ABSTRACT This study analysed the main changes in the concentration of daily precipitation totals in the Atlantic‐European region in 1961–1990 and 1991–2020. Precipitation concentration was characterised by the Gini index (GI), which measures unevenness in precipitation temporal distribution. GI was calculated from ERA5 reanalysis for individual seasons of the year. A comparison of the mean GI distribution and its trends in two 30‐year periods showed a gradual expansion of areas with increasing precipitation concentration over Europe since 1961. Areas with statistically significant GI increases occurred more frequently in the Mediterranean (winter, summer) and western and central Europe (spring). Trend analysis revealed a significant GI increase in parts of central (spring, summer) and eastern (all seasons except winter) Europe in 1991–2020. Significant rising trends appeared in coastal areas near the Iberian Peninsula (autumn) and along the coast of northern Scandinavia (winter). Although areas with significant trends did not exceed 10% of the Atlantic‐European region, these areas show apparent seasonality and dependence on the studied period. Precipitation concentration shows prevailing significant negative relationships with precipitation totals, and especially with the number of precipitation days, for much of mainland Europe. While the areas of significant correlations decrease in the case of precipitation totals, they increase in the case of the number of precipitation days. Changes in precipitation concentration showed no clear link to orography (altitude, slope orientation) and the maritime/continental precipitation regime. Comparison of changes in precipitation concentration derived from ERA5 with those calculated from the E‐OBS database shows generally higher GI mean and lower GI variability for E‐OBS. However, areas with significant changes between the study periods and significant trends are in excellent agreement for both datasets.
Dobrovolný et al. (Fri,) studied this question.