Sensitivity of aerosol concentrations and cloud properties to nucleation and secondary organic distribution in ECHAM5-HAM global circulation model

Show full item record



Permalink

http://hdl.handle.net/10138/314645

Citation

Makkonen , R , Asmi , A , Korhonen , H , Kokkola , H , Järvenoja , S , Räisänen , P , Lehtinen , K , Laaksonen , A , Kerminen , V-M , Järvinen , H , Lohmann , U , Bennartz , R , Feichter , J & Kulmala , M 2009 , ' Sensitivity of aerosol concentrations and cloud properties to nucleation and secondary organic distribution in ECHAM5-HAM global circulation model ' , Atmospheric Chemistry and Physics , vol. 9 , no. 5 , pp. 1747-1766 . https://doi.org/10.5194/acp-9-1747-2009

Title: Sensitivity of aerosol concentrations and cloud properties to nucleation and secondary organic distribution in ECHAM5-HAM global circulation model
Author: Makkonen, Risto; Asmi, Ari; Korhonen, H; Kokkola, H; Järvenoja, S; Räisänen, P; Lehtinen, Kari; Laaksonen, A; Kerminen, Veli-Matti; Järvinen, Heikki; Lohmann, Ulrike; Bennartz, Ralf; Feichter, Johann; Kulmala, Markku
Other contributor: University of Helsinki, Division of Atmospheric Sciences and Geophysics (Department of Physics) (-2009)
University of Helsinki, Division of Atmospheric Sciences and Geophysics (Department of Physics) (-2009)
University of Helsinki, Finnish Meteorological Institute
University of Helsinki, Division of Atmospheric Sciences and Geophysics (Department of Physics) (-2009)
Date: 2009
Language: eng
Number of pages: 20
Belongs to series: Atmospheric Chemistry and Physics
ISSN: 1680-7316
DOI: https://doi.org/10.5194/acp-9-1747-2009
URI: http://hdl.handle.net/10138/314645
Abstract: The global aerosol-climate model ECHAM5-HAM was modified to improve the representation of new particle formation in the boundary layer. Activation-type nucleation mechanism was introduced to produce observed nucleation rates in the lower troposphere. A simple and computationally efficient model for biogenic secondary organic aerosol (BSOA) formation was implemented. Here we study the sensitivity of the aerosol and cloud droplet number concentrations (CDNC) to these additions. Activation-type nucleation significantly increases aerosol number concentrations in the boundary layer. Increased particle number concentrations have a significant effect also on cloud droplet number concentrations and therefore on cloud properties. We performed calculations with activation nucleation coefficient values of 2 x 10(-7) s(-1), 2 x 10(-6) s(-1) and 2 x 10(-5) s(-1) to evaluate the sensitivity to this parameter. For BSOA we have used yields of 0.025, 0.07 and 0.15 to estimate the amount of monoterpene oxidation products available for condensation. The hybrid BSOA formation scheme induces large regional changes to size distribution of organic carbon, and therefore affects particle optical properties and cloud droplet number concentrations locally. Although activation-type nucleation improves modeled aerosol number concentrations in the boundary layer, the use of a global activation coefficient generally leads to overestimation of aerosol number. Overestimation can also arise from underestimation of primary emissions.
Subject: 114 Physical sciences
Rights:


Files in this item

Total number of downloads: Loading...

Files Size Format View
acp_9_1747_2009.pdf 1.885Mb PDF View/Open

This item appears in the following Collection(s)

Show full item record