LIM1D

LIM1D is a one-dimensional sea ice model specifically designed for testing physical parameterizations and for interpreting field observations. Its thermodynamic component is a multi-layer energy conserving model with thermal properties depending on the brine content. The brine dynamic component consists in an advection-diffusion equation that computes the sea ice salinity profile. The latter equation has been generalized to dissolved tracers in brine. There are currently two versions of the model, one also including an module for sea-ice biogeochemistry (for details and obtaining this model, contact Martin Vancoppenolle and Sebastien Moreau) and the other with a more advanced snow thermodynamic scheme (for details on this model, please contact Olivier Lecomte). These snow and sea-ice biogeochemistry modules are new features of the model that have been developed separately, that is why no version of the model with both operational modules is available yet. Work will be done soon to fix this.

 

Please quote the following reference in all scientific publications using LIM1D :

Vancoppenolle, M., H. Goosse, A. de Montety, T. Fichefet, B. Tremblay, and J.-L. Tison, 2010 : Modeling brine and nutrient dynamics in Antarctic sea ice : The case of dissolved silica. Journal of Geophysical research, 115, C02005, doi : 10.1029/2009JC005369.

Snow thermodynamic scheme

A multi-layer approach has been chosen as well for the model. We consider a horizontally uniform pack of snow on sea ice, with a thickness hs . At each depth z within the snow, the thermodynamic state of the medium is characterized by temperature T(z), density ρs (z) and effective thermal conductivity ks (z). The horizontal variability of snow on sea ice will be treated later, once the model nested into LIM3. Vertical heat diffusion, surface and internal melt, snowfall and snow-ice formation are all included in the model. Work is currently done to improve the radiative component of the scheme and to include the refreezing of meltwater in the snow pack (superimposed ice formation). The model strictly conserves mass and energy.

 


Lecomte, O., Fichefet, T., Vancoppenolle, M., Nicolaus, M., 2010. A new snow thermodynamic scheme to be applied in large scale sea-ice models.   Annals of Glaciology, Volume 52, Number 57, May 2011 , pp. 337-346(10)

 

Gas physics scheme

The physical dynamics of argon, a biogeochemically inert gas, are constrained within LIM1D. The incorporation and transport of dissolved argon within sea ice and its rejection via gas-enriched brine drainage to the ocean, are modeled following fluid transport equations through sea ice. Gas bubbles nucleate within sea ice when argon is above saturation and when the total partial pressure of all three major atmospheric gases (N2, O2 and argon) is above the brine hydrostatic pressure. The uplift of gas bubbles due to buoyancy is allowed when the brine network is connected with a brine volume above a given threshold. Ice-atmosphere argon fluxes are formulated as a diffusive process proportional to the differential partial pressure of argon between brine inclusions and the atmosphere. Next steps will include the parameterization of carbonates chemistry and primary production/respiration within LIM1D.


For a detailed description of gas physics within LIM1D, please have a look at Moreau et al. (in press). Modelling argon dynamics in first-year sea ice. Ocean Modelling.