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The H_2SO_4-HNO_3-NH_3 System at High Humidities and in Fogs: 2. Comparison of Field Data With Thermodynamic Calculations

Jacob, Daniel J. and Waldman, Jed M. and Munger, J. William and Hoffmann, Michael R. (1986) The H_2SO_4-HNO_3-NH_3 System at High Humidities and in Fogs: 2. Comparison of Field Data With Thermodynamic Calculations. Journal of Geophysical Research D, 91 (D1). pp. 1089-1096. ISSN 0148-0227. doi:10.1029/JD091iD01p01089.

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Concentrations of HNO_3(g) and NH_3(g) determined in the field were compared to predictions from aerosol equilibrium models. The products of HNO_3(g) and NH_3(g) concentrations measured under cool and humid nonfoggy conditions agreed in magnitude with predictions from a comprehensive thermodynamic model for the atmospheric H_2SO_4-HNO_3-NH_3-H_2O system. Observed concentrations of NH_3(g) in fogs were generally consistent with those predicted at equilibrium with fog water, but important discrepancies were noted in some cases. These discrepancies may be due to fluctuations in fog water composition over the course of sample collection or to the sampling of nonfoggy pockets of air present within the fog. Detectable concentrations of HNO_3(g) (up to 23 neq m^(−3)) were often found in fogs with pH < 5 and were attributed to the sampling of nonfoggy air or to the slow rate of HNO_3(g) diffusion to fog droplets. Concentrations of HNO_3(g) in fogs with pH > 5 were below the detection limit of 4–8 neq m^(−3).

Item Type:Article
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Jacob, Daniel J.0000-0002-6373-3100
Hoffmann, Michael R.0000-0001-6495-1946
Additional Information:© 1986 American Geophysical Union. Received February 15, 1985; revised July 25, 1985; accepted July 31, 1985. A. G. Russell and G. R. Cass (California Institute of Technology) are thanked for many helpful discussions. This work was funded by the California Air Resources Board (A2-048-32).
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California Air Resources Board (CARB)A2-048-32
Issue or Number:D1
Record Number:CaltechAUTHORS:20150818-100954075
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Official Citation:Jacob, D. J., J. M. Waldman, J. W. Munger, and M. R. Hoffmann (1986), The H2SO4-HNO3-NH3 system at high humidities and in fogs: 2. Comparison of field data with thermodynamic calculations, J. Geophys. Res., 91(D1), 1089–1096, doi:10.1029/JD091iD01p01089.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:59689
Deposited By: Ruth Sustaita
Deposited On:19 Aug 2015 16:17
Last Modified:10 Nov 2021 22:23

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