Séminaire
Due to their nonlinear nature, many processes involved in climate and its variability and future change are still not well understood. Today’s comprehensive General Circulation, Chemistry-Climate, and Earth System Models (GCMs/CCMs/ESMs) often capture these processes to some degree, but the complexity of the models can be almost as high as the real atmosphere as inferred by observational data.
In this talk, we attempt to simplify the problem by considering an idealized atmosphere in a hierarchy of GCMs, and study the interplay between radiation and dynamics in select cases, such as greenhouse gas forcing, stratosphere-troposphere coupling, and the annual cycle of the tropical cold point. We show that the dynamical response to greenhouse gas forcing of the stratosphere is opposite the response of the troposphere (but that the latter wins over the former), study the life cycle of stratospheric sudden warmings, and show that the annual cycle of the tropical cold point can be forced with zonal asymmetries in the midlatitudes.
MP Lefebvre 0144272799