An analysis of the oxidation potential of the South Pole boundary layer and the influence of stratospheric ozone depletion
Jones, Anna E.; Wolff, Eric W.. 2003 An analysis of the oxidation potential of the South Pole boundary layer and the influence of stratospheric ozone depletion. Journal of Geophysical Research, 108 (D18), 4565. 7, pp. 10.1029/2003JD003379Full text not available from this repository.
The summertime atmospheric boundary layer over the South Pole has recently been shown to be highly oxidizing, with greater concentrations of NO and OH than previously expected. The source of NO has been attributed to photolysis of nitrate impurities in the snowpack, with elevated OH from the reaction NO + HO2. However, the Antarctic troposphere is not currently in a “natural” state, being subject nowadays to greatly increased incidences of ultraviolet (UV) radiation each spring. Here we analyze the long-term record of surface ozone at the South Pole (1975–2001), to look for evidence of a changing oxidation potential. Daily averaged surface ozone concentrations during spring and early summer now regularly exceed the maximum concentration of the previous winter, while in the 1970s and 1980s this was not the case. This suggests that the proposed springtime ozone source is greater nowadays than before. Such a feature is consistent with increases in UV radiation accompanying the springtime stratospheric ozone hole. Model calculations show that the rate of nitrate photolysis in the South Pole snowpack has increased significantly since the onset of the ozone hole, such that production of NO2 in November has increased by 43% between the late 1960s and the late 1990s. It thus appears that the South Pole boundary layer is more highly oxidizing nowadays than under conditions before the onset of the ozone hole.
|Programmes:||BAS Programmes > Antarctic Science in the Global Context (2000-2005) > Signals in Antarctica of Past Global Changes|
|Additional Keywords:||oxidation potential, surface ozone, Antarctica, air/snow interaction, ultraviolet|
|Date made live:||12 Apr 2012 10:30|
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