6.2
A study of the effects of data assimilation on mesoscale meteorological modeling in the Beaufort Sea region
Don Morton, Arctic Region Supercomputing Center / University of Montana, Missoula, MT; and J. R. Krieger, X. Fan, M. Shulski, J. Zhang, and A. Klene
The Beaufort Sea and its adjacent continental areas are prominent geographical features which are largely covered by sea ice on a seasonal basis over the ocean and bounded by the Brooks Range in the south on land. The complex orographic dynamics and coast-ocean thermal contrast significantly complicate mesoscale weather systems and associated surface winds in this region. In addition, this area has been exhibiting great variability and change in sea ice, atmospheric, and oceanic conditions, which may further complicate the atmospheric circulation, underlying surface thermal conditions, and associated surface wind field. This research group is undertaking a study that, in part, investigates the use of mesoscale meteorological models to realistically capture the physical processes occurring in this regime.
The Weather Research and Forecasting (WRF) model is applied to a 10km-resolution domain encompassing the interface of the Beaufort Sea and Alaska's North Slope, nested inside a larger 30km-resolution domain. Initial conditions are obtained from coarse-grid reanalysis (e.g. NARR, ERA40) and fail to capture the fine-grid details of the actual starting weather. Hence, this study will utilize various conventional and unconventional observations for assimilation into the first-guess initial conditions, with the intent of providing more realistic simulation behavior.
This presentation will focus on high-wind events in August 2001 and October 2006. The effects of various data assimilation methods on model output will be compared with base simulations not employing data assimilation. In addition to the presentation of regional differences between the models, results will be compared with available regional observations.
.Session 6, Coastal ocean and atmosphere forecasting systems—II
Wednesday, 12 September 2007, 1:30 PM-3:00 PM, Boardroom
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