Fig. 4: Salinity stratification and the weakening of winter convective mixing.
From: Sustained freshening of Arabian Sea High Salinity Water induced by extreme precipitation events
a Potential density - 1000 (kg m−3), b salinity (psu, blue line) and temperature (°C, red line) averaged in the upper 100 m, c Mixed layer depth (MLD, m), and d Potential Energy Anomaly (PEA, J m−3) calculated from the Argo profiles in the northern Arabian Sea (Fig. 2a). Gray dashed lines represent the time average values and the error bars over the two 5-year periods for density temperature, salinity, PEA, while MLD is averaged for the December–February period. The difference in means between the two periods are statistically significant at the 95% confidence interval (p = 0.05) determined using a standard two-tailed Student’s t test. The error bars are calculated as the mean ± 1.96 × standard error of the mean. MLD is calculated from the density increase equivalent to a 0.5 °C temperature decrease from the surface. Cyclone occurrences are marked in each panel: circles indicate very severe to super cyclones, and diamonds indicate cyclones to severe cyclones. Cyclones penetrating north of 15°N are marked in red.
