Impact of Satellite Surface Wind Observations on the Tropical Cyclone Track Forecasts in the NRL NAVDAS/COAMPS and NRL NAVDAS-AR/NOGAPS Mesoscale and Global Data Assimilation and NWP Systems

In this study, the tropical cyclone (TC) track forecasts of the Navel Research Laboratory Atmospheric Variational Data Assimilation System/Coupled Ocean/Atmosphere Mesoscale Prediction System (NAVDAS/COAMPS) and the Navy Operational Global Atmospheric Prediction System (NOGAPS) were evaluated for a number of data assimilation experiments conducted from 1 August – 30 August, 2009. To evaluate the impact of different horizontal resolutions for different types of satellite observations on the NAVDAS/COAMPS and NOGAPS TC track forecasts, several experiments were performed. The satellite observations assimilated in these experiments consisted of surface winds from WindSat and the Advanced Scatterometer (ASCAT), QuikScatterometer (QuikSCAT), Special Sensor Microwave Imager (SSM/I) wind speeds, and European Remote Sensing Satellite-2 (ERS-2) scatterometer winds. The impact of the assimilation of WindSat, ASCAT, QuikSCAT, SSM/I wind speeds and scatterometer winds on the TC position track were slightly positive through forecast length 48hr. There were no significant improvement/degradations on the TC intensity track from the assimilation of the aforementioned satellite observation types.