P8     Impact of AMSU-B and MHS Radiance Assimilation for Regional    EnKF

Kathryn Newman, National Center for Atmopheric Research/RAL and DTC, Z. Liu, NCAR/MMM, C. Schwartz, NCAR/MMM, H. Shao, NCAR/RAL and DTC, X.-Y. Huang, NCAR/MMM

The DTC is conducting testing and evaluation of the Data Assimilation Research Testbed (DART) ensemble Kalman filter (EnKF) system for regional applications within an operational framework. In order to facilitate research to operations, a technique developed by research colleagues at NCAR/MMM for assimilating Advanced Microwave Sounding Unit (AMSU)-A radiances initialized with a limited-area EnKF will be evaluated and additional sensors will be assimilated to determine if there is an added benefit. Previous tests have shown improvement in basic forecast scores when assimilating AMSU-A radiance data, compared to assimilating conventional observations only. These tests were performed over a domain encompassing the Atlantic Basin during a one-month period in 2008. To build on current research, AMSU-B and Microwave Humidity Sounder (MHS) sensors will also be assimilated following the existing technique, where the radiance forward operators, bias-correction coefficients, and quality control measures will be computed using WRFDA. Runs using AMSU-B and MHS in addition to AMSU-A will be tested extensively over the same domain and time period as the AMSU-A tests. Deterministic forecasts using WRF-ARW initialized from the ensemble-mean analyses from DART will be verified to determine if assimilating AMSU-B and MHS provide additional forecast improvement over assimilating AMSU-A.