 |
| Titel |
A novel Whole Air Sample Profiler (WASP) for the quantification of volatile organic compounds in the boundary layer |
| VerfasserIn |
J. E. Mak, L. Su, A. Guenther, T. Karl |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1867-1381
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 6, no. 10 ; Nr. 6, no. 10 (2013-10-16), S.2703-2712 |
| Datensatznummer |
250085084
|
| Publikation (Nr.) |
 copernicus.org/amt-6-2703-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| The emission and fate of reactive volatile organic compounds (VOCs) is of
inherent interest to those studying chemical biosphere–atmosphere
interactions. In-canopy VOC observations are obtainable using tower-based
samplers, but the lack of suitable sampling systems for the full boundary
layer has limited the availability of data characterizing the vertical
structure of such gases above the canopy height and still in the boundary
layer. This is an important region where many reactive VOCs are oxidized or
otherwise removed. Here we describe an airborne sampling system designed to
collect a vertical profile of air into a 3/8 in. OD (outer diameter) tube 150 m in
length. The inlet ram air pressure is used to flow sampled air through the
tube, which results in a varying flow rate based on aircraft speed and
altitude. Since aircraft velocity decreases during ascent, it is necessary to
account for the variable flow rate into the tube. This is accomplished using
a reference gas that is pulsed into the air stream so that the precise
altitude of the collected air can be reconstructed post-collection. The
pulsed injections are also used to determine any significant effect from
diffusion/mixing within the sampling tube, either during collection or
subsequent extraction for gas analysis. This system has been successfully
deployed, and we show some measured vertical profiles of isoprene and its
oxidation products methacrolein and methyl vinyl ketone from a mixed canopy
near Columbia, Missouri. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|