Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Monoterpenes from the boreal coniferous forest: their role in atmospheric chemistry
Stockholm University, Faculty of Science, Department of Meteorology .
1992 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The goal of this work has been to increase our knowledge of the role of the monoteipenes emitted by the boreal coniferous forest in atmospheric chemical processes. To this end, measurements of air concentrations and emission rates have been made in forests of Scots pine (Pinus sylvestris) and Norwegian spruce (Picea abies) at 4 sites throughout Sweden, during the summers of 1989 and 1990. Sampling was done with Tenax absorption tubes and analysis by gas chromotography with ion trap detection. Emission experiments were done with the chamber technique.

Alpha-pinene and A’-carene were found to be the most abundant terpenes emitted by and in the air of the forests. Daytime concentrations were on the order of 0.1-0.3 ppbv total terpenes in the forest and a factor of 2-3 lower above, while nighttime concentrations could reach up to 7 ppbv on calm nights. Emission rates normalized to temperature were seen to have both a diumality with maximum at midday, and a seasonality with maxima observed in early May and October and a summer maximum in June-July. It is suggested that the maxima depend on plant-physiological processes in spring and fall and needle growth rate during the summer. Also wet vegetation was seen to emit a greater amount and different composition of terpenes than dry vegetatioa The forest floor emission rate was about 30-40% of the crown emission in the pine forest and had a seasonality similar to the crown emission. The ground emission could not be explained by sources in the litter and vegetation alone, and it is suggested that the roots of the trees are also important. An average July rate of emission of 0.6±0.5 pg(gdw h)'1 (20°Q and an annual flux of 370±180 thousand tons VOC yr'1 was determined for the boreal forest of Sweden. This flux is less than half of previous estimates, and about 80% of the emission of anthropogenic hydrocarbons in Sweden.

Model studies and a review of recent laboratory studies reported in the literature indicate that 8-40% of the oxidation products can be expected to contribute to the atmospheric aerosol. Knowledge is still too incomplete to determine an 03 production potential. A Onedimensional model of turbulent diffusion and chemistry was used to study the diurnal variations of the monoterpenes and 03. It was found that surface exchange and turbulent diffusion are the predominant factors governing the diurnal variation of the surface concentrations of these gases. The terpenes were seen to have a potential role as chemical sinks for 03 and N03 in the nighttime boundary layer, depending on the strength of the terpene emission rate and the stability of the boundary layer.

Place, publisher, year, edition, pages
Stockholm: Stockholm University, 1992. , p. 22
National Category
Meteorology and Atmospheric Sciences
Identifiers
URN: urn:nbn:se:su:diva-162696Libris ID: 7609000ISBN: 91-7146-980-X (print)OAI: oai:DiVA.org:su-162696DiVA, id: diva2:1268893
Public defence
1992-03-18, Hörsal G, Biologihusen, Frescati, Stockholm, 13:00
Note

Härtill 5 uppsatser

Available from: 2018-12-07 Created: 2018-12-07 Last updated: 2018-12-07Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

PDF (Not accessible to users outside Sweden)
By organisation
Department of Meteorology
Meteorology and Atmospheric Sciences

Search outside of DiVA

GoogleGoogle Scholar

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 12 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf