Plate 11.1 Two-year time-series of midnight fluorometer profiles interpreted as
chlorophyll concentration (color scale) collected every 5 days by ascending ARGOS
drifters in the vicinity of 50°N, 47°W. Dark line is a time-series of mixing-layer
depths defined as the shoalest level with σt greater by 0.125 from the surface.
Phytoplankton are consistently distributed evenly down to that boundary.
(^) (After Boss et al. 2008.)