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| Titel |
LIF measurements of HOx radicals in the lower troposphere aboard the Zeppelin NT during the PEGASOS campaign 2012 |
| VerfasserIn |
Sebastian Gomm, Sebastian Broch, Hendrik Fuchs, Andreas Hofzumahaus, Frank Holland, Birger Bohn, Rolf Häseler, Julia Jäger, Jennifer Kaiser, Frank Keutsch, Astrid Kiendler-Scharr, Xin Li, Insa Lohse, Keding Lu, Thomas Mentel, Franz Rohrer, Ralf Tillmann, Robert Wegener, Glenn Wolfe, Andreas Wahner |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250076833
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| Zusammenfassung |
| The hydroxyl (OH) and hydroperoxy (HO2) radicals are key compounds for the degradation
of pollutants in the atmosphere. Therefore, accurate and precise measurements
of HOx radicals (= OH + HO2) at different altitudes and in different regions are
necessary to test our understanding of atmospheric chemical processes. The planetary
boundary layer (PBL) is of special interest as it is chemically the most active part of
the atmosphere. Until today there is a general lack of measurements investigating
the distribution of radicals, trace gases, and aerosols in the PBL with high spatial
resolution.
Here, we present results of two measurement campaigns performed from
May – July 2012 in the metropolitan area of Rotterdam, the Netherlands, and in
the Po valley region in Italy as part of the Pan-European Gas-AeroSOls-climate
interaction Study (PEGASOS). We used the Zeppelin NT as an airborne platform for
measurements of HOx radical concentrations and total OH reactivity applying a
remotely controlled Laser Induced Fluorescence (LIF) instrument. In addition a
comprehensive set of other trace gases (O3, CO, NO, NO2, HCHO, HONO), photolysis
frequencies, particle number concentration, and meteorological parameters were measured.
The airship Zeppelin NT allowed us to perform unique flight patterns, including
localized height profiles up to 900 m above ground and transect flights at low flight
speeds.
We present measured data for the HOx radical concentrations and the total OH reactivity
along with a model analysis of the radical chemistry. Maximum daytime concentrations were
2.0 Ã 107cm-3 for OH and 1.5 Ã 109cm-3 for HO2. Typical values for the total OH
reactivity were smaller than 10 s-1. During the morning hours, vertical gradients in radical
and trace gas concentrations were observed indicating a layered atmospheric structure. The
vertical gradients vanished after sunrise due to enhanced convective mixing of the PBL. |
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