Séminaire
The free-drifting zooplankton of the open sea are key intermediaries in a variety of ocean biogeochemical processes, including C cycling and export, dissolved oxygen distributions, and net primary production. They also determine critical prey-predator linkages and pelagic food web stability. However, the zooplankton are often reduced to a single 'Z' term in pelagic ecosystem models and represented with simple parameterizations. This presentation seeks to open the 'black box' of the Z term for the physical scientist. Topics will include the size span of zooplankton and the implications of allometry (size-scaling) and different Reynolds number regimes; fundamental differences between single- and multi-cellular zooplankton and consequences for the biological C pump; the implications of an AR1 Double Integration model for understanding biological responses to physical forcing; and the role of zooplankton grazing in accelerating C export at (sub)mesoscale fronts. This presentation will also touch briefly on our newly developed Zooglider, which employs optical imaging and dual-frequency active acoustics to autonomously resolve zooplankton contributions to ecosystem processes.
marina.levy@locean-ipsl.upmc.fr