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| Titel |
Drift-corrected trends and periodic variations in MIPAS IMK/IAA ozone measurements |
| VerfasserIn |
E. Eckert, T. Clarmann, M. Kiefer, G. P. Stiller, S. Lossow, N. Glatthor, D. A. Degenstein, L. Froidevaux, S. Godin-Beekmann, T. Leblanc, S. McDermid, M. Pastel, W. Steinbrecht, D. P. J. Swart, K. A. Walker, P. F. Bernath |
| 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 ; 14, no. 5 ; Nr. 14, no. 5 (2014-03-13), S.2571-2589 |
| Datensatznummer |
250118478
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| Publikation (Nr.) |
 copernicus.org/acp-14-2571-2014.pdf |
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| Zusammenfassung |
| Drifts, trends and periodic variations were calculated
from monthly zonally averaged ozone profiles. The ozone profiles were derived
from level-1b data of the Michelson Interferometer for Passive Atmospheric
Sounding (MIPAS) by means of the scientific level-2 processor run by
the Karlsruhe Institute of Technology (KIT), Institute for Meteorology and Climate
Research (IMK). All trend and drift analyses were performed using a
multilinear parametric trend model which includes a linear term, several
harmonics with period lengths from 3 to 24 months and the
quasi-biennial oscillation (QBO). Drifts at 2-sigma significance level were
mainly negative for ozone relative to Aura MLS and Odin OSIRIS and negative
or near zero for most of the comparisons to lidar measurements. Lidar
stations used here include those at Hohenpeissenberg (47.8° N,
11.0° E), Lauder (45.0° S, 169.7° E),
Mauna Loa (19.5° N, 155.6° W), Observatoire Haute
Provence (43.9° N, 5.7° E) and Table Mountain
(34.4° N, 117.7° W). Drifts against the
Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) were
found to be mostly insignificant. The assessed MIPAS ozone trends cover the
time period of July 2002 to April 2012 and range from
−0.56 ppmv decade−1 to +0.48 ppmv decade−1
(−0.52 ppmv decade−1 to +0.47 ppmv decade−1 when displayed on
pressure coordinates) depending on altitude/pressure and latitude. From the
empirical drift analyses we conclude that the real ozone trends might be
slightly more positive/less negative than those calculated from the MIPAS
data, by conceding the possibility of MIPAS having a very small
(approximately within −0.3 ppmv decade−1) negative drift for ozone. This leads to
drift-corrected trends of −0.41 ppmv decade−1 to
+0.55 ppmv decade−1 (−0.38 ppmv decade−1 to
+0.53 ppmv decade−1 when displayed on pressure coordinates) for the time
period covered by MIPAS Envisat measurements, with very few negative and large
areas of positive trends at mid-latitudes for both hemispheres around and
above 30 km (~10 hPa). Negative trends are found in the tropics around
25 and 35 km (~25 and 5 hPa), while an area of positive trends is
located right above the tropical tropopause. These findings are in good
agreement with the recent literature. Differences of the trends compared with
the recent literature could be explained by a possible shift of the subtropical
mixing barriers. Results for the altitude–latitude distribution of amplitudes
of the quasi-biennial, annual and the semi-annual oscillation are overall in
very good agreement with recent findings. |
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