<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE article PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "http://dtd.nlm.nih.gov/publishing/3.0/journalpublishing3.dtd">
<article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" article-type="research-article" dtd-version="3.0" xml:lang="en">
<front>
<journal-meta>
<journal-id journal-id-type="publisher">ACPD</journal-id>
<journal-title-group>
<journal-title>Atmospheric Chemistry and Physics Discussions</journal-title>
<abbrev-journal-title abbrev-type="publisher">ACPD</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1680-7375</issn>
<publisher><publisher-name>Copernicus GmbH</publisher-name>
<publisher-loc>GÃ¶ttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/acpd-11-9249-2011</article-id>
<title-group>
<article-title>In situ observations of new particle formation in the tropical upper troposphere: the role of clouds and the nucleation mechanism</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Weigel</surname>
<given-names>R.</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>Borrmann</surname>
<given-names>S.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Kazil</surname>
<given-names>J.</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Minikin</surname>
<given-names>A.</given-names>
</name>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Stohl</surname>
<given-names>A.</given-names>
</name>
<xref ref-type="aff" rid="aff6">
<sup>6</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Wilson</surname>
<given-names>J. C.</given-names>
</name>
<xref ref-type="aff" rid="aff7">
<sup>7</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Reeves</surname>
<given-names>J. M.</given-names>
</name>
<xref ref-type="aff" rid="aff7">
<sup>7</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Kunkel</surname>
<given-names>D.</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>de Reus</surname>
<given-names>M.</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>Frey</surname>
<given-names>W.</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>Lovejoy</surname>
<given-names>E. R.</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Volk</surname>
<given-names>C. M.</given-names>
</name>
<xref ref-type="aff" rid="aff8">
<sup>8</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Viciani</surname>
<given-names>S.</given-names>
</name>
<xref ref-type="aff" rid="aff9">
<sup>9</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>D&apos;Amato</surname>
<given-names>F.</given-names>
</name>
<xref ref-type="aff" rid="aff9">
<sup>9</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Cairo</surname>
<given-names>F.</given-names>
</name>
<xref ref-type="aff" rid="aff10">
<sup>10</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Schlager</surname>
<given-names>H.</given-names>
</name>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Law</surname>
<given-names>K. S.</given-names>
</name>
<xref ref-type="aff" rid="aff11">
<sup>11</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Shur</surname>
<given-names>G. N.</given-names>
</name>
<xref ref-type="aff" rid="aff12">
<sup>12</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Belyaev</surname>
<given-names>G. V.</given-names>
</name>
<xref ref-type="aff" rid="aff13">
<sup>13</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Curtius</surname>
<given-names>J.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff14">
<sup>14</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Institut fÃ¼r Physik der AtmosphÃ¤re, Johannes Gutenberg-UniversitÃ¤t, Mainz, Germany</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Abteilung Partikelchemie, Max-Planck-Institut fÃ¼r Chemie, Mainz, Germany</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, Colorado, USA</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>NOAA Earth System Research Laboratory, Boulder, Colorado, USA</addr-line>
</aff>
<aff id="aff5">
<label>5</label>
<addr-line>Institut fÃ¼r Physik der AtmosphÃ¤re, Deutsches Zentrum fÃ¼r Luft- und Raumfahrt (DLR), Oberpfaffenhofen, Germany</addr-line>
</aff>
<aff id="aff6">
<label>6</label>
<addr-line>Norwegian Institute for Air Research (NILU), Kjeller, Norway</addr-line>
</aff>
<aff id="aff7">
<label>7</label>
<addr-line>Department of Engineering, University of Denver, Denver, Colorado, USA</addr-line>
</aff>
<aff id="aff8">
<label>8</label>
<addr-line>Department of Physics, University of Wuppertal, Germany</addr-line>
</aff>
<aff id="aff9">
<label>9</label>
<addr-line>Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, Firenze, Italy</addr-line>
</aff>
<aff id="aff10">
<label>10</label>
<addr-line>Istituto di Scienze dell&apos;Atmosfera e del Clima ISAC-CNR, Consiglio Nazionale delle Ricerche, Italy</addr-line>
</aff>
<aff id="aff11">
<label>11</label>
<addr-line>UPMC Univ. Paris 06; UniversitÃ© Versailles St-Quentin; CNRS/INSU, UMR 8190, LATMOS-IPSL, Paris, France</addr-line>
</aff>
<aff id="aff12">
<label>12</label>
<addr-line>Central Aerological Observatory, Dolgoprudny, Moskow Region, Russia</addr-line>
</aff>
<aff id="aff13">
<label>13</label>
<addr-line>MDB-Myasishchev Design Bureau, Zhukovsky-5, Moscow Region, Russia</addr-line>
</aff>
<aff id="aff14">
<label>14</label>
<addr-line>now at: Institut fÃ¼r AtmosphÃ¤re und Umwelt, Experimentelle AtmosphÃ¤renforschung, Goethe-UniversitÃ¤t Frankfurt/Main, Germany</addr-line>
</aff>
<pub-date pub-type="epub">
<day>21</day>
<month>03</month>
<year>2011</year>
</pub-date>
<volume>11</volume>
<issue>3</issue>
<fpage>9249</fpage>
<lpage>9312</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>
<self-uri xlink:href="http://www.atmos-chem-phys-discuss.net/11/9249/2011/acpd-11-9249-2011.html">This article is available from http://www.atmos-chem-phys-discuss.net/11/9249/2011/acpd-11-9249-2011.html</self-uri>
<self-uri xlink:href="http://www.atmos-chem-phys-discuss.net/11/9249/2011/acpd-11-9249-2011.pdf">The full text article is available as a PDF file from http://www.atmos-chem-phys-discuss.net/11/9249/2011/acpd-11-9249-2011.pdf</self-uri>
<abstract>
<p>New particle formation which generates ultrafine aerosol was observed in the
continental tropical Upper Troposphere (UT) and Tropical Tropopause Layer
(TTL), particularly at the bottom of the TTL, by in situ airborne
measurements over South America (Januaryâ€“March, 2005) and West Africa
(August, 2006). Measurements with a set of condensation particle counters
with different &lt;i&gt;d&lt;/i&gt;&lt;sub&gt;p50&lt;/sub&gt; (50% detection efficiency cut-off particle
diameter) were conducted in the altitude range of 12.0â€“20.5 km on board the
high altitude research aircraft M-55 &quot;Geophysica&quot; and at up to 11.5 km
altitude on board the research aircraft DLR Falcon-20. Concentrations of
ultrafine particles in the size range of 6 to 15 nm were derived from these
measurements and several events of new particle formation (NPF) were
identified. For two flight segments (24 February 2005 and 7 August 2006, at
12.5 km altitude) when recent lifting had influenced the probed air mass,
the concentration of ultrafine particles reached up to 16 000 particles cm&lt;sup&gt;âˆ’3&lt;/sup&gt;
(ambient concentration). A sensitivity study by using an aerosol
model which includes neutral and ion induced nucleation processes revealed
predicted concentrations of ultrafine particles in reasonable agreement with
the in situ observations. NPF over South America was observed in cloud free
air, above thin cirrus, while over West Africa, in the outflow of a
Mesoscale Convective System (MCS), newly formed particles in the range of
several hundred per cm&lt;sup&gt;3&lt;/sup&gt; were found to coexist with ice cloud particles
as long as the concentration of cloud particles (&lt;i&gt;d&lt;/i&gt;&lt;sub&gt;p&lt;/sub&gt;&gt;2 Î¼m)
remained below 2 cm&lt;sup&gt;âˆ’3&lt;/sup&gt;. The occurrence of NPF within the upper
troposphere and the TTL was generally confined within an altitude band
extending from 340 K to 380 K potential temperature, of particular strength
between 350 K and 370 K. By means of a heated aerosol inlet line (at 250 Â°C)
measurements of particle volatility were performed which show that
within the TTL over South America and West Africa, on average 10â€“25% of
the particles contained non-volatile cores. In background UT/TTL conditions
the fractions of non-volatile particles typically ranged up to 50%. Our
measurements provide further evidence for the hypothesis that the tropical
UT and the TTL are aerosol source regions supplying freshly nucleated
particles which, if lifted, may contribute to maintain the stratospheric
background aerosol. These particles can become important for cloud formation
in the tropical upper troposphere, if they further grow such that they can
act as cloud condensation nuclei.</p>
</abstract>
<counts><page-count count="64"/></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"> Barth, M. C., Stuart, A. L., and Skamarock, W. C.: Numerical simulations of the July 10, 1996, Stratospheric-Tropospheric Experiment: Radiation, Aerosols, and Ozone (STEREAO)-Deep Convection experiment storm: Redistribution of soluble tracers, J. Geophys. Res., 106, 12381â€“12400, 2001. </mixed-citation>
</ref>
<ref id="ref2">
<label>2</label><mixed-citation publication-type="other" xlink:type="simple"> Borrmann, S., Kunkel, D., Weigel, R., Minikin, A., Deshler, T., Wilson, J. C., Curtius, J., Volk, C. M., Homan, C. D., Ulanovsky, A., Ravegnani, F., Viciani, S., Shur, G. N., Belyaev, G. V., Law, K. S., and Cairo, F.: Aerosols in the tropical and subtropical UT/LS: in-situ measurements of submicron particle abundance and volatility, Atmos. Chem. Phys., 10, 5573â€“5592, http://dx.doi.org/10.5194/acp-10-5573-2010doi:10.5194/acp-10-5573-2010, 2010. </mixed-citation>
</ref>
<ref id="ref3">
<label>3</label><mixed-citation publication-type="other" xlink:type="simple"> Brock, C. A., Hamill, P., Wilson, J. C., Jonsson, H. H., and Chan, K. R.: Particle Formation in the Upper Tropical Troposphere - a Source of Nuclei for the Stratospheric Aerosol, Science, 270(5242), 1650â€“1653, 1995. </mixed-citation>
</ref>
<ref id="ref4">
<label>4</label><mixed-citation publication-type="other" xlink:type="simple"> Brock, C. A., SchrÃ¶der, F., KÃ¤rcher, B., Petzold, A., Busen, R., and Fiebig, M.: Ultrafine particle size distributions measured in aircraft exhaust plumes, J. Geophys. Res.-Atmos., 105(D21), 26555â€“26567, 2000. </mixed-citation>
</ref>
<ref id="ref5">
<label>5</label><mixed-citation publication-type="other" xlink:type="simple"> Brown, P. N., Byrne, G. D., and Hindmarsh, A. C.: VODE, A Variable-Coefficient ODE Solver, SIAM J. Sci. Stat. Comput., 10, 1038â€“-1051, 1989. </mixed-citation>
</ref>
<ref id="ref6">
<label>6</label><mixed-citation publication-type="other" xlink:type="simple"> Buontempo, C., Cairo, F., Di Donfrancesco, G., Morbidini, R., Viterbini, M., and Adriani, A.: Optical measurements of atmospheric particles from airborne platforms: in situ and remote sensing instruments for balloons and aircrafts, Ann. Geophys.-Italy, 49, 57â€“64, 2006. </mixed-citation>
</ref>
<ref id="ref7">
<label>7</label><mixed-citation publication-type="other" xlink:type="simple"> Cairo, F., Pommereau, J. P., Law, K. S., Schlager, H., Garnier, A., Fierli, F., Ern, M., Streibel, M., Arabas, S., Borrmann, S., Berthelier, J. J., Blom, C., Christensen, T., D&apos;Amato, F., Di Donfrancesco, G., Deshler, T., Diedhiou, A., Durry, G., Engelsen, O., Goutail, F., Harris, N. R. P., Kerstel, E. R. T., Khaykin, S., Konopka, P., Kylling, A., Larsen, N., Lebel, T., Liu, X., MacKenzie, A. R., Nielsen, J., Oulanowski, A., Parker, D. J., Pelon, J., Polcher, J., Pyle, J. A., Ravegnani, F., Rivière, E. D., Robinson, A. D., RÃ¶ckmann, T., Schiller, C., SimÃµes, F., Stefanutti, L., Stroh, F., Some, L., Siegmund, P., Sitnikov, N., Vernier, J. P., Volk, C. M., Voigt, C., von Hobe, M., Viciani, S., and Yushkov, V.: An introduction to the SCOUT-AMMA stratospheric aircraft, balloons and sondes campaign in West Africa, August 2006: rationale and roadmap, Atmos. Chem. Phys., 10, 2237â€“2256, http://dx.doi.org/10.5194/acp-10-2237-2010doi:10.5194/acp-10-2237-2010, 2010. </mixed-citation>
</ref>
<ref id="ref8">
<label>8</label><mixed-citation publication-type="other" xlink:type="simple"> Cairo, F., Di Donfrancesco, G., Snels, M., Fierli, F., Viterbini, M., Borrmann, S., and Frey, W.: A comparison of light backscattering and particle size distribution measurements in tropical cirrus clouds, Atmos. Meas. Tech., 4, 557â€“570, http://dx.doi.org/10.5194/amt-4-557-2011doi:10.5194/amt-4-557-2011, 2011. </mixed-citation>
</ref>
<ref id="ref9">
<label>9</label><mixed-citation publication-type="other" xlink:type="simple"> Carmichael, G. R., Ferm, M., Thongboonchoo, N., Woo, J.-H., Chan, L. Y., Murano, K., Viet, P. H., Mossberg, C., Bala, R., Boonjawat, J., Upatum, P., Mohan, M., Adhikary, S. P., Shrestha, A. B., Pienaar, J. J., Brunke, E. B., Chen, T., Jie, T., Guoan, D., Peng, L. C., Dhiharto, S., Harjanto, H., Jose, A. M., Kimani, W., Kirouane, A., Lacaux, J.-P., Richard, S., Barturen, O., Cerda, J. C., Athayde, A., Tavares, T., Cotrina, J. S., and Bilici, E.: Measurements of sulfur dioxide,ozone and ammonia concentrations in Asia, Africa, and South America using passive samplers, Atmos. Environ., 37, 1293â€“1308, http://dx.doi.org/10.1016/S1352-2310(02)01009-9doi:10.1016/S1352-2310(02)01009-9, 2003. </mixed-citation>
</ref>
<ref id="ref10">
<label>10</label><mixed-citation publication-type="other" xlink:type="simple"> Carn, S. A., Krueger, A. J., Krotkov, N. A., Yang, K., and Levelt, P. F.: Sulfur dioxide emissions from Peruvian copper smelters detected by the Ozone Monitoring Instrument, Geophys. Res. Lett., 34, L09801, http://dx.doi.org/10.1029/2006GL029020doi:10.1029/2006GL029020, 2007. </mixed-citation>
</ref>
<ref id="ref11">
<label>11</label><mixed-citation publication-type="other" xlink:type="simple"> Charlson, R. J., Lovelock, J. E., Andreae, M. O., and Warren, S. G.: Oceanic phytoplankton, atmospheric sulphur, cloud albedo and climate, Nature, 326, 655â€“661, 1987. </mixed-citation>
</ref>
<ref id="ref12">
<label>12</label><mixed-citation publication-type="other" xlink:type="simple"> Clarke, A. D., Eisele, F., Mauldin, R. L., Tanner, D., and Litchy, M.: Particle production in the remote marine atmosphere: Cloud outflow and subsidence during ACE 1, J. Geophys. Res.-Atmos., 103(D13), 16397â€“16409, 1998. </mixed-citation>
</ref>
<ref id="ref13">
<label>13</label><mixed-citation publication-type="other" xlink:type="simple"> Clarke, A. D., Clarke, A. D., Eisele, F., Kapustin, V. N., Moore, K., Tanner, D., Mauldin, R. L., Litchy, M., Lienert, B., Carrol, M. A., and Albercook, G.: Nucleation in the equatorial free troposphere: Favorable environments during PEM-Tropics, J. Geophys. Res.-Atmos., 104(D5), 5735â€“5744, 1999. </mixed-citation>
</ref>
<ref id="ref14">
<label>14</label><mixed-citation publication-type="other" xlink:type="simple"> Clarke, A. D. and Kapustin, V. N.: A pacific aerosol survey. Part I: A decade of data on particle production, transport, evolution, and mixing in the troposphere, J. Atmos. Sci., 59(3), 363â€“382, 2002. </mixed-citation>
</ref>
<ref id="ref15">
<label>15</label><mixed-citation publication-type="other" xlink:type="simple"> Clegg, S. L., Rard, J. A., and Pitzer, K. S.: Thermodynamic properties of 0-6 mol kg-1 aqueous sulfuric acid from 273.15 to 328.15 K, J. Chem. Soc., Faraday Trans., 90, 1875â€“1894, http://dx.doi.org/10.1039/FT9949001875doi:10.1039/FT9949001875, 1994. </mixed-citation>
</ref>
<ref id="ref16">
<label>16</label><mixed-citation publication-type="other" xlink:type="simple"> Curtius, J., Froyd, K. D., and Lovejoy, E. R.: Cluster Ion Thermal Decomposition (I): Experimental Kinetics Study and ab Initio Calculations for HSO4-(H2SO4)x(HNO3)y, J. Phys. Chem. A, 105(48), 10867â€“10873, 2001a. </mixed-citation>
</ref>
<ref id="ref17">
<label>17</label><mixed-citation publication-type="other" xlink:type="simple"> Curtius, J., Sierau, B., Arnold, F., de Reus, M., StrÃ¶m, J., Scheeren, H. A., and Lelieveld, J.: Measurement of aerosol sulfuric acid 2. Pronounced layering in the free troposphere during the second Aerosol Characterization Experiment (ACE 2), J. Geophys. Res.-Atmos., 106(D23), 31975â€“31990, 2001b. </mixed-citation>
</ref>
<ref id="ref18">
<label>18</label><mixed-citation publication-type="other" xlink:type="simple"> Curtius, J., Weigel, R., VÃ¶ssing, H.-J., Wernli, H., Werner, A., Volk, C.-M., Konopka, P., Krebsbach, M., Schiller, C., Roiger, A., Schlager, H., Dreiling, V., and Borrmann, S.: Observations of meteoric material and implications for aerosol nucleation in the winter Arctic lower stratosphere derived from in situ particle measurements, Atmos. Chem. Phys., 5, 3053â€“3069, http://dx.doi.org/10.5194/acp-5-3053-2005doi:10.5194/acp-5-3053-2005, 2005. </mixed-citation>
</ref>
<ref id="ref19">
<label>19</label><mixed-citation publication-type="other" xlink:type="simple"> Curtius, J.: Nucleation of atmospheric aerosol particles, C. R. Physique, 7, 1027â€“1045, 2006. </mixed-citation>
</ref>
<ref id="ref20">
<label>20</label><mixed-citation publication-type="other" xlink:type="simple"> Curtius, J., Lovejoy, E R., and Froyd, K D.: Atmospheric ion-induced aerosol nucleation, Space Sci. Rev., 125(1â€“4), 159â€“167, 2006. </mixed-citation>
</ref>
<ref id="ref21">
<label>21</label><mixed-citation publication-type="other" xlink:type="simple"> Crumeyrolle, S., Manninen, H. E., Sellegri, K., Roberts, G., Gomes, L., Kulmala, M., Weigel, R., Laj, P., and Schwarzenboeck, A.: New particle formation events measured on board the ATR-42 aircraft during the EUCAARI campaign, Atmos. Chem. Phys., 10, 6721â€“6735, http://dx.doi.org/10.5194/acp-10-6721-2010doi:10.5194/acp-10-6721-2010, 2010. </mixed-citation>
</ref>
<ref id="ref22">
<label>22</label><mixed-citation publication-type="other" xlink:type="simple"> Dye, J. E. and Baumgardner, D.: Evaluation of the Forward Scattering Spectrometer Probe. Part I: Electronic and optical studies, J. Atmos. Oceanic Technol., 1, 329â€“344, 1984. </mixed-citation>
</ref>
<ref id="ref23">
<label>23</label><mixed-citation publication-type="other" xlink:type="simple"> de Reus, M., Borrmann, S., Bansemer, A., Heymsfield, A. J., Weigel, R., Schiller, C., Mitev, V., Frey, W., Kunkel, D., KÃ¼rten, A., Curtius, J., Sitnikov, N. M., Ulanovsky, A., and Ravegnani, F.: Evidence for ice particles in the tropical stratosphere from in-situ measurements, Atmos. Chem. Phys., 9, 6775â€“6792, http://dx.doi.org/10.5194/acp-9-6775-2009doi:10.5194/acp-9-6775-2009, 2009. </mixed-citation>
</ref>
<ref id="ref24">
<label>24</label><mixed-citation publication-type="other" xlink:type="simple"> Eichkorn, S., Wilhelm, S., Aufmhoff, H., Wohlfrom, K. H., and Arnold, F.: Cosmic ray-induced aerosol-formation: First observational evidence from aircraft-based ion mass spectrometer measurements in the upper troposphere, Geophys. Res. Lett., 29, 1698, http://dx.doi.org/10.1029/2002GL015044doi:10.1029/2002GL015044, 2002. </mixed-citation>
</ref>
<ref id="ref25">
<label>25</label><mixed-citation publication-type="other" xlink:type="simple"> Ekman, A. M. L., Krejci, R., EngstrÃ¶m, A., StrÃ¶m, J., de Reus, M., Williams, J., and Andreae, M. O.: Do organics contribute to small particle formation in the Amazonian upper troposphere?, Geophys. Res. Lett., 35, L17810, http://dx.doi.org/10.1029/2008GL034970doi:10.1029/2008GL034970, 2008. </mixed-citation>
</ref>
<ref id="ref26">
<label>26</label><mixed-citation publication-type="other" xlink:type="simple"> Emanuel, K. A. and Å½ivkoviÄ‡-Rothman, M.: Development and evaluation of a convection scheme for use in climate models, J. Atmos. Sci., 56, 1766â€“1782, 1999. </mixed-citation>
</ref>
<ref id="ref27">
<label>27</label><mixed-citation publication-type="other" xlink:type="simple"> Fiebig, M., Stein, C., SchrÃ¶der, F., Feldpausch, P., and Petzold, A.: Inversion of data containing information on the aerosol particle size distribution usingmultiple instruments, J. Aerosol Sci., 36, 1353â€“1372, 2005. </mixed-citation>
</ref>
<ref id="ref28">
<label>28</label><mixed-citation publication-type="other" xlink:type="simple"> Fierli, F., Orlandi, E., Law, K. S., Cagnazzo, C., Cairo, F., Schiller, C., Borrmann, S., Di Donfrancesco, G., Ravegnani, F., and Volk, C. M.: Impact of deep convection in the tropical tropopause layer in West Africa: in-situ observations and mesoscale modelling, Atmos. Chem. Phys., 11, 201â€“214, http://dx.doi.org/10.5194/acp-11-201-2011doi:10.5194/acp-11-201-2011, 2011. </mixed-citation>
</ref>
<ref id="ref29">
<label>29</label><mixed-citation publication-type="other" xlink:type="simple"> Forster, C., Stohl, A., and Seibert, P.: Parameterization of convective transport in a Lagrangian particle dispersion model and its evaluation, J. Appl. Met. Clim., 46, 403â€“422, 2007. </mixed-citation>
</ref>
<ref id="ref30">
<label>30</label><mixed-citation publication-type="other" xlink:type="simple"> Frey, W., Borrmann, S., Kunkel, D., Weigel, R., de Reus, M., Schlager, H., Roiger, A., Voigt, C., Hoor, P., Curtius, J., KrÃ¤mer, M., Schiller, C., Volk, C. M., Homan, C. D., Fierli, F., Di Donfrancesco, G., Ulanovsky, A., Ravegnani, F., Sitnikov, N. M., Viciani, S., D&apos;Amato, F., Shur, G. N., Belyaev, G. V., Law, K. S., and Cairo, F.: In-situ measurements of tropical cloud properties in the West African monsoon: upper tropospheric ice clouds, mesoscale convective system outflow, and subvisual cirrus, Atmos. Chem. Phys. Discuss., 11, 745â€“812, http://dx.doi.org/10.5194/acpd-11-745-2011doi:10.5194/acpd-11-745-2011, 2011. </mixed-citation>
</ref>
<ref id="ref31">
<label>31</label><mixed-citation publication-type="other" xlink:type="simple"> Froyd, K. D. and Lovejoy, E. R.: Experimental Thermodynamics of Cluster Ions Composed of H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt; and H&lt;sub&gt;2&lt;/sub&gt;O. 1. Positive Ions, J. Phys. Chem. A, 107(46), 9800â€“9811, 2003a. </mixed-citation>
</ref>
<ref id="ref32">
<label>32</label><mixed-citation publication-type="other" xlink:type="simple"> Froyd, K. D. and Lovejoy, E. R.: Experimental Thermodynamics of Cluster Ions Composed of H2SO4 and H2O. 2. Measurements and ab Initio Structures of Negative Ions, J. Phys. Chem. A, 107, 46, 9812â€“9824, 2003b. </mixed-citation>
</ref>
<ref id="ref33">
<label>33</label><mixed-citation publication-type="other" xlink:type="simple"> Froyd, K. D., Murphy, D. M., Lawson, P., Baumgardner, D., and Herman, R. L.: Aerosols that form subvisible cirrus at the tropical tropopause, Atmos. Chem. Phys., 10, 209â€“218, http://dx.doi.org/10.5194/acp-10-209-2010doi:10.5194/acp-10-209-2010, 2010. </mixed-citation>
</ref>
<ref id="ref34">
<label>34</label><mixed-citation publication-type="other" xlink:type="simple"> Fuchs, N. A.: The Mechanics of Aerosols, translated from the Russian edition (Moscow) by R E. Daisley and Marina Fuchs, edited by: Davies, C. N., 408~pp., Pergamon Press, London, Macmillan, New York, 1964. </mixed-citation>
</ref>
<ref id="ref35">
<label>35</label><mixed-citation publication-type="other" xlink:type="simple"> Fueglistaler, S., Dessler, A. E., Dunkerton, T. J., Folkins, I., Fu, Q., and Mote, P. W.: Tropical Tropopause Layer, Rev. Geophys., 47, RG1004, http://dx.doi.org/10.1029/2008RG000267doi:10.1029/2008RG000267, 2009. </mixed-citation>
</ref>
<ref id="ref36">
<label>36</label><mixed-citation publication-type="other" xlink:type="simple"> Ferguson,D. J., Barnie,T. D., Pyle, D. M., Oppenheimer, C., Yirgu,G., Lewi, E., Kidane, T., Carn, S., and Hamling, I.: Recent rift-related volcanism in Afar, Ethiopia, Earth. Planet. Sc. Lett., 292(3â€“4), 409â€“418, http://dx.doi.org/10.1016/j.epsl.2010.02.010.doi:10.1016/j.epsl.2010.02.010., 2010. </mixed-citation>
</ref>
<ref id="ref37">
<label>37</label><mixed-citation publication-type="other" xlink:type="simple"> Gettelman, A., de F. Forster, P. M., Fujiwara, M., Fu, Q., Vomel, H., Gohar, L. K., Johanson, C., and Ammerman, M.: Radiation balance of the tropical tropopause layer, J. Geophys. Res., 109, D07103, http://dx.doi.org/10.1029/2003JD004190doi:10.1029/2003JD004190, 2004. </mixed-citation>
</ref>
<ref id="ref38">
<label>38</label><mixed-citation publication-type="other" xlink:type="simple"> Giauque, W. F., Hornung, E. W., Kunzler, J. E., and Rubin, T. T.: The thermodynamic properties of aqueous sulfuric acid solutions and hydrates from 15 to 300 K, Am. Chem. Soc. J., 82, 62â€“70, 1960. </mixed-citation>
</ref>
<ref id="ref39">
<label>39</label><mixed-citation publication-type="other" xlink:type="simple"> Hamill, P., Jensen, E. J., Russell, P. B., and Bauman, J. J.: The life cycle of stratospheric aerosol particles, B. Am. Meteorol. Soc., 78(7), 1395â€“1410, 1997. </mixed-citation>
</ref>
<ref id="ref40">
<label>40</label><mixed-citation publication-type="other" xlink:type="simple"> Hamling, I. J., Ayele, A., Bennati, L., Calais, E., Ebinger, C. J., Keir, D., Lewi, E., Wright, T. J., and Yirgu, G.: Geodetic observations of the ongoing Dabbahu rifting episode: new dyke intrusions in 2006 and 2007, Geophys. J. Int., 178(2), 989â€“1003, http://dx.doi.org/10.1111/j.1365-246X.2009.04163.xdoi:10.1111/j.1365-246X.2009.04163.x, 2009. </mixed-citation>
</ref>
<ref id="ref41">
<label>41</label><mixed-citation publication-type="other" xlink:type="simple"> Hanson, D. R. and Lovejoy, E. R.: Measurement of the thermodynamics of the hydrated dimer and trimer of sulfuric acid, J. Phys. Chem. A, 110(31), 9525â€“9528, http://dx.doi.org/10.1021/jp062844wdoi:10.1021/jp062844w, 2006. </mixed-citation>
</ref>
<ref id="ref42">
<label>42</label><mixed-citation publication-type="other" xlink:type="simple"> Heald, C. L., Jacob, D. J., Park, R. J., Russell, L. M., Huebert, B. J., Seinfeld, J. H., Liao, H., and Weber, R. J.: A large organic aerosol source in the free troposphere missing from current models, Geophys. Res. Lett., 32(18), L18809, http://dx.doi.org/10.1029/2005GL023831doi:10.1029/2005GL023831, 2005. </mixed-citation>
</ref>
<ref id="ref43">
<label>43</label><mixed-citation publication-type="other" xlink:type="simple"> Hermann, M., Heintzenberg, J., Wiedensohler, A., Zahn, A., Heinrich, G., and Brenninkmeijer, C. A. M.: Meridional distributions of aerosol particle number concentrations in the upper troposphere and lower stratosphere obtained by Civil Aircraft for Regular Investigation of the Atmosphere Based on an Instrument Container (CARIBIC) flights, J. Geophys. Res.-Atmos., 108(D3), 4114, doi:4110.1029/2001JD001077, 2003. </mixed-citation>
</ref>
<ref id="ref44">
<label>44</label><mixed-citation publication-type="other" xlink:type="simple"> Hermann, M., Adler, S., Caldow, R., Stratmann, F., and Wiedensohler, A.: Pressure-dependent efficiency of a condensation particle counter operated with FC-43 as working fluid, J. Aerosol Sci., 36(11), 1322â€“1337, 2005. </mixed-citation>
</ref>
<ref id="ref45">
<label>45</label><mixed-citation publication-type="other" xlink:type="simple"> Homan, C. D., Volk, C. M., Kuhn, A. C., Werner, A., Baehr, J., Viciani, S., Ulanovski, A., and Ravegnani, F.: Tracer measurements in the tropical tropopause layer during the AMMA/SCOUT-O3 aircraft campaign, Atmos. Chem. Phys., 10, 3615â€“3627, http://dx.doi.org/10.5194/acp-10-3615-2010doi:10.5194/acp-10-3615-2010, 2010. </mixed-citation>
</ref>
<ref id="ref46">
<label>46</label><mixed-citation publication-type="other" xlink:type="simple"> Huntrieser, H., Feigl, C., Schlager, H., SchrÃ¶der, F., Gerbig, C., van Velthoven, P., FlatÃ¸y, F., ThÃ©ry, C., Petzold, A., HÃ¶ller, H., Schumann, U., Airborne measurements of NO&lt;sub&gt;x&lt;/sub&gt;, tracer species and small particles during the European Lightning Nitrogen Oxides Experiment, J. Geophys. Res.-Atmos., 107(11), 4113, http://dx.doi.org/10.1029/2000JD000209doi:10.1029/2000JD000209, 2002. </mixed-citation>
</ref>
<ref id="ref47">
<label>47</label><mixed-citation publication-type="other" xlink:type="simple"> Kazil, J. and Lovejoy, E. R.: Tropospheric ionization and aerosol production: A model study, J. Geophys. Res.-Atmos., 109(D19), D19206, doi:19210.11029/12004JD004852, 2004. </mixed-citation>
</ref>
<ref id="ref48">
<label>48</label><mixed-citation publication-type="other" xlink:type="simple"> Kazil, J., Lovejoy, E. R., Barth, M. C., and O&apos;Brien, K.: Aerosol nucleation over oceans and the role of galactic cosmic rays, Atmos. Chem. Phys., 6, 4905â€“4924, http://dx.doi.org/10.5194/acp-6-4905-2006doi:10.5194/acp-6-4905-2006, 2006. </mixed-citation>
</ref>
<ref id="ref49">
<label>49</label><mixed-citation publication-type="other" xlink:type="simple"> Kazil, J., Lovejoy, E. R., Jensen, E. J., and Hanson, D. R.: Is aerosol formation in cirrus clouds possible?, Atmos. Chem. Phys., 7, 1407â€“1413, http://dx.doi.org/10.5194/acp-7-1407-2007doi:10.5194/acp-7-1407-2007, 2007. </mixed-citation>
</ref>
<ref id="ref50">
<label>50</label><mixed-citation publication-type="other" xlink:type="simple"> Kerminen, V.-M., PetÃ¤jÃ¤, T., Manninen, H. E., Paasonen, P., Nieminen, T., SipilÃ¤, M., Junninen, H., Ehn, M., GagnÃ©, S., Laakso, L., Riipinen, I., VehkamÃ¤ki, H., Kurten, T., Ortega, I. K., Dal Maso, M., Brus, D., HyvÃ¤rinen, A., Lihavainen, H., LeppÃ¤, J., Lehtinen, K. E. J., Mirme, A., Mirme, S., HÃµrrak, U., Berndt, T., Stratmann, F., Birmili, W., Wiedensohler, A., Metzger, A., Dommen, J., Baltensperger, U., Kiendler-Scharr, A., Mentel, T. F., Wildt, J., Winkler, P. M., Wagner, P. E., Petzold, A., Minikin, A., Plass-DÃ¼lmer, C., PÃ¶schl, U., Laaksonen, A., and Kulmala, M.: Atmospheric nucleation: highlights of the EUCAARI project and future directions, Atmos. Chem. Phys., 10, 10829â€“10848, http://dx.doi.org/10.5194/acp-10-10829-2010doi:10.5194/acp-10-10829-2010, 2010. </mixed-citation>
</ref>
<ref id="ref51">
<label>51</label><mixed-citation publication-type="other" xlink:type="simple"> Khosrawi, F. and Konopka, P.: Enhanced particle formation and growth due to mixing processes in the tropopause region, Atmos. Environ., 37(7), 903â€“910, 2003. </mixed-citation>
</ref>
<ref id="ref52">
<label>52</label><mixed-citation publication-type="other" xlink:type="simple"> Konopka, P., GÃ¼nther, G., MÃ¼ller, R., dos Santos, F. H. S., Schiller, C., Ravegnani, F., Ulanovsky, A., Schlager, H., Volk, C. M., Viciani, S., Pan, L. L., McKenna, D.-S., and Riese, M.: Contribution of mixing to upward transport across the tropical tropopause layer (TTL), Atmos. Chem. Phys., 7, 3285â€“3308, http://dx.doi.org/10.5194/acp-7-3285-2007doi:10.5194/acp-7-3285-2007, 2007. </mixed-citation>
</ref>
<ref id="ref53">
<label>53</label><mixed-citation publication-type="other" xlink:type="simple"> Krejci, R., StrÃ¶m, J., de Reus, M., Hoor, P., Williams, J., Fischer, H., and Hansson, H. C.: Evolution of aerosol properties over the rain forest in Surinam, South America, observed from aircraft during the LBA-CLAIRE 98 experiment, J. Geophys. Res.-Atmos., 108(D18), 4561, http://dx.doi.org/10.1029/2001JD001375doi:10.1029/2001JD001375, 2003. </mixed-citation>
</ref>
<ref id="ref54">
<label>54</label><mixed-citation publication-type="other" xlink:type="simple"> Kulmala, M., Reissell, A., SipilÃ¤, M., Bonn, B., Ruuskanen, T. M., Lehtinen, K. E. J., Kerminen, V.-M., and StrÃ¶m, J.: Deep convective clouds as aerosol production engines: Role of insoluble organics, J. Geophys. Res., 111, D17202, http://dx.doi.org/10.1029/2005JD006963doi:10.1029/2005JD006963, 2006. </mixed-citation>
</ref>
<ref id="ref55">
<label>55</label><mixed-citation publication-type="other" xlink:type="simple"> Law, K. S., Fierli, F., Cairo, F., Schlager, H., Borrmann, S., Streibel, M., Real, E., Kunkel, D., Schiller, C., Ravegnani, F., Ulanovsky, A., D&apos;Amato, F., Viciani, S., and Volk, C. M.: Air mass origins influencing TTL chemical composition over West Africa during 2006 summer monsoon, Atmos. Chem. Phys., 10, 10753â€“10770, http://dx.doi.org/10.5194/acp-10-10753-2010doi:10.5194/acp-10-10753-2010, 2010. </mixed-citation>
</ref>
<ref id="ref56">
<label>56</label><mixed-citation publication-type="other" xlink:type="simple"> Lee, S. H., Reeves, J. M. , Wilson, J. C. , Hunton, D. E., Viggiano, A. A., Miller, T. M., Ballenthin, J. O., and Lait, L. R.: Particle formation by ion nucleation in the upper troposphere and lower stratosphere, Science, 301(5641), 1886â€“1889, 2003. </mixed-citation>
</ref>
<ref id="ref57">
<label>57</label><mixed-citation publication-type="other" xlink:type="simple"> Lee, S. H., Wilson, J. C., Baumgardner, D., Herman, R. L., Weinstock, E. M., LaFleur, B. G., Kok, G., Anderson, B., Lawson, P., Baker, B., Strawa, A., Pittman, J. V., Reeves, J. M., and Bui, T. P.: New particle formation observed in the tropical/subtropical cirrus clouds, J. Geophys. Res.-Atmos., 109(D20), D20209, doi:20210.21029/22004JD005033, 2004. </mixed-citation>
</ref>
<ref id="ref58">
<label>58</label><mixed-citation publication-type="other" xlink:type="simple"> Lelieveld, J., Crutzen, P. J., Ramanathan, V., Andreae, M. O., Brenninkmeijer, C. A. M., Campos, T., Cass, G. R., Dickerson, R. R., Fischer, H., de Gouw, J. A., Hansel, A., Jefferson, A., Kley, D., de Laat, A. T. J., Lal, S., Lawrence, M. G., Lobert, J. M., Mayol-Bracero, O. L., Mitra, A. P., Novakov, T., Oltmans, S. J., Prather, K. A., Reiner, T., Rodhe, H., Scheeren, H. A., Sikka, D., and Williams, J.: The Indian Ocean Experiment: Widespread Air Pollution from South and Southeast Asia, Science, 291, 1031â€“1036, 2001. </mixed-citation>
</ref>
<ref id="ref59">
<label>59</label><mixed-citation publication-type="other" xlink:type="simple"> Li, K.-F., Cageao, R. P., Karpilovsky, E. M., Mills, F. P., Yung, Y. L., Margolis, J. S., and Sander, S. P.: OH column abundance over Table Mountain Facility, California: AM-PM diurnal asymmetry, Geophys. Res. Lett., 32, L13813, http://dx.doi.org/10.1029/2005GL022521doi:10.1029/2005GL022521, 2005. </mixed-citation>
</ref>
<ref id="ref60">
<label>60</label><mixed-citation publication-type="other" xlink:type="simple"> Lovejoy, E. R., Curtius, J., and Froyd, K. D.: Atmospheric ion-induced nucleation of sulfuric acid and water, J. Geophys. Res.-Atmos., 109(D8), D08204, doi:08210.01029/02003JD004460, 2004. </mixed-citation>
</ref>
<ref id="ref61">
<label>61</label><mixed-citation publication-type="other" xlink:type="simple"> Lovejoy, E. R. and Curtius, J.: Cluster Ion Thermal Decomposition (II): Master Equation Modeling in the Low-Pressure Limit and Fall-Off Regions. Bond Energies for HSO&lt;sub&gt;4&lt;/sub&gt;-(H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;)x(HNO&lt;sub&gt;3&lt;/sub&gt;)y, J. Phys. Chem. A, 105, 10874â€“10883, 2001. </mixed-citation>
</ref>
<ref id="ref62">
<label>62</label><mixed-citation publication-type="other" xlink:type="simple"> Lucas, D. D. and Akimoto, H.: Evaluating aerosol nucleation parameterizations in a global atmospheric model, Geophys. Res. Lett., 33 L10808, doi:10810.11029/12006GL025672, 2006. </mixed-citation>
</ref>
<ref id="ref63">
<label>63</label><mixed-citation publication-type="other" xlink:type="simple"> Merikanto, J., Napari, I., VehkamÃ¤ki, H., Anttila, T., and Kulmala, M.: New parameterization of sulfuric acid-ammonia-water ternary nucleation rates at tropospheric conditions, J. Geophys. Res.-Atmos., 112(D15), D15207, http://dx.doi.org/10.1029/2006JD007977doi:10.1029/2006JD007977, 2007. </mixed-citation>
</ref>
<ref id="ref64">
<label>64</label><mixed-citation publication-type="other" xlink:type="simple"> Metzger, A., Verheggen, B., Dommen, J., Duplissy, J., Prevot, A. S. H., Weingartner, E., Riipinen, I., Kulmala, M., Spracklen, D. V., Carslaw, K. S., and Baltensperger, U.: Evidence for the role of organics in aerosol particle formation under atmospheric conditions, P. Natl. Acad. Sci. USA , 107(15), 6646â€“6651, http://dx.doi.org/10.1073/pnas.0911330107doi:10.1073/pnas.0911330107, 2010. </mixed-citation>
</ref>
<ref id="ref65">
<label>65</label><mixed-citation publication-type="other" xlink:type="simple"> Minikin, A., Petzold, A., StrÃ¶m, J., Krejci, R., Seifert,M., van Velthoven, P., Schlager, H., and Schumann, U.: Aircraft observations of the upper tropospheric fine particle aerosol in the Northern and Southern Hemispheres at midlatitudes, Geophys. Res. Lett., 30(10), 1503, doi:1510.1029/2002GL016458, 2003. </mixed-citation>
</ref>
<ref id="ref66">
<label>66</label><mixed-citation publication-type="other" xlink:type="simple"> Mirme, S., Mirme, A., Minikin, A., Petzold, A., HÃµrrak, U., Kerminen, V.-M., and Kulmala, M.: Atmospheric sub-3 nm particles at high altitudes, Atmos. Chem. Phys., 10, 437â€“451, http://dx.doi.org/10.5194/acp-10-437-2010doi:10.5194/acp-10-437-2010, 2010. </mixed-citation>
</ref>
<ref id="ref67">
<label>67</label><mixed-citation publication-type="other" xlink:type="simple"> Murphy, D. M., Thomson, D. S., and Mahoney, M. J.: In situ measurements of organics, meteoritic material, mercury, and other elements in aerosols at 5 to 19 kilometers, Science, 282(5394), 1664â€“1669, 1998. </mixed-citation>
</ref>
<ref id="ref68">
<label>68</label><mixed-citation publication-type="other" xlink:type="simple"> Murphy, D. M., Cziczo, D. J., Froyd, K. D., Hudson, P. K., Matthew, B. M., Middlebrook, A. M., Peltier, R. E., Sullivan, A., Thomson, D. S., and Weber, R. J.: Single-particle mass spectrometry of tropospheric aerosol particles, J. Geophys. Res., 111, D23S32, http://dx.doi.org/10.1029/2006JD007340doi:10.1029/2006JD007340, 2006. </mixed-citation>
</ref>
<ref id="ref69">
<label>69</label><mixed-citation publication-type="other" xlink:type="simple"> O&apos;Brien, K.: The theory of cosmic-ray and high-energy solar-particle transport in the atmosphere, in: The natural radiation environment VII, edited by: McLaughlin, J. P. and Simopoulos, E. S., and SteinhÃ¤usler, F., Proceedings of the Seventh International Symposium on the Natural Radiation Environment, Rhodes, Greece, 20â€“24 May, 2002, Elsevier, 2005. </mixed-citation>
</ref>
<ref id="ref70">
<label>70</label><mixed-citation publication-type="other" xlink:type="simple"> Riediger, O., Volk, C. M., Strunk, M., and Schmidt, U.: HAGAR- A new in situ tracer instrument for stratospheric balloons and high altitude aircraft, Eur. Comm. Air Pollut. Res. Report 73, 727â€“730, 2000. </mixed-citation>
</ref>
<ref id="ref71">
<label>71</label><mixed-citation publication-type="other" xlink:type="simple"> Schumann, U.: TROCCINOX â€“ Tropical Convection, Cirrus and Nitrogen Oxides Experiment, Overview, General Assembly 2005 of the European Geosciences Union, Vienna, Austria, 24â€“29 April 2005, 2005. </mixed-citation>
</ref>
<ref id="ref72">
<label>72</label><mixed-citation publication-type="other" xlink:type="simple"> Schumann, U. and Huntrieser, H.: The global lightning-induced nitrogen oxides source, Atmos. Chem. Phys., 7, 3823â€“3907, http://dx.doi.org/10.5194/acp-7-3823-2007doi:10.5194/acp-7-3823-2007, 2007. </mixed-citation>
</ref>
<ref id="ref73">
<label>73</label><mixed-citation publication-type="other" xlink:type="simple"> Schiller, C., GrooÃŸ, J.-U., Konopka, P., PlÃ¶ger, F., Silva dos Santos, F. H., and Spelten, N.: Hydration and dehydration at the tropical tropopause, Atmos. Chem. Phys., 9, 9647â€“9660, http://dx.doi.org/10.5194/acp-9-9647-2009doi:10.5194/acp-9-9647-2009, 2009. </mixed-citation>
</ref>
<ref id="ref74">
<label>74</label><mixed-citation publication-type="other" xlink:type="simple"> Seinfeld, J. H. and Pandis, S. N.: Atmospheric Chemistry and Physics - From Air Pollution to Climate Change (2nd edition), John Wiley &amp; Sons, 2006. </mixed-citation>
</ref>
<ref id="ref75">
<label>75</label><mixed-citation publication-type="other" xlink:type="simple"> Shur, G. H., Sitnikov, N. M., and Drynkov, A. V.: A mesoscale structure of meteorological ?elds in the tropopause layer and in the lower stratosphere over the Southern tropics (Brazil), Russ. Meteorol. Hydrol., 32, 48749, 2007. </mixed-citation>
</ref>
<ref id="ref76">
<label>76</label><mixed-citation publication-type="other" xlink:type="simple"> Sokolov, L. and Lepuchov, B.: Protocol of interaction between Unit for Connection with Scientific Equipment (UCSE) and on-board scientific equipment of Geophysica aircraft (Second edition), Myasishchev Design Bureau (MDB), 1998. </mixed-citation>
</ref>
<ref id="ref77">
<label>77</label><mixed-citation publication-type="other" xlink:type="simple"> Stohl, A., Wotawa, G., Seibert, P., and Kromp-Kolb, H.: Interpolation errors in wind fields as a function of spatial and temporal resolution and their impact on different types of kinematic trajectories, J. Appl. Meteor., 34, 2149â€“2165, 1995. </mixed-citation>
</ref>
<ref id="ref78">
<label>78</label><mixed-citation publication-type="other" xlink:type="simple"> Stohl, A., Hittenberger, M., and Wotawa, G.: Validation of the Lagrangian particle dispersion model FLEXPART against large scale tracer experiments, Atmos. Environ., 32, 4245â€“4264, 1998. </mixed-citation>
</ref>
<ref id="ref79">
<label>79</label><mixed-citation publication-type="other" xlink:type="simple"> Stohl, A., Haimberger, L., Scheele, M. P., and Wernli, H.: An intercomparison of results from three trajectory models, Meteor. Appl., 8, 127â€“135, 2001. </mixed-citation>
</ref>
<ref id="ref80">
<label>80</label><mixed-citation publication-type="other" xlink:type="simple"> Stohl, A., Forster, C., Eckhardt, S., Spichtinger, N., Huntrieser, H., Heland, J., Schlager, H., Wilhelm, S., Arnold, F., and Cooper, O.: A backward modeling study of intercontinental pollution transport using aircraft measurements, J. Geophys. Res.-Atmos., 108(D12), 4370, http://dx.doi.org/10.1029/2002JD002862doi:10.1029/2002JD002862, 2003. </mixed-citation>
</ref>
<ref id="ref81">
<label>81</label><mixed-citation publication-type="other" xlink:type="simple"> Stohl, A., Forster, C., Frank, A., Seibert, P., and Wotawa, G.: Technical note: The Lagrangian particle dispersion model FLEXPART version 6.2, Atmos. Chem. Phys., 5, 2461â€“2474, http://dx.doi.org/10.5194/acp-5-2461-2005doi:10.5194/acp-5-2461-2005, 2005. </mixed-citation>
</ref>
<ref id="ref82">
<label>82</label><mixed-citation publication-type="other" xlink:type="simple"> Stohl, A., Andrews, E., Burkhart, J. F., Forster, C., Herber, A., Hoch, S. W., Kowal, D., Lunder, C. Mefford, T. , Ogren, J. A., Sharma, S., Spichtinger, N., Stebel, K., Stone, R., StrÃ¶m, J., TÃ¸rseth, K., Wehrli, C., and Yttri, K. E.: Pan-Arctic enhancements of light absorbing aerosol concentrations due to North American boreal forest fires during summer 2004, J. Geophys. Res., 111, D22214, http://dx.doi.org/10.1029/2006JD007216doi:10.1029/2006JD007216, 2006. </mixed-citation>
</ref>
<ref id="ref83">
<label>83</label><mixed-citation publication-type="other" xlink:type="simple"> Thomason, L. and Peter, T. (Eds.): SPARC Assessment of Stratospheric Aerosol Properties, WCRP-124, WMO/TD-No. 1295, SPARC Report No. 4, Toronto, Canada, 2006. </mixed-citation>
</ref>
<ref id="ref84">
<label>84</label><mixed-citation publication-type="other" xlink:type="simple"> Thornton, D. C., Bandy, A. R., Blomquist, B. W., Bradshaw, J. D., and Blake, D. R.: Vertical transport of sulfur dioxide and dimethyl sulfide in deep convection and its role in new particle formation, J. Geophys. Res., 102(D23), 28501â€“28509, 1997. </mixed-citation>
</ref>
<ref id="ref85">
<label>85</label><mixed-citation publication-type="other" xlink:type="simple"> Twohy, C. H., Clement, C. F., Gandrud, B. W., Weinheimer, A. J., Campos, T. L., Baumgardner, D., Brune, W. H., Faloona, I., Sachse, G. W., Vay, S. A., and Tan, D.: Deep convection as a source of new particles in the midlatitude upper troposphere, J. Geophys. Res., 107(D21), 4560, http://dx.doi.org/10.1029/2001JD000323doi:10.1029/2001JD000323, 2002. </mixed-citation>
</ref>
<ref id="ref86">
<label>86</label><mixed-citation publication-type="other" xlink:type="simple"> Viciani, S., D&apos;Amato, F., Mazzinghi, P., Castagnoli, F., Toci, G., and Werle, P. A.: A cryogenically operated laser diode spectrometer for airborne measurement of stratospheric trace gases, Appl. Phys. B., 90, 581â€“592, 2008. </mixed-citation>
</ref>
<ref id="ref87">
<label>87</label><mixed-citation publication-type="other" xlink:type="simple"> Wang, S., Pickett, H. M., Pongetti, T. J., Cheung, R., Yung, Y. L., Shim, C., Li, Q., Canty, T., Salawitch, R. J., Jucks, K. W., Drouin, B., and Sander, S. P.: Validation of Aura Microwave Limb Sounder OH measurements with Fourier Transform Ultra-Violet Spectrometer total OH column measurements at Table Mountain, California, J. Geophys. Res., 113, D22301, http://dx.doi.org/10.1029/2008JD009883doi:10.1029/2008JD009883, 2008. </mixed-citation>
</ref>
<ref id="ref88">
<label>88</label><mixed-citation publication-type="other" xlink:type="simple"> Weber, R. J., McMurry, P. H., Eisele, F. L., and Tanner, D. J.: Measurement of Expected Nucleation Precursor Species and 3-500-Nm Diameter Particles at Mauna-Loa-Observatory, Hawaii, J. Atmos. Sci., 52(12), 2242â€“2257, 1995. </mixed-citation>
</ref>
<ref id="ref89">
<label>89</label><mixed-citation publication-type="other" xlink:type="simple"> Weber, R. J., McMurry, P. H., Mauldin, R. L., Tanner, D. J., Eisele, F. L., Clarke, A. D., and Kapustin, V. N.: New particle formation in the remote troposphere: A comparison of observations at various sites, Geophys. Res. Lett., 26(3), 307â€“310, 1999. </mixed-citation>
</ref>
<ref id="ref90">
<label>90</label><mixed-citation publication-type="other" xlink:type="simple"> Weinzierl, B., Petzold, A., Esselborn, M., Wirth, M., Rasp, K., Kandler, K., SchÃ¼tz, L., Koepke, P., and Fiebig, M.: Airborne measurements of dust layer properties, particle size distribution and mixing state of Saharan dust during SAMUM 2006, Tellus, 61B, 96â€“117, http://dx.doi.org/10.1111/j.1600-0889.2008.00392.xdoi:10.1111/j.1600-0889.2008.00392.x, 2009. </mixed-citation>
</ref>
<ref id="ref91">
<label>91</label><mixed-citation publication-type="other" xlink:type="simple"> Weigel, R., Hermann, M., Curtius, J., Voigt, C., Walter, S., BÃ¶ttger, T., Lepukhov, B., Belyaev, G., and Borrmann, S.: Experimental characterization of the COndensation PArticle counting System for high altitude aircraft-borne application, Atmos. Meas. Tech., 2, 243â€“258, http://dx.doi.org/10.5194/amt-2-243-2009doi:10.5194/amt-2-243-2009, 2009. </mixed-citation>
</ref>
<ref id="ref92">
<label>92</label><mixed-citation publication-type="other" xlink:type="simple"> Wilson, J. C., Jonsson, H. H., Brock, C. A., Toohey, D. W., Avalone, L. M., Baumgardner, D., Dye, J. E., Poole, L. R., Woods, D. C., DeCoursey, R. J., Osborne, M., Pitts, M. C., Kelly, K. K., Chan, K. R., Ferry, G. V., Loewenstein, M., Podolske, J. R., and Weaver, S.: In situ observations of aerosol and chlorine monoxide after the 1991 eruption of Mount Pinatubo: effect of reactions on sulfate aerosol, Science, 261, 1140â€“1143, 1993. </mixed-citation>
</ref>
<ref id="ref93">
<label>93</label><mixed-citation publication-type="other" xlink:type="simple"> Wilson, J. C., Lee, S.-H., Reeves, J. M., Brock, C. A., Jonsson, H. H., Lafleur, B. G., Loewenstein, M., Podolske, J., Atlas, E., Boering, K., Toon, G., Fahey, D., Bui, T. P., Diskin, G., and Moore, F.: Steady-state aerosol distributions in the extra-tropical, lower stratosphere and the processes that maintain them, Atmos. Chem. Phys., 8, 6617â€“6626, http://dx.doi.org/10.5194/acp-8-6617-2008doi:10.5194/acp-8-6617-2008, 2008. </mixed-citation>
</ref>
<ref id="ref94">
<label>94</label><mixed-citation publication-type="other" xlink:type="simple"> Yu, F. Q. and Turco, R. P.: From molecular clusters to nanoparticles: Role of ambient ionization in tropospheric aerosol formation, J. Geophys. Res.-Atmos., 106(D5), 4797â€“4814, 2001. </mixed-citation>
</ref>
<ref id="ref95">
<label>95</label><mixed-citation publication-type="other" xlink:type="simple"> Zhang, R. Y., Suh, I. Zhao, J., Zhang, D., Fortner, E. C., Tie, X., Molina, L. T., and Molina, M. J.: Atmospheric new particle formation enhanced by organic acids, Science, 304(5676), 1487â€“1490, 2004. </mixed-citation>
</ref>
</ref-list>
</back>
</article>