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\batchmode \documentstyle[12pt]{article} \topmargin -20mm \textwidth 160mm \textheight 240mm \hoffset -10mm \pagestyle{empty} \begin{document} \noindent {\it Title: }{\bf Distribution of Reactive Chemical Species in Snow and Ice} (DPP-9123025) (R. Bales and M. Conklin) \vspace*{5mm} \noindent {\it Summary: } The aim of our research was to determine the relation between concentrations of hydrogen peroxide ($\rm{H_2O_2}$) in the atmosphere and corresponding levels in snow and shallow firn. A better understanding of the atmosphere-snow transfer function for $\rm{H_2O_2}$ and other volatile species is needed in order to relate concentrations found in ice cores to corresponding atmospheric levels. $\rm{H_2O_2}$ in the ice core offers the possibility to constrain modeling of past atmospheric oxidation capacity. The work involved: i) atmospheric and snow measurements at Summit, Greenland, ii) mathematical modeling, and iii) laboratory studies. Two general results are a conceptual understanding and mathematical model of processes affecting $\rm{H_2O_2}$ in ice cores. $\rm{H_2O_2}$ in surface snow equilibrates with atmospheric levels over a time scale of weeks to months. Once buried it is preserved, however redistribution continues throughout the firn. Firn gas $\rm{H_2O_2}$ concentrations are in equilibrium with those at the surface of the ice grains, but not the bulk ice grain. Equilibration times in the firn are limited by grain-scale redistribution of $\rm{H_2O_2}$ between grain interiors and surfaces rather than by diffusion in the open pore space. This equilibrium is temperature dependent, and influences the annual pattern of $\rm{H_2O_2}$ in snow. Both seasonal and year-to-year $\rm{H_2O_2}$ levels in snow (and thus ice) do respond to changes in atmospheric $\rm{H_2O_2}$. However, degassing of $\rm{H_2O_2}$ from surface snow also influences atmospheric concentrations. \end{document} \batchmode \documentstyle[12pt]{article} \topmargin -20mm \textwidth 160mm \textheight 240mm \hoffset -10mm \pagestyle{empty} \begin{document} \noindent {\it Title: }{\bf Distribution of Reactive Chemical Species in Snow and Ice} (DPP-9123025) (R. Bales and M. Conklin) \vspace*{5mm} \noindent {\it Publications}: \begin{description} \itemsep=-1mm \item M. H. Conklin, A. Sigg, A. Neftel and R. C. Bales, Atmosphere-snow transfer function for $\rm{H_2 O_2}$: Microphysical considerations, {\it EOS, V. 73, N. 43}, pp. 91, 1992. \item M. H. Conklin, A. Sigg, A. Neftel and R. C. Bales, Atmosphere-snow transfer function for $\rm{H_2 O_2}$: Microphysical considerations, {\it Journal of Geophysical Research, 98}, pp. 18367--18376, 1993. \item R. C. Bales, M. V. Losleben, M. H. Conklin, K. Fuhrer and A. Neftel, Atmosphere-snow exchange of $\rm{H_2 O_2}$: Transfer function for interpreting ice-core records, {\it EOS, V. 74, N. 43S}, p. 87, 1993. \item A. Neftel, R. C. Bales and D. J. Jacob, $\rm{H_2 O_2}$ and HCHO in polar snow and their relation to atmospheric chemistry, in {\it Ice Core Studies of Global Biogeochemical Cycles}, R. Delmas, ed. NATO Advanced Sciences Institutes Series, {\it in press}. \item R. C. Bales, Nitric acid in Firn: Discussion, in {\it Ice Core Studies of Global Biogeochemical Cycles}, R. Delmas, ed. NATO Advanced Sciences Institutes Series, {\it in press}. \item R. C. Bales, M. V. Losleben, J. R. McConnell, K. Fuhrer and A. Neftel, $\rm{H_2 O_2}$ in Snow, Air and Open Pore Space in Firn at Summit, Greenland, {\it submitted}, 1994. \item R. C. Bales, J. R. McConnell, M. V. Losleben, M. H. Conklin, K. Fuhrer, A. Neftel, J. E. Dibb, J. D. W. Kahl and C. R. Stearns, The Diel Variations of $\rm{H_2 O_2}$ in Greenland: A Discussion of the Cause and Effect Relationship, {\it submitted}, 1994. \end{description} \end{document}