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| Titel |
CARIBIC DOAS NO2 observation at Frankfurt Airport |
| VerfasserIn |
Klaus-Peter Heue, Carl Brenninkmeijer, David Walter, Udo Frieß, Ulrich Platt |
| 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 |
250052501
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| Zusammenfassung |
| The CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an
Instrument Container) project obviously is about measurement at cruise altitude (average
pressure altitude close to 10.8 km), as it uses a long range Airbus A340-600. Some
information is obtained during descend and ascend, yet, to protect the inlet system from
contamination, air intake stops at about 450 hPa. The DOAS (Differential Optical Absorption
Spectrometry) instrument not only is a popular instrument in CARIBIC because it has no
moving parts, it also is not prone to contamination. Moreover, it is the only instrument that is
regularly measuring at ground level and here we report on this aspect. The instrument
observes scattered sunlight under three elevation angles, one line of sight has an
elevation angle of 10Ë ; the other two are directed downwards and hence indeed are
less suitable for ground based observations. In the last years a series of monthly
DOAS NO2 measurements at Frankfurt airport was taken. Other airports (CARIBIC
has a range of destinations) are not considered, as there only few data points are
available. At Frankfurt the observed slant column densities show a clear seasonal cycle,
probably driven by the seasonal variation of incident radiation. The observed NO2
column amount seems not to be affected by the azimuth angle of the observation,
i.e. when the instruments points towards the runway or any other direction. First
results of the slant and vertical columns for the years 2008 and 2009 will be shown. |
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