TRMM Active/Passive Ocean Vector Wind Retrievals

This paper presents a novel ocean vector wind (OVW) retrieval algorithm that uses the Precipitation Radar (PR) and the TRMM Microwave Imager (TMI) on board of the Tropical Rainfall Measuring Mission (TRMM) satellite. In this paper, the modified 2nd Stokes parameter (weighted difference of V & H-pol Tb's) is used to cancel the atmosphere, which enhances the Wind Direction (WD) signal. Therefore, by combining linearly polarized Tb measurements with the anisotropic backscatter signature of the Ku-band scatterometer, it is possible to retrieve both the corresponding Wind Speed (WS) and WD of the ocean surface wind. Examples of retrieved ocean winds are compared with collocated GDAS wind vectors.