What are the role of mesoscale eddies in air-sea interaction and in sea surface salinity variability in the Tropical Atlantic Ocean?

The ocean kinetic energy is dominated by mesoscale eddies, which are quasi-circular structures with typical horizontal scales of 10 to 100 km and vertical extension of hundreds meters. the mesoscale eddies play significant roles in the transport and redistribution of water masses with their physical and biogeochemical properties throughout ocean. In this study, we used 8 years of satellite altimetry data, combined with sea surface temperature (SST), sea surface salinity (SSS), latent and sensible heat fluxes (LHF and SHF) and precipitation data, to investigate how mesoscale eddies impact on air-sea heat and fresh water exchange in the tropical Atlantic ocean (TAO). We show that an important fraction of eddies exhibit inverse SST anomalies, and that eddy-induced LHF and SHF anomalies are quasi-linearly proportional to SST anomalies. Moreover, eddies contribute to ~10 – 25 % of the total heat flux variability. However, no direct link has been observed between heat flux and precipitation anomalies over eddies in the TAO. Nevertheless, beneath the Intertropical Convergence Zone (ITCZ), significant correlation were found, suggesting that eddies may modulate both heat and freshwater fluxes in this region. Relative to SSS anomalies within eddies, their variability represents up to 30% of the total variability. In addition, beneath the ITCZ, freshwater fluxes would play an important role in their variability. However, oceanic processes such as horizontal and vertical advection and mixing are suspected to play a key role in the SSS variability at mesoscale beneath the ITCZ. To better understand the role of such processes, numerical modeling studies are needed for future investigations.