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| Titel |
Investigation of air mass origin during tropospheric ozone depletion events at Arrival Heights, Antarctica |
| VerfasserIn |
K. Riedel, K. Kreher, S. Nichol, S. J. Oltmans, T. Hay |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250024341
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| Zusammenfassung |
| Surface ozone (O3) measurements, performed between 1997 and 2008 at Arrival Heights,
Antarctica (77.8Ë S, 166.7Ë E), show sudden decreases in O3 mixing ratios during Antarctic
springtime. These low O3 events were often correlated with elevated concentrations of
bromine oxide (BrO) indicating that similar processes of halogen activation, involving sea ice
surfaces as proposed for Arctic and other Antarctic regions, also take place at Arrival
Heights.
The air mass origin during these O3 depletion events was investigated by calculating
5-day and 7-day backwards trajectories. Trajectory analysis showed that most commonly air
masses had contact with sea-ice, which was correlated with enhanced BrO columns. In the
case when O3 depletion events were observed without elevated BrO concentrations no sea-ice
contact was observed, suggesting that ozone depleted air masses must have been transported
to the site.
Mainly changes in wind velocities lead to the correlation of ENSO and sea ice coverage
of the Ross Sea. BrO measurements at Arrival Heights were below average during the El
Niño years 1997-1998 when sea ice coverage in the Ross Sea region was heavier than usual.
In contrast 2 and 3 high BrO events were observed in the La Niña years 1999-2000, when sea
ice coverage was below average. |
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