Working Package 4 is dedicated to investigate the scientific issues described above and is based on the algorithm and model developments performed within WPs 1 – 3. In particular, the evaluation of the two data sets derived in WP 1 and WP 2 requires specific, partly sequential tasks:
WP 4.1 Investigate the modeled and retrieved profiles of aerosol extinction and particle size, evaluate the structure and variability of the stratospheric aerosol layer, also taking into account corresponding data sets from other satellites (SAGE II, OSIRIS, GOMOS).
WP 4.2 Investigate the modeled interactions between aerosol modulations from various sources (natural, anthropogenic) and the stratospheric composition by means of correlative SCIAMACHY limb observations of ozone, H2O, NO2, BrO, PSCs and aerosol.
WP 4.3 Infer the trend in the stratospheric aerosol load during the last decade and investigate potential impacts on cycles forming ozone depleting substances and winter-time polar ozone losses.
WP 4.4 Investigation of changes in the spatio-temporal evolution of the stratospheric aerosol layer and changes in the aerosol composition caused by changes in the Brewer-Dobson circulation during the last decade, as far as these are reflected in the meteorological fields which drive the model.
WP 4.5 Conduct solar radiation management experiments with the CTM in order to globally project aerosol extinction as well as potential side-effects on the stratospheric composition.