Fig. 3. Long-term movement trends of the boundaries of the chlorophyll-rich tongue (CRT).

Temporal variation of the (a) western, (b) northern, and (c) southern boundaries of the CRT from 2002 to 2022. Definitions of the boundaries are provided in “Methods”. The red line and gray shading represent the long-term trend and the 95% confidence limit via empirical mode decomposition analysis, as in Fig. 2d.