Seminars

Host: Dr. Hendrik Bluhm

Multiphase chemistry in cold parts of the atmosphere:Supporting field and modeling scientists with results from X-ray excited photoelectron spectroscopy

AC Seminar
Snow may hold impurity deposits, such as sea salt aerosol, which show vivid chemistry. Snow's porosity guarantees the efficient gas exchange of reaction products with the overlaying air. That snow thus acts as a chemical reactor on Earth with impacts on air quality, climate, and geochemical cycles has long been recognized. X-ray excited electron spectroscopy at near ambient pressure offers the possibility to investigate the underlying processes at surfaces of atmospheric relevance with high sensitivity and chemical specificity. This approach thus fills a unique gap in atmospheric science.Here, I will present the results of our work at the Swiss Light Source tackling 2 seemingly simple questions: 1) At which temperature do aqueous solutions freeze, and 2) How do acidic trace gases dissociate at ice surfaces? [more]

Bridging scales from surface science to atmospheric chemistry and climate

Joint Seminar of AC and Theory
The development of ambient pressure X-ray photoelectron spectroscopy has from the beginning been motivated and justified by the context of atmospheric sciences, apart from other areas of fundamental and applied surface science. This has come in parallel with the recognition of important surface catalyzed processes in the stratosphere that are essential in ozone destruction. [more]
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