Influence of Vertical Wind Shear on the Ocean Response to Tropical Cyclones Based on Satellite Observations

We here investigate the effects of tropical cyclone (TC)-induced rainfall asymmetries driven by vertical wind shear on ocean salinity and temperature response to TCs using satellite and in situ observations. On average, TCs tend to initially freshen the ocean surface due to heavy rainfall and subsequently salinity from upwelling and vertical mixing, with strongest surface salinification on the right-hand side of the Northern Hemisphere TCs. The direction of shear has been found to control the location of maximum TC rainfall, resulting in more freshwater accumulation on the right-hand side of the right-sheared storms. The accumulated freshwater strengthens salinity stratification and inhibits right-side biased vertical mixing, reducing subsequent surface salinification by 0.15–0.3 psu and slightly suppressing the surface cooling by about 0.15°C, relative to left-sheared storms. Thus, the directionality of shear can impact ocean-TC coupling.