Diurnal Cycles of Near‐Surface Currents Across the Tropical Pacific

Solar radiative heat and wind-forced momentum can be trapped at the surface transmitted into ocean interior via a daily descending shear layer that mixes downwards. Here, we characterize extent of this mechanism across tropical Pacific seven mooring deployments spanning eastern western Inter-Tropical South Convergence Zones. We find wide range diurnal cycles in temperature velocity, from very weak upper 10 m to strong reach as deep 60 m. These deeper appear where background above equatorial undercurrent helps destabilize fluid, setting up persistent state marginal instability. At sites located these marginally unstable regions, linear relationship between wind speed depth strength cycle velocity.