Volume concentrations of secondary organic aerosol (SOA) are measured in 139 steady-state, single precursor hydrocarbon oxidation experiments after passing through a temperature controlled inlet. The response to change in temperature is well predicted through a feedforward Artificial Neural Network. The most parsimonious model, as indicated by Akaike’s Information Criterion, Corrected (AIC,C), utilizes 11 input variables, a single hidden layer of 4 tanh activation function nodes, and a single linear output function. This model predicts thermal behavior of single precursor aerosols to less than ± 5%, which is within the measurement uncertainty, while limiting the problem of overfitting. Prediction of thermal behavior of SOA can be achieved by a concise number of descriptors of the precursor hydrocarbon including the number of internal and external double bonds, number of methyl- and ethyl- functional groups, molecular weight, number of ring structures, in addition to the volume of SOA formed, and an indicator of which of four oxidant precursors was used to initiate reactions (NOx photo-oxidation, photolysis of H2O2, ozonolysis, or thermal decomposition of N2O5). Additional input variables, such as, chamber volumetric residence time, relative humidity, initial concentration of oxides of nitrogen, reacted hydrocarbon concentration, and further descriptors of the precursor hydrocarbon, including carbon number, number of oxygen atoms, and number of aromatic ring structures, lead to over fit models, and are unnecessary for an efficient, accurate predictive model of thermal behavior of SOA. This work indicates that predictive statistical modeling methods may be complementary to descriptive techniques for use in parameterization of air quality models. This dataset is associated with the following publication: Offenberg, J., M. Lewandowski, T. Kleindienst, K. Docherty, J. Krug, T. Riedel, D. Olson, and M. Jaoui. Predicting Thermal Behavior of Secondary Organic Aerosols. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, USA, 51(17): 9911-9919, (2017).

The relationship between the oxidation state and relative volatility of secondary organic aerosol (SOA) from the oxidation of a wide range of hydrocarbons is investigated using a fast-stepping, scanning thermodenuder interfaced with a high resolution time-of-flight aerosol mass spectrometer (AMS). SOA oxidation state varied widely across the investigated range of parent hydrocarbons but was relatively stable for replicate experiments using a single hydrocarbon precursor. On average, unit mass resolution indicators of SOA oxidation (e.g., AMS f43 and f44) are consistent with previously reported values. Linear regression of H:C vs O:C obtained from parameterization of f43 and f44 and elemental analysis of high resolution spectra in Van Krevelen space both yield a slope of ~0.5 across different SOA types. A similar slope was obtained for a distinct subset of toluene/NOx reactions in which the integrated oxidant exposure was varied to alter oxidation. The relative volatility of different SOA types displays similar variability and is strongly correlated with SOA oxidation state (OSC). On average, relatively low oxidation and volatility were observed for aliphatic alkene (including terpenes) and n-alkane SOA while the opposite is true for mono- and polycyclic aromatic hydrocarbon SOA. Effective enthalpy for total chamber aerosol obtained from volatility differential mobility analysis is also highly correlated with OSC indicating a primary role for oxidation levels in determining the volatility of chamber SOA. Effective enthalpies for chamber SOA are substantially lower than those of neat organic standards but are on the order of those obtained for partially oligomerized glyoxal and methyl glyoxal. This dataset is associated with the following publication: Docherty, K., E. Corse, M. Jaoui, J. Offenberg, T. Kleindienst, J. Krug, T. Riedel, and M. Lewandowski. Trends in the oxidation and relative volatility of chamber-generated secondary organic aerosol. AEROSOL SCIENCE AND TECHNOLOGY. Taylor & Francis, Inc., Philadelphia, PA, USA, 52(9): 992-1004, (2018).

The relationship between the oxidation state and relative volatility of secondary organic aerosol (SOA) from the oxidation of a wide range of hydrocarbons is investigated using a fast-stepping, scanning thermodenuder interfaced with a high resolution time-of-flight aerosol mass spectrometer (AMS). SOA oxidation state varied widely across the investigated range of parent hydrocarbons but was relatively stable for replicate experiments using a single hydrocarbon precursor. On average, unit mass resolution indicators of SOA oxidation (e.g., AMS f43 and f44) are consistent with previously reported values. Linear regression of H:C vs O:C obtained from parameterization of f43 and f44 and elemental analysis of high resolution spectra in Van Krevelen space both yield a slope of ~0.5 across different SOA types. A similar slope was obtained for a distinct subset of toluene/NOx reactions in which the integrated oxidant exposure was varied to alter oxidation. The relative volatility of different SOA types displays similar variability and is strongly correlated with SOA oxidation state (OSC). On average, relatively low oxidation and volatility were observed for aliphatic alkene (including terpenes) and n-alkane SOA while the opposite is true for mono- and polycyclic aromatic hydrocarbon SOA. Effective enthalpy for total chamber aerosol obtained from volatility differential mobility analysis is also highly correlated with OSC indicating a primary role for oxidation levels in determining the volatility of chamber SOA. Effective enthalpies for chamber SOA are substantially lower than those of neat organic standards but are on the order of those obtained for partially oligomerized glyoxal and methyl glyoxal. This dataset is associated with the following publication: Docherty, K., E. Corse, M. Jaoui, J. Offenberg, T. Kleindienst, J. Krug, T. Riedel, and M. Lewandowski. Trends in the oxidation and relative volatility of chamber-generated secondary organic aerosol. AEROSOL SCIENCE AND TECHNOLOGY. Taylor & Francis, Inc., Philadelphia, PA, USA, 52(9): 992-1004, (2018).

The volatile nature of biomass burning organics may complicate the evolution of organics in laboratory smog-chamber experiments and in ambient plumes. We simulate the evolution of organic mass (including gas and particles) in the chamber experiments using the TwO-Moment Aerosol Sectional (TOMAS) microphysics model combined with a secondary organic aerosol (SOA) production matrix. We estimate the effect of vapor wall loss by turning off the vapor wall loss, and also added Gaussian dispersion to our aerosol-microphysical model to SOA formation under different ambient-plume conditions. A detailed description of model setup and results can be found in Bian et al. 2017. The data publication here contains simulation datasets generated using the TOMAS microphysics model combined with a secondary organic aerosol (SOA) production matrix. Datasets are organized according to the figures in Bian et al. 2017 and include 1) chemistry-only simulation data; 2) data generated using the TOMAS model combined with particle and vapor wall-loss algorithms and a SOA production matrix with varying parameters; and 3) simulation data generated using the TOMAS model assuming the plume volume follows the Gaussian dispersion. Each ASCII dataset contains the time series of individual vapors and particles that were distributed in 36 size bins from 3 nanometers to 10 micrometers.

This is the data used to generate the figures published in the journal article titled, "Light Absorption of Secondary Organic Aerosol: Composition and Contribution of Nitro-aromatic Compounds". This dataset is associated with the following publication: Xie, M., X. Chen, M. Hays, M. Lewandowski, J. Offenberg, T. Kleindienst, and A. Holder. Light absorption of secondary organic aerosol: Composition and contribution of nitro-aromatic compounds. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, USA, 51(20): 11607-11616, (2017).

This is the data used to generate the figures published in the journal article titled, "Light Absorption of Secondary Organic Aerosol: Composition and Contribution of Nitro-aromatic Compounds". This dataset is associated with the following publication: Xie, M., X. Chen, M. Hays, M. Lewandowski, J. Offenberg, T. Kleindienst, and A. Holder. Light absorption of secondary organic aerosol: Composition and contribution of nitro-aromatic compounds. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, USA, 51(20): 11607-11616, (2017).

Data contains CMAQ code, VCPy code, CMAQ input files, and output files used in the work of Pennington et al.

Data contains CMAQ code, VCPy code, CMAQ input files, and output files used in the work of Pennington et al.

VCPy predicts organic emission from volatile chemical products. Data here includes year 2017 emissions by sub product use category (sub PUC) and total for the United States. In addition, the VCPy model code is linked.

VCPy predicts organic emission from volatile chemical products. Data here includes year 2017 emissions by sub product use category (sub PUC) and total for the United States. In addition, the VCPy model code is linked.