Examining the Constellation of Scatterometers and Radiometers for Diurnal and Sub-Diurnal Wind Vector Variability

With the activation of the RapidScat scatterometer in October 2014, the constellation of satellite-based ocean surface wind and precipitation observations consists of a diverse collection of both sun-synchronous (e.g, GCOM-W/AMSR-2, MetOp/ASCAT, Coriolis/WindSat) and asynchronous (e.g., RapidScat, GPM/GMI) orbiting satellite platforms. This provides a timely opportunity to jointly examine the time-of-day variability of these quantities over regions where the surface wind varies widely throughout the day, owing to various meteorological forcings, such as land/sea temperature differences near coasts, or variations associated with tropical precipitation processes. Results of an investigation are described whereby wind speed and wind vector products, created from these and other satellite platforms dating from 1999 to near-current, were used to investigate the diurnal and semi-diurnal ocean wind vector variability over specific regions. Since these satellite observations represent instantaneous snapshots, each with unique sensor capabilities sampling against the backdrop of continuously changing physical processes, its is important to carefully intercalibrate the multiple satellite datasets relative to a reference, prior to analysis for any geophysical patterns. A unique feature of the effort is the utilization of all capable sensors, including both wind speed and wind vector capable sensors, using overlapping asynchronous satellite observations to establish self-consistency, including inter-sensor bias correction to a common reference platform.