Interaction of Langmuir turbulence and inertial currents in the ocean surface boundary layer under tropical cyclones

The Stokes drift vector that drives LT is determined from spectral wave simulations. During maximum TC winds, LT substantially enhances the entrainment of cool water, causing rapid OSBL deepening.

This coincides with relatively strong wave forcing, weak inertial currents, and shallow OSBL depthHB, measured by smaller ratios ofHB/ds, where ds denotes a Stokes drift decay length scale. LT directly affects a near-surface layer whose depth HLT is estimated from enhanced anisotropy ratios of velocity variances. During rapid OSBL deepening, HLT is proportional to HB, and LT efficiently transports momentum in coherent structures, locally enhancing shear instabilities in a deeper shear-driven layer, which is controlled by LT.