The geostatistical analysis of the atmospheric precipitation in Europe on a West-East line transect

The general warming trend of the planet cannot be denied (the average global air temperature has increased by approx. 0.85°C between 1880-2012 (IPCC, 2013). The direct consequence of this warming is an increase in extreme weather events and hence in climate risks. The monitoring and assessing precipitation, identifying the physical laws governing its course in order to be able to estimate and forecast it in the future is therefore of great interest nowadays. Using geostatistical spatial analysis methods, this paper aims at identifying the correlations between longitude and precipitation (due to the specificity of the European climate, given by the major influence of the western circulation) and then an estimation - using linear regression equations - of precipitation amounts depending on longitude. Two variables were calculated for the statistical analysis: the proportion of the mean number of days with precipitation ≥ 10 mm of the multiannual mean of precipitation days (≥0,1 mm) and the precipitation ratio between the mean precipitation quantities in summer, compared to those in winter (hereinafter referred to as summer/winter precipitation ratio). The geostatistical analysis carried out on a sample of 40 weather stations aligned from west-south-west to east-north-east argues the existence of a strong correlation between longitude and the multiannual mean of days with precipitation ≥10 mm and between longitude and the summer/winter precipitation ratio.