Models we develop at LMD

Our team is dedicated to the development of Global Climate Models, mainly for terrestrial planet atmospheres. These models combine a General Circulation Model, i.e. a dynamical core with physical parameterisations for radiative forcing and subscale processes, with microphysical and photochemical modules.

The LMDZ5 dynamical core is based on a finite-difference discretization scheme that conserves both potential enstrophy for barotropic nondivergent flows, and total angular momentum for axisymmetric flows. The model uses a leapfrog time integration scheme, with a periodic predictor-corrector time-step. Horizontal dissipation is done using an iterated laplacian, and represents the dominant problem when conservation of angular momentum is required. A longitudinal filter is applied in polar regions (poleward of 60 degrees latitude) to limit the effective resolution to that at 60 degrees.
A new dynamical core (DYNAMICO) is currently under development at LMD, based on an icosaedric grid.

Radiative transfer is a crucial aspect for each application to a planet's atmosphere. We have developed a versatile tool able to compute k-distributions for any kind of atmospheric composition, over a large range of atmospheric conditions.

The Global Climate Model architecture.