Wave glider observations of surface winds and currents in the core of Typhoon Danas. Issue 21 (8th November 2016) - Mitarai, S.
Abstract: Simultaneous monitoring of surface winds and currents is essential to understand oceanic responses to tropical cyclones. We used a new platform, a Wave Glider (Liquid Robotics) to observe air‐sea processes during a typhoon, equivalent to a category 4‐hurricane, at peak strength, near Okinawa, Japan. Surface winds showed strong asymmetry in both speed and direction, faster fore than aft. Rotations of surface winds and currents were not coupled; currents rotated clockwise in the wake of the typhoon eye after passage of rapid wind rotations. Wind work was mostly done ahead of the eye, amplifying prior inertial motions with a phase shift. Wind‐induced energy was nearly balanced with an increase in estimated kinetic energy of the upper ocean current, relative to prior inertial oscillations. This study provides a newer, more complete view of actual atmosphere‐ocean interactions in a typhoon. Key Points: Surface winds and currents were monitored simultaneously in a typhoon Surface winds around the eye showed strong asymmetry both in speed and direction Wind‐induced energy was balanced with an increase in kinetic energy of currents