Precipitation over Sardinia (Italy) during the 1946-1993 rainy seasons and associated large-scale climate variations

Autor: Davide Cesari, Piero A. Chessa, Alessandro M. S. Delitala, M. Neil Ward
Rok vydání: 2000
Předmět:
Zdroj: International Journal of Climatology. 20:519-541
ISSN: 1097-0088
0899-8418
Popis: The interannual and decadal variability of seasonal precipitation (October through April) over Sardinia (Italy) is analysed for the years 1940–1995. It is shown that the area-average seasonal rainfall total can vary greatly from one year to the next. The spatial correlation of Sardinia seasonal rainfall with that of neighbouring Mediterranean regions is generally high, though the correlation is less to the south of Sardinia, suggesting other teleconnection structures may operate there. Over a slightly shorter period (1946–1993), correlations between precipitation and large-scale variables (sea level pressures (SLP), 500 hPa geopotential heights (Z500) and sea surface temperatures (SST)) are calculated and analysed. Clear connections between the North Atlantic Oscillation (NAO) and Sardinian precipitation are found and studied. Contrasting Atlantic storm tracks were found for the wet and dry seasons. In the wet years, the track is weaker over the North Atlantic (consistent with the NAO association), while over Europe there emerges a second minor storm track that enters the Mediterranean basin. In dry years this latter feature is less evident and is diverted to the lee of Sardinia, probably because of stronger intensity of the Azores High. Some apparent associations with other Northern Hemisphere remote teleconnections and large-scale structures also emerge, including the North Pacific and across North Africa. Copyright © 2000 Royal Meteorological Society
Databáze: OpenAIRE
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