Response of the upper ocean to tropical cyclone in the Northwest Pacific observed by gliders during fall 2018

The evolution of thermohaline structure at the upper ocean during three tropical cyclones (TCs) in the Northwest Pacific was studied in this study based on successive observation by two new-style underwater gliders during fall 2018. These remote-controllable gliders with CTD sensor enabled us to explore high frequency responses of temperature, salinity, mixed and barrier layers in the upper ocean to severe TCs in this area. Results showed that three significant cooling-to-warming and stratification destructing-to-reconstructing processes at the mixed layer occurred during the lives of three TCs. The maximal cooling of SST all reached >=0.5 degrees C although TCs with different intensities had different minimal distances to the observed area. Under potential impacts of solar radiation, tide and inertial motions, the mixed layer depth possessed significant high-frequency fluctuations during TC periods. In addition, barrier layers appeared and vanished quickly during TCs, accompanied with varied temperature inversion processes.

Automated summary

The study investigated the evolution of thermohaline structure during three tropical cyclones in the Northwest Pacific through observations by underwater gliders in fall 2018. Results showed significant changes in temperature, salinity, and layer structures in response to the cyclones, with the mixed layer experiencing cooling-to-warming transitions and stratification destructing-to-reconstructing processes.