The chemical and microphysical properties of secondary organic aerosols from Holm Oak emissions 1Department of Environmental Sciences, Weizmann Institute, Rehovot, 76100, Israel
2Institut für Chemie und Dynamik der Geosphäre (ICG), Forschungszentrum Jülich GmbH, Jülich, Germany
Received: 30 Jan 2010 – Published in Atmos. Chem. Phys. Discuss.: 17 Feb 2010Abstract. The Mediterranean region is expected to experience substantial climatic
change in the next 50 years. But, possible effects of climate change on
biogenic volatile organic compound (VOC) emissions as well as on the
formation of secondary organic aerosols (SOA) produced from these VOC are
yet unexplored. To address such issues, the effects of temperature on the
VOC emissions of Mediterranean Holm Oak and small Mediterranean stand of
Wild Pistacio, Aleppo Pine, and Palestine Oak have been studied in the
Jülich plant aerosol atmosphere chamber. For Holm Oak the optical and
microphysical properties of the resulting SOA were investigated.
Revised: 12 Jul 2010 – Accepted: 23 Jul 2010 – Published: 06 Aug 2010
Monoterpenes dominated the VOC emissions from Holm Oak (97.5%) and
Mediterranean stand (97%). Higher temperatures enhanced the overall VOC
emission but with different ratios of the emitted species. The amount of SOA
increased linearly with the emission strength with a fractional mass yield
of 6.0±0.6%, independent of the detailed emission pattern. The
investigated particles were highly scattering with no absorption abilities.
Their average hygroscopic growth factor of 1.13±0.03 at 90% RH with
a critical diameter of droplet activation was 100±4 nm at a
supersaturation of 0.4%. All microphysical properties did not depend on
the detailed emission pattern, in accordance with an invariant O/C ratio
(0.57(+0.03/−0.1)) of the SOA observed by high resolution aerosol mass
The increase of Holm oak emissions with temperature (≈20% per
degree) was stronger than e.g. for Boreal tree species (≈10%
per degree). The SOA yield for Mediterranean trees determined here is
similar as for Boreal trees. Increasing mean temperature in Mediterranean
areas could thus have a stronger impact on BVOC emissions and SOA formation
than in areas with Boreal forests.
Citation: Lang-Yona, N., Rudich, Y., Mentel, Th. F., Bohne, A., Buchholz, A., Kiendler-Scharr, A., Kleist, E., Spindler, C., Tillmann, R., and Wildt, J.: The chemical and microphysical properties of secondary organic aerosols from Holm Oak emissions, Atmos. Chem. Phys., 10, 7253-7265, doi:10.5194/acp-10-7253-2010, 2010.