Fig. 2

Buoy NTU2 observations of Nepartak. a Air pressure (black line) and wind speed (blue line); b temperature in the upper 300 m; c meridional current velocity V_curr at 25 m (thick black line) and 75 m (thin black line), and meridional wind velocity V_wind (red line). The two red vertical lines in a–c mark the beginning (left) and end (right) of the forced period. The black curve in b is the 27.2 °C isotherm. d Observed (red line), simulated (blue line), and pre-storm (black dashed line) temperature profiles at times 1–6 as indicated by the vertical black dashed lines in b and c. Black lines in d mark the mixed layer depth. The black vertical line in a–c marks the time of minimum sea level pressure. e Velocity shear square \(\bar S^2\) (red line), four times of buoyancy frequency square 4\(\bar{N}^{2}\) (blue line), and \(\bar {S}^{2}{/}4\bar N^{2}\) (black line). The two white lines in b indicate the depths of the two current meters measured by the pressure sensors of the current meter