hydroxyl radical and nox production rates, black carbon concentrations and light-ag贵宾会

photolytic production rates of no, no2 and oh radicals in snow and the total absorption spectrum due to impurities in snowpack have been calculated for the ocean-atmosphere-sea-ice-snowpack (oasis) campaign during spring 2009 at barrow, alaska. the photolytic production rate and snowpack absorption cross-sections were calculated from measurements of snowpack stratigraphy, light penetration depths (e-folding depths), nadir reflectivity (350–700 nm) and uv broadband atmospheric radiation. maximum nox fluxes calculated during the campaign owing to combined nitrate and nitrite photolysis were calculated as 72 nmol m_2 h_1 for the inland snowpack and 44 nmol m_2 h_1 for the snow on sea-ice and snowpack around the barrow arctic research center (barc). depth-integrated photochemical production rates of oh radicals were calculated giving maximum oh depth-integrated production rates of _160 nmol m_2 h_1 for the inland snowpack and _110–120 nmol m_2 h_1 for the snow around barc and snow on sea-ice. light penetration (e-folding) depths at a wavelength of 400 nm measured for snowpack in the vicinity of barrow and snow on sea-ice are _9 cm and 14 cm for snow 15 km inland. fitting scaled hulis (humic-like substances) and black carbon absorption cross-sections to the determined snow impurity absorption cross-sections show a “humic-like” component to snowpack absorption, with typical concentrations of 1.2–1.5 mgc g_1. estimates of black carbon concentrations for the four snowpacks are _40 to 70 ng g_1 for the terrestrial arctic snowpacks and _90 ng g_1 for snow on sea-ice.