SIMECH: Sea Ice Mechanics, from satellites to numerical models

SIMech proposes to develop a unique sea ice model based on a new rheology that will reproduce for the first time the brittle mechanical behaviour of the sea ice cover.

Objectives

The principal objective of the SIMech project is to develop and validate a new sea ice model capable of simulating the sea ice dynamics that are observed from space.

Secondary objectives are the following:

- to evaluate the forecasting skill of our model in predicting the Arctic sea ice motion and deformation over time periods of up to 10 days,
- to investigate the role of sea ice mechanics in the seasonal variability of the Arctic sea ice motion and deformation,
- to provide a flexible numerical tool that runs with feasible computational costs. This is for the purpose of making it usable for specific climate studies and forecast applications.

Project Summary

The Arctic region is currently experiencing rapid changes that are mainly driven by global warming. Over the last decade, we have observed a drastic shrinkage of the Arctic sea ice cover in summer accompanied by a spectacular thinning of mean thickness and an increased export of sea ice through the Fram Strait. These changes perturb the interactions between the atmosphere and the ocean and modify the Arctic climate.

To understand these changes, predict the state of the sea ice cover in the future and also produce short-term sea ice forecasts, numerical models implemented in realistic settings are necessary. These models are usually taken to be a 3-layered system where the sea ice cover, the ocean below and the atmosphere above are physically coupled. Several studies have reported that the current models poorly represent the sea ice dynamics, and in particular miss the observed acceleration of the sea ice motions over the last 30 years, as well as their seasonal cycle.

Sea ice dynamics are very complex and show strong similarities with plate tectonics and earthquake dynamics. Failure to represent these dynamics partly explains why current coupled models do not reproduce the recent changes in the Arctic, and presents one of the main challenges faced today by the Arctic modelling community at large.

The aim of this project is to demonstrate the validity of a completely new modelling approach to reproduce the dynamics of the Arctic ice pack. The model, which is inspired by solid mechanics, will be further developed, implemented in a coupled model framework on a parallelized supercomputer, and validated against satellite observations. Thanks to the development and implementation of our new elasto-brittle rheology, a model will be capable of simulating the drift and deformation of sea ice using the appropriate physics for the first time.

Project Details
Acronym: 
SIMECH
NERSC Principal Investigator: 
Pierre Rampal
Coordinating Institute: 
Nansen Environmental and Remote Sensing Center
Project Status: 
Completed