Nonseasonal variability of monthly mean sea level pressure and precipitation variability over Europe

Abstract

The spatial modes of nonseasonal variability in both monthly mean sea level pressure (MSLP) fields over the northeastern Atlantic and western Europe sector and precipitation over Europe are investigated by using principal component analysis (PCA). The relationships between the two fields are revealed by canonical correlation analysis (CCA). The data sets used refer both to the period from 1911 to 1990. The most important spatial mode in MSLP fields is the NAO pattern and its corresponding principal component (PC) is closely related to the NAO index. However, it is interesting that the NAO pattern seems to be responsible only for the second EOF in precipitation while the most important spatial mode of precipitation corresponds to the third EOF of MSLP (North Sea pattern). Furthermore, the second EOF (Scandinavian pattern) of MSLP is highly associated with the third EOF in precipitation. Significant pairs of canonical correlation patterns between the MSLP fields and precipitation were obtained being coherent to the conclusions above referred. The results can be used to assess potential changes of precipitation over Europe based on variability of MSLP simulated by GCMs.