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The present paper reviews existing knowledge with regard to Organic Aerosol (OA) of importance for global climate modelling and defines critical gaps needed to reduce the involved uncertainties. All pieces required for the representation of OA in a global climate model are sketched out with special attention to Secondary Organic Aerosol 5 (SOA): The(More)
  • G J Engelhart, A Asa-Awuku, A Nenes, S N Pandis
  • 2008
The ability of secondary organic aerosol (SOA) produced from the ozonolysis of α-pinene and monoterpene mixtures (α-pinene, β-pinene, limonene and 3-carene) to become cloud droplets was investigated. A static CCN counter and a Scanning Mobility CCN Analyser (a Scanning Mobility Particle Sizer coupled with a Continuous Flow counter) were used for the CCN(More)
  • C J Hennigan, A P Sullivan, C I Fountoukis, A Nenes, A Hecobian, O Vargas +5 others
  • 2008
Measurements of atmospheric gases and fine particle chemistry were made in the Mexico City Metropolitan Area (MCMA) at a site ∼30 km down wind of the city center. Ammonium nitrate (NH 4 NO 3) dominated the inorganic aerosol fraction and showed a distinct diurnal signature characterized by rapid morning production and a rapid mid-5 day concentration(More)
  • A Asa-Awuku, G J Engelhart, B H Lee, S N Pandis, A Nenes
  • 2008
This study investigates the droplet formation characteristics of secondary organic aerosol (SOA) formed during the ozonolysis of sesquiterpene β-caryophyllene (with and without hydroxyl radicals present). Emphasis is placed on understanding the role of semi-volatile material on Cloud Condensation Nucleus (CCN) activity and droplet 5 growth kinetics. Aging(More)
  • Luz T Padró, Daniel Tkacik, Terry Lathem, Chris J Hennigan, Amy P Sullivan, Rodney J Weber +7 others
  • 2010
[1] We present hygroscopic and cloud condensation nuclei (CCN) relevant properties of the water‐soluble fraction of Mexico City aerosol collected upon filters during the 2006 Megacity Initiative: Local and Global Research Observations (MILAGRO) campaign. Application of ‐Köhler theory to the observed CCN activity gave a fairly constant hygroscopicity(More)
Measurements of aerosol size distribution, chemical composition, and cloud condensation nuclei (CCN) concentration were performed during the Chemical Emission, Loss, Transformation, and Interactions with Canopies (CELTIC) field program at Duke Forest in North Carolina. A kinetic model of the cloud activation of ambient aerosol in the chamber of the CCN(More)
[1] An aerosol activation parameterization has been developed based on a generalized representation of aerosol size and composition within the framework of an ascending adiabatic parcel; this allows for parameterizing the activation of chemically complex aerosol with an arbitrary size distribution and mixing state. The new parameterization introduces the(More)
Cloud formation characteristics of the water-soluble organic fraction (WSOC) of secondary organic aerosol (SOA) formed from the ozonolysis of alkene hydrocarbons (terpinolene, 1-methlycycloheptene and cyclohep-tene) are studied. Based on size-resolved measurements of CCN activity (of the pure and salted WSOC samples) we estimate the average molar volume and(More)
Organic acids attract increasing attention as contributors to atmospheric acidity, secondary organic aerosol mass and aerosol hygroscopicity. Oxalic acid is globally the most abundant dicarboxylic acid, formed via chemical oxidation of gas-phase precursors in the aqueous phase of aerosols and droplets. Its lifecycle and atmospheric global distribution(More)
[1] The partitioning of total nitrate (TNO 3) and total ammonium (TNH 4) between gas and aerosol phases is studied with two thermodynamic equilibrium models, ISORROPIA and the aerosol inorganics model (AIM), and three data sets: high time resolution measurement data from the 1999 Atlanta Supersite Experiment (summer case) and the 2002 Pittsburgh Air Quality(More)