Chemical Analysis of Organic Matter in Cloudwater and Aerosol in High-Altitude Alps

Abstract

Chemical Analysis of Organic Matter in Cloudwater and Aerosol in High-Altitude Alps Hanne Notø1, Anne Kasper-Giebl2, Bernadette Kirchsteiger2, Daniela Kau2, Felix Happenhofer2, Thomas Riedelberger2, Elke Ludewig3, and Rupert Holzinger1

1Utrecht University, Institute for Marine and Atmospheric Research, Department of Physics, Utrecht, Netherlands (h.o.noto@uu.nl) 2TU Wien, Institute of Chemical Technologies and Analytics, Wien, Austria 3Geosphere Austria, Sonnblick Observatory, Salzburg, Austria

Organic matter in ice cores holds important climatic information, such as the prevalence of wildfires, marine algae blooms, terrestrial biosphere productivity, and antarctic sea ice extent. While organic compounds are specific tracers of the biosphere in paleoclimatic records, very little is known about their transport and deposition onto glaciers and ice sheets. Factors such as atmospheric transport, scavenging in the atmosphere and deposition efficiency can have a substantial effect on the amount of organic matter measured in the snow and ice. To better understand the deposition of organic matter onto glaciers and ice sheets, we determined the presence of organic species in clouds versus particulate matter in the atmosphere.

In this work we present data from a sampling campaign aimed at measuring organic matter in cloudwater and aerosol particles (PM1 and PM10). Samples were collected at the Sonnblick Observatory in the Austrian Alps (3106 m a.s.l.) across 10 days in November 2022. This site represents remote alpine atmospheric conditions. The samples were analyzed using a Thermal Desorption - Proton Transfer Reaction - Mass Spectrometer (TD-PTR-MS), which quantifies volatile and semi-volatile organic species. Further processing will reveal potential differences in organic composition between cloudwater and aerosol particles. This information can provide insight into the deposition of organic matter in the cryosphere, which affects the way ice core records are interpreted.