Articles | Volume 12, issue 16
Atmos. Chem. Phys., 12, 7647–7687, 2012

Special issue: Carbonaceous Aerosols and Radiative Effects Study (CARES)

Atmos. Chem. Phys., 12, 7647–7687, 2012

Research article 22 Aug 2012

Research article | 22 Aug 2012

Overview of the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES)

R. A. Zaveri1, W. J. Shaw1, D. J. Cziczo2, B. Schmid1, R. A. Ferrare3, M. L. Alexander4, M. Alexandrov5, R. J. Alvarez6, W. P. Arnott7, D. B. Atkinson8, S. Baidar9, R. M. Banta6, J. C. Barnard1, J. Beranek1, L. K. Berg1, F. Brechtel10, W. A. Brewer6, J. F. Cahill11, B. Cairns12, C. D. Cappa13, D. Chand1, S. China14, J. M. Comstock1, M. K. Dubey15, R. C. Easter1, M. H. Erickson16, J. D. Fast1, C. Floerchinger17, B. A. Flowers15, E. Fortner18, J. S. Gaffney19, M. K. Gilles20, K. Gorkowski14, W. I. Gustafson1, M. Gyawali7, J. Hair3, R. M. Hardesty6, J. W. Harworth8, S. Herndon18, N. Hiranuma1, C. Hostetler3, J. M. Hubbe1, J. T. Jayne18, H. Jeong21, B. T. Jobson16, E. I. Kassianov1, L. I. Kleinman22, C. Kluzek1, B. Knighton17, K. R. Kolesar13, C. Kuang22, A. Kubátová21, A. O. Langford6, A. Laskin4, N. Laulainen1, R. D. Marchbanks6, C. Mazzoleni14, F. Mei22, R. C. Moffet23, D. Nelson1, M. D. Obland3, H. Oetjen9, T. B. Onasch18, I. Ortega9, M. Ottaviani24, M. Pekour1, K. A. Prather11, J. G. Radney8, R. R. Rogers3, S. P. Sandberg6, A. Sedlacek22, C. J. Senff6, G. Senum22, A. Setyan25, J. E. Shilling1, M. Shrivastava1, C. Song1, S. R. Springston22, R. Subramanian26, K. Suski11, J. Tomlinson1, R. Volkamer9, H. W. Wallace16, J. Wang22, A. M. Weickmann6, D. R. Worsnop18, X.-Y. Yu1, A. Zelenyuk27, and Q. Zhang25 R. A. Zaveri et al.
  • 1Atmospheric Sciences & Global Change Division, Pacific Northwest National Laboratory, Richland, WA, USA
  • 2Massachusetts Institute of Technology, Cambridge, MA, USA
  • 3NASA Langley Research Center, Hampton, VA, USA
  • 4Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, USA
  • 5Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, USA
  • 6Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, USA
  • 7University of Nevada, Reno, NV, USA
  • 8Portland State University, Portland, OR, USA
  • 9Department of Chemistry and Biochemistry, University of Colorado at Boulder, CO, USA
  • 10Brechtel Manufacturing, Inc, Hayward, CA, USA
  • 11University of California, San Diego, CA, USA
  • 12NASA Goddard Institute for Space Studies, New York, NY, USA
  • 13Department of Civil and Environmental Engineering, University of California, Davis, CA, USA
  • 14Atmospheric Science Program, Michigan Technological University, Houghton, MI, USA
  • 15Los Alamos National Laboratory, Los Alamos, NM, USA
  • 16Washington State University, Pullman, WA, USA
  • 17Montana State University, Bozeman, MT, USA
  • 18Aerodyne Research, Inc., Billerica, MA, USA
  • 19University of Arkansas, Little Rock, AR, USA
  • 20Lawrence Berkeley National Laboratory, Berkeley, CA, USA
  • 21University of North Dakota, ND, USA
  • 22Brookhaven National Laboratory, Upton, NY, USA
  • 23University of the Pacific, Stockton, CA, USA
  • 24NASA Postdoctoral Program Fellow, NASA Goddard Institute for Space Studies, New York, NY, USA
  • 25Department of Environmental Toxicology, University of California, Davis, CA, USA
  • 26Droplet Measurements Technologies, Boulder, CO, USA
  • 27Chemical and Materials Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA

Abstract. Substantial uncertainties still exist in the scientific understanding of the possible interactions between urban and natural (biogenic) emissions in the production and transformation of atmospheric aerosol and the resulting impact on climate change. The US Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program's Carbonaceous Aerosol and Radiative Effects Study (CARES) carried out in June 2010 in Central Valley, California, was a comprehensive effort designed to improve this understanding. The primary objective of the field study was to investigate the evolution of secondary organic and black carbon aerosols and their climate-related properties in the Sacramento urban plume as it was routinely transported into the forested Sierra Nevada foothills area. Urban aerosols and trace gases experienced significant physical and chemical transformations as they mixed with the reactive biogenic hydrocarbons emitted from the forest. Two heavily-instrumented ground sites – one within the Sacramento urban area and another about 40 km to the northeast in the foothills area – were set up to characterize the evolution of meteorological variables, trace gases, aerosol precursors, aerosol size, composition, and climate-related properties in freshly polluted and "aged" urban air. On selected days, the DOE G-1 aircraft was deployed to make similar measurements upwind and across the evolving Sacramento plume in the morning and again in the afternoon. The NASA B-200 aircraft, carrying remote sensing instruments, was also deployed to characterize the vertical and horizontal distribution of aerosols and aerosol optical properties within and around the plume. This overview provides: (a) the scientific background and motivation for the study, (b) the operational and logistical information pertinent to the execution of the study, (c) an overview of key observations and initial findings from the aircraft and ground-based sampling platforms, and (d) a roadmap of planned data analyses and focused modeling efforts that will facilitate the integration of new knowledge into improved representations of key aerosol processes and properties in climate models.

Final-revised paper