Relationship between snow cover and atmospheric circulation, central North America, winter 1988

The stochastic relationships between terrestrial snow water equivalent (SWE) and measures of the atmosph eric circulation were il1\'estigated for the Canadian Prai rics and the American Great Plains for thc win tcr of 1988. Snow-cO\'Cr extent, deri\'Cd from EASE-grid SSI /I satellite data, and gridded atmospheric data from the :\ational ;\fcteorological Celller were averaged at (j\'e day illlen'als, Principal componellls analysis (PCA) were performed for the time series or SS)'l!l snO\\-co\'er imagery as well as for 700 mb geop oten tia l heigh t and temperature, 500 mb hei ght and 700 -500 mb thickness. Canonical correlation analysis of the derived principal component weights was used to identify relationships between atmospheric variables and SWE, Results of the PCA incli­ cate that a high degr ee of\'ariance in upper air \'ariables (>75%) can be explained by the first three principal components, while the first three S\\'E components account for over 90% orthe variance in the original data. Results orthe canonical correlation analysis sho\\' positive relationships between snow-cover acculllulation and a meridional pressurc distri­ bution pattern, while snow ablation is linked to a zonal atmosphe ric pressure pattern.