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The application of mass spectrometric techniques to the real-time measurement and characterization of aerosols represents a significant advance in the field of atmospheric science. This review focuses on the aerosol mass spectrometer (AMS), an instrument designed and developed at Aerodyne Research, Inc. (ARI) that is the most widely used thermal(More)
Composition, shape factor, size, and fractal dimension of soot aerosol particles generated in a propane/O 2 flame were determined as a function of the fuel equivalence ratio (φ). Soot particles were first size-selected by a differential mobility analyzer (DMA) and then analyzed by an Aerodyne aerosol mass spectrometer (AMS). The DMA provides particles of(More)
Organic aerosol (OA) particles affect climate forcing and human health, but their sources and evolution remain poorly characterized. We present a unifying model framework describing the atmospheric evolution of OA that is constrained by high-time-resolution measurements of its composition, volatility, and oxidation state. OA and OA precursor gases evolve by(More)
Motivated by the need to develop instrumental techniques for characterizing organic aerosol aging, we report on the performance of the Toronto Photo-Oxidation Tube (TPOT) and Potential Aerosol Mass (PAM) flow tube reactors under a variety of experimental conditions. The PAM system was designed with lower surface-area-to-volume (SA/V) ratio to minimize wall(More)
[1] Laboratory experiments investigated the relationship between oxidation level and hygroscopic properties of secondary organic aerosol (SOA) particles generated via OH radical oxidation in an aerosol flow reactor. The hygroscopic growth factor at 90% RH (HGF 90%), the CCN activity (ORG,CCN) and the level of oxidation (atomic O:C ratio) of the SOA(More)
The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Abstract. Elemental compositions of organic aerosol (OA) particles provide useful constraints on OA sources, chemical evolution, and effects. The Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) is widely used(More)
We report the first measurements of particulate lead (Pb) from Aerodyne Aerosol Mass Spectrometers, which were deployed in and around Mexico City during the Megacity Initiative: Local and Global Research Observations (MILAGRO)/Mexico City Metropolitan Area 2006 (MCMA-2006) field campaigns. The high resolution mass spectrometer of one of the AMS instruments(More)
We detect a dip of 20-30% in the surface brightness and number counts of NVSS sources smoothed to a few degrees at the location of the WMAP cold spot. The dip has structure on scales of ∼ 1 • to 10 •. We suggest that the dip in extra-galactic brightness and number counts and the WMAP cold spot are physically related, i.e., that the coincidence is neither a(More)