The North-Atlantic ocean is known to be a sink of atmospheric CO2. The study area in the North-East Atlantic ocean shows a large range of dynamical scale, from large to sub-mesoscale. In this framework, the present study aims to estimate the impact of these different scales on planktonic ecosystem structure and functionning relying on modeling tools. It was achieved within the POMME program.

In a first part, we investigate the ecosystem seasonal cycle using 1D model configuration. On average, the model shows a strong annual cycle, with important regeneration fluxes, forced by the mixed layer depth (MLD) evolution. Considering the MLD spatial variability, the model reproduces variations of the seasonal cycle and of the fluxes amplitude with latitude.

In a second part, a 3D configuration was applied. It shows contrasting ecosystem behavior in eddies structure and in external waters. At sub-mesoscale, the model indicates important MLD gradients and vertical velocities which modify the input of light and nutrients, hence the primary production.

Overall, this work shows that the three considered scales have significant impact on the plankton distribution and production that vary according to the seasonal cycle.


s.roudesli@uea.ac.uk