Abstract

During warm air intrusion (WAI) episodes, moist air masses are advected poleward through the large-scale meridional flow and are transformed along the way, due to processes that are yet not well-understood and often misrepresented in numerical models. Here, we study the transformation of the air masses that reach the MOSAiC site in April 2020 from a Lagrangian view-point, using the Atmosphere Ocean Single Column Model (AOSCM). Backward trajectories initialized at different heights appear to line up vertically for up to 48-hours before the air-masses reach Polarstern, which indicates that advection could be represented by temporally varying surface boundary conditions. Analysis of observations collected from observation stations along the air-mass path, as well as ERA5 reanalysis data are used in addition to the Lagrangian simulations in order to help distinguish the timescales of the transformation and its driving mechanisms.

If you want to be added to the seminar mailing list to receive regular information about our seminars, please contact our IT person.

Welcome!