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| Titel |
A global historical ozone data set and prominent features of stratospheric variability prior to 1979 |
| VerfasserIn |
S. Brönnimann, J. Bhend, J. Franke, S. Flückiger, A. M. Fischer, R. Bleisch, G. Bodeker, B. Hassler, E. Rozanov, M. Schraner |
| 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. 18 ; Nr. 13, no. 18 (2013-09-30), S.9623-9639 |
| Datensatznummer |
250085722
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| Publikation (Nr.) |
 copernicus.org/acp-13-9623-2013.pdf |
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| Zusammenfassung |
| We present a vertically resolved zonal mean monthly mean global ozone data
set spanning the period 1901 to 2007, called HISTOZ.1.0. It is based on a
new approach that combines information from an ensemble of chemistry climate
model (CCM) simulations with historical total column ozone information. The
CCM simulations incorporate important external drivers of stratospheric
chemistry and dynamics (in particular solar and volcanic effects, greenhouse
gases and ozone depleting substances, sea surface temperatures, and the
quasi-biennial oscillation). The historical total column ozone observations
include ground-based measurements from the 1920s onward and satellite
observations from 1970 to 1976. An off-line data assimilation approach is
used to combine model simulations, observations, and information on the
observation error. The period starting in 1979 was used for validation with
existing ozone data sets and therefore only ground-based measurements were
assimilated. Results demonstrate considerable skill from the CCM simulations
alone. Assimilating observations provides additional skill for total column
ozone. With respect to the vertical ozone distribution, assimilating
observations increases on average the correlation with a reference data set,
but does not decrease the mean squared error. Analyses of HISTOZ.1.0 with
respect to the effects of El Niño–Southern Oscillation (ENSO) and of the
11 yr solar cycle on stratospheric ozone from 1934 to 1979 qualitatively
confirm previous studies that focussed on the post-1979 period. The ENSO
signature exhibits a much clearer imprint of a change in strength of the
Brewer–Dobson circulation compared to the post-1979 period. The imprint of
the 11 yr solar cycle is slightly weaker in the earlier period.
Furthermore, the total column ozone increase from the 1950s to around 1970
at northern mid-latitudes is briefly discussed. Indications for
contributions of a tropospheric ozone increase, greenhouse gases, and
changes in atmospheric circulation are found. Finally, the paper points at
several possible future improvements of HISTOZ.1.0. |
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