7B.1 Assimilation of Microwave All-Sky
Radiances and Hydrometeor Retrievals in HWRF
Wu, Ting-Chi, Milija
Zupanski, Lewis Grasso, and Christian Kummerow,
Cooperative Institute
for Research in the Atmosphere/Colorado State University, Sid-Ahmed Boukabara, National
Aeronautics and Space Administration/Center for Satellite Applications and Research
Satellite all-sky radiances from the Advanced Technology
Microwave Sounder (ATMS) and microwave hydrometeor retrievals from the
Hurricane GPROF are assimilated into Hurricane Weather Research and
Forecasting (HWRF) using the hybrid Gridpoint
Statistical Interpolation (GSI). Hurricane GPROF is an algorithm that
produces hydrometeor retrievals from the Global Precipitation Measurement
mission (GPM) and the Tropical Rainfall Measuring Mission (TRMM) microwave
imagers for hurricanes. In order
to improve the assimilation of cloud and precipitation information from the
hydrometeor retrievals and all-sky radiances, cloud variables are included as
additional control and state variables in GSI. That is, the above-mentioned
observations are assimilated using observation operators that consider cloud
variables and Jacobians with respect to cloud
variables. As a consequence, the analysis will include cloud variable updates
along with the default temperature, pressure, horizontal wind, and specific
humidity updates. Results indicate that the assimilation of Hurricane GPROF
hydrometeor retrievals and ATMS all-sky radiances showed an improvement of
the analysis field. Synthetic satellite data from HWRF forecasts was used to
show that there are too many cloud top pixels that
are too cold compared to observations. In addition, several metrics were used
to evaluate the forecasts. |