89th American Meteorological Society Annual Meeting

Monday, 12 January 2009
Sensitivity of WRF model forecasts to different physical parameterizations in the Beaufort Sea region
Hall 5 (Phoenix Convention Center)
Jeremy R. Krieger, University of Alaska, Fairbanks, AK; and J. Zhang, D. E. Atkinson, M. D. Shulski, and X. Zhang
Poster PDF (1.4 MB)
The Weather Research and Forecasting (WRF) model has been applied to the Beaufort Sea region to investigate the mesoscale features of the Beaufort Sea surface winds. One of the foremost challenges in tuning a mesoscale model for use in a particular region is the establishment of the most appropriate model configuration. Different regions experience varied conditions and present unique problems, and the optimal setup for one area may therefore generate poorer results in another. One of the most important elements in configuring a model is the selection of the physical parameterizations to be used. While current mesoscale models provide a large pool of options from which to choose schemes governing several different types of model physics, this diversity presents its own problems for the modeler, as identifying the best physics package becomes highly complex. Aside from the large array of available options, the best combination of which for one region is not necessarily applicable to another, an additional complication arises when new, untested physical parameterizations are introduced into updated versions of the model.

The recent release of WRF v3.0 is one such instance, as several advanced parameterizations have been introduced in this version that are potentially valuable for use in the Arctic. In addition, the Beaufort Sea region, including the North Slope of Alaska, is a particularly unique area. Though previous studies have attempted to determine the best physics options to use in polar regions, their conclusions are not necessarily fully applicable to this region, with its combination of complex geographical features, including a sea covered by seasonal sea ice with a coast that borders a rugged mountain range. We have conducted a study with WRF v3.0 that attempts to identify the best-performing physics package for this region through a series of month-long simulations in which all available physics options are tested and the results verified against observations from not only land-based stations, but also from the QuikSCAT SeaWinds instrument, which provides high-resolution surface wind data over the open ocean. Through this statistical analysis, we aim to ascertain the most suitable combination of physical schemes applicable to the Beaufort Sea region as a whole, including both land and ocean areas, with a special emphasis given to evaluating the simulation of surface winds over the sea.

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