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<front>
<journal-meta>
<journal-id journal-id-type="publisher">ACP</journal-id>
<journal-title-group>
<journal-title>Atmospheric Chemistry and Physics</journal-title>
<abbrev-journal-title abbrev-type="publisher">ACP</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1680-7324</issn>
<publisher><publisher-name>Copernicus GmbH</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/acp-12-5429-2012</article-id>
<title-group>
<article-title>New representation of water activity based on a single solute specific constant to parameterize the hygroscopic growth of aerosols in atmospheric models</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Metzger</surname>
<given-names>S.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Steil</surname>
<given-names>B.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Xu</surname>
<given-names>L.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Penner</surname>
<given-names>J. E.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Lelieveld</surname>
<given-names>J.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Max Planck Institute for Chemistry, Mainz, Germany</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>University of Michigan, Ann Arbor, Michigan, USA</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>The Cyprus Institute, Nicosia, Cyprus</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>King Saud University, Riyadh, Saudi Arabia</addr-line>
</aff>
<pub-date pub-type="epub">
<day>22</day>
<month>06</month>
<year>2012</year>
</pub-date>
<volume>12</volume>
<issue>12</issue>
<fpage>5429</fpage>
<lpage>5446</lpage>
<permissions>
<license xlink:type="simple">
<license-p>This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.</license-p>
</license>
</permissions>
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<self-uri xlink:href="http://www.atmos-chem-phys.net/12/5429/2012/acp-12-5429-2012.pdf">The full text article is available as a PDF file from http://www.atmos-chem-phys.net/12/5429/2012/acp-12-5429-2012.pdf</self-uri>
<abstract>
<p>Water activity is a key factor in aerosol thermodynamics and hygroscopic
growth. We introduce a new representation of water activity (&lt;i&gt;a&lt;/i&gt;&lt;sub&gt;w&lt;/sub&gt;),
which is empirically related to the solute molality (&amp;mu;&lt;sub&gt;s&lt;/sub&gt;) through a
single solute specific constant, &amp;nu;&lt;sub&gt;&lt;i&gt;i&lt;/i&gt;&lt;/sub&gt;. Our approach is widely
applicable, considers the Kelvin effect and covers ideal solutions at high
relative humidity (RH), including cloud condensation nuclei (CCN) activation.
It also encompasses concentrated solutions with high ionic strength at low RH
such as the relative humidity of deliquescence (RHD). The constant &amp;nu;&lt;sub&gt;&lt;i&gt;i&lt;/i&gt;&lt;/sub&gt;
can thus be used to parameterize the aerosol hygroscopic growth over a wide
range of particle sizes, from nanometer nucleation mode to micrometer coarse
mode particles. In contrast to other &lt;i&gt;a&lt;/i&gt;&lt;sub&gt;w&lt;/sub&gt;-representations, our
&amp;nu;&lt;sub&gt;&lt;i&gt;i&lt;/i&gt;&lt;/sub&gt; factor corrects the solute molality both linearly and in exponent
form &lt;i&gt;x · a&lt;sup&gt;x&lt;/sup&gt;&lt;/i&gt;. We present four representations of our basic &lt;i&gt;a&lt;/i&gt;&lt;sub&gt;w&lt;/sub&gt;-parameterization at different levels of complexity for different
&lt;i&gt;a&lt;/i&gt;&lt;sub&gt;w&lt;/sub&gt;-ranges, e.g. up to 0.95, 0.98 or 1. &amp;nu;&lt;sub&gt;&lt;i&gt;i&lt;/i&gt;&lt;/sub&gt; is constant over
the selected &lt;i&gt;a&lt;/i&gt;&lt;sub&gt;w&lt;/sub&gt;-range, and in its most comprehensive form, the
parameterization describes the entire &lt;i&gt;a&lt;/i&gt;&lt;sub&gt;w&lt;/sub&gt; range (0–1). In this
work we focus on single solute solutions. &amp;nu;&lt;sub&gt;&lt;i&gt;i&lt;/i&gt;&lt;/sub&gt; can be pre-determined
with a root-finding method from our water activity representation using an
&lt;i&gt;a&lt;/i&gt;&lt;sub&gt;w&lt;/sub&gt;&amp;minus;&amp;mu;&lt;sub&gt;s&lt;/sub&gt; data pair, e.g. at solute saturation using RHD
and solubility measurements. Our &lt;i&gt;a&lt;/i&gt;&lt;sub&gt;w&lt;/sub&gt; and supersaturation
(Köhler-theory) results compare well with the thermodynamic reference
model E-AIM for the key compounds NaCl and (NH&lt;sub&gt;4&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;
relevant for CCN modeling and calibration studies. Envisaged applications
include regional and global atmospheric chemistry and climate modeling.</p>
</abstract>
<counts><page-count count="18"/></counts>
</article-meta>
</front>
<body/>
<back>
<ref-list>
<title>References</title>
<ref id="ref1">
<label>1</label><mixed-citation publication-type="other" xlink:type="simple"> Biskos, G., Paulsen, D., Russell, L. M., Buseck, P. R., and Martin, S. T.: Prompt deliquescence and efflorescence of aerosol nanoparticles, Atmos. Chem. Phys., 6, 4633–4642, http://dx.doi.org/10.5194/acp-6-4633-2006doi:10.5194/acp-6-4633-2006, 2006a. </mixed-citation>
</ref>
<ref id="ref2">
<label>2</label><mixed-citation publication-type="other" xlink:type="simple"> Biskos, G., Russell, L. M., Buseck, P. R., and Martin, S. T.: Nano-size effect on the hygroscopic growth factor of aerosol particles, Geophys. Res. Lett., 33, L07801, http://dx.doi.org/10.1029/2005GL025199doi:10.1029/2005GL025199, 2006b. </mixed-citation>
</ref>
<ref id="ref3">
<label>3</label><mixed-citation publication-type="other" xlink:type="simple"> Brechtel, F. J. and Kreidenweis, S. M.: Predicting Particle Critical Supersaturation from Hygroscopic Growth Measurements in the Humidified TDMA. Part I: Theory and Sensitivity Studies, J. Atmos. Sci., 57, 1854–1871, 2000. </mixed-citation>
</ref>
<ref id="ref4">
<label>4</label><mixed-citation publication-type="other" xlink:type="simple"> Charlson, R. J., Schwartz, S. E., Hales, J. M., Cess, R. D., Coakley, J. A., Jr., Hansen, J. E., and Hofmann D. J.: Climate forcing of anthropogenic aerosols, Science, 255, 423–430, 1992. </mixed-citation>
</ref>
<ref id="ref5">
<label>5</label><mixed-citation publication-type="other" xlink:type="simple"> Charlson, R. J., Seinfeld, J. H., Nenes, A., Kulmala, M., Laaksonen, A., and Facchini, M. C.: Reshaping the theory of cloud formation, Science, 292, 2025–2026, 2001. </mixed-citation>
</ref>
<ref id="ref6">
<label>6</label><mixed-citation publication-type="other" xlink:type="simple"> Clegg, S. L., Brimblecombe, P., and Wexler, A. S.: A thermodynamic model of the system \chemH^+-NH_4^+-SO_4^2-NO_3^–H_2O at tropospheric temperatures, J. Phys. Chem. A, 102, 2137–2154, 1998a. </mixed-citation>
</ref>
<ref id="ref7">
<label>7</label><mixed-citation publication-type="other" xlink:type="simple"> Clegg, S. L., Brimblecombe, P., and Wexler, A. S.: A thermodynamic model of the system \chemH^+-NH_4^+-Na^+-SO_4^2-NO3^–Cl^–H_2O at 298.15~K, J. Phys. Chem. A, 102, 2155–2171, 1998b. </mixed-citation>
</ref>
<ref id="ref8">
<label>8</label><mixed-citation publication-type="other" xlink:type="simple"> Clegg, S. L., Seinfeld, J. H., and Brimblecombe, P.: Thermodynamic modelling of aqueous aerosols containing electrolytes and dissolved organic compounds, J. Aer. Sci., 32, 713–738, 2001. </mixed-citation>
</ref>
<ref id="ref9">
<label>9</label><mixed-citation publication-type="other" xlink:type="simple"> Clegg, S. L. and Wexler, A. S.: Interactive comment on &quot;Calibration and measurement uncertainties of a continuous-flow cloud condensation nuclei counter (DMT-CCNC): CCN activation of ammonium sulfate and sodium chloride aerosol particles in theory and experiment&quot; by Rose, D., Gunthe, S. S., Mikhailov, E., Frank, G. P., Dusek, U., Andreae, M. O., and Pöschl, Atmos. Chem. Phys. Discuss., 7, S4180–S4183, 2007. </mixed-citation>
</ref>
<ref id="ref10">
<label>10</label><mixed-citation publication-type="other" xlink:type="simple"> Chemical Rubber Company (CRC): Handbook of Chemistry and Physics, 86th Edition, Taylor and Francis Group LLC, 2004–2005, CD-ROM version, 2006. </mixed-citation>
</ref>
<ref id="ref11">
<label>11</label><mixed-citation publication-type="other" xlink:type="simple"> Dusek, U., Frank, G. P., Hildebrandt, L., Curtius, J., Schneider, J., Walter, S., Chand, D., Drewnick, F., Hings, S., Jung, D., Borrmann, S., and Andreae, M. O.: Size Matters More Than Chemistry for Cloud-Nucleating Ability of Aerosol Particles, Science, 312, 1375–1378, 2006. </mixed-citation>
</ref>
<ref id="ref12">
<label>12</label><mixed-citation publication-type="other" xlink:type="simple"> Fountoukis, C. and Nenes, A.: ISORROPIA II: a computationally efficient thermodynamic equilibrium model for K$^+$-Ca$^2+$-Mg$^2+$-NH$_4^+$-Na$^+$-SO$_4^2-$-NO$_3^-$-Cl$^-$-H&lt;sub&gt;2&lt;/sub&gt;O aerosols, Atmos. Chem. Phys., 7, 4639–4659, http://dx.doi.org/10.5194/acp-7-4639-2007doi:10.5194/acp-7-4639-2007, 2007. </mixed-citation>
</ref>
<ref id="ref13">
<label>13</label><mixed-citation publication-type="other" xlink:type="simple"> Frank, G. P., Dusek, U., and Andreae, M. O.: Technical note: A method for measuring size-resolved CCN in the atmosphere, Atmos. Chem. Phys. Discuss., 6, 4879–4895, http://dx.doi.org/10.5194/acpd-6-4879-2006doi:10.5194/acpd-6-4879-2006, 2006. </mixed-citation>
</ref>
<ref id="ref14">
<label>14</label><mixed-citation publication-type="other" xlink:type="simple"> Frank, G. P., Dusek, U., and Andreae, M. O.: Technical Note: Characterization of a static thermal-gradient CCN counter, Atmos. Chem. Phys., 7, 3071–3080, http://dx.doi.org/10.5194/acp-7-3071-2007doi:10.5194/acp-7-3071-2007, 2007. </mixed-citation>
</ref>
<ref id="ref15">
<label>15</label><mixed-citation publication-type="other" xlink:type="simple"> Fredenslund, A., Jones, R. L., and Prausnitz, J. M.: Group contribution estimation of activity coefficients in non-ideal liquid mixtures (UNIFAC), American Institute of Chemical Engineers Journal (AIChE. J.), 21, 1086–1099, 1975. </mixed-citation>
</ref>
<ref id="ref16">
<label>16</label><mixed-citation publication-type="other" xlink:type="simple"> Hanford, K. L., Mitchem, L. Reid, J. P., Clegg, S. L., Topping, D. O., and McFiggans, G. B., Comparative Thermodynamic Studies of Aqueous Glutaric Acid, Ammonium Sulfate and Sodium Chloride Aerosol at High Humidity, J. Phys. Chem., 112, 9413–9422, 2008. </mixed-citation>
</ref>
<ref id="ref17">
<label>17</label><mixed-citation publication-type="other" xlink:type="simple"> Harmon, C. W., Ronald L. Grimm, T. M. McIntire, M. D. Peterson, B. Njegic, V. M. Angel, A. Alshawa, J. S. Underwood, D. J. Tobias, R. B. Gerber, M. S. Gordon, J. C. Hemminger, and S. A. Nizkorodov, Hygroscopic Growth and Deliquescence of NaCl Nanoparticles Mixed with Surfactant SD, J. Phys. Chem. B, 114, 2435–2449, 2010. </mixed-citation>
</ref>
<ref id="ref18">
<label>18</label><mixed-citation publication-type="other" xlink:type="simple"> IPCC: Climate Change 2007: The Physical Science Basis: Sum- mary for Policymakers. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, 2007. </mixed-citation>
</ref>
<ref id="ref19">
<label>19</label><mixed-citation publication-type="other" xlink:type="simple"> Jacobson, M. Z.: Studying the effects of calcium and magnesium on size-distributed nitrate and ammonium with EQUISOLV II, Atmos. Environ., 33, 3635–3649, 1999. </mixed-citation>
</ref>
<ref id="ref20">
<label>20</label><mixed-citation publication-type="other" xlink:type="simple"> Jacobson, M. Z., Tabazadeh, A., and Turco, R.: Simulating equilibrium within aerosols and non-equilibrium between gases and aerosols, J. Geophys. Res., 101, 9079–9091. 1996.  </mixed-citation>
</ref>
<ref id="ref21">
<label>21</label><mixed-citation publication-type="other" xlink:type="simple"> Konopka, P.: A re-examination of the derivation of the equilibrium supersaturation curve for soluble particles, J. Atmos. Sci., 53, 3157–3163, 1996. </mixed-citation>
</ref>
<ref id="ref22">
<label>22</label><mixed-citation publication-type="other" xlink:type="simple"> Köhler, H.: The nucleus in and the growth of hygroscopic droplets, Trans. Faraday Soc., 32, 1152–1161, 1936. </mixed-citation>
</ref>
<ref id="ref23">
<label>23</label><mixed-citation publication-type="other" xlink:type="simple"> Kreidenweis, S. M., Koehler, K., DeMott, P. J., Prenni, A. J., Carrico, C., and Ervens, B.: Water activity and activation diameters from hygroscopicity data – Part I: Theory and application to inorganic salts, Atmos. Chem. Phys., 5, 1357–1370, http://dx.doi.org/10.5194/acp-5-1357-2005doi:10.5194/acp-5-1357-2005, 2005. </mixed-citation>
</ref>
<ref id="ref24">
<label>24</label><mixed-citation publication-type="other" xlink:type="simple"> Kreidenweis, S. M., Petters, M. D., and DeMott, P. J., Single parameter estimates of aerosol water content, Environ. Res. Lett., 3, 035002, http://dx.doi.org/10.1088/1748-9326/3/3/035002doi:10.1088/1748-9326/3/3/035002, 2008; </mixed-citation>
</ref>
<ref id="ref25">
<label>25</label><mixed-citation publication-type="other" xlink:type="simple"> Künzli, N., Kaiser, R., Medina, S., Studnicka, M., Chanel, O., Filliger, P., Herry, M., Horak Jr., F., Puybonnieux-Texier, V., Quénel, P., Schneider, J., Seethaler, R., Vergnaud, J.-C., and Sommer, H.: Public-health impact of outdoor and traffic-related air pollution: a European assessment, The Lancet, 356, 795–801, 2000. </mixed-citation>
</ref>
<ref id="ref26">
<label>26</label><mixed-citation publication-type="other" xlink:type="simple"> Laaksonen, A., Korhonen, P., Kulmala, M., and Charlson, R. J., Modification of the Köhler equation to include soluble trace gases and slightly soluble substances, J. Atmos. Sci., 55, 853–862, 1998. </mixed-citation>
</ref>
<ref id="ref27">
<label>27</label><mixed-citation publication-type="other" xlink:type="simple"> Low, R. D. H.: A generalized equation for the solution effect in droplet growth, Atmos. Sci., 26, 608–611, 1969. </mixed-citation>
</ref>
<ref id="ref28">
<label>28</label><mixed-citation publication-type="other" xlink:type="simple"> McFiggans, G., Artaxo, P., Baltensperger, U., Coe, H., Facchini, M. C., Feingold, G., Fuzzi, S., Gysel, M., Laaksonen, A., Lohmann, U., Mentel, T. F., Murphy, D. M., O&apos;Dowd, C. D., Snider, J. R., and Weingartner, E.: The effect of physical and chemical aerosol properties on warm cloud droplet activation, Atmos. Chem. Phys., 6, 2593–2649, http://dx.doi.org/10.5194/acp-6-2593-2006doi:10.5194/acp-6-2593-2006, 2006. </mixed-citation>
</ref>
<ref id="ref29">
<label>29</label><mixed-citation publication-type="other" xlink:type="simple"> Metzger, S. and Lelieveld, J.: Reformulating atmospheric aerosol thermodynamics and hygroscopic growth into fog, haze and clouds, Atmos. Chem. Phys., 7, 3163–3193, http://dx.doi.org/10.5194/acp-7-3163-2007doi:10.5194/acp-7-3163-2007, 2007. </mixed-citation>
</ref>
<ref id="ref30">
<label>30</label><mixed-citation publication-type="other" xlink:type="simple"> Metzger, S., Steil, B., Penner, J. E., Xu, L., and Lelieveld, J.: Derivation of the stoichiometric coefficient of water ($\nu_\rm w$) to account for water uptake by atmospheric aerosols, Atmos. Chem. Phys. Discuss., 10, 8165–8188, http://dx.doi.org/10.5194/acpd-10-8165-2010doi:10.5194/acpd-10-8165-2010, 2010. </mixed-citation>
</ref>
<ref id="ref31">
<label>31</label><mixed-citation publication-type="other" xlink:type="simple"> Metzger, S., Steil, B., Xu, L., Penner, J. E., and Lelieveld, J.: Description of EQSAM4: gas-liquid-solid partitioning model for global simulations, Geosci. Model Dev. Discuss., 4, 2791–2847, http://dx.doi.org/10.5194/gmdd-4-2791-2011doi:10.5194/gmdd-4-2791-2011, 2011. </mixed-citation>
</ref>
<ref id="ref32">
<label>32</label><mixed-citation publication-type="other" xlink:type="simple"> Mikhailov, E., Vlasenko, S., Niessner, R., and Pöschl, U.: Interaction of aerosol particles composed of protein and saltswith water vapor: hygroscopic growth and microstructural rearrangement, Atmos. Chem. Phys., 4, 323–350, http://dx.doi.org/10.5194/acp-4-323-2004doi:10.5194/acp-4-323-2004, 2004. </mixed-citation>
</ref>
<ref id="ref33">
<label>33</label><mixed-citation publication-type="other" xlink:type="simple"> Mikhailov, E., Vlasenko, S., Martin, S. T., Koop, T., and Pöschl, U.: Amorphous and crystalline aerosol particles interacting with water vapor: conceptual framework and experimental evidence for restructuring, phase transitions and kinetic limitations, Atmos. Chem. Phys., 9, 9491–9522, http://dx.doi.org/10.5194/acp-9-9491-2009doi:10.5194/acp-9-9491-2009, 2009. </mixed-citation>
</ref>
<ref id="ref34">
<label>34</label><mixed-citation publication-type="other" xlink:type="simple"> Naono M. and Nakuman C.: Analysis of adsorption isotherms of water vapor for nonporous and porous adsorbents, J. Colloid Interface Sci., 145, 405–412, 1991. </mixed-citation>
</ref>
<ref id="ref35">
<label>35</label><mixed-citation publication-type="other" xlink:type="simple"> Numerical Recipes (http://www.nr.com/) in Fortran 90, Second Edition, 1996. </mixed-citation>
</ref>
<ref id="ref36">
<label>36</label><mixed-citation publication-type="other" xlink:type="simple"> Petters, M. D. and Kreidenweis, S. M.: A single parameter representation of hygroscopic growth and cloud condensation nucleus activity, Atmos. Chem. Phys., 7, 1961–1971, http://dx.doi.org/10.5194/acp-7-1961-2007doi:10.5194/acp-7-1961-2007, 2007. </mixed-citation>
</ref>
<ref id="ref37">
<label>37</label><mixed-citation publication-type="other" xlink:type="simple"> Pilinis, C., Pandis, S. N., and Seinfeld, J. H.: Sensitivity of direct climate forcing by atmospheric aerosols to aerosol size and composition, J. Geophys. Res., 100, 18739–18754, 1995. </mixed-citation>
</ref>
<ref id="ref38">
<label>38</label><mixed-citation publication-type="other" xlink:type="simple"> Pitzer, K. S. and Mayorga, G.: Thermodynamics of electrolytes. II. Activity and osmotic coefficients for strong electrolytes with one or both ions univalent, J. Phys. Chem., 77, 2300–2308, 1973. </mixed-citation>
</ref>
<ref id="ref39">
<label>39</label><mixed-citation publication-type="other" xlink:type="simple"> Pringle, K. J., Tost, H., Message, S., Steil, B., Giannadaki, D., Nenes, A., Fountoukis, C., Stier, P., Vignati, E., and Lelieveld, J.: Description and evaluation of GMXe: a new aerosol submodel for global simulations (v1), Geosci. Model Dev., 3, 391–412, http://dx.doi.org/10.5194/gmd-3-391-2010doi:10.5194/gmd-3-391-2010, 2010. </mixed-citation>
</ref>
<ref id="ref40">
<label>40</label><mixed-citation publication-type="other" xlink:type="simple"> Pruppacher, H. R. and Klett, J. D.: Microphysics of clouds and precipitation, Dordrecht, Kluwer Academic Publishers, 1997. </mixed-citation>
</ref>
<ref id="ref41">
<label>41</label><mixed-citation publication-type="other" xlink:type="simple"> Raoult, F. M.: Über die Dampfdrucke ätherischer Lösungen, Z. Phys. Chem., 2, 353–373, 1888. </mixed-citation>
</ref>
<ref id="ref42">
<label>42</label><mixed-citation publication-type="other" xlink:type="simple"> Reiss, H.: The kinetics of phase transitions in binary systems, J. Chem. Phys., 18, 840–848, 1950. </mixed-citation>
</ref>
<ref id="ref43">
<label>43</label><mixed-citation publication-type="other" xlink:type="simple"> Robinson, R. A. and Stokes, R. H.: Electrolyte Solutions, (revised), London: Butterworth, 1959. </mixed-citation>
</ref>
<ref id="ref44">
<label>44</label><mixed-citation publication-type="other" xlink:type="simple"> Robinson, R. A. and Stokes, R. H.: Electrolyte Solutions, 2nd ed. (revised); Butterworths: London, 1965. </mixed-citation>
</ref>
<ref id="ref45">
<label>45</label><mixed-citation publication-type="other" xlink:type="simple"> Rose, D., Gunthe, S. S., Mikhailov, E., Frank, G. P., Dusek, U., Andreae, M. O., and Pöschl, U.: Calibration and measurement uncertainties of a continuous-flow cloud condensation nuclei counter (DMT-CCNC): CCN activation of ammonium sulfate and sodium chloride aerosol particles in theory and experiment, Atmos. Chem. Phys., 8, 1153–1179, http://dx.doi.org/10.5194/acp-8-1153-2008doi:10.5194/acp-8-1153-2008, 2008. </mixed-citation>
</ref>
<ref id="ref46">
<label>46</label><mixed-citation publication-type="other" xlink:type="simple"> Ruehl, C. R., Chuang, P. Y., and Nenes, A.: Aerosol hygroscopicity at high (99 to 100%) relative humidities, Atmos. Chem. Phys., 10, 1329–1344, http://dx.doi.org/10.5194/acp-10-1329-2010doi:10.5194/acp-10-1329-2010, 2010. </mixed-citation>
</ref>
<ref id="ref47">
<label>47</label><mixed-citation publication-type="other" xlink:type="simple"> Russell, L. M. and Ming, Y.: Deliquescence of small particles, J. Chem. Phys., 116, 311–321, 2002. </mixed-citation>
</ref>
<ref id="ref48">
<label>48</label><mixed-citation publication-type="other" xlink:type="simple"> Seinfeld, J. H. and Pandis, S. N.: Atmospheric chemistry and physics, J. Wiley and Sons, Inc., New York, 1998. </mixed-citation>
</ref>
<ref id="ref49">
<label>49</label><mixed-citation publication-type="other" xlink:type="simple"> Seinfeld, J. H. and Pandis, S. N.: Atmospheric chemistry and physics, J. Wiley and Sons, Inc., New York, 2006. </mixed-citation>
</ref>
<ref id="ref50">
<label>50</label><mixed-citation publication-type="other" xlink:type="simple"> Stokes, R. H. and Robinson, R. A.: Interactions in aqueous non-electrolyte solutions, I. Solute-solvent equilibria, J. Phys. Chem., 70, 2126–2130, 1966. </mixed-citation>
</ref>
<ref id="ref51">
<label>51</label><mixed-citation publication-type="other" xlink:type="simple"> Shulman, M. L., Jacobson, M. C., Carlson, R. J., Synovec, R. E., and Young, T. E.: Dissolution behavior and surface tension ef-fects of organic compounds in nucleating cloud droplets, Geophys. Res. Lett., 23, 277–280, 1996. </mixed-citation>
</ref>
<ref id="ref52">
<label>52</label><mixed-citation publication-type="other" xlink:type="simple"> Tang, I. N.: Chemical and size effects of hygroscopic aerosols on light scattering coefficients, J. Geophys. Res., 101, 19245–19250, 1996. </mixed-citation>
</ref>
<ref id="ref53">
<label>53</label><mixed-citation publication-type="other" xlink:type="simple"> Tang, I. N. and Munkelwitz, H. R.: Water activities, densities, and refractive indices of aqueous sulfates and sodium nitrate droplets of atmospheric importance, J. Geophys. Res., 99, 18801–18808, 1994. </mixed-citation>
</ref>
<ref id="ref54">
<label>54</label><mixed-citation publication-type="other" xlink:type="simple"> van&apos;t Hoff, J. H.: Die Rolle des osmotischen Druckes in der Analogie zwischen Lösungen und Gasen, Z. Phys. Chem., 1, 481, 1887. </mixed-citation>
</ref>
<ref id="ref55">
<label>55</label><mixed-citation publication-type="other" xlink:type="simple"> Wang, Z., King, S. M., Freney, E., Rosenoern, T., Smith, M. L., Chen, Q., Kuwata, M., Lewis, E. R., Pöschl, U., Wang, W., Buseck, P. R., and Martin S. T.: The Dynamic Shape Factor of Sodium Chloride Nanoparticles as Regulated by Drying Rate, Aerosol Sci. Technol., 44, 939–953, 2010.  </mixed-citation>
</ref>
<ref id="ref56">
<label>56</label><mixed-citation publication-type="other" xlink:type="simple"> Warneck, P.: Chemistry of the Natural Atmosphere, Internat, Geophys. Series, 41, Academic Press. Inc., 1988. </mixed-citation>
</ref>
<ref id="ref57">
<label>57</label><mixed-citation publication-type="other" xlink:type="simple"> Wexler, A. S. and Clegg, S. L.: Atmospheric aerosol models for systems including the ions H$^+$, NH$_4^+$, Na$^+$, SO$_4^2-$, NO$_3^-$, Cl$^-$, Br$^-$ and H&lt;sub&gt;2&lt;/sub&gt;O, J. Geophys. Res., 107, 4207, http://dx.doi.org/10.1029/2001JD000451doi:10.1029/2001JD000451, 2002.  </mixed-citation>
</ref>
<ref id="ref58">
<label>58</label><mixed-citation publication-type="other" xlink:type="simple"> Wexler, A. S. and Potukuchi, S.: Kinetics and Thermodynamics of Tropospheric Aerosols, Atmospheric Particles, John Wiley &amp; Sons Ltd., 1998.  </mixed-citation>
</ref>
<ref id="ref59">
<label>59</label><mixed-citation publication-type="other" xlink:type="simple"> Wexler, A. S. and Seinfeld, J. H.: Second-generation inorganic aerosol model, Atmos. Environ., 25A, 2731–2748, 1991.  </mixed-citation>
</ref>
<ref id="ref60">
<label>60</label><mixed-citation publication-type="other" xlink:type="simple"> Xu, L., Penner, J. E., Metzger, S., and Lelieveld, J.: A comparison of water uptake by aerosols using two thermodynamic models, Atmos. Chem. Phys. Discuss., 9, 9551–9595, http://dx.doi.org/10.5194/acpd-9-9551-2009doi:10.5194/acpd-9-9551-2009, 2009. </mixed-citation>
</ref>
<ref id="ref61">
<label>61</label><mixed-citation publication-type="other" xlink:type="simple"> Xu, L.: Global simulation of nitrate and ammonium aerosols and their radiative effects and comparison of satellite-based and modeled aerosol indirect forcing, Dissertation, University of Michigan, 2011. </mixed-citation>
</ref>
<ref id="ref62">
<label>62</label><mixed-citation publication-type="other" xlink:type="simple"> Young, K. C. and Warren, A. J.: A reexamination of the derivation of the equilibrium supersaturation curve for soluble particles, J. Atmos. Sci., 49, 1138–1143, 1992. </mixed-citation>
</ref>
<ref id="ref63">
<label>63</label><mixed-citation publication-type="other" xlink:type="simple"> Zdanovskii, A. B.: New methods of calculating solubilities of electrolytes in multicomponent systems, Zhu. Fiz. Khim., 22, 1475–1485, 1948. </mixed-citation>
</ref>
</ref-list>
</back>
</article>