Fig. 5: Seasonal cycle of chlorophyll, nitracline depth, EUC core depth and mixing.
From: Seasonal productivity of the equatorial Atlantic shaped by distinct wind-driven processes
a–c, Shown are the seasonal cycles of the depth difference, \({D}_{\mathrm{EUC}}-{D}_{20^\circ\mathrm{C}}\), at the locations of equatorial PIRATA buoys from moored observations (solid lines represent mean values; shadings mark standard errors) and from shipboard measurements (crosses) (a) and the seasonal cycles at 23° W (b) and 10° W (c) of \({D}_{\mathrm{EUC}}\) (dashed lines), \({D}_{20^\circ\mathrm{C}}\) (lower black solid line). Included in a is chlorophyll averaged between 1° S and 1° N, 30° W and 0° (green dashed line with shaded standard error, right axis). Also included in b and c are mixed layer depth, \({D}_{\mathrm{ML}}\) (upper black solid line), Richardson number, \(\mathrm{Ri}\) (grey scale with grey contour lines for \(\mathrm{Ri}=1\) and red contour lines for \(\mathrm{Ri}=0.25\)), and turbulence dissipation rate, \(\varepsilon\) (coloured bars). The depth of the 20 °C isotherm, \({D}_{20^\circ\mathrm{C}}\), is a proxy for the nitracline.
