Atmospheric Physics and Chemistry Group (APCG)


Research Topic

Reactive organic trace gases in the atmosphere - pollution, emissions from the biosphere and their role for aerosol formation

Due to their reactivity, most organic trace gases do not reach concentrations high enough to be relevant greenhouse gases. Yet, they are important players in the climate system for three important reasons: First, they control the oxidation capacity of the atmosphere which feeds back to the concentration of important greenhouses gases such as methane. Second, together with nitrogen oxides they control tropospheric levels of ozone. Ozone is another greenhouse gas, but further causes respiratory illnesses and at elevate levels cell damage in plants. Degradation products of various greenhouse gases contribute to the formation of fine aerosols, which reflect sunlight and exhibit a cooling effect on the climate and act as condensation nuclei, causing feedback to the climate via several indirect effects between aerosols and cloud formation.

We use chemical ionization mass spectrometry techniques, including a proton transfer reaction time of flight mass spectrometer (PTR-TOF-MS) to quantify reactive organic trace gases and their degradation products in the gas phase and in the condensed phase of aerosols. Projects include laboratory studies in smog and plant chambers, field deployments in different regions covering the whole range from remote high mountain stations (Mt. Sonnblick, Austria), rural/polluted regions (CESAT site, the Netherlands) to heavily polluted environments such as the Los Angeles basin in California, USA.