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| Titel |
Characteristics of tropospheric ozone depletion events in the Arctic spring: analysis of the ARCTAS, ARCPAC, and ARCIONS measurements and satellite BrO observations |
| VerfasserIn |
J.-H. Koo, Y. Wang, T. P. Kurosu, K. Chance, A. Rozanov, A. Richter, S. J. Oltmans, A. M. Thompson, J. W. Hair, M. A. Fenn, A. J. Weinheimer, T. B. Ryerson, S. Solberg, L. G. Huey, J. Liao, J. E. Dibb, J. A. Neuman, J. B. Nowak, R. B. Pierce, M. Natarajan, J. Al-Saadi |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 12, no. 20 ; Nr. 12, no. 20 (2012-10-29), S.9909-9922 |
| Datensatznummer |
250011543
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| Publikation (Nr.) |
 copernicus.org/acp-12-9909-2012.pdf |
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| Zusammenfassung |
| Arctic ozone depletion events (ODEs) are caused by halogen catalyzed ozone
loss. In situ chemistry, advection of ozone-poor air mass, and vertical
mixing in the lower troposphere are important factors affecting ODEs. To
better characterize the ODEs, we analyze the combined set of surface,
ozonesonde, and aircraft in situ measurements of ozone and bromine compounds
during the Arctic Research of the Composition of the Troposphere from
Aircraft and Satellites (ARCTAS), the Aerosol, Radiation, and Cloud
Processes affecting Arctic Climate (ARCPAC), and the Arctic Intensive
Ozonesonde Network Study (ARCIONS) experiments (April 2008). Tropospheric
BrO columns retrieved from satellite measurements and back trajectory
calculations are also used to investigate the characteristics of observed
ODEs. In situ observations from these field experiments are inadequate to
validate tropospheric BrO columns derived from satellite measurements. In
view of this difficulty, we construct an ensemble of tropospheric column BrO
estimates from two satellite (OMI and GOME-2) measurements and with three
independent methods of calculating stratospheric BrO columns. Furthermore,
we select analysis methods that do not depend on the absolute magnitude of
column BrO, such as time-lagged correlation analysis of ozone and
tropospheric column BrO, to understand characteristics of ODEs. Time-lagged
correlation analysis between in situ (surface and ozonesonde) measurements
of ozone and satellite derived tropospheric BrO columns indicates that the
ODEs are due to either local halogen-driven ozone loss or short-range (∼1 day) transport from nearby regions with ozone depletion. The effect of in
situ ozone loss is also evident in the diurnal variation difference between
low (10th and 25th percentiles) and higher percentiles of surface ozone
concentrations at Alert, Canada. Aircraft observations indicate low-ozone
air mass transported from adjacent high-BrO regions. Correlation analyses of
ozone with potential temperature and time-lagged tropospheric BrO column
show that the vertical extent of local ozone loss is surprisingly deep (1–2 km) at Resolute and Churchill, Canada. The unstable boundary layer during
ODEs at Churchill could potentially provide a source of free-tropospheric
BrO through convective transport and explain the significant negative
correlation between free-tropospheric ozone and tropospheric BrO column at
this site. |
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