Séminaire
In the past decades, both modeling and theoretical studies have identified the submesoscale as a dynamical regime with large consequences for planktonic ecosystems. Modelers also generally highlight the need for in situ measurements at the submesoscale. Nevertheless, this represents a big challenge due to the ephemeral nature of submesoscale structures. Moreover, in order to study physical-biological coupling at the submesoscale it is crucial to perform biological measurements at high frequency.
In 2015, we conducted two oceanic cruises, OUTPACE (SW Pacific) and OSCAHR (NW Mediterranean), utilizing an adaptive approach based on both satellite and numerical modeling data to identify the dynamical features of interest. Our methodology also includes the use of novel platforms of observation for sampling the ocean surface layer at a high spatial and temporal frequency. In particular, a MVP (Moving Vessel Profiler) is deployed with CTD, Fluorescence and LOPC (Laser Optical Particle Counter) sensors. Furthermore, a new version of automated flow cytometer is installed for real-time, high-throughput sampling of phytoplankton functional groups, from micro-phytoplankton down to cyanobacteria (including Prochlorococcus).
Our preliminary results suggest that the fine-scale structure of the physical field is a driver for the spatial organisation of the planktonic communities.
marina.levy@locean-ipsl.upmc.fr