ANALYSIS OF WIND FIELD FOR TYPHOON RUSA IN SOUTH KOREA: BASED ON WIND DIRECTION OF TYPHOON MODEL

Abstract

A RADARSAT-SAR image ofTY RUSA acquired on August 30, 2002 at 2112 UTCseems like the center where the NRCS is quite low, butbelongs to the eye wall. To retrieve wind speeds, CMOD5was originally developed for the scatterometer aboard ERS-1 and 2 operating at VV polarization and consequentlyrequires modification if applied to HH-polarized SAR data.However, because the Extended High mode used here hascomparatively high incidence angles of 54.24° – 57.31°, thepolarization ratio in a hybrid model function is supposed tobe 1. The retrieved SAR wind is compared with the resultof the typhoon model with a fine computing grid of 1/60degrees. It is shown that wind structure of eye wall can bedescribed by using SAR based on wind directions fromQuikSCAT.