Italy is the Mediterranean country most affected by hail

A year ago the researchers of the Cnr-Isac, led by Sante Laviola, had ascertained that hailstorms had increased by 30% in the last decade in the Mediterranean. Today, a further study by the Bologna group has led to the first detailed map of hail phenomena which shows how Italy, within the Mediterranean area, is the country where hailstorms occur most frequently.

The data collected and processed by Laviola, Monte, Cattani and Levizzani are particularly valuable because it is not easy to study hailstorms, given their nature as events of short duration and limited spatial extension, factors that greatly complicate observation if ground-based measuring instruments, such as radars, are not available. Researchers from the Institute of Atmospheric and Climate Sciences of the National Research Council of Bologna have used the data provided by satellites as part of the surveys on the incidence of hail storms in the Mediterraneanan area of ​​particular interest because it is one of those most affected by effects of climate change. They have thus come to define the first high-resolution global hail map, built using a comprehensive data set from space.

“We have analyzed the entire network of satellite sensors that are part of the Global Precipitation Measurements (GPM) international space mission. This type of sensors allow the use of a wide range of probing frequencies and have a high spatial coverage, offering considerable potential in terms of detection and investigation of hailstorms”, he explains Sante LaviolaCnr-Isac researcher and first author of the study.

According to this research, Italy appears to be the country in the Mediterranean area most affected by hail events, driving the increase in rainfall in the entire basin. “The measured values ​​indicate that in the last twenty years the Mediterranean is warming 20% ​​faster than the global averagewith the consequent variation of rainfall regimes, which increase in intensity and frequency. Although there is great variability from year to year, throughout the area we can see an increasing trend, equal to 30%, as regards hail precipitation both intense and extreme. In particular, in our peninsula the highest average number of this type of precipitation has been reachedwhich are mostly concentrated in the north during the summer, while they grow in the central-south between the end of summer and autumn”, continues the Cnr researcher.

Tools such as the map and the data collected as part of the research on hail phenomena in the Mediterranean are essential for improve meteorological and climatic models, essential for risk management and strategies for mitigating the effects of hail on the territory and on human activities. “A global hail map, which can be produced every three hours, provides information – non-existent up to now – useful for being able to study the distribution of hail patterns over every area of ​​the planet, and especially at sea. If from an operational point of view our global maps allow us to observe hailstorms even on areas of the planet discovered by ground measurement systems, from a climatic point of view they would make it possible to replicate our study on other climatic hotspots on Earth”, concludes Laviola .