Oceanic mixed layer
The oceanic mixed layer is the warm layer on the ocean surface that maintains a homogeneous temperature.
The oceanic mixed layer is located above the thermocline, which separates the warm surface water from the cold deep ocean water. Its thickness, which varies from a few metres to a few hundred metres, depends on the strength of the wind and the atmospheric temperature.
In winter, the lower level of the mixed layer drops down to the depths where nutrients are found. The nutrients are brought towards the surface when the atmospheric temperature rises, providing plankton with better growing conditions in spring.
The waves and swell generated by the wind help mix the waters on the ocean surface. © Nitot CC by-nc-sa