Extreme precipitation events and their relationships with circulation types in Italy

• DOI: 10.1002/joc.7109
• Publication Date: 2021-03-22T15:16:51Z
• Authors: Maurizio Iannuccilli; Giorgio Bartolini; Giulio Betti; Alfonso Crisci; Daniele Grifoni; Bernardo Gozzini; Alessandro Messeri; Marco Morabito; Claudio Tei; Tommaso Torrigian...; Roberto Vallorani; Gianni Messeri
• Keywords: Anticyclone; Orographic lift; Atmospheric Circulation; Peninsula; Orography

Abstract Extreme precipitation (EP) events are life‐threatening phenomena that expected to continue increase because of ongoing climate change. In the past decade, these have been caused by important and well‐documented variations in large‐scale atmospheric circulation. Identifying trends, dynamics, related causes EP could help recognizing geographical areas at great risk reducing their adverse impacts, particularly on a relatively small area such as Italian peninsula. The relationships between circulation types (CTs) were investigated using long time‐series (1979–2015) meteorological data recorded 46 weather stations Italy. was defined number days with accumulated above 90th percentile (R90p). seasonal trends R90p not homogeneous showed significant increases primarily winter spring. Only few CTs significantly R90p, this relationship strongly dependent latitude, orographic exposure, season. Heterogeneous for daily CT occurrences also observed. ‘Cyclonic’ grouped together increasing all seasons, whereas ‘Anticyclonic’ ones generalized decreasing trend, explaining, only partially, observed some stations. Meanwhile, seem be more influenced internal characteristics (i.e., variation parameters characterize them) over decades than changes frequencies but still high heterogeneity results other similar studies can provide useful support implementation mitigation adaptation strategies minimize impacts severe weather, complex Mediterranean basin.