The impact of a spring super typhoon on sea surface temperature and heat budget analysis in the Western Pacific

Typhoon Maysak (2015 No. 04), the strongest typhoon in the western North Pacific in March over the past 70 years, serves as a representative case for studying oceanic responses to typhoons. This study employs the COAWST coupled model to simulate the ocean-atmosphere background fields during Maysak’s passage, with model validation through comparisons of the typhoon’s track, wind field, and pressure. The research focuses on near-inertial oscillations in sea surface temperature (SST), particularly the maximum cooling effects observed at three points: the right side of the track (S1), the left side (S2), and the center (S3). Results indicate a reduction in oscillation amplitude and an increase in frequency in the weaker typhoon regions. A heat budget analysis quantitatively evaluates the dominant factors driving temperature changes 24 hours before and after the typhoon’s passage, as well as over the entire simulation period. Findings show that, prior to the typhoon’s passage, vertical diffusion dominates temperature variation at depths of 0–65 m, while both vertical diffusion and total advection contribute at 65–75 m, with total advection controlling below 75 m. After the typhoon, the depth of vertical diffusion’s influence becomes shallower, while advection extends deeper, with the transition depth shifting to approximately 48 m. This study elucidates the depth-dependent thermal response of the ocean to a springtime super typhoon.