand, cover areas far greater than this, and therefore observations from surrounding countries need to be included. As of today there is no central collection and redistribution of volume data in Europe. In recent years, there has been an initiative to collect and harmonize European radar observations, but the redistribution of data for this purpose has only been of centrally constructed composites. This study describes the efforts to collect volume reflectivity data from several data providers and make them available for use in an NWP model. A preprocessing of the reflectivity data has been set up to handle the different incoming data and to make a first data reduction for the NWP models to be able to include the new observations. Assimilation experiments have been performed that prove it is possible to assimilate operational radar reflectivity data from several countries, with a neutral to positive impact.