After obtaining my diploma in chemistry from the University of Jena in 2004, and a PhD in chemistry from the University of Frankfurt in 2008, I joined UEA as an independent researcher by winning a 3-year NERC Postdoctoral Research Fellowship: 'CLEARFOGG - Checking Layers of the Earths AtmospheRe For halogenated Ozone-depleting and Greenhouse Gases'. In 2011 I won a 5-year NERC Advanced Research Fellowship to work on forensic innovations to constrain greenhouse trace gas budgets. More recently I have been awarded a 5-year Starting Grant ("EXC³ITE - Exploring stratospheric Composition, Chemistry and Circulation with Innovative TEchniques") by the European Research Council, which started in April 2016.

In December 2018 I started a new position at the Institute for Energy and Climate 7: Stratosphere, which is part of the Juelich Research Centre in Germany. I will retain strong links to UEA and have therefore been awarded an Honorary Lecturer position.

I am and have been involved in a number of EU projects such as SCOUT-O3, RECONCILE, INGOS and StratoClim. From 2009 to 2018 I have also been teaching various aspects of atmospheric and analytical chemistry including the supervision of BSc, MSc, and PhD students.

Research examples

• Chlorinated trace gases such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are damaging to the life-protecting stratospheric ozone layer and therefore controlled by an international treaty, the 'Montreal Protocol'. Three new CFCs and one new HCFC have been detected in 2014. Albeit present at levels much smaller than many known similar gases two of them continue to increase in concentration. The emissions of CFC-113a have been estimated to have more than doubled between 2010 and 2012, while those of HCFC-133a have approximately tripled between 2009 and 2012. These findings were initially reported in Nature Geoscience. More recent updates published in GRL (Vollmer et al., 2015) and ACP (Adcock et al., 2018) showed that global CFC-113a emissions remained stable at these higher levels while those of HCFC-133a have been declining in the short term.
• A kinetic isotope effect was discovered during the decomposition of the powerful ozone-depleting chlorofluorocarbons (CFCs) in the stratosphere. These findings were published in Science. Current work focusses on the simulation of these processes in the laboratory and the detection of similar effects in other trace gases.
• The detection and quantification of 1,1,1,2,3,3,3-Heptafluoropropane (HFC-227ea) in the atmosphere. HFC-227ea is replacing ozone-depleting substances in a number of industrial applications such as asthma inhalers or fire extinguishers. Air extracted from deep firn snow in Greenland was used to reconstruct its atmospheric history. HFC-227ea was found to have had very low abundances before the 1990s and to have exhibited accelerating growth since then. A recent update (Elvidge et al., 2018) confirmed that this strong greenhouse gas is still increasing fast.
• Perfluoroalkanes are powerful greenhouse gases with Global Warming Potentials thousands of times higher than that of carbon dioxide. Before 2012 only four perfluoroalkanes were known to be present in the atmosphere in significant amounts. We identified and quantified four additional compounds. These have contributed the equivalent of several hundred million metric tonnes of carbon dioxide to global warming by 2018. This is an essentially permanent contribution as all four newly detected perfluoroalkanes have atmospheric lifetimes of thousands of years. Current work has focused on updating these trends as well as adding one newly detected species.

Detection, quantification, distribution long-term trends, sources and sinks of the large variety of halogenated and related trace gases in the atmosphere with a focus on molecules relevant for stratospheric ozone depletion and Global Warming.

Regions of special interest are the upper troposphere, the stratosphere, the remote unpolluted troposphere and the "natural archive" of air trapped in deep firn snow. Moreover I am interested in decomposition processes of trace gases in the stratosphere including their fractional release, lifetimes and isotope fractionation.

Recent work has focused on the development of AirCores to measure stratospheric distributions of 30+ halogenated trace gases and air archive measurements to shed more light on changes of the Brewer-Dobson circulation over the last decades - more here.
Publications: EPrints Digital Repository