Robock_Pub_15 Yang, Z.-L., R. E. Dickinson, A. Robock, and K. Y. Vinnikov, 1997: On validation of the snow sub-model of the Biosphere-Atmosphere Transfer Scheme with Russian snow cover and meteorological observational data. J. Climate, 10, 353-373.


Snow cover is one of the most important variables affecting agriculture, hydrology and climate, but it is unfortunately not operationally measured. Therefore, the effectiveness and validity of snow schemes in general circulation models have been difficult to assess. Using long-term snow cover data from the former Soviet Union, this paper focuses on validation of the snow sub-model in the Biosphere-Atmosphere Transfer Scheme (BATS) using six years of data (1978-1983) at six stations. The results have demonstrated that the scheme is capable of reproducing the observed water equivalent for all the six stations considered. In particular, the time of accumulation and the end of ablation, the melting and freezing cycles, and the alteration due to aging are well captured. It is found that the simulated snow depth and water equivalent are sensitive to snow-rain criterion and downward longwave radiation, and that the simulated surface albedo is sensitive to the parameterization of snow cover fraction. It is demonstrated that the use of the cosine of solar zenith angle as a constant 0.6 in the albedo parameterization is a reasonable approximation. Overall, our results have indicated that more complicated snow models may not be necessary for GCMs and that the Russian data are valuable for these types of model tests.

Prepared by Alan Robock ( ) - Last updated on February 2, 1999