Title: First measurements of Nitric Oxide (NO) at the WAIS Divide site in West Antarctica and implications for atmospheric oxidation
Author: Masclin, S., Frey, M.M., Rogge, W.F. and Bales, R.C.
Periodical: American Geophysical Union, Fall Meeting 2009, abstract #A31C-0124
Abstract: Nitrogen oxides (NO and NO2), play key roles in determining reactivity and ozone (O3) formation in the polar boundary layer. This influence is achieved through shifting hydroxyl radical (OH+HO2) partitioning towards OH and through NO2 photolysis, the only in situ source of tropospheric O3. Recent field campaigns and laboratory research confirmed that NOx emissions from the snowpack have a significant impact on the oxidative capacity of the polar boundary layer. We present here first measurements of atmospheric NO at WAIS Divide (79 ° S, 112 ° W) during austral summer 2008-09. Overall concentrations during the period measured give a median of 9 pptv, with 25th and 75th percentiles of 4 and 20 pptv, respectively. These values are slightly higher but in the range of those observed at lower-latitude Antarctic stations, but only about one tenth the values measured at South Pole. Our NO results, plus measurements and modeling of ozone and other reactive gases, suggest that in terms of oxidizing atmosphere, WAIS Divide site can be regarded as an intermediate site, linking the Antarctic coast and East Antarctic Plateau. Prior summer NO observations at Summit, Greenland were slightly higher than the current WAIS-Divide values.
Year: 2009