Evaluation of European regional reanalyses and downscalings for precipitation in the Alpine region

Abstract

Datasets of the observed weather and climate on a regular grid are an important requisite for environmental and climate change research. In this paper we evaluate several European-scale regional reanalyses, developed in the EU project EURO4M, and compare them to existing datasets popularly used in applications today. The evaluation focuses on precipitation in the region of the European Alps, which, due to the marked topographic imprints, poses a challenging test bed. Utilizing a set of statistical indicators, we examine how the datasets represent the spatial pattern, annual cycle, frequency distribution and interannual variations. The evaluated datasets encompass new model-based regional reanalyses (UKMO and HIRLAM) and downscaling datasets (MESAN and MESCAN), one global reanalysis (ERA-Interim), and three station-based interpolation datasets (E-Obs, CRU, GPCC). The reference (APGD) is a gridded interpolation derived from very dense rain-gauge observations.