G01_P06

Characterization of Carbonaceous Components and Fossil and Non-Fossil Carbon Contents in Fine Aerosols in the Eastern Mediterranean Troposphere

Pavuluri C^1,2, Mihalopoulos N³, Uchida M⁴, Mantoku K⁴, Fu P^1,2, Kawamura K^1,5

¹Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan, ²Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin, China, ³ECPL, Department of Chemistry, University of Crete, Heraklion, Greece, ⁴AMS Facility (NIES-TERRA), National Institute for Environmental Studies, Tsukuba, Japan, ⁵Chubu Institute for Advanced Studies, Chubu University, Kasugai, Japan

Atmospheric fine (PM₁) aerosols are mainly produced by secondary processes and contain a major fraction of organic compounds, which have serious impacts on the Earth’s climate system directly by scattering and absorbing solar radiation and indirectly by acting as cloud condensation nuclei. They also cause adverse effects on human health and play an important role in atmospheric chemistry. It is well recognized that summertime ozone is enhanced in the Mediterranean troposphere and the aerosol radiative forcing is among the highest in the world over this region in summer. Although carbonaceous components have been studied well, their origins and atmospheric processing are not yet fully understood in the Mediterranean. We collected PM₁ samples at a remote marine background site, the Finokalia research station, in the Eastern Mediterranean troposphere on a weekly basis for two consecutive days each during a one-year period: October 2009 to October 2010. We measured the carbonaceous components: elemental carbon (EC) organic carbon (OC) and water-soluble OC (WSOC) and stable carbon (δ¹³C) and radiocarbon (Δ¹⁴C), a unique tracer for distinct fossil and non-fossil carbon, isotope ratios of total carbon (TC) in the PM1.0. Here we report (i) the characteristics of carbonaceous components and (ii) percent of modern carbon (pMC) in TC. Based on the results obtained together with their comparison with molecular marker species, we explore the origins and the extent of secondary formation of carbonaceous aerosols as well as their seasonality in the Eastern Mediterranean.