Changing structure of European precipitation: Longer wet periods leading to more abundant rainfalls

TLDR

The changes in the distribution of temporal characteristics of precipitation toward longer events and higher intensities should have a significant impact on the terrestrial hydrologic cycle, including subsurface hydrodynamics, surface runoff, and European flooding. Analysis of the duration of wet spells (consecutive days with significant precipitation) in Europe and associated precipitation was performed over 1950–2008 using daily rain gauge data. Over the past 60 years, European wet periods have lengthened by 15–20 %, not because of more wet days but because longer spells now bring more abundant precipitation, with heavy events in the last two decades increasingly associated with these extended wet spells and intensified relative to the 1950s and 1960s.

Abstract

Analysis of the duration of wet spells (consequent days with significant precipitation) in Europe and associated precipitation is performed over the period 1950–2008 using daily rain gauge data. During the last 60 years wet periods have become longer over most of Europe by about 15–20%. The lengthening of wet periods was not caused by an increase of the total number of wet days. Becoming longer, wet periods in Europe are now characterized by more abundant precipitation. Heavy precipitation events during the last two decades have become much more frequently associated with longer wet spells and intensified in comparison with 1950s and 1960s. The changes in the distribution of temporal characteristics of precipitation towards longer events and higher intensities should have a significant impact on the terrestrial hydrologic cycle including subsurface hydrodynamics, surface runoff and European flooding.