ACP Atmospheric Chemistry and Physics ACP Atmos. Chem. Phys. 1680-7324 Copernicus Publications Göttingen, Germany 10.5194/acp-14-7807-2014 Organosulfates and organic acids in Arctic aerosols: speciation, annual variation and concentration levels Hansen A. M. K. 1 Kristensen K. 1 Nguyen Q. T. 1 2 Zare A. https://orcid.org/0000-0002-6378-8435 1 2 3 Cozzi F. 1 Nøjgaard J. K. 2 Skov H. https://orcid.org/0000-0003-1167-8696 2 4 Brandt J. 2 Christensen J. H. 2 Ström J. 5 Tunved P. 5 Krejci R. https://orcid.org/0000-0002-9384-9702 5 6 Glasius M. https://orcid.org/0000-0002-4404-6989 1 Department of Chemistry and iNANO, Aarhus University, Aarhus, Denmark Department of Environmental Science, Aarhus University, Roskilde, Denmark Institute of Geophysics, University of Tehran, Tehran, Iran University of Southern Denmark, Institute of Chemical Engineering and Biotechnology and Environmental Technology, Odense, Denmark Department of Applied Environmental Science, Stockholm University, Stockholm, Sweden Department of Physics, University of Helsinki, Helsinki, Finland 07 08 2014 14 15 7807 7823 Copyright: © 2014 A. M. K. Hansen et al. 2014 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://acp.copernicus.org/articles/14/7807/2014/acp-14-7807-2014.html The full text article is available as a PDF file from https://acp.copernicus.org/articles/14/7807/2014/acp-14-7807-2014.pdf

Sources, composition and occurrence of secondary organic aerosols in the Arctic were investigated at Zeppelin Mountain, Svalbard, and Station Nord, northeastern Greenland, during the full annual cycle of 2008 and 2010, respectively. Speciation of organic acids, organosulfates and nitrooxy organosulfates – from both anthropogenic and biogenic precursors were in focus. A total of 11 organic acids (terpenylic acid, benzoic acid, phthalic acid, pinic acid, suberic acid, azelaic acid, adipic acid, pimelic acid, pinonic acid, diaterpenylic acid acetate and 3-methyl-1,2,3-butanetricarboxylic acid), 12 organosulfates and 1 nitrooxy organosulfate were identified in aerosol samples from the two sites using a high-performance liquid chromatograph (HPLC) coupled to a quadrupole Time-of-Flight mass spectrometer. At Station Nord, compound concentrations followed a distinct annual pattern, where high mean concentrations of organosulfates (47 ± 14 ng m<sup>−3</sup>) and organic acids (11.5 ± 4 ng m<sup>−3</sup>) were observed in January, February and March, contrary to considerably lower mean concentrations of organosulfates (2 ± 3 ng m<sup>−3</sup>) and organic acids (2.2 ± 1 ng m<sup>−3</sup>) observed during the rest of the year. At Zeppelin Mountain, organosulfate and organic acid concentrations remained relatively constant during most of the year at a mean concentration of 15 ± 4 ng m<sup>−3</sup> and 3.9 ± 1 ng m<sup>−3</sup>, respectively. However during four weeks of spring, remarkably higher concentrations of total organosulfates (23–36 ng m<sup>−3</sup>) and total organic acids (7–10 ng m<sup>−3</sup>) were observed. Elevated organosulfate and organic acid concentrations coincided with the Arctic haze period at both stations, where northern Eurasia was identified as the main source region. Air mass transport from northern Eurasia to Zeppelin Mountain was associated with a 100% increase in the number of detected organosulfate species compared with periods of air mass transport from the Arctic Ocean, Scandinavia and Greenland. The results from this study suggested that the presence of organic acids and organosulfates at Station Nord was mainly due to long-range transport, whereas indications of local sources were found for some compounds at Zeppelin Mountain. Furthermore, organosulfates contributed significantly to organic matter throughout the year at Zeppelin Mountain (annual mean of 13 ± 8%) and during Arctic haze at Station Nord (7 ± 2%), suggesting organosulfates to be important compounds in Arctic aerosols.

 References ACIA: Arctic Climate Impact Assessment, Overview Report, Cambridge Univ. Press, Cambridge, 140 pp., 2004. Albrecht, B. A.: Aerosols, Cloud Microphysics, and Fractional Cloudiness, Science, 245, 1227–1230, <a href="http://dx.doi.org/10.1126/science.245.4923.1227">https://doi.org/10.1126/science.245.4923.1227</a>, 1989. Austin, J. F.: The Blocking of Middle Latitude Westerly Winds by Planetary-Waves, Q. J. Roy. Meteor. Soc., 106, 327–350, <a href="http://dx.doi.org/10.1002/qj.49710644807">https://doi.org/10.1002/qj.49710644807</a>, 1980. Barrie, L. A., Hoff, R. M., and Daggupaty, S. M.: The Influence of Mid-Latitudinal Pollution Sources on Haze in the Canadian Arctic, Atmos. Environ., 15, 1407–1419, <a href="http://dx.doi.org/10.1016/0004-6981(81)90347-4">https://doi.org/10.1016/0004-6981(81)90347-4</a>, 1981. Beine, H. J., Argentini, S., Maurizi, A., Mastrantonio, G., and Viola, A.: The local wind field at Ny-Ålesund and the Zeppelin mountain at Svalbard, Meteorol. Atmos. Phys., 78, 107–113, <a href="http://dx.doi.org/10.1007/s007030170009">https://doi.org/10.1007/s007030170009</a>, 2001. Bennartz, R., Shupe, M. D., Turner, D. D., Walden, V. P., Steffen, K., Cox, C. J., Kulie, M. S., Miller, N. B., and Pettersen, C.: July 2012 Greenland melt extent enhanced by low-level liquid clouds, Nature, 496, 83–86, <a href="http://dx.doi.org/10.1038/Nature12002">https://doi.org/10.1038/Nature12002</a>, 2013. Biesenthal, T. A. and Shepson, P. B.: Observations of anthropogenic inputs of the isoprene oxidation products methyl vinyl ketone and methacrolein to the atmosphere, Geophys. Res. Lett., 24, 1375–1378, <a href="http://dx.doi.org/10.1029/97GL01337">https://doi.org/10.1029/97GL01337</a>, 1997. Brandt, J., Silver, J. D., Frohn, L. M., Geels, C., Gross, A., Hansen, A. B., Hansen, K. M., Hedegaard, G. B., Skjoth, C. A., Villadsen, H., Zare, A., and Christensen, J. H.: An integrated model study for Europe and North America using the Danish Eulerian Hemispheric Model with focus on intercontinental transport of air pollution, Atmos. Environ., 53, 156–176, <a href="http://dx.doi.org/10.1016/j.atmosenv.2012.01.011">https://doi.org/10.1016/j.atmosenv.2012.01.011</a>, 2012. Bunce, N. J., Liu, L., Zhu, J., and Lane, D. A.: Reaction of naphthalene and its derivatives with hydroxyl radicals in the gas phase, Environ. Sci. Technol., 31, 2252–2259, <a href="http://dx.doi.org/10.1021/Es960813g">https://doi.org/10.1021/Es960813g</a>, 1997. Cavalli, F., Viana, M., Yttri, K. E., Genberg, J., and Putaud, J.-P.: Toward a standardised thermal-optical protocol for measuring atmospheric organic and elemental carbon: the EUSAAR protocol, Atmos. Meas. Tech., 3, 79–89, <a href="http://dx.doi.org/10.5194/amt-3-79-2010">https://doi.org/10.5194/amt-3-79-2010</a>, 2010. Chan, M. N., Surratt, J. D., Chan, A. W. H., Schilling, K., Offenberg, J. H., Lewandowski, M., Edney, E. O., Kleindienst, T. E., Jaoui, M., Edgerton, E. S., Tanner, R. L., Shaw, S. L., Zheng, M., Knipping, E. M., and Seinfeld, J. H.: Influence of aerosol acidity on the chemical composition of secondary organic aerosol from ?-caryophyllene, Atmos. Chem. Phys., 11, 1735–1751, <a href="http://dx.doi.org/10.5194/acp-11-1735-2011">https://doi.org/10.5194/acp-11-1735-2011</a>, 2011. Charlson, R. J., Schwartz, S. E., Hales, J. M., Cess, R. D., Coakley, J. A., Hansen, J. E., and Hofmann, D. J: Climate Forcing by Anthropogenic Aerosols, Science, 255, 423–430, <a href="http://dx.doi.org/10.1126/science.255.5043.423">https://doi.org/10.1126/science.255.5043.423</a>, 1992. Christensen, J. H.: The Danish Eulerian hemispheric model – A three-dimensional air pollution model used for the Arctic, Atmos. Environ., 31, 4169–4191, <a href="http://dx.doi.org/10.1016/S1352-2310(97)00264-1">https://doi.org/10.1016/S1352-2310(97)00264-1</a>, 1997. Claeys, M., Iinuma, Y., Szmigielski, R., Surratt, J. D., Blockhuys, F., Van Alsenoy, C., Böge, O., Sierau, B., Gomez-Gonzalez, Y., Vermeylen, R., Van der Veken, P., Shahgholi, M., Chan, A. W. H., Herrmann, H., Seinfeld, J. H., and Maenhaut, W.: Terpenylic Acid and Related Compounds from the Oxidation of alpha-Pinene: Implications for New Particle Formation and Growth above Forests, Environ. Sci. Technol., 43, 6976–6982, <a href="http://dx.doi.org/10.1021/Es9007596">https://doi.org/10.1021/Es9007596</a>, 2009. Draxler, R. R. and Hess, G. D.: An overview of the HYSPLIT\textunderscore 4 modelling system for trajectories, dispersion and deposition, Aust. Meteorol. Mag., 47, 295–308, 1998. Fenger, M., Sørensen, L. L., Kristensen, K., Jensen, B., Nguyen, Q. T., Nøjgaard, J. K., Massling, A., Skov, H., Becker, T., and Glasius, M.: Sources of anions in aerosols in northeast Greenland during late winter, Atmos. Chem. Phys., 13, 1569–1578, <a href="http://dx.doi.org/10.5194/acp-13-1569-2013">https://doi.org/10.5194/acp-13-1569-2013</a>, 2013. Frossard, A. A., Shaw, P. M., Russell, L. M., Kroll, J. H., Canagaratna, M. R., Worsnop, D. R., Quinn, P. K., and Bates, T. S.: Springtime Arctic haze contributions of submicron organic particles from European and Asian combustion sources, J. Geophys. Res.-Atmos., 116, D05205, <a href="http://dx.doi.org/10.1029/2010jd015178">https://doi.org/10.1029/2010jd015178</a>, 2011. Fu, P. Q., Kawamura, K., Chen, J., and Barrie, L. A.: Isoprene, Monoterpene, and Sesquiterpene Oxidation Products in the High Arctic Aerosols during Late Winter to Early Summer, Environ. Sci. Technol., 43, 4022–4028, <a href="http://dx.doi.org/10.1021/Es803669a">https://doi.org/10.1021/Es803669a</a>, 2009. Glasius, M., Lahaniati, M., Calogirou, A., Di Bella, D., Jensen, N. R., Hjorth, J., Kotzias, D., and Larsen, B. R.: Carboxylic acids in secondary aerosols from oxidation of cyclic monoterpenes by ozone, Environ. Sci. Technol., 34, 1001–1010, <a href="http://dx.doi.org/10.1021/Es990445r">https://doi.org/10.1021/Es990445r</a>, 2000. Gómez-Gonzàlez, Y., Surratt, J. D., Cuyckens, F., Szmigielski, R., Vermeylen, R., Jaoui, M., Lewandowski, M., Offenberg, J. H., Kleindienst, T. E., Edney, E. O., Blockhuys, F., Van Alsenoy, C., Maenhaut, W., and Claeys, M.: Characterization of organosulfates from the photooxidation of isoprene and unsaturated fatty acids in ambient aerosol using liquid chromatography/(−) electrospray ionization mass spectrometry, J. Mass Spectrom., 43, 371–382, <a href="http://dx.doi.org/10.1002/Jms.1329">https://doi.org/10.1002/Jms.1329</a>, 2008. Guenther, A.: Seasonal and spatial variations in natural volatile organic compound emissions, Ecol. Appl., 7, 34–45, <a href="http://dx.doi.org/10.2307/2269405">https://doi.org/10.2307/2269405</a>, 1997. Guenther, A., Karl, T., Harley, P., Wiedinmyer, C., Palmer, P. I., and Geron, C.: Estimates of global terrestrial isoprene emissions using MEGAN (Model of Emissions of Gases and Aerosols from Nature), Atmos. Chem. Phys., 6, 3181–3210, <a href="http://dx.doi.org/10.5194/acp-6-3181-2006">https://doi.org/10.5194/acp-6-3181-2006</a>, 2006. Hakola, H., Hellen, H., Tarvainen, V., Back, J., Patokoski, J., and Rinne, J.: Annual variations of atmospheric VOC concentrations in a boreal forest, Boreal Environ. Res., 14, 722–730, 2009. 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., Prévôt, 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, 5155–5236, <a href="http://dx.doi.org/10.5194/acp-9-5155-2009">https://doi.org/10.5194/acp-9-5155-2009</a>, 2009. Hatakeyama, S., Ohno, M., Weng, J. H., Takagi, H., and Akimoto, H.: Mechanism for the Formation of Gaseous and Particulate Products from Ozone-Cycloalkene Reactions in Air, Environ. Sci. Technol., 21, 52–57, <a href="http://dx.doi.org/10.1021/Es00155a005">https://doi.org/10.1021/Es00155a005</a>, 1987. Heidam, N. Z.: On the Origin of the Arctic Aerosol – a Statistical Approach, Atmos. Environ., 15, 1421–1427, <a href="http://dx.doi.org/10.1016/0004-6981(81)90348-6">https://doi.org/10.1016/0004-6981(81)90348-6</a>, 1981. Heidam, N. Z., Wahlin, P., and Christensen, J. H.: Tropospheric gases and aerosols in northeast Greenland, J. Atmos. Sci., 56, 261–278, <a href="http://dx.doi.org/10.1175/1520-0469(1999)056<0261:Tgaain>2.0.CO;2">https://doi.org/10.1175/1520-0469(1999)056<0261:Tgaain>2.0.CO;2</a>, 1999. Heidam, N. Z., Christensen, J., Wahlin, P., and Skov, H.: Arctic atmospheric contaminants in NE Greenland: levels, variations, origins, transport, transformations and trends 1990–2001, Sci. Total Environ., 331, 5–28, <a href="http://dx.doi.org/10.1016/j.scitotenv.2004.03.033">https://doi.org/10.1016/j.scitotenv.2004.03.033</a>, 2004. Heintzenberg, J. and Larssen, S.: SO<sub>2</sub> and SO$_4^=$ in the Arctic - Interpretation of Observations at 3 Norwegian Arctic-Subarctic Stations, Chem. Phys. Meteorol., 35, 255–265, 1983. Hirdman, D., Sodemann, H., Eckhardt, S., Burkhart, J. F., Jefferson, A., Mefford, T., Quinn, P. K., Sharma, S., Ström, J., and Stohl, A.: Source identification of short-lived air pollutants in the Arctic using statistical analysis of measurement data and particle dispersion model output, Atmos. Chem. Phys., 10, 669–693, <a href="http://dx.doi.org/10.5194/acp-10-669-2010">https://doi.org/10.5194/acp-10-669-2010</a>, 2010. Ho, K. F., Lee, S. C., Cao, J. J., Kawamura, K., Watanabe, T., Cheng, Y., and Chow, J. C.: Dicarboxylic acids, ketocarboxylic acids and dicarbonyls in the urban roadside area of Hong Kong, Atmos. Environ., 40, 3030–3040, <a href="http://dx.doi.org/10.1016/j.atmosenv.2005.11.069">https://doi.org/10.1016/j.atmosenv.2005.11.069</a>, 2006. Ho, K. F., Cao, J. J., Lee, S. C., Kawamura, K., Zhang, R. J., Chow, J. C., and Watson, J. G.: Dicarboxylic acids, ketocarboxylic acids, and dicarbonyls in the urban atmosphere of China, J. Geophys. Res.-Atmos., 112, D22S27, <a href="http://dx.doi.org/10.1029/2006jd008011">https://doi.org/10.1029/2006jd008011</a>, 2007. Hoyle, C. R., Boy, M., Donahue, N. M., Fry, J. L., Glasius, M., Guenther, A., Hallar, A. G., Huff Hartz, K., Petters, M. D., Petäjä, T., Rosenoern, T., and Sullivan, A. P.: A review of the anthropogenic influence on biogenic secondary organic aerosol, Atmos. Chem. Phys., 11, 321–343, <a href="http://dx.doi.org/10.5194/acp-11-321-2011">https://doi.org/10.5194/acp-11-321-2011</a>, 2011. Hudson, S. R.: Estimating the global radiative impact of the sea ice-albedo feedback in the Arctic, J. Geophys. Res.-Atmos., 116, D16102, <a href="http://dx.doi.org/10.1029/2011jd015804">https://doi.org/10.1029/2011jd015804</a>, 2011. Iinuma, Y., Müller, C., Berndt, T., Böge, O., Claeys, M., and Herrmann, H.: Evidence for the existence of organosulfates from beta-pinene ozonolysis in ambient secondary organic aerosol, Environ. Sci. Technol., 41, 6678–6683, <a href="http://dx.doi.org/10.1021/Es070938t">https://doi.org/10.1021/Es070938t</a>, 2007. Iinuma, Y., Böge, O., Kahnt, A., and Herrmann, H.: Laboratory chamber studies on the formation of organosulfates from reactive uptake of monoterpene oxides, Phys. Chem. Chem. Phys., 11, 7985–7997, <a href="http://dx.doi.org/10.1039/B904025k">https://doi.org/10.1039/B904025k</a>, 2009. Intrieri, J. M., Shupe, M. D., Uttal, T., and McCarty, B. J.: An annual cycle of Arctic cloud characteristics observed by radar and lidar at SHEBA, J. Geophys. Res.-Oceans, 107, 8030, <a href="http://dx.doi.org/10.1029/2000jc000423">https://doi.org/10.1029/2000jc000423</a>, 2002. IPCC: Summary for Policymakers. In: Climate Change 2013: The Physical Science Basis, Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Stocker, T. F., Qin, D., Plattner, G.-K., Tignor, M., Allen, S. K., Boschung, J., Nauels, A., Xia, Y., Bex, V., and Midgley, P. M., Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 3–28, 2013. Iversen, T. and Joranger, E.: Arctic Air-Pollution and Large-Scale Atmospheric Flows, Atmos. Environ., 19, 2099–2108, <a href="http://dx.doi.org/10.1016/0004-6981(85)90117-9">https://doi.org/10.1016/0004-6981(85)90117-9</a>, 1985. Kahnt, A., Behrouzi, S., Vermeylen, R., Safi Shalamzari, M., Vercauteren, J., Roekens, E., Claeys, M., and Maenhaut, W.: One-year study of nitro-organic compounds and their relation to wood burning in PM<sub>10</sub> aerosol from a rural site in Belgium, Atmos. Environ., 81, 561–568, <a href="http://dx.doi.org/10.1016/j.atmosenv.2013.09.041.">https://doi.org/10.1016/j.atmosenv.2013.09.041.</a>, 2013. Kawamura, K. and Gagosian, R. B.: Implications of Omega-Oxocarboxylic Acids in the Remote Marine Atmosphere for Photooxidation of Unsaturated Fatty-Acids, Nature, 325, 330–332, <a href="http://dx.doi.org/10.1038/325330a0">https://doi.org/10.1038/325330a0</a>, 1987. Kawamura, K. and Yasui, O.: Diurnal changes in the distribution of dicarboxylic acids, ketocarboxylic acids and dicarbonyls in the urban Tokyo atmosphere, Atmos. Environ., 39, 1945–1960, <a href="http://dx.doi.org/10.1016/j.atmosenv.2004.12.014">https://doi.org/10.1016/j.atmosenv.2004.12.014</a>, 2005. Kawamura, K., Kasukabe, H., and Barrie, L. A.: Source and reaction pathways of dicarboxylic acids, ketoacids and dicarbonyls in arctic aerosols: One year of observations, Atmos. Environ., 30, 1709–1722, <a href="http://dx.doi.org/10.1016/1352-2310(95)00395-9">https://doi.org/10.1016/1352-2310(95)00395-9</a>, 1996. Kawamura, K., Imai, Y., and Barrie, L. A.: Photochemical production and loss of organic acids in high Arctic aerosols during long-range transport and polar sunrise ozone depletion events, Atmos. Environ., 39, 599–614, <a href="http://dx.doi.org/10.1016/j.atmosenv.2004.10.020">https://doi.org/10.1016/j.atmosenv.2004.10.020</a>, 2005. Kawamura, K., Okuzawa, K., Aggarwal, S. G., Irie, H., Kanaya, Y., and Wang, Z.: Determination of gaseous and particulate carbonyls (glycolaldehyde, hydroxyacetone, glyoxal, methylglyoxal, nonanal and decanal) in the atmosphere at Mt. Tai, Atmos. Chem. Phys., 13, 5369–5380, <a href="http://dx.doi.org/10.5194/acp-13-5369-2013">https://doi.org/10.5194/acp-13-5369-2013</a>, 2013. Krecl, P., Strom, J., and Johansson, C.: Carbon content of atmospheric aerosols in a residential area during the wood combustion season in Sweden, Atmos. Environ., 41, 6974–6985, <a href="http://dx.doi.org/10.1016/j.atmosenv.2007.06.025">https://doi.org/10.1016/j.atmosenv.2007.06.025</a>, 2007. Kristensen, K. and Glasius, M.: Organosulfates and oxidation products from biogenic hydrocarbons in fine aerosols from a forest in North West Europe during spring, Atmos. Environ., 45, 4546–4556, <a href="http://dx.doi.org/10.1016/j.atmosenv.2011.05.063">https://doi.org/10.1016/j.atmosenv.2011.05.063</a>, 2011. Lin, Y. H., Zhang, Z. F., Docherty, K. S., Zhang, H. F., Budisulistiorini, S. H., et al.: Isoprene Epoxydiols as Precursors to Secondary Organic Aerosol Formation: Acid-Catalyzed Reactive Uptake Studies with Authentic Compounds, Environ. Sci. Technol., 46, 250–258, <a href="http://dx.doi.org/10.1021/Es202554c">https://doi.org/10.1021/Es202554c</a>, 2012. Ma, Y., Willcox, T. R., Russell, A. T., and Marston, G.: Pinic and pinonic acid formation in the reaction of ozone with alpha-pinene, Chem. Commun., 2007, 1328–1330, <a href="http://dx.doi.org/10.1039/B617130C">https://doi.org/10.1039/B617130C</a>, 2007. Minerath, E. C. and Elrod, M. J.: Assessing the Potential for Diol and Hydroxy Sulfate Ester Formation from the Reaction of Epoxides in Tropospheric Aerosols, Environ. Sci. Technol., 43, 1386–1392, <a href="http://dx.doi.org/10.1021/Es8029076">https://doi.org/10.1021/Es8029076</a>, 2009. Mochida, M., Kawabata, A., Kawamura, K., Hatsushika, H., and Yamazaki, K.: Seasonal variation and origins of dicarboxylic acids in the marine atmosphere over the western North Pacific, J. Geophys. Res.-Atmos., 108, 4193, <a href="http://dx.doi.org/10.1029/2002JD002355">https://doi.org/10.1029/2002JD002355</a>, 2003. Myriokefalitakis, S., Vrekoussis, M., Tsigaridis, K., Wittrock, F., Richter, A., Brühl, C., Volkamer, R., Burrows, J. P., and Kanakidou, M.: The influence of natural and anthropogenic secondary sources on the glyoxal global distribution, Atmos. Chem. Phys., 8, 4965–4981, <a href="http://dx.doi.org/10.5194/acp-8-4965-2008">https://doi.org/10.5194/acp-8-4965-2008</a>, 2008. Lin, Y. H., Zhang, Z. F., Docherty, K. S., Zhang, H. F., Budisulistiorini, S. H., Rubitschun, C. L., Shaw, S. L., Knipping, E. M., Edgerton, E. S., Kleindienst, T. E., Gold, A., and Surratt, J. D.: Characterization of humic-like substances in Arctic aerosols, J. Geophys. Res., 46, 250–258, <a href="http://dx.doi.org/10.1021/Es202554c">https://doi.org/10.1021/Es202554c</a>, 2013. Nguyen, Q. T., Skov, H., Sørensen, L. L., Jensen, B. J., Grube, A. G., Massling, A., Glasius, M., and Nøjgaard, J. K.: Source apportionment of particles at Station Nord, North East Greenland during 2008–2010 using COPREM and PMF analysis, Atmos. Chem. Phys., 13, 35–49, <a href="http://dx.doi.org/10.5194/acp-13-35-2013">https://doi.org/10.5194/acp-13-35-2013</a>, 2013. Nguyen, Q. T., Kristensen, T. B., Hansen, A. M. K., Skov, H., Bossi, R., Massling, A., Sørensen, L. L., Bilde, M., Glasius, M., and Nøjgaard, J. K.: Characterization of humic-like substances in Arctic aerosols, J. Geophys. Res. Atmos., 119, 5011–5027, <a href="http://dx.doi.org/10.1002/2013jd020144">https://doi.org/10.1002/2013jd020144</a>, 2014. Ottar, B.: Arctic Air-Pollution – a Norwegian Perspective, Atmos. Environ., 23, 2349–2356, <a href="http://dx.doi.org/10.1016/0004-6981(89)90248-5">https://doi.org/10.1016/0004-6981(89)90248-5</a>, 1989. Pacyna, J. M., Ottar, B., Tomza, U., and Maenhaut, W.: Long-Range Transport of Trace-Elements to Ny-Ålesund, Spitsbergen, Atmos. Environ., 19, 857–865, <a href="http://dx.doi.org/10.1016/0004-6981(85)90231-8">https://doi.org/10.1016/0004-6981(85)90231-8</a>, 1985. Rahn, K. A.: Relative Importances of North-America and Eurasia as Sources of Arctic Aerosol, Atmos. Environ., 15, 1447–1455, <a href="http://dx.doi.org/10.1016/0004-6981(81)90351-6">https://doi.org/10.1016/0004-6981(81)90351-6</a>, 1981. Rahn, K. A., Borys, R. D., and Shaw, G. E.: Asian Source of Arctic Haze Bands, Nature, 268, 713–715, <a href="http://dx.doi.org/10.1038/268713a0">https://doi.org/10.1038/268713a0</a>, 1977. Rankin, A. M., Wolff, E. W., and Martin, S.: Frost flowers: Implications for tropospheric chemistry and ice core interpretation, J. Geophys. Res.-Atmos., 107, 4683, <a href="http://dx.doi.org/10.1029/2002JD002492">https://doi.org/10.1029/2002JD002492</a>, 2002. Rybka, A., Kolinski, R., Kowalski, J., Szmigielski, R., Domagala, S., Wozniak, K., Wieckowska, A., Bilewicz, R., and Korybut-Daszkiewicz, B.: Tuning the properties of neutral tetraazamacrocyclic complexes of copper(II) and nickel(II) for use as host-guest compounds with bismacrocyclic transition metal cations, Eur. J. Inorg. Chem., 2007, 172–185, <a href="http://dx.doi.org/10.1002/ejic.200600744">https://doi.org/10.1002/ejic.200600744</a>, 2007. Sakulyanontvittaya, T., Duhl, T., Wiedinmyer, C., Helmig, D., Matsunaga, S., Potosnak, M., Milford, J., and Guenther, A.: Monoterpene and sesquiterpene emission estimates for the United States, Environ. Sci. Technol., 42, 1623–1629, <a href="http://dx.doi.org/10.1021/Es702274e">https://doi.org/10.1021/Es702274e</a>, 2008. Sciare, J., Bardouki, H., Moulin, C., and Mihalopoulos, N.: Aerosol sources and their contribution to the chemical composition of aerosols in the Eastern Mediterranean Sea during summertime, Atmos. Chem. Phys., 3, 291–302, <a href="http://dx.doi.org/10.5194/acp-3-291-2003">https://doi.org/10.5194/acp-3-291-2003</a>, 2003. Shaw, G. E.: Eddy Diffusion Transport of Arctic Pollution from the Mid-Latitudes – a Preliminary Model, Atmos. Environ., 15, 1483–1490, <a href="http://dx.doi.org/10.1016/0004-6981(81)90356-5">https://doi.org/10.1016/0004-6981(81)90356-5</a>, 1981. Shaw, G. E.: Evidence for a Central Eurasian Source Area of Arctic Haze in Alaska, Nature, 299, 815–818, <a href="http://dx.doi.org/10.1038/299815a0">https://doi.org/10.1038/299815a0</a>, 1982. Shaw, G. E.: The arctic haze phenomenon, B. Am. Meteorol. Soc., 76, 2403–2413, <a href="http://dx.doi.org/10.1175/1520-0477(1995)076<2403:Tahp>2.0.CO;2">https://doi.org/10.1175/1520-0477(1995)076<2403:Tahp>2.0.CO;2</a>, 1995. Shupe, M. D. and Intrieri, J. M.: Cloud radiative forcing of the Arctic surface: The influence of cloud properties, surface albedo, and solar zenith angle, J. Climate, 17, 616–628, <a href="http://dx.doi.org/10.1175/1520-0442(2004)017<0616:Crfota>2.0.CO;2">https://doi.org/10.1175/1520-0442(2004)017<0616:Crfota>2.0.CO;2</a>, 2004. Skov, H., Christensen, J. H., Goodsite, M. E., Heidam, N. Z., Jensen, B., Wahlin, P., and Geernaert, G.:: Fate of elemental mercury in the arctic during atmospheric mercury depletion episodes and the load of atmospheric mercury to the arctic, Environ. Sci. Technol., 38, 2373–2382, <a href="http://dx.doi.org/10.1021/Es030080h">https://doi.org/10.1021/Es030080h</a>, 2004. Solgaard, P., Aarkrog, A., Fenger, J., Flyger, H., and Graabaek, A. M.: Lead in Danish Food-Stuffs – Evidence of Decreasing Concentrations, Dan. Med. Bull., 26, 179–182, 1979. Stohl, A.: Characteristics of atmospheric transport into the Arctic troposphere, J. Geophys. Res.-Atmos., 111, D11306, <a href="http://dx.doi.org/10.1029/2005jd006888">https://doi.org/10.1029/2005jd006888</a>, 2006. Stohl, A., Berg, T., Burkhart, J. F., Fjae'raa, A. M., Forster, C., Herber, A., Hov, Ø., Lunder, C., McMillan, W. W., Oltmans, S., Shiobara, M., Simpson, D., Solberg, S., Stebel, K., Ström, J., Tørseth, K., Treffeisen, R., Virkkunen, K., and Yttri, K. E.: Arctic smoke – record high air pollution levels in the European Arctic due to agricultural fires in Eastern Europe in spring 2006, Atmos. Chem. Phys., 7, 511–534, https://doi.org/10.5194/acp-7-511-2007, 2007. Stone, E. A., Yang, L. M., Yu, L. Y. E., and Rupakheti, M.: Characterization of organosulfates in atmospheric aerosols at Four Asian locations, Atmos. Environ., 47, 323–329, <a href="http://dx.doi.org/10.1016/j.atmosenv.2011.10.058">https://doi.org/10.1016/j.atmosenv.2011.10.058</a>, 2012. Surratt, J. D., Kroll, J. H., Kleindienst, T. E., Edney, E. O., Claeys, M., Sorooshian, A., Ng, N. L., Offenberg, J. H., Lewandowski, M., Jaoui, M., Flagan, R. C., and Seinfeld, J. H.: Evidence for organosulfates in secondary organic aerosol, Environ. Sci. Technol., 41, 517–527, <a href="http://dx.doi.org/10.1021/Es062081q">https://doi.org/10.1021/Es062081q</a>, 2007. Surratt, J. D., Gómez-Gonzàlez, Y., Chan, A. W. H., Vermeylen, R., Shahgholi, M., Kleindienst, T. E., Edney, E. O., Offenberg, J. H., Lewandowski, M., Jaoui, M., Maenhaut, W., Claeys, M., Flagan, R. C., and Seinfeld, J. H.: Organosulfate formation in biogenic secondary organic aerosol, J. Phys. Chem. A, 112, 8345–8378, <a href="http://dx.doi.org/10.1021/Jp802310p">https://doi.org/10.1021/Jp802310p</a>, 2008. Surratt, J. D., Chan, A. W. H., Eddingsaas, N. C., Chan, M. N., Loza, C. L., Kwan, A. J., Hersey, S. P., Flagan, R. C., Wennberg, P. O., and Seinfeld, J. H.: Reactive intermediates revealed in secondary organic aerosol formation from isoprene, P. Natl. Acad. Sci. USA, 107, 6640–6645, <a href="http://dx.doi.org/10.1073/pnas.0911114107">https://doi.org/10.1073/pnas.0911114107</a>, 2010. Szmigielski, R., Surratt, J. D., Vermeylen, R., Szmigielska, K., Kroll, J. H., Ng, N. L., Murphy, S. M., Sorooshian, A., Seinfeld, J. H., and Claeys, M.: Characterization of 2-methylglyceric acid oligomers in secondary organic aerosol formed from the photooxidation of isoprene using trimethylsilylation and gas chromatography/ion trap mass spectrometry, J. Mass Spectrom., 42, 101–116, <a href="http://dx.doi.org/10.1002/Jms.1146">https://doi.org/10.1002/Jms.1146</a>, 2007. Treffeisen, R., Tunved, P., Ström, J., Herber, A., Bareiss, J., Helbig, A., Stone, R. S., Hoyningen-Huene, W., Krejci, R., Stohl, A., and Neuber, R.: Arctic smoke – aerosol characteristics during a record smoke event in the European Arctic and its radiative impact, Atmos. Chem. Phys., 7, 3035–3053, <a href="http://dx.doi.org/10.5194/acp-7-3035-2007">https://doi.org/10.5194/acp-7-3035-2007</a>, 2007. Tuazon, E. C. and Atkinson, R.: A Product Study of the Gas-Phase Reaction of Isoprene with the OH Radical in the Presence of NO<sub>x</sub>, Int. J. Chem. Kinet., 22, 1221–1236, <a href="http://dx.doi.org/10.1002/kin.550221202">https://doi.org/10.1002/kin.550221202</a>, 1990. Tunved, P., Strom, J., and Krejci, R.: Arctic aerosol life cycle: linking aerosol size distributions observed between 2000 and 2010 with air mass transport and precipitation at Zeppelin station, Ny-Ålesund, Svalbard, Atmos. Chem. Phys., 13, 3643–3660, <a href="http://dx.doi.org/10.5194/acp-13-3643-2013">https://doi.org/10.5194/acp-13-3643-2013</a>, 2013. Walsh, J. E. and Chapman, W. L.: Arctic cloud-radiation-temperature associations in observational data and atmospheric reanalyses, J. Climate, 11, 3030–3045, <a href="http://dx.doi.org/10.1175/1520-0442(1998)011<3030:Acrtai>2.0.CO;2">https://doi.org/10.1175/1520-0442(1998)011<3030:Acrtai>2.0.CO;2</a>, 1998. Williams, B. J., Goldstein, A. H., Kreisberg, N. M., and Hering, S. V.: In situ measurements of gas/particle-phase transitions for atmospheric semivolatile organic compounds, P. Natl. Acad. Sci. USA, 107, 6676–6681, <a href="http://dx.doi.org/10.1073/pnas.0911858107">https://doi.org/10.1073/pnas.0911858107</a>, 2010. Zare, A., Christensen, J. H., Irannejad, P., and Brandt, J.: Evaluation of two isoprene emission models for use in a long-range air pollution model, Atmos. Chem. Phys., 12, 7399–7412, <a href="http://dx.doi.org/10.5194/acp-12-7399-2012">https://doi.org/10.5194/acp-12-7399-2012</a>, 2012. Zare, A., Christensen, J. H., Gross, A., Irannejad, P., Glasius, M., and Brandt, J.: Quantifying the contributions of natural emissions to ozone and total fine PM concentrations in the Northern Hemisphere, Atmos. Chem. Phys., 14, 2735–2756, <a href="http://dx.doi.org/10.5194/acp-14-2735-2014">https://doi.org/10.5194/acp-14-2735-2014</a>, 2014. Zhang, H. F., Lin, Y. H., Zhang, Z. F., Zhang, X. L., Shaw, S. L., Knipping, E. M., Weber, R. J., Gold, A., Kamens, R. M., and Surratt, J. D.: Secondary organic aerosol formation from methacrolein photooxidation: roles of NO<sub>x</sub> level, relative humidity and aerosol acidity, Environ. Chem., 9, 247–262, <a href="http://dx.doi.org/10.1071/En12004">https://doi.org/10.1071/En12004</a>, 2012. Zhang, H. F., Lin, Y. H., Zhang, Z. F., Zhang, X. L., Shaw, S. L., Knipping, E. M., Weber, R. J., Gold, A., Kamens, R. M., and Surratt, J. D.: Formation of nanoparticles of blue haze enhanced by anthropogenic pollution, Proc. Natl. Acad. Sci. USA, 106, 17650–17654, <a href="http://dx.doi.org/10.1073/pnas.0910125106">https://doi.org/10.1073/pnas.0910125106</a>, 2009. Zhang, R. Y., Wang, L., Khalizov, A. F., Zhao, J., Zheng, J., McGraw, R. L., and Molina, L. T.: Seasonal cycle and temperature dependence of pinene oxidation products, dicarboxylic acids and nitrophenols in fine and coarse air particulate matter, Atmos. Chem. Phys., 10, 7859–7873, <a href="http://dx.doi.org/10.5194/acp-10-7859-2010">https://doi.org/10.5194/acp-10-7859-2010</a>, 2010.