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Heavy precipitation processes in a warmer climate
Author(s) -
Frei Christoph,
Schär Christoph,
Lüthi Daniel,
Davies Huw C.
Publication year - 1998
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/98gl51099
Subject(s) - precipitation , environmental science , atmosphere (unit) , atmospheric sciences , climatology , humidity , climate model , moisture , relative humidity , climate change , greenhouse gas , water cycle , magnitude (astronomy) , meteorology , geology , geography , oceanography , ecology , biology , physics , astronomy
Climate simulations have suggested that a greenhouse‐gas induced global warming would also lead to a moistening of the atmosphere and an intensification of the mean hydrological cycle. Here we study possible attendant effects upon the frequency of heavy precipitation events. For this purpose simulations with a regional climate model are conducted, driven by observed and modified lateral boundary conditions and sea‐surface temperature distributions. The modifications correspond to a uniform 2K temperature increase and an attendant 15% increase of the specific humidity (unchanged relative humidity). This strategy allows to isolate the effects of an increased atmospheric moisture content from changes in the atmospheric circulation. The numerical experiments, carried out over Europe and for the fall season, indicate a substantial shift towards more frequent events of strong precipitation. The magnitude of the response increases with the intensity of the event and reaches several 10s of percent for events exceeding 30 mm per day. These results appear to apply to all precipitation events dominated by sea‐to‐land moisture transport.