Donald Dabdub

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[1] This series of three papers addresses the representation of secondary organic aerosol (SOA) in atmospheric models. SOA forms when gas-phase organic species undergo oxidation, leading to products of sufficiently low vapor pressure that can partition between the gas and aerosol phases. The present paper, part 1, is devoted to the development of a(More)
The formation of secondary organic aerosol (SOA) results from the absorption of gasphase organic oxidation products by airborne aerosol. Historically, modeling the formation of SOA has relied on relatively crude estimates of the capability of given parent hydrocarbons to form SOA. In more recent work, surrogate organic oxidation products have been separated(More)
[1] The California Institute of Technology (CIT) three-dimensional urban/regional atmospheric model is used to perform comprehensive gasand aerosol-phase simulations of the 8 September 1993 smog episode in the South Coast Air Basin of California (SoCAB) using the atmospheric chemical mechanism of part 1 [Griffin et al., 2002] and the thermodynamic module of(More)
Photochemical mechanisms are a critical module of air quality models. In the past 20 years, several mechanisms have been developed to study the chemistry of the troposphere. This work compares several state-of-the-science photochemical mechanisms (including LCC, CBM-IV, RADM2, EMEP, RACM, SAPRC99, and CACM which have never been compared before in other(More)
The ability of photochemical models to predict observed coastal chlorine levels and their corresponding effect on ozone formation is explored. Current sea-spray generation functions, a comprehensive gas-phase chlorine chemistry mechanism, and several heterogeneous/multiphase chemical reactions considered key processes leading to reactive chlorine formation(More)
[1] This paper presents a global uncertainty and sensitivity analysis of the Caltech Atmospheric Chemistry Mechanism (CACM). Emphasis is placed on the characterization of uncertainties for product concentrations that constitute secondary organic aerosol (SOA) in CACM. The sensitivity analysis of the chemical mechanism is performed using Monte Carlo(More)
The reaction of ozone with aqueous sodium bromide particles is investigated with a combination of aerosol chamber experiments, kinetics modeling, and molecular dynamics simulations. The molecular bromine production in the chamber experiments is approximately an order of magnitude greater than that predicted by known chemistry in the gas and bulk aqueous(More)
A combination of experimental, molecular dynamics, and kinetics modeling studies is applied to a system of concentrated aqueous sodium chloride particles suspended in air at room temperature with ozone, irradiated at 254 nanometers to generate hydroxyl radicals. Measurements of the observed gaseous molecular chlorine product are explainable only if(More)
[1] In this paper, aerosol composition and size distributions in east Asia are simulated using a comprehensive chemical transport model. Three-dimensional aerosol simulations for the TRACE-P and ACE-Asia periods are performed and used to help interpret actual observations. The regional chemical transport model, STEM-2K3, which includes the on-line(More)