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| Titel |
On the relationship between total ozone and atmospheric dynamics and chemistry at mid-latitudes – Part 2: The effects of the El Niño/Southern Oscillation, volcanic eruptions and contributions of atmospheric dynamics and chemistry to long-term total ozone changes |
| VerfasserIn |
H. E. Rieder, L. Frossard, M. Ribatet, J. Staehelin, J. A. Maeder, S. Rocco, A. C. Davison, T. Peter, P. Weihs, F. Holawe |
| 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 ; 13, no. 1 ; Nr. 13, no. 1 (2013-01-08), S.165-179 |
| Datensatznummer |
250011721
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| Publikation (Nr.) |
 copernicus.org/acp-13-165-2013.pdf |
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| Zusammenfassung |
| We present the first spatial analysis of "fingerprints" of the El
Niño/Southern Oscillation (ENSO) and atmospheric aerosol load
after major volcanic eruptions (El Chichón and Mt. Pinatubo) in
extreme low and high (termed ELOs and EHOs, respectively) and mean
values of total ozone for the northern and southern mid-latitudes
(defined as the region between 30° and 60° north and
south, respectively). Significant influence on ozone extremes was
found for the warm ENSO phase in both hemispheres during spring,
especially towards low latitudes, indicating the enhanced ozone
transport from the tropics to the extra-tropics. Further, the
results confirm findings of recent work on the connection between
the ENSO phase and the strength and extent of the southern ozone
"collar". For the volcanic eruptions the analysis confirms
findings of earlier studies for the northern mid-latitudes and gives
new insights for the Southern Hemisphere. The results provide
evidence that the negative effect of the eruption of El Chichón
might be partly compensated by a strong warm ENSO phase in 1982–1983
at southern mid-latitudes. The strong west-east gradient in the
coefficient estimates for the Mt. Pinatubo eruption and the analysis
of the relationship between the AAO and ENSO phase, the extent and
the position of the southern ozone "collar" and the polar vortex
structure provide clear evidence for a dynamical "masking" of the
volcanic signal at southern mid-latitudes. The paper also analyses
the contribution of atmospheric dynamics and chemistry to long-term
total ozone changes. Here, quite heterogeneous results have been
found on spatial scales. In general the results show that EESC and
the 11-yr solar cycle can be identified as major contributors to
long-term ozone changes. However, a strong contribution of dynamical
features (El Niño/Southern Oscillation (ENSO), North Atlantic
Oscillation (NAO), Antarctic Oscillation (AAO), Quasi-Biennial
Oscillation (QBO)) to ozone variability and trends is found at
a regional level. For the QBO (at 30 and 50 hPa), strong
influence on total ozone variability and trends is found over large
parts of the northern and southern mid-latitudes, especially towards
equatorial latitudes. Strong influence of ENSO is found over the
Northern and Southern Pacific, Central Europe and central southern
mid-latitudes. For the NAO, strong influence on column ozone is
found over Labrador/Greenland, the Eastern United States, the
Euro-Atlantic Sector, and Central Europe. For the NAO's southern
counterpart, the AAO, strong influence on ozone variability and
long-term changes is found at lower southern mid-latitudes,
including the southern parts of South America and the Antarctic
Peninsula, and central southern mid-latitudes. |
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