Lay summary

For the fluorinated substances explicitly listed as greenhouse gases in the Kyoto-Protocol industrialized countries annually report their emissions, based on information about usage and specific source factors (bottom-up estimates). However, a real-world verification of emissions with atmospheric measurements is yet missing (top-down estimates). In addition, the industry is continuously marketing new halocarbons as replacements of forbidden compounds (e.g. CFCs) or is using them as feedstock in production processes. For these so far unregulated halocarbons it is important to initiate measurement capabilities to provide an early-warning tool.

At the high-Alpine site of Jungfraujoch halogenated greenhouse gases are continuously measured since 2000 uisng gas chromatography-mass spectrometry (GCMS). These measurements are exploited for detecting atmospheric background trends and for localizing and quantifying regional European emissions.

With this PhD work this approach will be extended and new developments will be incorporated to advance both analytical and instrumental techniques for atmospheric halocarbons and to employ new tools for emission estimation. Furthermore, existing methods to quantify regional sources will be applied in campaigns in currently still under-sampled European regions (Spain, Greece).

The PhD work will be composed of three tasks:

1) Use the new abilities of the highly sensitive Medusa-GCMS measurement technology to detect new halocarbons in the atmosphere. This will be achieved by both screening for unknown substances and selectively searching for newly marketed substances and halocarbons used as feedstock.

2) Use the newly developed high-resolution transport model COSMO-FLEXPART for improved independent estimations of Swiss and regional European emissions of halogenated greenhouse gases by measurements at the high-Alpine site Jungfraujoch.

3) Perform measurement campaigns in Greece and Spain (under-sampled regions of Europe) and independently verify regional emission of halocarbons.

The main expected impact will be an improved understanding of the spatial distribution of European halocarbon emissions. This will be an important step for the verification of inventories used within international treaties by real-world atmospheric measurements.