The Effect of Spatial and Temporal Averaging on Sampling Strategies for Cloud Amount Data

Abstract

Sampling and averaging strategies are as significant an influence upon the resulting cloud climatologies as the resolution of the original cloud archives. An investigation of total cloud amount data, as represented by the U.S. Air Force 3-dimensional nephanalysis, illustrates the effects of temporal and spatial processing. Analysis of mean cloud amount as a function of the standard deviation provides a quantitative method for determining cloud size and assessing regional time series of variability. Careful definition of spatially and temporally homogeneous cloud climatology regions facilitates stratified sampling and could obviate the need for averaged data.