Change search
ReferencesLink to record
Permanent link

Direct link
Airborne in situ characterization of dry aerosol optical properties in a multisource influenced marine region
Stockholm University, Faculty of Science, Department of Meteorology.
2005 In: Tellus B, ISSN 0280-6509, Vol. 57, no 3, 247-260 p.Article in journal (Refereed) Published
Place, publisher, year, edition, pages
2005. Vol. 57, no 3, 247-260 p.
URN: urn:nbn:se:su:diva-24720OAI: diva2:198189
Part of urn:nbn:se:su:diva-740Available from: 2005-11-21 Created: 2005-11-21Bibliographically approved
In thesis
1. Regional studies of the optical, chemical and microphysical properties of atmospheric aerosols: Radiative impacts and cloud formation
Open this publication in new window or tab >>Regional studies of the optical, chemical and microphysical properties of atmospheric aerosols: Radiative impacts and cloud formation
2005 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Atmospheric particles are ubiquitous in the Earth’s atmosphere and have potential to influence atmospheric chemistry, visibility, global climate and human health, particularly downwind from major pollution sources. The main objective of this thesis was to investigate questions pertaining to the microphysical, chemical and optical properties of aerosol particles by using in situ data collected during four experiments carried out in different regions of the Northern Hemisphere.

The first two papers of this thesis reports on airborne measurements of the aerosol optical properties performed over the North Atlantic and the Los Angeles basin. Airmasses from Europe and North Africa are usually advected in over the North Atlantic, alternating with the background marine conditions. The results showed that the aerosols are not uniformly distributed in the area and variability in the aerosol fields occurs at sub-synoptic scales. It was also observed that the single scattering coefficient varied as the polluted plumes aged, suggesting a relationship between this quantity and transport time. The measurements performed around the Los Angeles basin showed that the area’s complex topography and local meteorological circulations exert a strong control on the distribution of the aerosol in the basin. Large spatio-temporal gradients in the aerosol optical properties were observed along a transect flown from the shore towards the mountains. Profiles flown over sites located on the mountains displayed a stratified configuration with elevated aerosol layers.

Airborne data of residual particles collected in orographic wave clouds over Scandinavia were analyzed using a single particle analysis technique. Mineral dust, organic aerosols and sea salt were the main group of particles identified. Residuals composed predominantly of mineral dust were found in glaciated clouds while organic residuals were found in liquid clouds. The results suggest that organic material may inhibit freezing and have considerable influence on supercooled clouds that form through heterogeneous pathways.

The partitioning of the aerosol particles between cloud droplets and interstitial air has been addressed in terms of their microphysical properties using data obtained at a mountain-top site in Sweden during a stratocumulus event. The results showed that the scavenging efficiency varied during the cloud event, and Aitken-mode particles were also efficiently scavenged in addition to accumulation-mode particles. It is hypothesized that alterations of the aerosol chemical composition occurred during the measurement period, modifying the hygroscopic nature of the particles and decreasing their activation diameter.

Place, publisher, year, edition, pages
Stockholm: Meteorologiska institutionen (MISU), 2005. 174 p.
atmospheric aerosols, particles, optical properties, cloud, ice crystals, chemical composition
National Category
Meteorology and Atmospheric Sciences
urn:nbn:se:su:diva-740 (URN)91-7155-141-7 (ISBN)
Public defence
2005-12-16, William-Olssonsalen, Geovetenskapens hus, Svante Arrhenius väg 8 A, Stockholm, 10:00
Available from: 2005-11-21 Created: 2005-11-21Bibliographically approved

Open Access in DiVA

No full text

By organisation
Department of Meteorology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 22 hits
ReferencesLink to record
Permanent link

Direct link