Robock_Pub_23
Schlosser, C. Adam, Alan Robock, Konstantin Ya. Vinnikov,
Nina A. Speranskaya, and Yongkang Xue, 1997: 18-Year land-surface hydrology
model simulations for a midlatitude grassland catchment in Valdai,
Russia. Mon. Weather Rev., 125, 3279-3296.
ABSTRACT:
Off-line simulations of improved bucket hydrology and SSiB models are
performed for a grassland vegetation catchment region, locted at the Valdai
water-balance research station in Russia, forced by observed meteorological
and simulated actinometric data for 1966-1983. Evaluation of the simulations
is performed using observations of total soil moisture in the top 1 meter,
runoff, evaporation, snow depth, and water table depth made within the
catchment. The Valdai study demonstrates that with routine meteorological
measurements and even in the absence of radiation data, long-term simulations
of land-surface schemes suitable for model evaluations can be made. The Valdai
data are available for use in the evaluation of other land-surface schemes.
Both the SSiB and the bucket models reproduce the observed hydrology averaged
over the simulation period (1967-1983) and its interannual variability
reasonably well, but some discrepancies in the models' seasonal behavior
with respect to observations are seen. In addition, models cannot accurately
and consistently reproduce extreme hydrological events. The bucket model's
soil moisture variability is limited by its inability to rise above its
prescribed field capacity for the case where the observed water table rises
into the top 1 meter of soil, which can lead to erroneous simulations of
evaporation and runoff. SSiB's results show that its runoff simulations
disagree with observations, especially during the summer. The runoff
discrepancies of SSiB can then lead to erroneous soil moisture and
evaporation simulations.
Prepared by Alan Robock (robock@envsci.rutgers.edu ) -
Last updated on March 30, 1999