Ocean Sciences

Wind stress is defined as the tangential (drag) force per unit area exerted on the surface of the ocean by the adjacent layer of moving air. Wind stress is the most important forcing parameter in the upper ocean circulation. OSCAT Daily Wind Stress Composites have been generated using DIVA generated 2-days wind field composites. For wind stress computation, Large and Pond (1981) drag coefficients, modified by Trenberth et al. 1990, are used. These products are available on daily basis from 2010-2013. The output products consist of zonal and meridional wind stress components.

The pressure charts prepared by interpolatingpoint measurements/generated through Numerical Weather Forecast (NWF) models or data assimilation techniques. But these data sets may not provide true field situation. As of today, no remote sensing sensor is capable to measure the pressure fields directly. In the present technical report we presented the methodology of retrieve pressure fields from Quick-Scat/Oceansat-2 Scatterometer (OSCAT) winds using the University of Washington Planetary Boundary Layer (UWPBL) model of Patoux et al (2003) during some selected period. These pressure values are validated with all the available in situ observations.

The ocean surface currents are estimated from satellite observations of surface wind from Oceansat-2 Scatterometer and Sea Surface height from SARAL AltiKa. The Ekman Surface current estimated from wind stress components and geostrophic current estimated form SARAL AltiKa are combined to generated ocean surface currents. The data sets available since March 2013. The products are validated with drifting buoy observations indicating a good relationship between the observations