Tracer Relations Theory

Investigation Description: An analysis of the temporal development of the relation of tracers throughout the existence of the polar vortex will be conducted. In the past, in particular the relationships of quasi-inert tracers (like e.g., N₂O of CH₄) with compounds that are either chemically active (like O₃ and HCl) or are sequestered by polar stratospheric cloud particles have been employed to deduce chemical change in the presence of variations caused by dynamical processes. Recent studies have further addressed the question in how far tracer relationships inside the polar vortex will be affected by mixing processes through the vortex boundary.

For tracers with sufficiently long chemical lifetimes compact relationships are expected. This is in particular true for the relation of ozone and a tracer inside the polar vortex as long as substantial mixing and chemical change does not occur. A breakdown of an ozone/tracer relation in the vortex is (assuming negligible mixing in winter) therefore an indication of chemical change. By considering the changing relations it is thus possible to deduce the local chemical loss and, by integrating over the lower stratosphere, an estimate of the loss in total column can be calculated.

Within SOLVE we will build on the strategy of the analysis of HALOE profiles to deduce Arctic ozone loss applied in several past winters. The availability of SOLVE data however, will allow a more comprehensive analysis as weaknesses of the HALOE data set, namely an incomplete temporal and spatial coverage of the polar vortex, can be compensated for by the availability of SOLVE data.