Mean Structure of the Ocean Surface Haline Wake Left by Tropical Cyclones as Observed by SMOS and SMAP
[18-Feb-2020] Nicolas, S., Chapron, B., Grodsky, S., Guimbard, S., Kudryavtsev, V., Foltz, G.R., and Balaguru, K.
Presented at the 2020 Ocean Sciences Meeting
The mean structure of the Sea Surface Salinity (SSS) response to Tropical Cyclone (TC) passage is determined using the data from the Soil Moisture and Ocean Salinity (SMOS) and Soil Moisture Active Passive (SMAP) satellite missions. Post- minus pre- storm Sea Surface Salinity (SSSA) and satellite-derived Sea Surface Temperature Anomalies (SSTA) are determined in the wake of about 750 storms that developed in all TC basins during the period 2010-2018. The rain accumulated during the storm passage is also co-registered with an ensemble of local storm characteristics (such as intensity Vmax and size). On average, the ocean surface is fresher after the passage of storms with intensity ranging from Tropical Depression to Tropical Storm force (20≤Vmax≤64 kt) but storms with intensity above hurricane force (> 64 kt) leave salty wakes at the sea surface. SSSA in the storm highest wind region is thus steadily increasing from ~-0.1 to ~+0.4 pss for Vmax increasing from 34 kt to greater than 135 kt. The maximum SSS increase and SST drops are consistently found on the right hand (resp. left hand) side of the storm tracks in the Northern (resp. Southern) Hemisphere. The coldest and saltiest domain of the wake extend radially on average from the maximum wind radii to about the 34 kt wind radii. Other dependencies of the wake structure's as function of storm translation speed and pre-cyclonic ocean state are discussed.