Spatial Variability of Seasonal Sea Level Pressure and 500 mb Height Anomalies

Abstract

Abstract The spatial variability of seasonal mean sea level pressure (SLP) and 500 mb height anomalies are determined using eigenvector analysis. Previously, spatial variability had only been analyzed in such a manner during winter months, and the time coefficients of the eigenvectors of SLP and 500 mb heights were not compared. The eigenvectors of SLP and 500 mb heights obtained here are compared during each season, and the vectors are compared between seasons. Surface and 500 mb level eigenvector coefficients are found to be correlated and they are correlated in some seasons to air temperatures at surface stations. The data used were National Meteorological Center analyses of daily SLP and 500 mb heights between 1946 and 1977. The eigenvectors are determined for the covariance matrices of seasonal mean pressure and height departures from the 31 or 32 year long term normal over a 132 grid-point network. The coefficients of the first eigenvector of 500 mb heights are most highly correlated to the coeffici...