Fig. 2: Linear trends of summer (June–September) mixed layer depths (MLDs) over two different periods.

The trends based on ship-based CTD/XCTD profiles during a 1996–2006 and b 2007–2021 in each 1° × 2° grid cell. Statistically significant trends (p < 0.1) based on Global Ocean Reanalysis and Simulations (GLORYS2V4) during c 1996–2006 and d 2007–2021 in each 0.25° × 0.25° grid cell. Only significant trends with p < 0.1 are shown in blue (negative values) to red (positive values) colors; black crosses illustrate grid cells without significant trends. Gray lines represent isobaths of 50, 250, and 500 m. Source data are provided as a Source Data file.