EGU21-4178, updated on 31 Mar 2023
EGU General Assembly 2021
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Modification of phytoplankton group diversity over submesoscale fronts

Clément Haëck1, Marina Levy1, Laurent Bopp2, and Roy El Hourany3
Clément Haëck et al.
  • 1CNRS/Sorbonne Université/IRD/MNHN LOCEAN, Paris, France (
  • 2CNRS/IPSL LMD Paris, France
  • 3ENS IBENS Paris, France

Over large parts of the ocean, submesoscale fronts are known to enhance total phytoplankton abundance because they are the location of intense vertical transport of nutrients. Disparate in situ observations suggest that such frontal dynamics not only affects the total biomass of phytoplankton, but also significantly modifies its composition. Here we make use of a newly developed algorithm able to distinguish a set of phytoplankton-specific pigments to statistically explore the change in phytoplankton community composition over basin-wide regions. We use 15 years of SST and reflectance data from the MODIS sensor on the Aqua satellite, at 1km and daily resolutions and focus on the oligotrophic North Atlantic subtropical gyre and on the more productive gulf stream region. We locate submesoscale fronts by computing an index quantifying SST patchiness. Our results confirm that submesoscale fronts are collocated with elevated Chlorophyll-a concentration and show significant changes in phytoplankton composition. These results underline the influence of submesocale dynamics on phytoplankton diversity, and stress the need to better understand the underlying mechanisms.

How to cite: Haëck, C., Levy, M., Bopp, L., and El Hourany, R.: Modification of phytoplankton group diversity over submesoscale fronts, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4178,, 2021.


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