To understand the mechanisms and extent of sudden arctic tropospheric ozone loss.
The arctic troposphere is subject to quite unique boundary conditions, like very stable stratification near the ground, or complete darkness during the arctic winter. Therefore, the chemical balance of the arctic troposphere is likely to be very sensitive to disturbing influences, for instance to free radical processes catalyzing boundary layer ozone destruction, as observed at several arctic sites. Those processes might have natural causes, but also possible is initiation by pollutants advected from western Europe. The phenomena certainly point to significant deficiencies in the understanding of the chemical species and processes involved. This project will address the following questions :
1. What is the role of free (halogen oxide) radicals in the phenomenon of arctic troposphere ozone loss ?
2. Is this disturbance a natural or an anthropogenic phenomenon ?
3. Which are the possible consequences of sudden arctic tropospheric ozone loss, in particular on the chemical conditions of the arctic lower troposphere ?
4. What is the spatial extent of the sudden tropospheric ozone loss phenomenon ?
The project will consist of three components :
1. Two field studies planned during springtime at arctic sites in Ny-Alesund/Spitzbergen and one to be selected.
2. Laboratory kinetic investigations of relevant homogeneous and heterogenous reactions at low temperature.
3. Modelling studies including gas phase and heterogeneous reactions and trajectory calculations.
Funding SchemeCSC - Cost-sharing contracts
NR4 7TJ Norwich