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.