Are photochemical processes on the snow surface important for the exchange of H2O2 and HCHO between the atmosphere and snow?

• Main Authors: Jacobi, Hans-Werner, Hutterli, M. A., Frey, M. M., Bales, R. C., Schrems, Otto
• Format: Conference Object
• Language: unknown
• Published: 2000
• Subjects: Antarc*; Antarctic; Greenland; ice core
• Online Access: https://epic.awi.de/id/eprint/4469/; https://hdl.handle.net/10013/epic.15044

Hydrogen peroxide (H2O2) and formaldehyde (HCHO) are importantreactive intermediates characterizing the oxidation capacityof the atmosphere. Moreover, both compounds are also preservedin ice cores an could be used to reconstruct past atmosphericcompoistions if a quantitative analysis of ice core profilesis possible. While transfer models including only physical processes(e.g. deposition, emission, precipitation, diffusion) have beensuccessfully used to interpret H2O2 and HCHO profiles in shallowice cores at different Arctic and Antarctic locations, recentexperiments have demonstrated that active photochemistry occursabove the snow and within the firn pore space of the upper layersof the snow pack influencing at least nitrogen containing compounds.Therefore, we performed several experiments like gradient measurements,firn air measurements, and snow chamber experiments at Summit,Greenland, to further investigate the impact of these photochemicalprocesses on the boundary layer composition, concentrationsin the snow, and the transfer between both compartments. Wewill present results of combined gradients and firn air measurementsto analyze and quantify fluxes of H2O2 and HCHO in the boundarylayer. In addition, we will compare the fluxes with photochemicalproduction and destruction rates and discuss the implicationsfor snow-enhanced photochemistry for the atmosphere-to-snowtransfer of both compounds.