On the Applicability of Current Land Surface Schemes for Arctic Tundra: An Intercomparison Study.
Tilley, J.S. and Lynch, A.H.
Abstract
In this paper, we examine the performance of three land surface schemes (the Biosphere-Atmosphere Transfer Scheme, BATS1E; the National Center for Atmospheric Research Land Surface Model NCARLSM; the Canadian Land Surface Scheme, CLASS) in simulations at two sites on the Alaskan North Slope: Barrow and Imnavait Creek. These sites are characterized by similar large-scale meteorological conditions but different land surface environments and soil characteristics. The simulations are driven and validated by field data collected in several observational programs during the 1992 Arctic summer season. The simulation results indicate that the schemes with multi-layer diffusion schemes (NCARLSM, CLASS) capture the basic seasonal behavior of temperature somewhat successfully while the BATS1E force-restore method is less satisfactory. The simulation of freeze-thaw physics particularly appears to benefit from higher vertical resolution. The presence of organic soils is also shown to be important for an accurate simulation. The results suggest that improvements in the treatment of Arctic biological processes, water and energy partitioning and freeze-thaw physics are needed before higher confidence in prediction from not only the land surface models, but also their host climate models, is possible for the Arctic regions.