Martin Vancoppenolle1,2
1Laboratoire d’Océanographie et du Climat, CNRS, Paris, France.
2Centre Georges Lemaître for Earth and Climate Research,
Université catholique de Louvain, Louvain-la-Neuve, Belgium.
Date/Time: Tuesday April 3, 15:30 – 16:30
Venue: IMAS Sandy Bay seminar room
Abstract:
The interactions between sea ice and the global marine biogeochemical cycles are not well understood and not yet well represented in Earth System Models. One-dimensional models are a classical first step.
A specificity of sea ice is the presence of liquid brine inclusions into a pure ice matrix. Micro-algae grow within those inclusions. Previous sea ice micro-algal models neglect brine-biogeochemistry interactions, prescribing the location of the microbial communities. We introduced a one-dimensional sea ice model is introduced, with explicit brine dynamics coupled to a simple nutrient-phytoplankton (N-P) module.
We showed results for a one-year-long model test at the location of Ice Station Polarstern (ISPOL) in the Weddell Sea. The model naturally predicts bottom micro-algal populations, with abundance, seasonality and vertical distribution in agreement with observations. The model predicts some previously unexplored mechanisms. Simulated ice algae developments are sensitive to diatom physiological parameters, radiative transfer parameters and snow depth.