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| Titel |
Measurements of O3, NO2 and BrO during the INDOEX campaign using ground based DOAS and GOME satellite data |
| VerfasserIn |
A. Ladstätter-Weißenmayer, H. Altmeyer, M. Bruns, A. Richter, A. Rozanov, V. Rozanov, F. Wittrock, J. P. Burrows |
| 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 ; 7, no. 2 ; Nr. 7, no. 2 (2007-01-18), S.283-291 |
| Datensatznummer |
250004457
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| Publikation (Nr.) |
 copernicus.org/acp-7-283-2007.pdf |
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| Zusammenfassung |
| The INDian Ocean EXperiment (INDOEX) was an
international, multi-platform field campaign to measure long-range
transport of air masses from South and South-East-(SE) Asia
towards the Indian Ocean. During the dry monsoon season between
January and March 1999, local measurements were carried out from
ground based platforms and were compared with satellite based
data. The objective of this study was to characterise
stratospheric and tropospheric trace gas amounts in the equatorial
region, and to investigate the impact of air pollution at this
remote site. For the characterisation of the chemical composition
of the outflow from the S-SE-Asian region, we performed ground
based dual-axis-DOAS (Differential Optical Absorption
Spectroscopy) measurements at the KCO (Kaashidhoo Climate
Observatory) in the Maldives (5.0° N,
73.5° E). The measurements were conducted using two
different observation modes (off-axis and zenith-sky). This
technique allows the separation of the tropospheric and
stratospheric columns for different trace gases like O3
and NO2. These dual-axis DOAS data were compared with
O3-sonde measurements performed at KCO and satellite based
GOME (Global Ozone Measuring Experiment) data during the intensive
measuring phase of the INDOEX campaign in February and March 1999.
From GOME observations, tropospheric and stratospheric columns for
O3 and NO2 were retrieved. In addition, the
analysis of the O3-sonde measurements allowed the
determination of the tropospheric O3 amount. The
comparison shows that the results of all three measurement systems
agree within their error limits. During the INDOEX campaign,
mainly background conditions were observed, but in a single case
an increase of tropospheric NO2 during a short pollution
event was observed from the ground and the impact on the vertical
columns was calculated. GOME measurements showed evidence for
small tropospheric contributions to the BrO budget,
probably located in the free troposphere and present over long
periods of the year. The amounts of BrO have been
investigated by the comparison of satellite pixels influenced by
high and low cloud conditions based on GOME data which allows the
determination of the detection limit of
3.8×1013molecules cm−2 of tropospheric BrO
columns. |
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