“Overall” Cloud and Snow Cover Effects on Internal Climate Variables: The Use of Clear Sky Climatology

Abstract

This paper is a continuation of empirical studies of cloud and snow cover effects on climate based on a blend of observational meteorological data for the past several decades. It employs the idea that the analysis of climate variability observed during the period of intensive instrumental observations can provide ?overall estimates? of these effects. A climatology of clear skies for northern extratropical lands is presented in the form of deviations from the average climate conditions. Clouds are an internal component of the climate system, and these deviations indicate specific climate conditions associated with clear skies. At the same time, they may be considered as estimates of the overall cloud effect on the regional climate. A similar approach is applied to estimate the potential effect of snow on the ground, and an attempt is made to divide the effects of snow and clouds.