Observations of the ocean surface using an aircraft altimeter, scatterometer and ROWS

Open-ocean radar measurements acquired from an aircraft are examined. Two Ku-band systems, NASA´s Radar Ocean Wave Spectrometer (ROWS) and the University of Massachusetts´ Ku-band scatterometer (KUSCAT) were used to derive data on sea surface wind and waves for several long transects over the Atlantic Ocean. Noteworthy in this effort is the complete time/space coincidence of data products. This includes scatterometer data at 20°, 30°, 40° and 50° incidence as well as altimeter and directional swell measurements. Altimeter and scatterometer-derived 10 m wind speeds are generated using current satellite geophysical model functions (GMF). The two estimates agree very closely for the available light-to-moderate speeds thus providing further validation of these inversion algorithms. Long wave effects on scatterometer wind direction estimation are examined by comparing off-wind swell to the peak direction derived for near-incidence, 200 KUSCAT data. For the conditions examined, no significant tie is found between swell direction and the scatterometer´s peak direction