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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>GÃ¶ttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/acp-11-9375-2011</article-id>
<title-group>
<article-title>Source apportionment of the carbonaceous aerosol in Norway &amp;ndash; quantitative estimates based on &lt;sup&gt;14&lt;/sup&gt;C, thermal-optical and organic tracer analysis</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Yttri</surname>
<given-names>K. E.</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>Simpson</surname>
<given-names>D.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>StenstrÃ¶m</surname>
<given-names>K.</given-names>
</name>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Puxbaum</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>Svendby</surname>
<given-names>T.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Norwegian Institute for Air Research, Kjeller, Norway</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>EMEP MSC-W, Norwegian Meteorological Institute, Oslo, Norway</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>Dept. Earth &amp; Space Sciences, Chalmers Univ. Technology, Gothenburg, Sweden</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>Dept. Physics, Lund University, Lund, Sweden</addr-line>
</aff>
<aff id="aff5">
<label>5</label>
<addr-line>Inst. for Chemical Technologies and Analytics; Vienna University of Technology, Vienna, Austria</addr-line>
</aff>
<pub-date pub-type="epub">
<day>09</day>
<month>09</month>
<year>2011</year>
</pub-date>
<volume>11</volume>
<issue>17</issue>
<fpage>9375</fpage>
<lpage>9394</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.net/11/9375/2011/acp-11-9375-2011.html">This article is available from http://www.atmos-chem-phys.net/11/9375/2011/acp-11-9375-2011.html</self-uri>
<self-uri xlink:href="http://www.atmos-chem-phys.net/11/9375/2011/acp-11-9375-2011.pdf">The full text article is available as a PDF file from http://www.atmos-chem-phys.net/11/9375/2011/acp-11-9375-2011.pdf</self-uri>
<abstract>
<p>In the present study, source apportionment of the ambient summer
and winter time particulate carbonaceous matter (PCM) in aerosol
particles (PM&lt;sub&gt;1&lt;/sub&gt; and PM&lt;sub&gt;10&lt;/sub&gt;) has been conducted for the Norwegian urban
and rural background environment. Statistical treatment of data from
thermal-optical, &lt;sup&gt;14&lt;/sup&gt;C and organic tracer analysis using Latin Hypercube
Sampling has allowed for quantitative estimates of seven different sources
contributing to the ambient carbonaceous aerosol. These are: elemental
carbon from combustion of biomass (EC&lt;sub&gt;bb&lt;/sub&gt;) and fossil fuel (EC&lt;sub&gt;ff&lt;/sub&gt;),
primary and secondary organic carbon arising from combustion of
biomass (OC&lt;sub&gt;bb&lt;/sub&gt;) and fossil fuel (OC&lt;sub&gt;ff&lt;/sub&gt;), primary biological aerosol
particles (OC&lt;sub&gt;PBAP&lt;/sub&gt;, which includes plant debris, OC&lt;sub&gt;pbc&lt;/sub&gt;, and fungal
spores, OC&lt;sub&gt;pbs&lt;/sub&gt;), and secondary organic aerosol from biogenic precursors
(OC&lt;sub&gt;BSOA&lt;/sub&gt;).

&lt;br&gt;&lt;br&gt;

Our results show that emissions from natural sources were particularly
abundant in summer, and with a more pronounced influence at the rural
compared to the urban background site. 80% of total carbon (TC&lt;sub&gt;p&lt;/sub&gt;,
corrected for the positive artefact) in PM&lt;sub&gt;10&lt;/sub&gt; and ca. 70% of TC&lt;sub&gt;p&lt;/sub&gt;in
PM&lt;sub&gt;1&lt;/sub&gt; could be attributed to natural sources at the rural background site
in summer.  Natural sources account for about 50% of TC&lt;sub&gt;p&lt;/sub&gt; in PM&lt;sub&gt;10&lt;/sub&gt;
at the urban background site as well.  The natural source contribution
was always dominated by OC&lt;sub&gt;BSOA&lt;/sub&gt;, regardless of season, site and size
fraction. During winter anthropogenic sources totally dominated the
carbonaceous aerosol (80â€“90%). Combustion of biomass contributed
slightly more than fossil-fuel sources in winter, whereas emissions from
fossil-fuel sources were more abundant in summer.

&lt;br&gt;&lt;br&gt;

Mass closure calculations show that PCM made significant contributions to  the mass concentration of the ambient PM regardless of
size fraction, season, and site. A larger fraction of PM&lt;sub&gt;1&lt;/sub&gt; (ca. 40â€“60%) was
accounted for by carbonaceous matter compared to PM&lt;sub&gt;10&lt;/sub&gt; (ca. 40â€“50%), but
only by a small margin. In general, there were no pronounced differences
in the relative contribution of carbonaceous matter to PM with respect
to season or between the two sites.</p>
</abstract>
<counts><page-count count="20"/></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"> Achard, F., Eva, H D., Mollicone, D., and Beuchle, R.: The effect of climate anomalies and human ignition factor on wildfires in Russian boreal forests, Phil. Trans. R. Soc. Lond. B, 363, 2331â€“2339, 2008.  </mixed-citation>
</ref>
<ref id="ref2">
<label>2</label><mixed-citation publication-type="other" xlink:type="simple"> Aiken, A C., Decarlo, P F., Kroll, J H., Worsnop, D R., Huffman, J A., Docherty, K S., Ulbrich, I M., Mohr, C., Kimmel, J R., Sueper, D., Sun, Y., Zhang, Q., Trimborn, A., Northway, M., Ziemann, P J., Canagaratna, M R., Onasch, T B., Alfarra, M R., PrÃ©vÃ´t, A. S H., Dommen, J., Duplissy, J., Metzger, A., Baltensperger, U., and Jimenez, J L.: O/C and OM/OC ratios of primary, secondary, and ambient organic aerosols with high-resolution time-of-flight aerosol mass spectrometry, Environ. Sci. Technol., 42, 4478â€“4485, http://dx.doi.org/10.1021/es703009qdoi:10.1021/es703009q, 2008. </mixed-citation>
</ref>
<ref id="ref3">
<label>3</label><mixed-citation publication-type="other" xlink:type="simple"> Andersson-SkÃ¶ld, Y. and Simpson, D.: Secondary organic aerosol formation in Northern Europe: a model study, J. Geophys. Res., 106, 7357â€“7374, 2001. </mixed-citation>
</ref>
<ref id="ref4">
<label>4</label><mixed-citation publication-type="other" xlink:type="simple"> Baltensperger, U., Kalberer, M., Dommen, J., Paulsen, D., Alfarra, M R., Coe, H., Fisseha, R., Gascho, A., Gysel, M., Nyeki, S., Sax, M., Steinbacher, M., PrÃ©vÃ´t, A. S H., SjÃ¶gren, S., Weingartner, E., and R., Z.: Secondary organic aerosols from anthropogenic and biogenic precursors, Faraday Discuss., 130, 265â€“278, http://dx.doi.org/10.1039/b417367hdoi:10.1039/b417367h, 2005. </mixed-citation>
</ref>
<ref id="ref5">
<label>5</label><mixed-citation publication-type="other" xlink:type="simple"> Bauer, H., Kasper-Giebl, A., Loflund, M., Giebl, H., Hitzenberger, R., Zibuschka, F., and Puxbaum, H.: The contribution of bacteria and fungal spores to the organic carbon content of cloud water, precipitation and aerosols, Atmos. Res., 64, 109â€“119, 2002. </mixed-citation>
</ref>
<ref id="ref6">
<label>6</label><mixed-citation publication-type="other" xlink:type="simple"> Bauer, H., Claeys, M., Vermeylen, R., Schueller, E., Weinke, G., Berger, A., and Puxbaum, H.: Arabitol and mannitol as tracers for the quantification of airborne fungal spores, Atmos. Environ., 42, 588â€“593, 2008a. </mixed-citation>
</ref>
<ref id="ref7">
<label>7</label><mixed-citation publication-type="other" xlink:type="simple"> Bauer, H., Schueller, E., Weinke, G., Berger, A., Hitzenberger, R., Marr, I L., and Puxbaum, H.: Significant contributions of fungal spores to the organic carbon and to the aerosol mass balance of the urban atmospheric aerosol, Atmos. Environ., 42, 5542â€“5549, 2008b. </mixed-citation>
</ref>
<ref id="ref8">
<label>8</label><mixed-citation publication-type="other" xlink:type="simple"> Beachkofski, B. and Grandhi, R.: Improved Distributed Hypercube Sampling,, Paper 2002-1274, American Institute of Aeronautics and Astronautics, prefixhttp://people.scs.fsu.edu/~burkardt/f_src/ihs/ihs.html, 2002. </mixed-citation>
</ref>
<ref id="ref9">
<label>9</label><mixed-citation publication-type="other" xlink:type="simple"> Bell, M L., Ebisu, K., Peng, R D., Samet, J M., and Dominici, F.: Hospital Admissions and Chemical Composition of Fine Particle Air Pollution, Am. J. Resp. Crit. Care, 179, 1115â€“1120, http://dx.doi.org/10.1164/rccm.200808-1240OCdoi:10.1164/rccm.200808-1240OC, 2009.  </mixed-citation>
</ref>
<ref id="ref10">
<label>10</label><mixed-citation publication-type="other" xlink:type="simple"> Bessagnet, B., Seigneur, C., and Menut, L.: Impact of dry deposition of semi-volatile organic compounds on secondary organic aerosols, Atmos. Environ., 44, 1781â€“1787, http://dx.doi.org/10.1016/j.atmosenv.2010.01.027doi:10.1016/j.atmosenv.2010.01.027, 2010.  </mixed-citation>
</ref>
<ref id="ref11">
<label>11</label><mixed-citation publication-type="other" xlink:type="simple"> Cabada, J., Pandis, S., Subramanian, R., Robinson, A., Polidori, A., and Turpin, B.: Estimating the secondary organic aerosol contribution to PM$_2.5$ using the EC tracer method, Aerosol Sci. Technol., 38, 140â€“155, 2004. </mixed-citation>
</ref>
<ref id="ref12">
<label>12</label><mixed-citation publication-type="other" xlink:type="simple"> Carlton, A G., Pinder, R W., Bhave, P V., and Pouliot, G A.: To What Extent Can Biogenic SOA be Controlled?, Environ. Sci. Technol., 44, 3376â€“3380, 2010. </mixed-citation>
</ref>
<ref id="ref13">
<label>13</label><mixed-citation publication-type="other" xlink:type="simple"> Carvalho, A., Pio, C., and Santos, C.: Water-soluble hydroxylated organic compounds in German and Finnish aerosols, Atmos. Environ., 37, 1775â€“1783, 2003. </mixed-citation>
</ref>
<ref id="ref14">
<label>14</label><mixed-citation publication-type="other" xlink:type="simple"> Castro, L M., Pio, C A., Harrison, R M., and Smith, D. J T.: Carbonaceous aerosol in urban and rural European atmospheres: estimation of secondary organic carbon concentrations, Atmos. Environ., 33, 2771â€“2781, 1999.  </mixed-citation>
</ref>
<ref id="ref15">
<label>15</label><mixed-citation publication-type="other" xlink:type="simple"> Ceburnis, D., Garbaras, A., Szidat, S., Rinaldi, M., Fahrni, S., Perron, N., Wacker, L., Leinert, S., Remeikis, V., Facchini, M. C., PrÃ©vÃ´t, A. S. H., Jennings, S. G., Ramonet, M., and O&apos;Dowd, C. D.: Quantification of the carbonaceous matter origin in submicron marine aerosol by $^13$C and $^14$C isotope analysis, Atmos. Chem. Phys., 11, 8593â€“8606, http://dx.doi.org/10.5194/acp-11-8593-2011doi:10.5194/acp-11-8593-2011, 2011. </mixed-citation>
</ref>
<ref id="ref16">
<label>16</label><mixed-citation publication-type="other" xlink:type="simple"> Chirico, R., DeCarlo, P. F., Heringa, M. F., Tritscher, T., Richter, R., PrÃ©vÃ´t, A. S. H., Dommen, J., Weingartner, E., Wehrle, G., Gysel, M., Laborde, M., and Baltensperger, U.: Impact of aftertreatment devices on primary emissions and secondary organic aerosol formation potential from in-use diesel vehicles: results from smog chamber experiments, Atmos. Chem. Phys., 10, 11545â€“11563, http://dx.doi.org/10.5194/acp-10-11545-2010doi:10.5194/acp-10-11545-2010, 2010. </mixed-citation>
</ref>
<ref id="ref17">
<label>17</label><mixed-citation publication-type="other" xlink:type="simple"> Chirico, R., PrÃ©vÃ´t, A S., DeCarlo, P F., Heringa, M F., Richter, R., Weingartner, E., and Baltensperger, U.: Aerosol and trace gas vehicle emission factors measured in a tunnel using and Aerosol Mass Spectrometer and other on-line instrumentation, Atmos. Environ., 45, 2182â€“2192, http://dx.doi.org/10.1016/j.atmosenv.2011.01.069doi:10.1016/j.atmosenv.2011.01.069, 2011. </mixed-citation>
</ref>
<ref id="ref18">
<label>18</label><mixed-citation publication-type="other" xlink:type="simple"> Chow, J C., Watson, J G., Chen, L. W A., Rice, J., and Frank, N H.: Quantification of PM$_2.5$ organic carbon sampling artifacts in US networks, Atmos. Chem. Physics, 10, 5223â€“5239, http://dx.doi.org/10.5194/acp-10-5223-2010doi:10.5194/acp-10-5223-2010, 2010. </mixed-citation>
</ref>
<ref id="ref19">
<label>19</label><mixed-citation publication-type="other" xlink:type="simple"> Chung, S H. and Seinfeld, J.: Global distribution and climate forcing of carbonaceous aerosols, J. Geophys. Res., 107, 4407, doi:101029/2001JD001397, 2002.  </mixed-citation>
</ref>
<ref id="ref20">
<label>20</label><mixed-citation publication-type="other" xlink:type="simple"> Currie, L A., Klouda, G., Schjoldager, J., and Ramdahl, T.: The power of $^14$C measurements combined with chemical characterization for tracing urban aerosol in Norway, Radiocarbon, 28, 673â€“680, 1986. </mixed-citation>
</ref>
<ref id="ref21">
<label>21</label><mixed-citation publication-type="other" xlink:type="simple"> Currie, L A., B A Benner, J., Kessler, J D., Klinedinst, D B., Klouda, G A., Marolf, J V., Slater, J F., Wise, S A., Cachier, H., Cary, R., Chow, J C., Watson, J., Druffel, E. R M., Masiello, C A., Eglinton, T I., Pearson, A., Reddy, C M., Gustafsson, O., Hartmann, P C., Quinn, J G., Hedges, J I., Prentice, K M., Kirchstetter, T W., Novakov, T., Puxbaum, H., and Schmid, H.: A critical evaluation of interlaboratory data on total, elemental, and isotopic carbon in the carbonaceous particle reference material, NIST SRM 1694a, J. Res. Natl. Inst. Stand. Technol., 107, 279â€“298, prefixwww.nist.gov/jres, 2002. </mixed-citation>
</ref>
<ref id="ref22">
<label>22</label><mixed-citation publication-type="other" xlink:type="simple"> Donahue, N., Hartz, K., Chuong, B., Presto, A., Stanier, C., RosenhÃ¸rn, T., Robinson, A., and Pandis, S.: Critical factors determining the variation in SOA yields from terpene ozonolysis: a combined experimental and computational study, Faraday Discuss., 130, 295â€“309, http://dx.doi.org/10.1039/b417369ddoi:10.1039/b417369d, 2005. </mixed-citation>
</ref>
<ref id="ref23">
<label>23</label><mixed-citation publication-type="other" xlink:type="simple"> Donahue, N., Robinson, A., Stanier, C., and Pandis, S.: Coupled Partitioning, Dilution, and Chemical Aging of Semivolatile Organics, Environ. Sci. Technol., 40, 2635â€“2643, prefixhttp://pubs3.acs.org/acs/journals/doilookup?in_doi=10.1021/e%s052297c, 2006. </mixed-citation>
</ref>
<ref id="ref24">
<label>24</label><mixed-citation publication-type="other" xlink:type="simple"> Donahue, N M., Robinson, A L., and Pandis, S N.: Atmospheric organic particulate matter: From smoke to secondary organic aerosol, Atmos. Environ., 43, 94â€“106, \doi10.1016/j.atmosenv.2008.09.055, 2009. </mixed-citation>
</ref>
<ref id="ref25">
<label>25</label><mixed-citation publication-type="other" xlink:type="simple"> Dye, C. and Yttri, K.: Determination of monosaccharide anhydrides in atmospheric aerosols by use of high-resolution mass spectrometry combined with high performance liquid chromatography, Anal. Chem., 77, 1853â€“1858, 2005. </mixed-citation>
</ref>
<ref id="ref26">
<label>26</label><mixed-citation publication-type="other" xlink:type="simple"> EdeskÃ¤r, T.: Technical and Environmental Properties of Tyre Shreds Focusing on Ground Engineering Applications, Tech Rep 2004:05, Department of Soil Mechanics and Foundation Engineering Division of Structural Engineering, LuleÃ¥ University of Technology, iSRN:LTU-TRâ€“2004/5â€“SE, 2004. </mixed-citation>
</ref>
<ref id="ref27">
<label>27</label><mixed-citation publication-type="other" xlink:type="simple"> GelencsÃ©r, A., May, B., Simpson, D., SÃ¡nchez-Ochoa, A., Kasper-Giebl, A., Puxbaum, H., Caseiro, A., Pio, C., and Legrand, M.: Source apportionment of PM$_2.5$ organic aerosol over Europe: primary/secondary, natural/anthropogenic, fossil/biogenic origin, J. Geophys. Res., 112, D23S04, http://dx.doi.org/10.1029/2006JD008094doi:10.1029/2006JD008094, 2007.  </mixed-citation>
</ref>
<ref id="ref28">
<label>28</label><mixed-citation publication-type="other" xlink:type="simple"> Gilardoni, S., Vignati, E., Cavalli, F., Putaud, J. P., Larsen, B. R., Karl, M., StenstrÃ¶m, K., Genberg, J., Henne, S., and Dentener, F.: Better constraints on sources of carbonaceous aerosols using a combined $^14$C â€“ macro tracer analysis in a European rural background site, Atmos. Chem. Phys., 11, 5685â€“5700, http://dx.doi.org/10.5194/acp-11-5685-2011doi:10.5194/acp-11-5685-2011, 2011.  </mixed-citation>
</ref>
<ref id="ref29">
<label>29</label><mixed-citation publication-type="other" xlink:type="simple"> Glasius, M., Ketzel, M., Wahlin, P., Jensen, B., Monster, J., Berkowicz, R., and Palmgren, F.: Impact of wood combustion on particle levels in a residential area in Denmark, Atmos. Environ., 40, 7115â€“7124, 2006.  </mixed-citation>
</ref>
<ref id="ref30">
<label>30</label><mixed-citation publication-type="other" xlink:type="simple"> Glasius, M., la Cour, A., and Lohse, C.: Contemporary and fossil carbon in fine particulate matter â€“ a study of five European cities, J. Geophys. Res., 116, D11302, doi:10.1029/2011JD015646, 2011.  </mixed-citation>
</ref>
<ref id="ref31">
<label>31</label><mixed-citation publication-type="other" xlink:type="simple"> Graham, B., Guyon, P., Maenhaut, W., Taylor, P., Ebert, M., Matthias-Maser, S., Mayol-Bracero, O., Godoi, R., Artaxo, P., Meixner, F., Moura, M., Rocha, C., Van~Grieken, R., Glovsky, M., Flagan, R., and Andreae, M.: Composition and diurnal variability of the natural Amazonian aerosol, J. Geophys. Res., 108, 4765, http://dx.doi.org/10.1029/2003JD004049doi:10.1029/2003JD004049, 2003. </mixed-citation>
</ref>
<ref id="ref32">
<label>32</label><mixed-citation publication-type="other" xlink:type="simple"> Grieshop, A. P., Donahue, N. M., and Robinson, A. L.: Laboratory investigation of photochemical oxidation of organic aerosol from wood fires 2: analysis of aerosol mass spectrometer data, Atmos. Chem. Phys., 9, 2227â€“2240, http://dx.doi.org/10.5194/acp-9-2227-2009doi:10.5194/acp-9-2227-2009, 2009a. </mixed-citation>
</ref>
<ref id="ref33">
<label>33</label><mixed-citation publication-type="other" xlink:type="simple"> Grieshop, A. P., Logue, J. M., Donahue, N. M., and Robinson, A. L.: Laboratory investigation of photochemical oxidation of organic aerosol from wood fires 1: measurement and simulation of organic aerosol evolution, Atmos. Chem. Phys., 9, 1263â€“1277, http://dx.doi.org/10.5194/acp-9-1263-2009doi:10.5194/acp-9-1263-2009, 2009b. </mixed-citation>
</ref>
<ref id="ref34">
<label>34</label><mixed-citation publication-type="other" xlink:type="simple"> Haakonsen, G. and Kvingedal, E.: Utslipp til luft fra vedfyring i Norge utslippsfaktorer, ildstedsbestand og fyringsvaner (in Norwegian), Statistics Norway Report 2001/36, Statistics Norway, Norway, Oslo, 2001.  </mixed-citation>
</ref>
<ref id="ref35">
<label>35</label><mixed-citation publication-type="other" xlink:type="simple"> Hallquist, M., Wenger, J. C., Baltensperger, U., Rudich, Y., Simpson, D., Claeys, M., Dommen, J., Donahue, N. M., George, C., Goldstein, A. H., Hamilton, J. F., Herrmann, H., Hoffmann, T., Iinuma, Y., Jang, M., Jenkin, M. E., Jimenez, J. L., Kiendler-Scharr, A., Maenhaut, W., McFiggans, G., Mentel, Th. F., Monod, A., PrÃ©vÃ´t, A. S. H., Seinfeld, J. H., Surratt, J. D., Szmigielski, R., and Wildt, J.: The formation, properties and impact of secondary organic aerosol: current and emerging issues, Atmos. Chem. Phys., 9, 5155â€“5236, http://dx.doi.org/10.5194/acp-9-5155-2009doi:10.5194/acp-9-5155-2009, 2009. </mixed-citation>
</ref>
<ref id="ref36">
<label>36</label><mixed-citation publication-type="other" xlink:type="simple"> Heal, M R., Naysmith, P., Cook, G T., Xu, S., Duran, T R., and Harrison, R M.: Application of $^14$C analyses to source apportionment of carbonaceous PM$_2.5$ in the UK, Atmos. Environ., 45, 2341â€“2348, http://dx.doi.org/10.1016/j.atmosenv.2011.02.029doi:10.1016/j.atmosenv.2011.02.029, 2011. </mixed-citation>
</ref>
<ref id="ref37">
<label>37</label><mixed-citation publication-type="other" xlink:type="simple"> Hedberg, E., Johansson, C., Johansson, L., Swietlicki, E., and BrorstrÃ¶m-LundÃ©n, E.: Is levoglucosan a suitable quantitative tracer for wood burning? Comparison with receptor modeling on trace elements in Lycksele, Sweden, J. Air Waste Manage., 56, 1669â€“1678, 2006. </mixed-citation>
</ref>
<ref id="ref38">
<label>38</label><mixed-citation publication-type="other" xlink:type="simple"> Heringa, M. F., DeCarlo, P. F., Chirico, R., Tritscher, T., Dommen, J., Weingartner, E., Richter, R., Wehrle, G., PrÃ©vÃ´t, A. S. H., and Baltensperger, U.: Investigations of primary and secondary particulate matter of different wood combustion appliances with a high-resolution time-of-flight aerosol mass spectrometer, Atmos. Chem. Phys., 11, 5945â€“5957, http://dx.doi.org/10.5194/acp-11-5945-2011doi:10.5194/acp-11-5945-2011, 2011. </mixed-citation>
</ref>
<ref id="ref39">
<label>39</label><mixed-citation publication-type="other" xlink:type="simple"> Hodzic, A., Jimenez, J. L., PrÃ©vÃ´t, A. S. H., Szidat, S., Fast, J. D., and Madronich, S.: Can 3-D models explain the observed fractions of fossil and non-fossil carbon in and near Mexico City?, Atmos. Chem. Phys., 10, 10997â€“11016, http://dx.doi.org/10.5194/acp-10-10997-2010doi:10.5194/acp-10-10997-2010, 2010. </mixed-citation>
</ref>
<ref id="ref40">
<label>40</label><mixed-citation publication-type="other" xlink:type="simple"> Iman, R., Helton, J., and Campbell, J.: An Approach to Sensitivity Analysis of Computer Models: Part I â€“ Introduction, Variable Selection and Preliminary Variable Assessment, J. Qual. Tech., 13, 174â€“183, 1981. </mixed-citation>
</ref>
<ref id="ref41">
<label>41</label><mixed-citation publication-type="other" xlink:type="simple"> Ion, A. C., Vermeylen, R., Kourtchev, I., Cafmeyer, J., Chi, X., Gelencsér, A., Maenhaut, W., and Claeys, M.: Polar organic compounds in rural PM$_2.5$ aerosols from K-puszta, Hungary, during a 2003 summer field campaign: Sources and diel variations, Atmos. Chem. Phys., 5, 1805â€“1814, http://dx.doi.org/10.5194/acp-5-1805-2005doi:10.5194/acp-5-1805-2005, 2005. </mixed-citation>
</ref>
<ref id="ref42">
<label>42</label><mixed-citation publication-type="other" xlink:type="simple"> Jimenez, J L., Canagaratna, M R., Donahue, N M., PrÃ©vÃ´t, A. S H., Zhang, Q., Kroll, J H., DeCarlo, P F., Allan, J D., Coe, H., Ng, N L., Aiken, A C., Docherty, K S., Ulbrich, I M., Grieshop, A P., Robinson, A L., Duplissy, J., Smith, J D., Wilson, K R., Lanz, V A., Hueglin, C., Sun, Y L., Tian, J., Laaksonen, A., Raatikainen, T., Rautiainen, J., Vaattovaara, P., Ehn, M., Kulmala, M., Tomlinson, J M., Collins, D R., Cubison, M J., E., Dunlea, J., Huffman, J A., Onasch, T B., Alfarra, M R., Williams, P I., Bower, K., Kondo, Y., Schneider, J., Drewnick, F., Borrmann, S., Weimer, S., Demerjian, K., Salcedo, D., Cottrell, L., Griffin, R., Takami, A., Miyoshi, T., Hatakeyama, S., Shimono, A., Sun, J Y., Zhang, Y M., Dzepina, K., Kimmel, J R., Sueper, D., Jayne, J T., Herndon, S C., Trimborn, A M., Williams, L R., Wood, E C., Middlebrook, A M., Kolb, C E., Baltensperger, U., and Worsnop, D R.: Evolution of Organic Aerosols in the Atmosphere, Science, 326, 1525â€“1529, http://dx.doi.org/10.1126/science.1180353doi:10.1126/science.1180353, prefixhttp://www.sciencemag.org/cgi/content/abstract/326/5959/1525, 2009.  </mixed-citation>
</ref>
<ref id="ref43">
<label>43</label><mixed-citation publication-type="other" xlink:type="simple"> Kanakidou, M., Seinfeld, J. H., Pandis, S. N., Barnes, I., Dentener, F. J., Facchini, M. C., Van Dingenen, R., Ervens, B., Nenes, A., Nielsen, C. J., Swietlicki, E., Putaud, J. P., Balkanski, Y., Fuzzi, S., Horth, J., Moortgat, G. K., Winterhalter, R., Myhre, C. E. L., Tsigaridis, K., Vignati, E., Stephanou, E. G., and Wilson, J.: Organic aerosol and global climate modelling: a review, Atmos. Chem. Phys., 5, 1053â€“1123, http://dx.doi.org/10.5194/acp-5-1053-2005doi:10.5194/acp-5-1053-2005, 2005.   </mixed-citation>
</ref>
<ref id="ref44">
<label>44</label><mixed-citation publication-type="other" xlink:type="simple"> Kiss, G., Varga, B., Galambos, I., and Ganszky, I.: Characterization of water-soluble organic matter isolated from atmospheric fine aerosol, J. Geophys. Res., 107, 8339, http://dx.doi.org/10.1029/2001JD000603doi:10.1029/2001JD000603, 2002. </mixed-citation>
</ref>
<ref id="ref45">
<label>45</label><mixed-citation publication-type="other" xlink:type="simple"> Kroll, J H. and Seinfeld, J H.: Chemistry of secondary organic aerosol: Formation and evolution of low-volatility organics in the atmosphere, Atmos. Environ., 16, 3593â€“3624, 2008. </mixed-citation>
</ref>
<ref id="ref46">
<label>46</label><mixed-citation publication-type="other" xlink:type="simple"> Kunit, M. and Puxbaum, H.: Enzymatic determination of the cellulose content of atmospheric aerosols, Atmos. Environ., 30, 1233â€“1236, 1996. </mixed-citation>
</ref>
<ref id="ref47">
<label>47</label><mixed-citation publication-type="other" xlink:type="simple"> Kupiainen, K. and Klimont, Z.: Primary emissions of submicron and carbonaceous particles and the potential for their control., IIASA IR-04-079, International Institute for Applied Systems Analysis, 2004. </mixed-citation>
</ref>
<ref id="ref48">
<label>48</label><mixed-citation publication-type="other" xlink:type="simple"> Kupiainen, K. and Klimont, Z.: Primary emissions of fine carbonaceous particles in Europe, Atmos. Environ., 41, 2156â€“2170, http://dx.doi.org/10.1016/j.atmosenv.2006.10.066doi:10.1016/j.atmosenv.2006.10.066, 2007.  </mixed-citation>
</ref>
<ref id="ref49">
<label>49</label><mixed-citation publication-type="other" xlink:type="simple"> Lanz, V. A., Alfarra, M. R., Baltensperger, U., Buchmann, B., Hueglin, C., and PrÃ©vÃ´t, A. S. H.: Source apportionment of submicron organic aerosols at an urban site by factor analytical modelling of aerosol mass spectra, Atmos. Chem. Phys., 7, 1503â€“1522, http://dx.doi.org/10.5194/acp-7-1503-2007doi:10.5194/acp-7-1503-2007, 2007. </mixed-citation>
</ref>
<ref id="ref50">
<label>50</label><mixed-citation publication-type="other" xlink:type="simple"> Lanz, V A., Alfarra, M R., Baltensperger, U., Buchmann, B., Hueglin, C., Szidat, S., Wehrli, M N., Wacker, L., Weimer, S., Caseiro, A., Puxbaum, H., and PrÃ©vÃ´t, A. S H.: Source Attribution of Submicron Organic Aerosols during Wintertime Inversions by Advanced Factor Analysis of Aerosol Mass Spectra, Environ. Sci. Technol., 42, 214â€“220, prefixhttp://pubs3.acs.org/acs/journals/doilookup?in_doi=10.1021/e%s0707207, 2008. </mixed-citation>
</ref>
<ref id="ref51">
<label>51</label><mixed-citation publication-type="other" xlink:type="simple"> Lanz, V. A., PrÃ©vÃ´t, A. S. H., Alfarra, M. R., Weimer, S., Mohr, C., DeCarlo, P. F., Gianini, M. F. D., Hueglin, C., Schneider, J., Favez, O., D&apos;Anna, B., George, C., and Baltensperger, U.: Characterization of aerosol chemical composition with aerosol mass spectrometry in Central Europe: an overview, Atmos. Chem. Phys., 10, 10453-=10471, http://dx.doi.org/10.5194/acp-10-10453-2010doi:10.5194/acp-10-10453-2010, 2010. </mixed-citation>
</ref>
<ref id="ref52">
<label>52</label><mixed-citation publication-type="other" xlink:type="simple"> Legrand, M. and Puxbaum, H.: Summary of the CARBOSOL project: Present and retrospective state of organic versus inorganic aerosol over Europe, J. Geophys. Res., 112, D23S01, http://dx.doi.org/10.1029/2006JD008271doi:10.1029/2006JD008271, 2007. </mixed-citation>
</ref>
<ref id="ref53">
<label>53</label><mixed-citation publication-type="other" xlink:type="simple"> Lewis, C W., Klouda, G., and Ellenson, W.: Radiocarbon measurement of the biogenic contribution to summertime PM-2.5 ambient aerosol in Nashville, TN, Atmos. Environ., 38, 6053â€“6061, 2004. </mixed-citation>
</ref>
<ref id="ref54">
<label>54</label><mixed-citation publication-type="other" xlink:type="simple"> Matthias-Maser, S.: Primary biological aerosol particles: Their significance, sources, sampling methods and size distribution in the atmosphere, in: Atmospheric particles, edited by: Harrison, R M. and van Grieken, R., 349â€“368, John Wiley &amp; Sons, Chichester, 1998. </mixed-citation>
</ref>
<ref id="ref55">
<label>55</label><mixed-citation publication-type="other" xlink:type="simple"> McDonald, J D., Eide, I., Seagrave, J., Zielinska, B., Whitney, K., Lawson, D R., and Mauderly, J L.: Relationship between Composition and Toxicity of Motor Vehicle Emission Samples, Environ. Health Persp., 1527â€“1538, 2004. </mixed-citation>
</ref>
<ref id="ref56">
<label>56</label><mixed-citation publication-type="other" xlink:type="simple"> McDow, S. and Huntzicker, J.: Vapor adsorption artifact in the sampling of organic aerosols: face velocity effects, Atmos. Environ., 24A, 2563â€“2571, 1990. </mixed-citation>
</ref>
<ref id="ref57">
<label>57</label><mixed-citation publication-type="other" xlink:type="simple"> McKay, M D., Beckman, R J., and Conover, W J.: A Comparison of Three Methods for Selecting Values of Input Variables in the Analysis of Output from a Computer Code, Technometrics, 21, 239â€“245, prefixhttp://www.jstor.org/stable/1268522, 1979. </mixed-citation>
</ref>
<ref id="ref58">
<label>58</label><mixed-citation publication-type="other" xlink:type="simple"> NIST/SEMATECH: e-handbook, prefixhttp://www.itl.nist.gov/div898/handbook/index.htm, 2010. </mixed-citation>
</ref>
<ref id="ref59">
<label>59</label><mixed-citation publication-type="other" xlink:type="simple"> Novakov, T. and Penner, J.: Large contribution of organic aerosols to cloud condensation nuclei concentrations, Nature, 365, 823â€“826, 1993. </mixed-citation>
</ref>
<ref id="ref60">
<label>60</label><mixed-citation publication-type="other" xlink:type="simple"> PÃ¶schl, U.: Atmospheric Aerosols: Composition, Transformation, Climate and Health Effects, Angew. Chem. Int. Ed., 44, 7520â€“7540, http://dx.doi.org/10.1002/anie.200501122doi:10.1002/anie.200501122, 2005. </mixed-citation>
</ref>
<ref id="ref61">
<label>61</label><mixed-citation publication-type="other" xlink:type="simple"> Putaud, J.-P., Raes, F., Van~Dingenen, R., Bruggemann, E., Facchini, M C., Decesari, S., Fuzzi, S., Gehrig, R., Huglin, C., Laj, P., Lorbeer, G., Maenhaut, W., Mihalopoulos, N., Muller, K., Querol, X., Rodriguez, S., Schneider, J., Spindler, G., Brink, H t., Torseth, K., and Wiedensohler, A.: A European aerosol phenomenologyâ€“2: chemical characteristics of particulate matter at kerbside, urban, rural and background sites in Europe, Atmos. Environ., 38, 2579â€“2595, 2004. </mixed-citation>
</ref>
<ref id="ref62">
<label>62</label><mixed-citation publication-type="other" xlink:type="simple"> Puxbaum, H. and Tenze-Kunit, M.: Size distribution and seasonal variation of atmospheric cellulose, Atmos. Environ., 37, 3693â€“3699, http://dx.doi.org/10.1016/S1352-2310(03)00451-5doi:10.1016/S1352-2310(03)00451-5, 2003. </mixed-citation>
</ref>
<ref id="ref63">
<label>63</label><mixed-citation publication-type="other" xlink:type="simple"> Puxbaum, H., Caseiro, A., SÃ¡nchez-Ochoa, A., Kasper-Giebl, A., Claeys, M., GelencsÃ©r, A., Legrand, M., Preunkert, S., and Pio, C.: Levoglucosan levels at background sites in Europe for assessing of the impact of biomass combustion on the European aerosol background, J. Geophys. Res., 112, D23S05, http://dx.doi.org/10.1029/2006JD008114doi:10.1029/2006JD008114, 2007. </mixed-citation>
</ref>
<ref id="ref64">
<label>64</label><mixed-citation publication-type="other" xlink:type="simple"> Reimer, P J., Brown, T A., and Reimer, R W.: Discussion: Reporting and calibration of post-bomb $^14$C data, Radiocarbon, 46, 1299â€“1304, 2004. </mixed-citation>
</ref>
<ref id="ref65">
<label>65</label><mixed-citation publication-type="other" xlink:type="simple"> Robinson, A L., Donahue, N M., Shrivastava, M K., Weitkamp, E A., Sage, A M., Grieshop, A P., Lane, T E., Pierce, J R., and Pandis, S N.: Rethinking Organic Aerosols: Semivolatile Emissions and Photochemical Aging, Science, 315, 1259â€“1262, http://dx.doi.org/10.1126/science.1133061doi:10.1126/science.1133061, 2007. </mixed-citation>
</ref>
<ref id="ref66">
<label>66</label><mixed-citation publication-type="other" xlink:type="simple"> Saarikoski, S., Timonen, H., Saarnio, K., Aurela, M., JÃ¤rvi, L., Keronen, P., Kerminen, V.-M., and Hillamo, R.: Sources of organic carbon in fine particulate matter in northern European urban air, Atmos. Chem. Phys., 8, 6281â€“6295, http://dx.doi.org/10.5194/acp-8-6281-2008doi:10.5194/acp-8-6281-2008, 2008. </mixed-citation>
</ref>
<ref id="ref67">
<label>67</label><mixed-citation publication-type="other" xlink:type="simple"> SÃ¡nchez-Ochoa, A., Kasper-Giebl, A., Puxbaum, H., GelencsÃ©r, A., Legrand, M., and Pio, C A.: Concentrations of Atmospheric Cellulose: A Proxy for Plant Debris, across a West-East Transect over Europe, J. Geophys. Res., 112, D23S08, http://dx.doi.org/10.1029/2006JD008180doi:10.1029/2006JD008180, 2007. </mixed-citation>
</ref>
<ref id="ref68">
<label>68</label><mixed-citation publication-type="other" xlink:type="simple"> Schauer, J., Kleeman, M., Cass, G., and Simoneit, B.: Measurement of Emissions from Air Pollution Sources. 3. C1â€“C29 Organic Compounds from Fireplace Combustion of Wood, Environ. Sci. Technol., 35, 1716â€“1728, prefixhttp://pubs3.acs.org/acs/journals/doilookup?in_doi=10.1021/e%s001331e, 2001. </mixed-citation>
</ref>
<ref id="ref69">
<label>69</label><mixed-citation publication-type="other" xlink:type="simple"> Schmid, H., Laskus, L., Jurgen~Abraham, H., Baltensperger, U., Lavanchy, V., Bizjak, M., Burba, P., Cachier, H., Crow, D., Chow, J., Gnauk, T., Even, A., ten Brink, H M., Giesen, K.-P., Hitzenberger, R., Hueglin, C., Maenhaut, W., Pio, C., Carvalho, A., Putaud, J.-P., Toom-Sauntry, D., and Puxbaum, H.: Results of the &quot;carbon conference&quot; international aerosol carbon round robin test stage I, Atmos. Environ., 35, 2111â€“2121, 2001. </mixed-citation>
</ref>
<ref id="ref70">
<label>70</label><mixed-citation publication-type="other" xlink:type="simple"> Simoneit, B.: Biomass burning â€“ a review of organic tracers for smoke from incomplete combustion, Appl. Geochem., 17, 129â€“162, 2002. </mixed-citation>
</ref>
<ref id="ref71">
<label>71</label><mixed-citation publication-type="other" xlink:type="simple"> Simpson, D., Yttri, K., Klimont, Z., Kupiainen, K., Caseiro, A., GelencsÃ©r, A., Pio, C., and Legrand, M.: Modeling Carbonaceous Aerosol over Europe. Analysis of the CARBOSOL and EMEP EC/OC campaigns, J. Geophys. Res., 112, D23S14, http://dx.doi.org/10.1029/2006JD008158doi:10.1029/2006JD008158, 2007. </mixed-citation>
</ref>
<ref id="ref72">
<label>72</label><mixed-citation publication-type="other" xlink:type="simple"> Skog, G.: The single stage AMS machine at Lund University: Status Report, Nucl. Instrum. Meth. Phys. B, 259, 1â€“6, 2007. </mixed-citation>
</ref>
<ref id="ref73">
<label>73</label><mixed-citation publication-type="other" xlink:type="simple"> Skog, G., Rundgren, M., and Skold, P.: Status of the Single Stage AMS machine at Lund University after 4 years of operation, Nucl. Instrum. Meth. Phys. B â€“ Interactions with Materials and Atoms, 268, 895â€“897, 2010.  </mixed-citation>
</ref>
<ref id="ref74">
<label>74</label><mixed-citation publication-type="other" xlink:type="simple"> Szidat, S., Jenk, T.M .and Synal, H.-A., Kalberer, M., Wacker, L., Hajdas, I., Kasper-Giebl, A., and Baltensperger, U.: Contributions of fossil fuel, biomass burning, and biogenic emissions to carbonaceous aerosols in ZÃ¼rich as traced by $^14$C, J. Geophys. Res., 111, D07206, http://dx.doi.org/10.1029/2005JD006590doi:10.1029/2005JD006590, 2006. </mixed-citation>
</ref>
<ref id="ref75">
<label>75</label><mixed-citation publication-type="other" xlink:type="simple"> Szidat, S., PrÃ©vÃ´t, A. S H., Sandradewi, J., Alfarra, M R., Synal, H.-A., Wacker, L., and Baltensperger, U.: Dominant impact of residential wood burning on particulate matter in Alpine valleys during winter, Geophys. Res. Lett., 34, L05820, http://dx.doi.org/10.1029/2006GL028325doi:10.1029/2006GL028325, 2007.  </mixed-citation>
</ref>
<ref id="ref76">
<label>76</label><mixed-citation publication-type="other" xlink:type="simple"> Szidat, S., Ruff, M., Perron, N., Wacker, L., Synal, H.-A., Hallquist, M., Shannigrahi, A. S., Yttri, K. E., Dye, C., and Simpson, D.: Fossil and non-fossil sources of organic carbon (OC) and elemental carbon (EC) in GÃ¶teborg, Sweden, Atmos. Chem. Phys., 9, 1521â€“1535, http://dx.doi.org/10.5194/acp-9-1521-2009doi:10.5194/acp-9-1521-2009, 2009.  </mixed-citation>
</ref>
<ref id="ref77">
<label>77</label><mixed-citation publication-type="other" xlink:type="simple"> Tsigaridis, K. and Kanakidou, M.: Global modelling of secondary organic aerosol in the troposphere: a sensitivity analysis, Atmos. Chem. Phys., 3, 1849â€“1869, http://dx.doi.org/10.5194/acp-3-1849-2003doi:10.5194/acp-3-1849-2003, 2003. </mixed-citation>
</ref>
<ref id="ref78">
<label>78</label><mixed-citation publication-type="other" xlink:type="simple"> Tsyro, S., Simpson, D., TarrasÃ³n, L., Kupiainen, K., Klimont, Z., Yttri, K., and Pio, C.: Modelling of black carbon over Europe, J. Geophys. Res., 112, D23S19, http://dx.doi.org/10.1029/2006JD008164doi:10.1029/2006JD008164, 2007.  </mixed-citation>
</ref>
<ref id="ref79">
<label>79</label><mixed-citation publication-type="other" xlink:type="simple"> Tunved, P., Hansson, H.-C., Kerminen, V.-M., StrÃ¶m, J., Dal~Maso, M., Lihavainen, H., Viisanen, Y., Aalto, P P., Komppula, M., and M., K.: High Natural Aerosol Loading over Boreal Forests, Science, 312, 261â€“263, 2006. </mixed-citation>
</ref>
<ref id="ref80">
<label>80</label><mixed-citation publication-type="other" xlink:type="simple"> Turpin, B J. and Lim, H J.: Species contributions to PM$_2.5$ mass concentrations: Revisiting common assumptions for estimating organic mass, Aerosol Sci. Technol., 35, 602â€“610, 2001.  </mixed-citation>
</ref>
<ref id="ref81">
<label>81</label><mixed-citation publication-type="other" xlink:type="simple"> Winiwarter, W., Haberl, H., and Simpson, D.: On the boundary between man-made and natural emissions: Problems in defining European ecosystems, J. Geophys. Res., 104, 8153â€“8159, 1999. </mixed-citation>
</ref>
<ref id="ref82">
<label>82</label><mixed-citation publication-type="other" xlink:type="simple"> Yttri, K.: Concentrations of particulate matter (PM$_10$, PM$_2.5$) in Norway. Annual and seasonal trends and spatial variability, EMEP Particulate Matter Assessment Report, Part B, Annex A, NILU EMEP/CCC-Report 8/2007, The Norwegian Institute for Air Research (NILU), Kjeller, Norway, 2007.  </mixed-citation>
</ref>
<ref id="ref83">
<label>83</label><mixed-citation publication-type="other" xlink:type="simple"> Yttri, K., Dye, C., SlÃ¸rdal, L., and Braathen, O.: Quantification of monosaccharide anhydrides by negative electrospray HPLC/HRMS-TOF â€“ application to aerosol samples from an urban and a suburban site influenced by small scale wood burning, J. Air Waste Manage., 55, 1169â€“1177, 2005.   </mixed-citation>
</ref>
<ref id="ref84">
<label>84</label><mixed-citation publication-type="other" xlink:type="simple"> Yttri, K. E., Aas, W., Bjerke, A., Cape, J. N., Cavalli, F., Ceburnis, D., Dye, C., Emblico, L., Facchini, M. C., Forster, C., Hanssen, J. E., Hansson, H. C., Jennings, S. G., Maenhaut, W., Putaud, J. P., and TÃ¸rseth, K.: Elemental and organic carbon in PM$_10$: a one year measurement campaign within the European Monitoring and Evaluation Programme EMEP, Atmos. Chem. Phys., 7, 5711â€“5725, http://dx.doi.org/10.5194/acp-7-5711-2007doi:10.5194/acp-7-5711-2007, 2007a. </mixed-citation>
</ref>
<ref id="ref85">
<label>85</label><mixed-citation publication-type="other" xlink:type="simple"> Yttri, K. E., Dye, C., and Kiss, G.: Ambient aerosol concentrations of sugars and sugar-alcohols at four different sites in Norway, Atmos. Chem. Phys., 7, 4267â€“4279, http://dx.doi.org/10.5194/acp-7-4267-2007doi:10.5194/acp-7-4267-2007, 2007b.   </mixed-citation>
</ref>
<ref id="ref86">
<label>86</label><mixed-citation publication-type="other" xlink:type="simple"> Yttri, K. E., Dye, C., Braathen, O.-A., Simpson, D., and Steinnes, E.: Carbonaceous aerosols in Norwegian urban areas, Atmos. Chem. Phys., 9, 2007â€“2020, http://dx.doi.org/10.5194/acp-9-2007-2009doi:10.5194/acp-9-2007-2009, 2009. </mixed-citation>
</ref>
<ref id="ref87">
<label>87</label><mixed-citation publication-type="other" xlink:type="simple"> Yttri, K. E., Simpson, D., NÃ¸jgaard, J. K., Kristensen, K., Genberg, J., StenstrÃ¶m, K., Swietlicki, E., Hillamo, R., Aurela, M., Bauer, H., Offenberg, J. H., Jaoui, M., Dye, C., Eckhardt, S., Burkhart, J. F., Stohl, A., and Glasius, M.: Source apportionment of the summer time carbonaceous aerosol at Nordic rural background sites, Atmos. Chem. Phys. Discuss., 11, 16369â€“16416, http://dx.doi.org/10.5194/acpd-11-16369-2011doi:10.5194/acpd-11-16369-2011, 2011. </mixed-citation>
</ref>
</ref-list>
</back>
</article>