FRASIL: FRActal properties of Sea Ice Leads and their impact on the Arctic physical and biological environments

On simulating leads in the Arctic sea ice using the new Lagrangian model neXtSIM, and on studying their impact on the ocean mixing, heat budget and primary production.

Objectives

Primary objective:
The primary objective of this project is to advance our knowledge on how the multifractal scaling invariance properties of sea ice deformation interact with the upper ocean and its ecosystem.

Secondary objectives:
Four secondary objectives have been defined:
- To assess the effect of a more accurate simulation of sea ice drift and deformation on the Arctic sea ice mass balance and distribution properties of sea ice age.
- To evaluate the impact of a more realistic representation of sea ice drift and deformation on the simulation of the upper Arctic Ocean heat budget.
- To investigate how a more realistic representation of sea ice drift affects the simulation of freshwater mass distribution in the Arctic Ocean.
- To investigate to what extent simulations of primary production in the Arctic Ocean are affected by a more realistic simulation of leads in sea ice. 

Project Summary

The Arctic has proven very sensitive to increased global temperatures, warming substantially faster than the rest of the globe. This has resulted in thinning and reduction in sea ice cover leading to a new dynamical regime in which sea ice fracturing and ridging are more frequent. The fractal properties of the ice cover and its extreme variability strongly influence the atmosphere-ocean interactions and the dynamics of the Arctic marine ecosystems. These interactions and their influence on climate are actively debated, although the supporting model premises are presently weak. FRASIL will enable a new perspective on the changes endured by the Arctic and their consequences for marine life.

In this project, we will assess the role of sea ice dynamics on the upper part of the Arctic Ocean energy budget and on primary production using for the first time a Lagrangian sea ice model, neXtSIM, coupled to an ocean-marine ecosystem model. The neXtSIM model is currently being developed at the Nansen Environmental and Remote Sensing Center, and is unique among sea ice models owing to its rheological framework that is based on solid mechanics and allowing to reproduce the multifractal scaling invariance of sea ice deformation with an unprecedented realism. Leads opening in the ice will change the fluxes of heat and light penetration through the sea surface and the lower trophic levels of the marine ecosystem. Sea ice deformations also impact melting and freezing in leads, ridging and sea ice circulation, which are key players in determining sea ice mass balance and age, and freshwater mass distribution in the Arctic Ocean. Advancing the knowledge on the effects of sea ice deformations on upper ocean stratification and ecosystem will have profound implications on our ability to forecast ongoing changes in Arctic Ocean. The new coupled system will represent a major contribution towards giving the Norwegian research community a leading role in studying the Arctic climate system. 

 
Project Details
Acronym: 
FRASIL
Funding Agency: 
Research Council of Norway
NERSC Principal Investigator: 
Pierre Rampal
Coordinating Institute: 
Nansen Environmental and Remote Sensing Center
Project Status: 
Ongoing