Evaluating Sea Ice Enhancements to the Noah LSM in Polar WRF

The current version of the polar-optimized code for the Weather Research and Forecasting model known as "Polar WRF" is updated to a base of WRF version 3.4.1. Polar WRF is developed and provided since September 2012 to the scientific community by the Polar Meteorology Group of The Ohio State University's Byrd Polar Research Center as a code supplement to the standard WRF release from the National Center for Atmospheric Research. The optimizations for Polar WRF include changes to the sea ice treatment used with the Noah land surface model. These polar optimizations allow users to specify sea ice thickness rather than using the default thickness 3 m. High resolution Arctic datasets organized by the University of Illinois and the National Snow and Ice Data Center can provide sea ice concentration and estimated sea ice thickness for the years 2000 onward, which represent the time period of the Arctic System Reanalysis. Specified variable snow cover over sea ice and specified variable sea ice albedo can also be treated. A supplemental algorithm designed for use with the WRF Preprocessing System is available to represent the seasonal progression of Arctic sea ice albedo.

These sea ice capabilities for Polar WRF 3.4.1 with the Noah land surface model are tested in comparison to summer and winter 1998 observations over the pack ice at the Surface Heat Budget of the Arctic Ocean (SHEBA). Sensitivities to the sea ice capabilities are also explored for an Antarctic domain.