Overview of recent field experiments for the study of the air-snow transfer of H2O2 and HCHO

The analysis of hydrogen peroxide and formaldehyde in ice cores offers the potential to reconstruct the oxidation capacity of the atmosphere in the past [Neftel and Fuhrer, 1993], since these species are closely linked to the odd H and the odd O budget of the atmosphere [Thompson, 1992]. These species are so-called reversibly deposited on the snow surface since they show a strong exchange with the gas phase after deposition and their ice concentrations are dominated to a large extent by postdepositional changes in the firn. Therefore, the transfer from the atmosphere into the snow is an important step in the overall transfer function of these species [Neftel, this issue]. To get a better understanding of this step several field experiments were carried out during the 1993 and 1994 summer seasons at Summit in Central Greenland, in the 1993/94 Austral summer in Antarctica along the Swedish traverse (SWEDARP), and at South Pole in November and December, 1994. We will give an overview of the data and point out possible contradictions and knowledge gaps.