On the variability of convective available potential energy in the Mediterranean Region for the 83-year period 1940–2022; signals of climate emergency

Abstract

Some aspects of the variability of Convective Available Potential Energy (CAPE) in the Mediterranean region are examined for the 83-year period 1940–2022 with the use of the daily ERA5 database. The mean monthly patterns, the linear trends of monthly time series and the inter-annual variations of the frequency of extreme CAPE cases are studied, while a classification of spatially extended extreme CAPE events is performed with the combined use of Factor Analysis and k-means Cluster Analysis. According to the results, the spatial distribution of CAPE presents a remarkable seasonal variability due to the strong seasonality of other relevant climatic variables. Also, there is a statistically significant increase of the mean monthly CAPE in most parts of the Mediterranean region in all seasons except spring. This increase appears also in the frequency of extreme cases and in the frequency of the summer spatially extended extreme events. The above positive trends are in line with other signals of the ongoing climate change in the Mediterranean region.