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Fine-particle Water and Ph in the Southeastern United States : Volume 15, Issue 9 (11/05/2015)

By Guo, H.

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Book Id: WPLBN0003988825
Format Type: PDF Article :
File Size: Pages 18
Reproduction Date: 2015

Title: Fine-particle Water and Ph in the Southeastern United States : Volume 15, Issue 9 (11/05/2015)  
Author: Guo, H.
Volume: Vol. 15, Issue 9
Language: English
Subject: Science, Atmospheric, Chemistry
Collections: Periodicals: Journal and Magazine Collection (Contemporary), Copernicus GmbH
Publication Date:
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications


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Xu, L., Hite Jr, J. R., Bougiatioti, A., Bergin, M. H., Ng, N. L., Capps, S. L.,...Nenes, A. (2015). Fine-particle Water and Ph in the Southeastern United States : Volume 15, Issue 9 (11/05/2015). Retrieved from

Description: School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA. Particle water and pH are predicted using meteorological observations (relative humidity (RH), temperature (T)), gas/particle composition, and thermodynamic modeling (ISORROPIA-II). A comprehensive uncertainty analysis is included, and the model is validated. We investigate mass concentrations of particle water and related particle pH for ambient fine-mode aerosols sampled in a relatively remote Alabama forest during the Southern Oxidant and Aerosol Study (SOAS) in summer and at various sites in the southeastern US during different seasons, as part of the Southeastern Center for Air Pollution and Epidemiology (SCAPE) study. Particle water and pH are closely linked; pH is a measure of the particle H+ aqueous concentration and depends on both the presence of ions and amount of particle liquid water. Levels of particle water, in turn, are determined through water uptake by both the ionic species and organic compounds. Thermodynamic calculations based on measured ion concentrations can predict both pH and liquid water but may be biased since contributions of organic species to liquid water are not considered. In this study, contributions of both the inorganic and organic fractions to aerosol liquid water were considered, and predictions were in good agreement with measured liquid water based on differences in ambient and dry light scattering coefficients (prediction vs. measurement: slope = 0.91, intercept = 0.5 μg m−3, R2 = 0.75). ISORROPIA-II predictions were confirmed by good agreement between predicted and measured ammonia concentrations (slope = 1.07, intercept = −0.12 μg m−3, R2 = 0.76). Based on this study, organic species on average contributed 35% to the total water, with a substantially higher contribution (50%) at night. However, not including contributions of organic water had a minor effect on pH (changes pH by 0.15 to 0.23 units), suggesting that predicted pH without consideration of organic water could be sufficient for the purposes of aqueous secondary organic aerosol (SOA) chemistry. The mean pH predicted in the Alabama forest (SOAS) was 0.94 ± 0.59 (median 0.93). pH diurnal trends followed liquid water and were driven mainly by variability in RH; during SOAS nighttime pH was near 1.5, while daytime pH was near 0.5. pH ranged from 0.5 to 2 in summer and 1 to 3 in the winter at other sites. The systematically low pH levels in the southeast may have important ramifications, such as significantly influencing acid-catalyzed reactions, gas–aerosol partitioning, and mobilization of redox metals and minerals. Particle ion balances or molar ratios, often used to infer pH, do not consider the dissociation state of individual ions or particle liquid water levels and do not correlate with particle pH.

Fine-particle water and pH in the southeastern United States

Bacarella, A. L., Grunwald, E., Marshall, H. P., and Purlee, E. L.: The Potentiometric Measurement of Acid Dissociation Constants and pH in the System Methanol-Water. pKa Values for Carboxylic Acids and Anilinium Ions, J. Org. Chem., 20, 747–762, doi:10.1021/Jo01124a007, 1955.; Bertram, A. K., Martin, S. T., Hanna, S. J., Smith, M. L., Bodsworth, A., Chen, Q., Kuwata, M., Liu, A., You, Y., and Zorn, S. R.: Predicting the relative humidities of liquid-liquid phase separation, efflorescence, and deliquescence of mixed particles of ammonium sulfate, organic material, and water using the organic-to-sulfate mass ratio of the particle and the oxygen-to-carbon elemental ratio of the organic component, Atmos. Chem. Phys., 11, 10995–11006, doi:10.5194/acp-11-10995-2011, 2011.; Canagaratna, M. R., Jayne, J. T., Jimenez, J. L., Allan, J. D., Alfarra, M. R., Zhang, Q., Onasch, T. B., Drewnick, F., Coe, H., Middlebrook, A., Delia, A., Williams, L. R., Trimborn, A. M., Northway, M. J., DeCarlo, P. F., Kolb, C. E., Davidovits, P., and Worsnop, D. R.: Chemical and microphysical characterization of ambient aerosols with the aerodyne aerosol mass spectrometer, Mass Spectrom. Rev., 26, 185–222, doi:10.1002/mas.20115, 2007.; Capps, S. L., Henze, D. K., Hakami, A., Russell, A. G., and Nenes, A.: ANISORROPIA: the adjoint of the aerosol thermodynamic model ISORROPIA, Atmos. Chem. Phys., 12, 527–543, doi:10.5194/acp-12-527-2012, 2012.; Carlton, A. G. and Turpin, B. J.: Particle partitioning potential of organic compounds is highest in the Eastern US and driven by anthropogenic water, Atmos. Chem. Phys., 13, 10203–10214, doi:10.5194/acp-13-10203-2013, 2013.; Carrico, C. M., Rood, M. J., and Ogren, J. A.: Aerosol light scattering properties at Cape Grim, Tasmania, during the First Aerosol Characterization Experiment (ACE 1), J. Geophys. Res., 103, 16565, doi:10.1029/98jd00685, 1998.; Carrico, C. M., Rood, M. J., Ogren, J. A., Neususs, C., Wiedensohler, A., and Heintzenberg, J.: Aerosol optical properties at Sagres, Portugal during ACE-2, Tellus B, 52, 694–715, doi:10.1034/j.1600-0889.2000.00049.x, 2000.; Cerully, K. M., Bougiatioti, A., Hite Jr., J. R., Guo, H., Xu, L., Ng, N. L., Weber, R., and Nenes, A.: On the link between hygroscopicity, volatility, and oxidation state of ambient and water-soluble aerosol in the Southeastern United States, Atmos. Chem. Phys. Discuss., 14, 30835–30877, doi:10.5194/acpd-14-30835-2014, 2014.; Clegg, S. L., Brimblecombe, P., and Wexler, A. S.: Thermodynamic model of the system H+-NH4+-SO42--NO3--H2O at tropospheric temperatures, J. Phys. Chem. A, 102, 2137–2154, doi:10.1021/Jp973042r, 1998.; Czoschke, N. M. and Jang, M.: Acidity effects on the formation of Α-pinene ozone SOA in the presence of inorganic seed, Atmos. Environ., 40, 4370–4380, doi:10.1016/j.atmosenv.2006.03.030, 2006.; DeCarlo, P. F., Kimmel, J. R., Trimborn, A., Northway, M. J., Jayne, J. T., Aiken, A. C., Gonin, M., Fuhrer, K., Horvath, T., Docherty, K. S., Worsnop, D. R., and Jimenez, J. L.: Field-deployable, high-resolution, time-of-flight aerosol mass spectrometer, Anal


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