Blended Satellite Ocean Surface Wind Product Development for the Indian Ocean: Error Variance Optimization and Seasonal Variability Analysis

This study presents the development of a blended Ocean Surface Wind (OSW) product, integrating data from SCATSAT, ASCAT, and ECMWF through optimized linear least square methods (LLSM) and error variances for October 2016 to December 2020. A triple collocation analysis determined the relative mean squared errors, which were used to weight the datasets in the blended product. The product’s consistency with original datasets was assessed to describe seasonal variability across the Indian Ocean (IO). The wind speed distribution aligns with ASCAT in the Arabian Sea (AS) and with SCATSAT in the Bay of Bengal (BoB), Equatorial Indian Ocean (EIO), and Southern Indian Ocean (SIO). Harmonic analysis revealed high wind velocities ($\sim 9$ $\mathrm{m} / \mathrm{s}$) in the SIO and western AS, moderate speeds ($\sim 5 \mathrm{~m} / \mathrm{s}$) in most of the AS and BoB, and lower speeds ($\lt \sim 4 \mathrm{~m} / \mathrm{s}$) in the northern EIO. Moment fields were also estimated, revealing differences in annual and semi-annual harmonics and statistical moments at local scales. These findings highlight the importance of regional assessments, the limitations of individual OSW datasets, and the value of a merged OSW product.