Rinne, J; Taipale, R; Markkanen, T; Ruuskanen, TM; Hellén, H; Kajos, MK; Vesala, T; Kulmala, M: Hydrocarbon fluxes above a Scots pine forest canopy: Measurements and modeling, Atmospheric Chemistry and Physics, Discussion, 7, 2357-2388 (2007)
We measured the fluxes of several hydrocarbon species above a Scots pine (Pinus sylvestris) stand using disjunct eddy covariance technique with proton transfer reac- reaction – mass spectrometry. The measurements were conducted during four days in July tion at SMEAR II research station in Hyyti ¨ al ¨ a, Finland. Compounds which showed signif- 5 icant emission fluxes were methanol, acetaldehyde, acetone, and monoterpenes. A stochastic Lagrangian transport model with simple chemical degradation was applied to assess the sensitivity of the above canopy fluxes to chemistry. According to the model, the chemical degradation had a minor eect on the fluxes measured in this study but has a major eect on the vertical flux profiles of more reactive compounds, 10 such as sesquiterpenes. The monoterpene fluxes followed the traditional exponen- exponential temperature dependent emission algorithm but were considerably higher than the tial fluxes measured before at the same site. The normalized emission potential (30C) was 2.5 µg g−1 h−1 obtained using the temperature dependence coecient of 0.09C−1.

last modified 2007-07-20