REGENTS OF THE UNIVERSITY OF CALIFORNIA, THE
The objective of this project is to identify major sources and physico-chemical processes that produce secondary organic aerosol (SOA) in a polluted urban atmosphere. The principal investigators will investigate Los Angeles SOA through participation in the Research at the Nexus of Air Quality and Climate Change (CalNex) 2010 experiment. This project will support the deployment and application of advanced instrumentation and data analysis techniques for chemical characterization of organic trace gases and fine particle organic aerosol in central Los Angeles during a 6-week period in June and July 2010. Highly detailed in-situ chemical speciation of organic aerosol by automated Thermal-desorption Aerosol Gas Chromatograph, and radiocarbon analysis of elemental, organic, water-insoluble, and water-soluble carbon collected on integrated filters will provide unique data to identify sources of SOA precursors. Processes and factors affecting gas/particle partitioning will be explored with instruments capable of measuring both gas- and particle-phase components. A combination of Particle Into Liquid Sampler, Mist Chamber and Total Organic Carbon (TOC) analyzer (PILS/MC/TOC) will comprehensively measure water-soluble gas/particle partitioning. This will be augmented by chemically specific measurements of gas/particle organic acids (PILS/MC/Ion Chromatography), and volatile and semi-volatile organic compounds via high-resolution Proton-Transfer Reaction Time of Flight Mass Spectrometer equipped with a thermal-desorption inlet. These instruments will add to the measurement capabilities at the CalNex central Los Angeles ground site and provide a unique data set for addressing the scientific objective through in-depth data analysis following the experiment. This project will build upon the strong collaboration started in the Study of Organic Aerosols in Riverside (SOAR-2005) to continue investigation of SOA sources and transformation in the urban environment.
Development of analytical methods and measurement capabilities, the operation of a wide range of instruments over extended periods, and analysis of the large data sets will require a range in technical ability and make the project well suited for research teams of undergraduate and graduate students, and post-doctoral researchers, and promote interaction with researchers from diverse backgrounds and disciplinary areas. Knowledge and experience gained by these co-workers will be valuable to both the atmospheric chemistry and local air quality communities.