High-resolution reanalysis


A reanalysis of past weather can be obtained by combining observational datasets from surface stations and satellites with a comprehensive Numerical Weather Prediction (NWP) model. Using modern data assimilation methods, a complete estimate of the atmospheric state is computed that is both dynamically consistent and optimally close to the observations. The great benefit of a reanalysis is that it provides a complete picture of the atmosphere, covering the whole of the 3-dimensional domain, not only of the observed variables, but also of those that are not directly measured.

EURO4M delivers new state-of-the-art regional reanalysis methods and datasets for Europe. Some of these datasets cover most of the last 20 years whereas the potential of other more advanced systems are demonstrated for shorter periods. The spatial resolution of the data assimilation systems and the use of precipitation and surface data are improved within the project. Selected products are evaluated in detail and compared to existing products from relatively coarse global reanalyses.

In order to further enhance the resolution of the regional reanalyses to the local scale, EURO4M also performs 2-dimensional downscaling. These high-resolution reanalyses employ regional variations given by observational statistics and physiographic factors such as land-sea mask and orography.

Other reanalysis activities in Europe
 
Soil Wetness Index over France
Soil Wetness Index over France for July 2006, derived from a high-resolution analyses of precipitation data. (Low values correspond to areas of increased drought risk during this summer.) (Source: Meteo France)