An Early Overview of the Soot Aerosol Aging Study (SAAS) Laboratory Campaign
Authors
Rahul Zaveri — Pacific Northwest National Laboratory
John E Shilling — Pacific Northwest National Laboratory
Mikhail S. Pekour — Pacific Northwest National Laboratory
Gourihar Kulkarni — Pacific Northwest National Laboratory
Duli Chand — Pacific Northwest National Laboratory
Jacqueline Mary Wilson — Pacific Northwest National Laboratory
Alla Zelenyuk-Imre — Pacific Northwest National Laboratory
Alexander Laskin — Purdue University
Shang Liu — Los Alamos National Laboratory
Allison C Aiken — Los Alamos National Laboratory
Manvendra K. Dubey — Los Alamos National Laboratory
R. Subramanian — Carnegie Mellon University
Noopur Sharma — Michigan Technological University
Swarup China — Pacific Northwest National Laboratory
Claudio Mazzoleni — Michigan Technological University
Arthur J Sedlacek — Brookhaven National Laboratory
Timothy B Onasch — Aerodyne Research
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Mary Gilles — Lawrence Berkeley National Laboratory
Ryan Moffet — Sonoma Technology Inc.
Category
Aerosol Mixing State
Description
Soot aerosol from fossil fuel combustion plays an important role in the warming of the atmosphere. However, there still exists a large uncertainty in the warming potential of the aged soot. This poster presents an early overview of the Soot Aerosol Aging Study (SAAS) laboratory campaign that was designed to characterize the evolution of soot mixing state and the associated climate-related properties as a result of aging. The experiments were conducted in the environmental chamber facility at Pacific Northwest National Laboratory over four weeks between November 11, 2013 and January 17, 2014. In one set of experiments, size-selected soot aerosol (from a small diesel engine) was injected into the environmental chamber and aged by condensing secondary organic aerosol (SOA) formed from photooxidation of -pinene. In another set, size-selected soot was allowed to coagulate with pre-existing SOA in the chamber over a period of 20 hours. The highly coagulated mixture was then further aged by condensing additional SOA. Dry as well as high relative humidity SOA condensation-only experiments were conducted to probe the effects of aqueous phase on the evolution of soot morphology and mixing state. Several state-of-the-art instruments were deployed to measure single particle, size-resolved, and bulk composition of diesel soot aerosol and the associated optical, cloud condensation nuclei (CCN), and ice nucleation (IN) properties. Aerosol samples were also collected for detailed offline analyses with scanning electron microscopy (SEM), tunneling electron microscopy (TEM), and microspectroscopy (STXM/NEXAFS). A summary of experimental strategy, instruments, and preliminary analyses will be presented.Lead PI
Rahul Zaveri — Pacific Northwest National Laboratory