 |
| Titel |
Characteristics, sources, and transport of aerosols measured in spring 2008 during the aerosol, radiation, and cloud processes affecting Arctic Climate (ARCPAC) Project |
| VerfasserIn |
C. A. Brock, J. Cozic, R. Bahreini, K. D. Froyd, A. M. Middlebrook, A. McComiskey, J. Brioude, O. R. Cooper, A. Stohl, K. C. Aikin, J. A. Gouw, D. W. Fahey, R. A. Ferrare, R.-S. Gao, W. Gore, J. S. Holloway, G. Hübler, A. Jefferson, D. A. Lack, S. Lance, R. H. Moore, D. M. Murphy, A. Nenes, P. C. Novelli, J. B. Nowak, J. A. Ogren, J. Peischl, R. B. Pierce, P. Pilewskie, P. K. Quinn, T. B. Ryerson, K. S. Schmidt, J. P. Schwarz, H. Sodemann, J. R. Spackman, H. Stärk, D. S. Thomson, T. Thornberry, P. Veres, L. A. Watts, C. Warneke, A. G. Wollny |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 11, no. 6 ; Nr. 11, no. 6 (2011-03-16), S.2423-2453 |
| Datensatznummer |
250009500
|
| Publikation (Nr.) |
 copernicus.org/acp-11-2423-2011.pdf |
|
|
|
|
|
| Zusammenfassung |
We present an overview of the background, scientific goals, and execution of
the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate
(ARCPAC) project of April 2008. We then summarize airborne measurements,
made in the troposphere of the Alaskan Arctic, of aerosol particle size
distributions, composition, and optical properties and discuss the sources
and transport of the aerosols. The aerosol data were grouped into four
categories based on gas-phase composition. First, the background troposphere
contained a relatively diffuse, sulfate-rich aerosol extending from the top
of the sea-ice inversion layer to 7.4 km altitude. Second, a region of
depleted (relative to the background) aerosol was present within the surface
inversion layer over sea-ice. Third, layers of dense, organic-rich smoke
from open biomass fires in southern Russia and southeastern Siberia were
frequently encountered at all altitudes from the top of the inversion layer
to 7.1 km. Finally, some aerosol layers were dominated by components
originating from fossil fuel combustion.
Of these four categories measured during ARCPAC, the diffuse background
aerosol was most similar to the average springtime aerosol properties
observed at a long-term monitoring site at Barrow, Alaska. The biomass
burning (BB) and fossil fuel layers were present above the sea-ice inversion
layer and did not reach the sea-ice surface during the course of the ARCPAC
measurements. The BB aerosol layers were highly scattering and were
moderately hygroscopic. On average, the layers produced a noontime net
heating of ~0.1 K day−1 between 3 and 7 km and a slight
cooling at the surface. The ratios of particle mass to carbon monoxide (CO)
in the BB plumes, which had been transported over distances >5000 km, were
comparable to the high end of literature values derived from previous
measurements in wildfire smoke. These ratios suggest minimal precipitation
scavenging and removal of the BB particles between the time they were
emitted and the time they were observed in dense layers above the sea-ice
inversion layer. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|