CGRG Bibliography of Canadian Geomorphology
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Author : Arora, V.; and Boer, G.
Date : 2002.
Title : A GCM-based analysis of the temporal variability of soil moisture and surface hydrological quantities.
Publication : American Geophysical Union 2002 Fall Meeting, Moscone Center, San Francisco, California, 6-10 December 2002.
Issue :
Page(s) :
Abstract
The variability of land surface hydrological quantities is analyzed in an AMIP 2 simulation made with the Canadian Centre for Climate Modeling and Analysis (CCCma) third-generation general circulation model (AGCM3). The land surface parameterization in this model is the comparatively sophisticated Canadian Land Surface Scheme (CLASS). Second order statistics, namely variances and covariances, of surface hydrological quantities are assessed by comparison with observation-based estimates and related to soil moisture variance and the persistence time-scales of soil moisture anomalies. Model values of precipitation and evapotranspiration variance compare reasonably well with observation-based and reanalysis estimates. Soil moisture variance estimates are compared with those simulated by the VIC-2L hydrological model and are qualitatively similar although generally somewhat larger. A budget equation is developed linking the relative contribution of variances of precipitation, evapotranspiration, and runoff to soil moisture variability. Soil moisture persistence time-scales are found to be shorter in the tropics and longer at high-latitudes, consistent with the latitudinal dependence of soil moisture persistence on potential evaporation found in earlier studies. Model results indicate that soil moisture variability in the tropics is driven mainly by the variability of surface hydrological quantities, in particular precipitation and runoff. At high-latitudes, however, higher soil moisture variability is linked to long persistence of soil moisture anomalies. Although these results are specific to the CLASS land surface scheme, other land surface schemes and the actual climate system are expected to behave in a similar fashion.
Bibliography of Canadian Geomorphology