qgs is a Python implementation of an atmospheric model for midlatitudes. It models the dynamics of a 2-layer quasi-geostrophic (QG) channel atmosphere on a beta-plane, coupled to a simple land or shallow-water ocean component.
It currently has three main modes of operation:
A QG atmosphere coupled to a land surface with topography through friction and with a simple thermal relaxation toward a climatological temperature. See Model with an orography and a temperature profile for a description of this model version. It is also described in detail in the following articles:
Reinhold, B. B., & Pierrehumbert, R. T. (1982). Dynamics of weather regimes: Quasi-stationary waves and blocking. Monthly Weather Review, 110 (9), 1105-1145. doi:10.1175/1520-0493(1982)110%3C1105:DOWRQS%3E2.0.CO;2
Cehelsky, P., & Tung, K. K. (1987). Theories of multiple equilibria and weather regimes—A critical reexamination. Part II: Baroclinic two-layer models. Journal of the atmospheric sciences, 44 (21), 3282-3303. doi:10.1175/1520-0469(1987)044%3C3282%3ATOMEAW%3E2.0.CO%3B2
A QG atmosphere coupled to a closed-basin shallow-water ocean through friction and heat exchanges. This configuration is the model MAOOAM by De Cruz, Demaeyer and Vannitsem. This model exhibits low-frequency variability in a coupled ocean-atmosphere mode. See Coupled ocean-atmosphere model (MAOOAM) for a description of this model version. It is also described in detail in the articles:
Vannitsem, S., Demaeyer, J., De Cruz, L., & Ghil, M. (2015). Low-frequency variability and heat transport in a low-order nonlinear coupled ocean–atmosphere model. Physica D: Nonlinear Phenomena, 309, 71-85. doi:10.1016/j.physd.2015.07.006
De Cruz, L., Demaeyer, J. and Vannitsem, S. (2016). The Modular Arbitrary-Order Ocean-Atmosphere Model: MAOOAM v1.0, Geosci. Model Dev., 9, 2793-2808. doi:10.5194/gmd-9-2793-2016
A QG atmosphere coupled to a land surface with topography through friction and heat exchanges. See Model with an orography and heat exchanges for a description of this model version. It is also described in detail in the following article:
Li, D., He, Y., Huang, J., Bi, L., & Ding, L. (2018). Multiple equilibria in a land–atmosphere coupled system. Journal of Meteorological Research, 32 (6), 950-973. doi:10.1007/s13351-018-8012-y
The shallow-water ocean can in principle be used as a stand-alone model, but this is not implemented for the moment.
The modes over which the equations are projected can be modified, leading to other model version. See Recovering the result of Vannitsem, Solé-Pomies and De Cruz (2019) for an example. More developments are yet to come, see the Forthcoming developments section.
Model versions description
- Model with an orography and a temperature profile
- Coupled ocean-atmosphere model (MAOOAM)
- Model with an orography and heat exchanges