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| Titel |
Trend analysis of stratospheric NO2 above Jungfraujoch (46.5°N, 8.0°E) using long-term ground-based UV-visible and FTIR observations |
| VerfasserIn |
Francois Hendrick, Philippe Demoulin, Karin Kreher, Martine De Mazière, Caroline Fayt, Christian Hermans, Bernard Lejeune, Christian Servais, Michel Van Roozendael |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250052312
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| Zusammenfassung |
| Nitrogen dioxide (NO2) plays an important role in controlling ozone abundances in the
stratosphere, either directly through the NOx (NO+NO2) catalytic cycle, or indirectly by
converting active chlorine, bromine, and hydrogen into their reservoir forms, reducing their
availability for ozone-destroying catalytic cycles.
Ground-based zenith-sky UV-visible and Fourier transform infrared (FTIR) solar absorption
measurements have been performed at the NDACC (Network for the Detection of
Atmospheric Composition Change) station of Jungfraujoch (46.5°N, 8.0°E) since 1991
and 1984, respectively. Stratospheric NO2 columns are retrieved from UV-visible
and FTIR observations by applying Optimal Estimation Method (OEM)-based
and non-linear least-squares fitting algorithms, respectively. The inclusion of a
stacked-box photochemical model in the forward model of the UV-visible OEM algorithm
allows the photochemical matching between the UV-visible and FTIR NO2 column
retrievals.
In this presentation, we will first investigate the consistency between both UV-visible and
FTIR NO2 column data sets given their respective error budgets. Then a trend analysis
performed on monthly means time-series using a statistical model including functions for
annual, semi-annual and four-month period variations, 10.7 cm solar flux, Quasi-Biennal
Oscillation, Southern Oscillation Index, and volcanic terms will be presented. The volcanic
terms are essential since both UV-visible and FTIR observations started before
the Mount Pinatubo eruption. The consistency between inferred NO2 trend values
and the increase of N2O (nitrous oxide) also monitored at Jungfraujoch will be
discussed. |
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