Seasonal variability of monoterpene emission factors for a ponderosa pine plantation in California R. Holzinger1,*, A. Lee1, M. McKay1, and A. H. Goldstein1 1University of California at Berkeley, Dept Environm Sci Policy & Management, Berkeley, CA 94720 USA *now at: Institute for Marine and Atmospheric Research Utrecht, Utrecht University, Utrecht, The Netherlands
Abstract. Monoterpene fluxes have been measured over an 11 month period from June 2003
to April 2004. During all seasons ambient air temperature was the
environmental factor most closely related to the measured emission rates.
The monoterpene flux was modeled using a basal emission rate multiplied by
an exponential function of a temperature, following the typical practice for
modelling temperature dependent biogenic emissions. A basal emission of 1.0 μmol h−1 m−2
(at 30°C, based on leaf area) and a
temperature dependence (β) of 0.12°C−1 reproduced measured
summer emissions well but underestimated spring and winter measured
emissions by 60–130%. The total annual monoterpene emission may be
underestimated by ~50% when using a model optimized to reproduce
monoterpene emissions in summer. The long term dataset also reveals an
indirect connection between non-stomatal ozone and monoterpene flux beyond
the dependence on temperature that has been shown for both fluxes.
Citation: Holzinger, R., Lee, A., McKay, M., and Goldstein, A. H.: Seasonal variability of monoterpene emission factors for a ponderosa pine plantation in California, Atmos. Chem. Phys., 6, 1267-1274, doi:10.5194/acp-6-1267-2006, 2006.