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UP: Umweltphysik

UP 25: Atmosph
ärische Spurengase und Aerosole: Laboruntersuchungen

UP 25.3: Fachvortrag

Wednesday, March 15, 2006, 12:30–12:45, E

Investigation of the microphysics and uptake kinetics of trace gas uptake into artificial snow using radioactive tracer and micro tomography — •Thomas Huthwelker¹, Michael Kerbrat¹, Thomas Kaempfer², Bernd Pinzer², Martin Schneebeli², Markus Maria Miedaner³, and Markus Ammann¹ — ¹Laboratory for Radiochemistry and Environmental Chemistry, Paul Scherrer Institute, CH-5232 Villigen (Switzerland) — ²SLF Davos, Abteilung Schnee und Lawinen, Davos (Switzerland) — ³Johannes Gutenberg-Universität, Institut für Geowissenschaften, Becherweg 2, 55099 Mainz (Germany)

Uptake and chemical reactions of nitrogen oxides on natural ice in clouds or on snow are important processes in atmospheric science, for example for the atmospheric ozone budget. The interpretation of adsorption experiments requires a good understanding of both the microphysical uptake processes and the micro morphology of the snow.

We address these issues using different techniques. Nitrous acid (HONO) which is labelled with a short lived radioactive tracer. This technique allows studying the migration of the trace gas through artificial snow non-destructively and in situ. By this method we obtain additional kinetic information about the trace gas/ice interaction. Furthermore, the relative importance of bulk and surface processes can be determined.

Using standard and synchrotron based mictrotomography, we can characterize the internal surface area of porous ice beds. With this technique we determine the surface area and compare with BET adsorption measurements.