Investigating the Possible Mechanisms by Which the Salinity Fronts Form and Grow Under the Pacific Intertropical Convergence Zone

Abstract:

The Pacific Intertropical Convergence Zone (ITCZ) is a zonal band of atmospheric convective instability, clouds and rainfall near the equator. High-resolution sea surface salinity (SSS) measurements from the Aquarius satellite reveals more detail in the band of lower salinity and a sharp front that aligns with the strong ITCZ atmospheric convection. In the upper ocean, the strong salinity gradient (i.e. the salinity front, SF) can be the main contributor for sharp surface density fronts where the sea surface temperature in near homogeneous under the ITCZ. To check the possible mechanisms by which the SF form and grow, we examine (a) the freshwater flux to study how the intensity of precipitation contributes to the strength of SF, and (b) the ocean surface currents and study how the horizontal advection changes the SSS gradients. From this, we expect to achieve a better understanding of the fine scale upper ocean dynamics under the Pacific ITCZ.