Analysis of Tropical Cyclone Wakes with multi-sensors observation: contribution of altimeters and synthetic aperture radar (SAR).

Tropical cyclones (TC) are hazardous atmospheric systems occuring every year across the tropical oceans. As active coupled systems, TCs are fed by the warm mixed layer that prescribes a large part of the wind field variability. In turn, it results in a bunch of disturbances in the ocean from turbulent shearing stress in the mixed layer but also from upwelling, surface fluxes and large sea states. As a consequence, TCs let a cold wake associated with a barotropic trough (negative sea level) whose variability is a signature of both the ocean and atmosphere characteristic parameters. Taking an approach combining in situ and satellite altimeter and radiometer observations available from the Copernicus Environment Monitoring Service (CMEMS), we analyse the sea surface temperature (SSTA) and sea surface height (SSHA) anomaly fields in the wake of selected cyclones among the different basins from 2010 to 2018. For the atmospheric forcing information, we take advantage of the high resolution Synthetic Aperture Radar (SAR) observations, to get an improved description of the TC’s wind field and of the derived main parameters. The observed SSTA and SSHA signatures in the wake of the selected TCs are well explained using scaling laws derived from a 2-layer ocean model. The obtained results open new perspectives for the operational use of satellite data, namely altimeter and SAR in this study, for TC analysis and monitoring.

Tropical cyclones (TC) are hazardous atmospheric systems occuring every year across the tropical oceans. As active coupled systems, TCs are fed by the warm mixed layer that prescribes a large part of the wind field variability. In turn, it results in a bunch of disturbances in the ocean from turbulent shearing stress in the mixed layer but also from upwelling, surface fluxes and large sea states. As a consequence, TCs let a cold wake associated with a barotropic trough (negative sea level) whose variability is a signature of both the ocean and atmosphere characteristic parameters. Taking an approach combining in situ and satellite altimeter and radiometer observations available from the Copernicus Environment Monitoring Service (CMEMS), we analyse the sea surface temperature (SSTA) and sea surface height (SSHA) anomaly fields in the wake of selected cyclones among the different basins from 2010 to 2018. For the atmospheric forcing information, we take advantage of the high resolution Synthetic Aperture Radar (SAR) observations, to get an improved description of the TC’s wind field and of the derived main parameters. The observed SSTA and SSHA signatures in the wake of the selected TCs are well explained using scaling laws derived from a 2-layer ocean model. The obtained results open new perspectives for the operational use of satellite data, namely altimeter and SAR in this study, for TC analysis and monitoring.