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| Titel |
Pernitric acid in a coastal Antarctic boundary layer |
| VerfasserIn |
Anna Jones, Neil Brough, Greg Huey, David Tanner, Eric Wolff |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250054388
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| Zusammenfassung |
| Pernitric acid (HO2NO2) has been mooted to play an important role in low altitude
photochemistry of the polar regions. This potential arises from the intrinsic link between
PNA and atmospheric NOx and HOx radicals. For example, gas-phase production
and destruction reactions are, respectively, sinks and sources of NOx and HOx.
Further, PNA can strongly adsorb to ice/snow surfaces, so has the potential to form
reservoirs of radicals within the condensed phase, either temporary or longer-term.
Previous measurements at the South Pole detected significant amounts of boundary
layer PNA with a lifetime controlled predominantly by dry deposition and thermal
decomposition. No observations at warmer, coastal, Antarctic sites have yet been
reported.
As part of a year-round field campaign at the British Antarctic Survey station, Halley, in
coastal Antarctica, measurements of PNA were made using a Chemical Ionisation Mass
Spectrometer (CIMS). Observations extended from March (austral autumn) through to
September (austral spring) with further periods in late spring and summer. The CIMS
concurrently measured nitric acid, and measurements of NO and NO2 were obtained by a
chemiluminescence analyser.
Here we report the PNA observations made at Halley and compare them with the
measurements made at South Pole. We discuss the data within the context of additional
supporting chemical and meteorological observations and consider the influence of PNA on
atmospheric radicals both through gas phase reactions and via exchange between the air and
the snowpack. |
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