On the performance of two advanced land surface schemes as applied to simulations of Arctic land environments

Recent work on schemes to simulate land processes and land interactions with the atmosphere have resulted in the development of schemes, as components of regional models, that contain relatively advanced treatment of snow and frozen soil physical processes. To date, little work to intercompare performance of such schemes has been done. In this paper, we compare the results provided by offline tests of: 1) the Hydro-Thermodynamic Soil Vegetation Scheme (HTSVS) and 2) the most recent version of the NCEP/Oregon State/AFWA/Office of Hydrology (NOAH) land surface models (LSMs), both of which have been recently improved to better treat such wintertime processes.

The results of simulations applying the two LSMs alternatively are evaluated by multi-year atmospheric and soil observations taken in the context of an unrelated project at Fort Wainwright, Alaska. The performance evalution of the LSMs, to be presented at the conference, focuses on comparison of surface heat, moisture and momentum fluxes, a water budget, and the variation, over the simulation periods, of the vertical profiles of soil temperature, total soil moisture, and soil liquid water. We also conduct sensitivity experiments, using both LSMs, to various soil parameters contained within the models, to better understand not only the model sensitivities but the potential uncertainties of the model simulations that are related to these parameters. Preliminary results of these sensitivity/uncertainty experiments will be presented for discussion at the conference.