I. Polyak et G. North, EVALUATION OF THE GEOPHYSICAL FLUID DYNAMIC LABORATORY GENERAL-CIRCULATION MODEL CLIMATE VARIABILITY .1. VARIANCES AND ZONAL TIME-SERIES, JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 102(D2), 1997, pp. 1921-1929
This paper statistically analyzes and compares the variability of the
observed and simulated (by the Geophysical Fluid Dynamic Laboratory ge
neral circulation model(GCM)) northern hemisphere monthly surface air
temperatures, averaged within different latitude bands. The objects us
ed for the analysis are: seasonal cycle of variances and univariate sp
ectral and autocorrelation functions of zonal time series. The estimat
es reveal a significant latitudinal trend of all second moments. A com
parison shows a statistically significant distinction of the variances
of the observed and simulated stochastic systems. In some cases the s
hapes of the corresponding univariate spectra and autocorrelation func
tions are quite similar, but their numerical values and some features
differ markedly, especially for the tropical regions. The approach dev
eloped gives reasonable descriptions of the univariate temperature pro
cesses, thereby providing an opportunity for solving some of the vital
problems of theoretical and practical aspects surrounding validation
and diagnosis of GCMs.