Experiments of hurricane initialization with airborne doppler radar data for the advanced-research hurricane WRF (AHW) model

Airborne Doppler radar (ADR) data have sufficiently high horizontal and vertical resolution to resolve the hurricane vortex and its imbedded structures but have not been extensively used in hurricane initialization. Using the Weather Research and Forecasting (WRF) three-dimensional variational data assimilation (3DVAR) system, the ADR data are assimilated to recover the hurricane vortex dynamic and thermodynamic structures at the WRF model initial time.

The impact of the ADR data on three hurricanes, Jeanne (2004), Katrina (2005) and Rita (2005), are examined during their rapid intensification and subsequent weakening periods before landfall. With theADRwind data assimilated, the three-dimensional winds in the hurricane vortex become stronger and the maximum 10-m winds agree better with independent estimates from best-track data than without ADRdata assimilation. Through the multivariate incremental structure inWRF3DVARanalysis, the central sea level pressures (CSLPs) for the three hurricanes are lower in response to the stronger vortex at initialization.