The Louvain-la-Neuve sea ice model : current
status and ongoing developments
T. Fichefet, Y. Aksenov, S. Bouillon, A. de Montety,
L. Girard, H. Goosse, C. König, O. Lecomte,
O. Lietaer, G. Madec, F. Massonnet, P. Mathiot,
M.A. Morales Maqueda, M. Vancoppenolle and J. Weiss
LIM3, a 5-category sea ice thickness, enthalpy, salinity and age distribution model
Sea ice halo-thermodynamics
• Energy conserving thermodynamic model with 1 snow
layer and 5 ice layers (effect of brine pockets on ice
thermal properties explictly accounted for)
• Bulk sea ice salinity calculated by taking into
consideration brine entrapment during freezing and
the most important brine drainage mechansims
• Surface albedo parameterised as a function of surface
state, snow and ice thicknesses, and cloudiness
• Vertical salinity profile parameterised as a function of
bulk salinity and ice thickness
• Snow ice formation scheme
• Parameterisation of frazil ice production in open
water areas
• Transport in thickness space : linear remapping
Sea ice dynamics
Elastic-viscous-plastic (EVP)
rheology on a C-grid
Transport of snow/ice
properties
C-grid, numerical method
that conserves the secondorder moments of the
advected quantity
Sea ice mechanical
redistribution
Redistribution functions that
take into account ridging and
rafting processes as well as
ridge porosity
Sea ice age
Prognostic equation for sea
ice age
NEMO-LIM3 and its forcing
Forcing
NCEP/NCAR daily surface air temperatures and wind speeds (1948-2006)
+ monthly climatological surface relative humidities, cloud fractions
and precipitation rates + monthly climatological river runoffs
Bulk formulas
Surface fluxes of heat, freshwater and momentum (no salinity restoring)
Tripolar global grid, 2° resolution
LIM3 (sea ice model)
NEMO (ocean model)
• Explicit representation of the
• Primitive equation, free surface
subgrid-scale ice thickness,
enthalpy, salinity and age
distributions (5 categories)
• Multi-layer halo-thermodynamic
component (1 snow layer + 5 ice
layers)
• Mechanical redistribution that
takes into account ridging/rafting
processes and ridge porosity
• EVP rheology on a C-grid
ocean general circulation model on
a C-grid
• Level-1.5 turbulence closure
scheme
• Isopycnal mixing +
G&M parameterisation of eddyinduced tracer advection
• Bottom boundary layer scheme +
partial step topography, L31
Sea ice concentrations averaged over 1979-2004
Comiso (2007)
September sea ice concentrations averaged over 1979-2004
OBS = Comiso (2007)
Time series of monthly sea ice area anomaly
Model
Comiso (2007)
NH : correlation = 0.74 ; SH : correlation : 0.65.
Bulk sea ice salinities averaged over 1979-2006 (in psu)
March
Sept.
March
Sept.
Annual maximum mixed layer depths averaged over 1979-2006 (in m)
OBS = de Boyer Montégut et al. (2004)
Impact of a prognostic sea ice salinity on the annual mean
ice thickness (left) and sea surface salinity (right)
CTRL  BK5
∆ ice thickness (m)
CTRL  BK5
∆ sea surface salinity (psu)
CTRL = control run ; BK5 : run with a prescribed sea ice salinity of 5 psu.
Impact of a prognostic sea ice salinity on the annual mean
ice thickness (left) and sea surface salinity (right)
CTRL  BK5
∆ ice thickness (m)
CTRL  BK5
∆ sea surface salinity (psu)
CTRL = control run ; BK5 : run with a prescribed sea ice salinity of 5 psu.
For further details, see
 Vancoppenolle, M., T. Fichefet, H. Goosse, S. Bouillon, G. Madec and
M.A. Morales Maqueda, 2009 : Simulating the mass balance and
salinity of Arctic and Antarctic sea ice. 1. Model description and
validation. Ocean Modell., 27, 33-53 ;
 Vancoppenolle, M., T. Fichefet and H. Goosse, 2009 : Simulating the
mass balance and salinity of Arctic and Antarctic sea ice. 2. Sensitivity
to salinity processes. Ocean Modell., 27, 54-69.
Ongoing developments
• Implementation in LIM3 of a data assimilation scheme based on an
ensemble Kalman filter approach (done ; tests under way by means
of twin experiments).
• Inclusion in NEMO-LIM3 of the re-scaled vertical coordinate z*
proposed by Campin et al. [2008] (done ; validation under way).
• Development of a parameterisation of ice growth in pancake fields
for incorporation into LIM3 (under way).
• Development and inclusion in LIM3 of a comprehensive snow model
(1D version nearly ready).
• Development of a new sea ice rheology formulation based on a
progressive damage model (under way).
Undamaged
Damage level
at the end of a
stress loading
Entirely damaged
Fixed boundary
Progressive
stress loading
[Girard et al., JSTAT, submitted]
• Coupling of LIM3 with a sea ice biogeochemistry module (1D version
validated ; extension to 3D in progress).
Example of simulation of the seasonal cycle of temperature, brine
volume and algae concentration in Antarctic sea ice
[Vancoppenolle et al., JGR, in press]
• Development of a finite element (FE) version of LIM3 (FE version of
LIM2 in both Eulerian and Lagrangian formulations validated on a
cartesian grid ; introduction of spherical geometry completed ;
inclusion of LIM3 physics in progress ; coupling with the LLN FE
ocean model planned).
(m)
[Lietaer et al., Ocean Modell., 2008]
www.climate.be/slim