Impact of Assimilating Environmental Satellite Observations on Tropical Storm Position and Intensity Analyses and Forecasts
As a first example, GPS radio occultation (RO) refractivity profiles are assimilated in NCAR's WRF/DART ensemble system. The first case is over the western Pacific Ocean during the TPARC period (August 11 - September 30, 2008). A second case covers the genesis period of Hurricane Ernesto (2008). The impact of the RO data on the analyses and forecasts of the storms' track and intensity are examined.
The impact of assimilating environmental satellite microwave and IR soundings of water vapor and temperature is also examined for the Ernesto case. It is found that the satellite observations improve the analyses and forecasts of the intensifying tropical cyclones.
The mechanisms of the positive impacts of the observations are explored.