Characterization of Surface Ozone Depletion Events in the Arctic and Sub-Arctic During TOPSE
Abstract
Previous studies at Alert or during the ARCTOC program have shown that removal of ozone in the Arctic surface layer occurs frequently in spring and results from catalyzed destruction by active bromine that is believed to derive from sea salt. More recent studies have shown that the snow/ice surface can also be a source of other reactive constituents such as carbonyls and reactive nitrogen. During the TOPSE aircraft study from early Feb. to mid- May, 2000, the occurrence and extent of depletion events were investigated using the NASA Langley ozone/aerosol lidar instrument (DIAL) and the distribution of photochemical constituents was studied by flying the aircraft at ~30 m altitude over the frozen ocean surface for ~30 min and sometimes longer. Ozone depletion events were observed over the Arctic Ocean on three occasions and at lower latitudes over Lancaster Sound, Baffin Bay, and Smith/Kane Bay. Ozone mixing ratios were as low as 40 pptv over the Arctic Ocean. In some cases, depletion was significant to altitudes as high as 1-2 km. For the first time a very large area depletion event was recorded by the DIAL instrument in the sub-Arctic over Hudson Bay. This event was investigated in detail using the in-situ instruments on a dedicated flight made two days later. There were many other occasions where no ozone depletion was observed during low altitude flight legs north of 58o. A comparison of constituent distributions (peroxides, HCHO, PAN, HNO3, OH, RO2, NOx, NOy, soluble bromide, CO, hydrocarbons, and aerosols) is made between the different cases of ozone depleted air masses and with the undepleted low altitude air masses.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2001
- Bibcode:
- 2001AGUSM...A32A02R
- Keywords:
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- 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0322 Constituent sources and sinks;
- 0365 Troposphere--composition and chemistry;
- 0368 Troposphere--;
- onstituent transport and chemistry