Retrieval of typhoon wind fields from Doppler radar and dropsonde data using an efficient 2-step approach

A novel and efficient 2-step wind retrieval approach is applied to data collected during the TPARC/TCS-08 field campaign to document kinematic characteristics of typhoon Nuri during its development from a tropical wave to a typhoon. This developing system was observed by the NRL P3 and USAF C130 research aircraft. Both planes, had a variety of instruments to collect data and both launched dropsondes into the system. Of particular interest here are radar observations obtained by the ELDORA radar mounted on the tail of the NRL P3. Radar and dropsonde data are used to retrieve a snapshot of the three dimensional wind field of the system.

Our retrieval method is a variation of the so called three dimensional variational approach to the retrieval of wind fields from radar data. The novelty consists in separating the task in steps that reduce the amount of data processed by the minimization algorithm while keeping the most relevant information from the radar observations. The method is flexible enough to incorporate observations from several radars and to accommodate complex sampling geometries. Furthermore, dropsonde observations are quickly incorporated into the analysis.

An overview of the development of Nuri as revealed by our analysis will be presented.