Environmental & Climate Sciences Department Seminar

Large Eddy Simulations (LES) are the tool of choice to study the dynamics, microphysics, and aerosol-cloud interactions of boundary layer clouds. LES traditionally operate with idealized large scale meteorological conditions, derived from a snapshot of the atmospheric state, and leave aside the role of mesoscale organization. The need for better scientific understanding, supported by technical progress, has prompted the development of LES approaches geared towards greater realism. This seminar will introduce realistic Lagrangian LES, which capture boundary layer and cloud state development and mesoscale organization along reanalysis trajectories. The approach is applied, together with satellite observations and in-situ data, to study the impact of continental outflow on the transition from the closed- to the open-cell stratocumulus state, and the impact of long-range transport of biomass burning aerosol on a pocket of open cells in the South-east Atlantic. Furthermore, some fundamental questions on the dynamics of stratocumulus clouds with relevance for large scale modeling and satellite remote sensing are answered.