Principal component analysis of precipitation in the Adriatic‐Pannonian area of Yugoslavia

Abstract

AbstractUsing the principal component method, some characteristics of the precipitation pattern are established for an area from the Adriatic Sea to the Pannonian lowland (territory of Croatia). The data of monthly precipitation amounts for the 20‐year period (1961–1980) from 108 meteorological stations are used. The first four principal components (PCs), which describe 79‐4 per cent of the total precipitation field variance, are considered. It is shown, graphically and numerically, that the first PC is related to the frequency of cyclones on van Beber's paths IVb, Vb and Vc, the second one is related to their frequency on the paths Vd, Vd1 and Ve, the third to the anticyclonic and non‐gradient weather type and the fourth one is related to the frequency of cold fronts crossing Yugoslavian territory. Using the loadings of the PCs, four homogeneous precipitation sectors are determined and compared to those obtained by Koppen's scheme. Finally, some details of the annual pattern of precipitation for these sectors are discussed.