Massonnet, François
[UCL]
Fichefet, Thierry
[UCL]
Goosse, Hugues
[UCL]
Vancoppenolle, Martin
[UCL]
Mathiot, Pierre
[UCL]
König Beatty, C.
[UCL]
Two hindcast (1983–2007) simulations are performed
with the global, ocean-sea ice models NEMO-LIM2
and NEMO-LIM3 driven by atmospheric reanalyses and climatologies.
The two simulations differ only in their sea ice
component, while all other elements of experimental design
(resolution, initial conditions, atmospheric forcing) are kept
identical. The main differences in the sea ice models lie in
the formulation of the subgrid-scale ice thickness distribution,
of the thermodynamic processes, of the sea ice salinity
and of the sea ice rheology. To assess the differences
in model skill over the period of investigation, we develop
a set of metrics for both hemispheres, comparing the main
sea ice variables (concentration, thickness and drift) to available
observations and focusing on both mean state and seasonal
to interannual variability. Based upon these metrics,
we discuss the physical processes potentially responsible for
the differences in model skill. In particular, we suggest that
(i) a detailed representation of the ice thickness distribution
increases the seasonal to interannual variability of ice
extent, with spectacular improvement for the simulation of
the recent observed summer Arctic sea ice retreats, (ii) the
elastic-viscous-plastic rheology enhances the response of ice
to wind stress, compared to the classical viscous-plastic approach,
(iii) the grid formulation and the air-sea ice drag coefficient
affect the simulated ice export through Fram Strait
and the ice accumulation along the Canadian Archipelago,
and (iv) both models show less skill in the Southern Ocean,
probably due to the low quality of the reanalyses in this region
and to the absence of important small-scale oceanic processes
at the models’ resolution (~1°).
Bibliographic reference |
Massonnet, François ; Fichefet, Thierry ; Goosse, Hugues ; Vancoppenolle, Martin ; Mathiot, Pierre ; et. al. On the influence of model physics on simulations of Arctic and Antarctic sea ice. In: The Cryosphere, no. 5, p. 687-699 (2011) |
Permanent URL |
http://hdl.handle.net/2078.1/93440 |