Download Abstracts Here - IGAC Project

List of Abstracts 222double bond in hydroxylated unsaturated fatty acid residues present in algal biomass at the sea-air interface.To our knowledge, the formation of organosulfates from oxidation of marine biomass is a novel aerosolformation process. MSA and the organosulfates only explain a fraction of the water-soluble organic carbon(on average, 20 ± 8 % and between 1 and 5%, respectively). However, they both could contribute to thecloud condensation nuclei effects that have been observed above algal bloom regions and have beenattributed to SOA from biogenic emissions. No evidence was found for SOA from the photooxidation ofisoprene.Transformation 1.3 ID:4240 14:45Organic Aerosol: from oxidation to optical depthColette Heald 1 , Kateryna Lapina 1 , David Ridley 1 , Jesse Kroll 2 , Jose Jimenez 3 , Ken Docherty 3 , PeterDecarlo 4 , Allison Aiken 5 , Qi Chen 6 , Scot Martin 6 , Delphine Farmer 3 , Paulo Artaxo 71 Colorado State University2 MIT3 University of Colorado4 PSI5 ETH6 Harvard University7 University of Sao PauloContact: heald@atmos.colostate.eduOrganic aerosol in the atmosphere consists of a multitude of organic species which are the products of avariety of chemical reactions. Recent years have shown that the complexity of formation processes andatmospheric aging is not well captured by simplified model descriptions and thus uncertainties on the globalbudgets of OA remain large. In an effort to reduce some of the uncertainties on these budgets fromobservational constraints, we will present here two investigations: (1) Exploring observed bulk organicaerosol composition and how changes associated with physical and chemical aging processes can be simplydescribed using a Van Krevelen diagram. (2) Investigating remote observations of aerosol optical depth andwhether these measurements provide a constraint on the organic aerosol budget simulated in global models.Transformation 1.4 ID:4128 15:00Evolution of organics in the atmosphere: Dependence on technology of diesel vehicles and woodburning facilityAndre Prevot, Roberto Chirico, Maarten Heringa, Peter Decarlo, Urs BaltenspergerPaul Scherrer InstitutContact: andre.prevot@psi.chRecently it was shown that organics are an important fraction of PM1 in the whole Northern hemisphere(Jimenez et al., 2009). Most of the organics are found nearly everywhere as oxygenated organic aerosol andis interpreted mostly as secondary organic aerosol. Robinson et al. (2007) showed recently that semi-volatileor intermediate volatile organics are crucial for the formation of secondary organic aerosols. We show nowin smogchamber experiments that the amount of primary and! secondary organic aerosol strongly depend ontechnology of the diesel vehicle or also on the wood burning technology when wood is used for heating. Weshow that a diesel oxidation catalyst strongly reduces the formation of secondary organic aerosols. Pelletburners are shown to be much cleaner than a log-wood stove not only concerning their primary carbonaceousemissions but concerning their secondary organic aerosol formation potential.Jimenez, J.L. et al. (2009) Evolution of Organic Aerosols in the Atmosphere, Science, 326, 1525-1529.iCACGP-IGAC 2010 14 July, 2010