elib
DLR-Header
DLR-Logo -> http://www.dlr.de
DLR Portal Home | Imprint | Contact | Deutsch
Fontsize: [-] Text [+]

Scavenging of black carbon in mixed phase clouds at the high alpine site Jungfraujoch

Cozic, Julie and Verheggen, Bart and Mertes, Stephan and Connolly, Paul and Bower, Keith and Petzold, Andreas and Baltensperger, Urs and Weingartner, Ernest (2007) Scavenging of black carbon in mixed phase clouds at the high alpine site Jungfraujoch. Atmospheric Chemistry and Physics, 7, pp. 1797-1807.

[img]
Preview
PDF - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
1MB

Official URL: http://www.atmos-chem-phys.net/7/1797/2007/

Abstract

The scavenging of black carbon (BC) in liquid and mixed phase clouds was investigated during intensive experiments in winter 2004, summer 2004 and winter 2005 at the high alpine research station Jungfraujoch (3580m a.s.l., Switzerland). Aerosol residuals were sampled behind two well characterized inlets; a total inlet which collected cloud particles (droplets and ice particles) as well as interstitial (unactivated) aerosol particles; an interstitial inlet which collected only interstitial aerosol particles. BC concentrations were measured behind each of these inlets along with the submicrometer aerosol number size distribution, from which a volume concentration was derived. These measurements were complemented by in-situ measurements of cloud microphysical parameters. BC was found to be scavenged into the condensed phase to the same extent as the bulk aerosol, which suggests that BC was covered with soluble material through aging processes, rendering it more hygroscopic. The scavenged fraction of BC (FScav,BC), defined as the fraction of BC that is incorporated into cloud droplets and ice crystals, decreases with increasing cloud ice mass fraction (IMF) from F(Scav, BC) = 60% in liquid phase clouds to F(Scav,BC) = 5–10% in mixed-phase clouds with IMF>0.2. This can be explained by the evaporation of liquid droplets in the presence of ice crystals (Wegener-Bergeron-Findeisen process), releasing BC containing cloud condensation nuclei back into the interstitial phase. In liquid clouds, the scavenged BC fraction is found to decrease with decreasing cloud liquid water content. The scavenged BC fraction is also found to decrease with increasing BC mass concentration since there is an increased ompetition for the available water vapour.

Document Type:Article
Title:Scavenging of black carbon in mixed phase clouds at the high alpine site Jungfraujoch
Authors:
AuthorsInstitution or Email of Authors
Cozic, JuliePSI, Villigen, CH
Verheggen, BartPSI, Villigen, CH
Mertes, StephanLeibniz-Inst. for Tropospheric Research, Leipzig
Connolly, PaulUniv. of Manchester, UK
Bower, KeithUniv. of Manchester, UK
Petzold, AndreasUNSPECIFIED
Baltensperger, UrsPSI, Villigen, CH
Weingartner, ErnestPSI, Villigen, CH
Date:2007
Journal or Publication Title:Atmospheric Chemistry and Physics
Volume:7
Page Range:pp. 1797-1807
Status:Published
Keywords:black carbon, soot, aerosol scavenging, aerosol indirect effect, MAAP
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Transport
HGF - Program Themes:V UR - Schonung von Umwelt und Ressourcen (old)
DLR - Research area:Transport
DLR - Program:V UR - Schonung von Umwelt und Ressourcen
DLR - Research theme (Project):V - Umweltwirkungen des Verkehrs (old)
Location: Oberpfaffenhofen
Institutes and Institutions:Institute of Atmospheric Physics > Atmospheric Trace Species
Deposited By: Dr.rer.nat. Andreas Petzold
Deposited On:25 Jun 2007
Last Modified:12 Dec 2013 20:25

Repository Staff Only: item control page

Browse
Search
Help & Contact
Informationen
electronic library is running on EPrints 3.3.12
Copyright © 2008-2012 German Aerospace Center (DLR). All rights reserved.