Markus Frey

I investigate ice-snow-atmosphere interactions in the polar regions to better understand trace gas and aerosol composition of the lower atmosphere and related impacts on climate now and in the recent past.

Research Area

My research is about physical and chemical air-snow exchange processes to gain a better understanding of how snow and ice surfaces influence atmospheric composition and oxidation capacity, and ultimately climate, with a focus on tropospheric ozone, the nitrogen and sulfur cycle, halogen chemistry, as well as aerosol formation and growth. Further aims are to quantify the preservation of chemical trace species in snow and ice to develop proxies of atmospheric composition in the past using ice cores. My focus is on field and lab experiments to investigate processes controlling atmospheric composition (trace gases, aerosol), and I collaborate with modellers to quantify their wider impacts on air quality and climate. Recently I observed for the first time sea salt aerosol being produced by sublimating blowing snow above Antarctic sea ice during and after storms, thereby validating an existing model hypothesis. In a follow-up study we showed that additional sea salt particles during Arctic winter/ spring from a source hither-to unaccounted for impacts cloud optical properties leading to significant surface warming.

Project Interests

Cloud condensation nuclei (CCN) and ice nucleating particles (INPs) play a key role for the phase, occurrence and lifetime of clouds. Yet little is known about the particle chemical composition, sources, abundance and climate impacts in the polar regions. Recently we have collected data and samples from the year-round MOSAiC expedition in the Arctic and the SAICA-SWOS sea ice cruise in the Antarctic. Topics to develop underpinned by field, lab and modelling experiments include

• Exploring the sources, chemistry and potential impacts on clouds and climate of bioaerosol, INPs and CCNs above the Southern Ocean and coastal Antarctica 
• Development of a millennial atmospheric record of INPs from an existing Antarctic ice core