|Title:||NOx emission from snowpack at the WAIS-Divide site and its impact on local tropospheric photochemistry|
|Author:||Masclin, S., Frey, M.M., Rogge, W.F. and Bales, R.C.|
|Periodical:||American Geophysical Union, Fall Meeting 2010, abstract #C33D-0577|
Nitrogen oxides (NOx= NO+NO2) play key roles in the photochemistry of the polar boundary layer. They control production of major tropospheric oxidants, e.g. HOx (HO+HO2) and O3. Recent studies from field campaigns and laboratory research suggest that NOx emission from snowpack through nitrate photolysis impacts significantly the oxidative capacity of the polar boundary layer. From first measurements of nitric oxide (NO) at the WAIS-Divide site (79°S, 112°W), we estimated and compared local NOx production to measured tropospheric NO concentrations. Assuming a boundary-layer height of 100 m, results suggest that up to 10% of atmospheric NO at the WAIS-Divide site can be attributed to nitrate photolysis from the near-surface snowpack. Analysis of chemical lifetimes and back trajectories indicate the impact of transport from the coast or off the East Antarctic Plateau on boundary layer chemical composition at the WAIS-Divide site.