(1) Master Thesis: Impact of climate change on the Rossby wave activity over the Northern Hemisphere and impacts to temperature Extremes over Europe (2) Master Thesis: Physical constraints on the emission of water vapor and ash from Hunga Tonga eruption January 2022 (3) tbd (4) tbd

The moisture content and vertical distribution in the extratropical UTLS is important for radiative properties in particular with a perspective to anticipated change of tropopause height and moisture content due to rising greenhouse gas concentrations. We present a Lagrangian perspective on various processes that control the extratropical UTLS moisture content including deep convection and warm-conveyor belts as well as cloud and mixing processes close to the local tropopause. The analysis combines various data sources on UTLS moisture including high-resolution ICON simulation and ERA5, but also observational data from aircraft and satellite. 
 

If you are interested in the zoom link, please contact tabea.unser@student.kit.edu .

The top of the atmosphere reflectivity of the planet, depends in part, on the optical properties of aerosol in the atmosphere. Frequently atmospheric chemists use chemical proxies for aerosol and here we describe a series of experiment using optical trapping with material extracted from atmospheric filter samples. The experiments demonstrating to a first approximation that organic matter may for core-shell morphologies, have refractive indexes that vary with location and that thin films on aerosol have chemical removal rates comparable to mechanical removal rates from the atmosphere. Basic radiative transfer modelling also demonstrates that thin organic films on atmospheric aerosol may have appreciable effects on planetary reflectivity. We will also show some early data that near-field scattering effects between pairs of aerosol particles predicted by theory (T-matrix) may not agree with experiment.

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