European source and sink areas of CO2 retrieved from Lagrangian transport model interpretation of combined O2 and CO2 measurements at the high alpine research station Jungfraujoch

Atmospheric Chemistry and Physics

Volumn 11, Issue 15, 2011, Pages 8017-8036

  Uglietti, C ^a   Leuenberger, M ^a   Brunner, D ^b  

^a UNIVERSITY OF BERN   (Switzerland)

^b SWISS FEDERAL LABORATORIES FOR MATERIALS SCIENCE AND TECHNOLOGY   (Switzerland)

Author keywords

[No Author keywords available]

Indexed keywords

AIR MASS; ALPINE ENVIRONMENT; ATMOSPHERIC CHEMISTRY; ATMOSPHERIC POLLUTION; ATMOSPHERIC TRANSPORT; BIOSPHERE; BOUNDARY LAYER; CARBON DIOXIDE; CARBON SINK; COMPUTER SIMULATION; LAGRANGIAN ANALYSIS; OXYGEN; TROPOSPHERE;

BERN [SWITZERLAND]; ITALY; JUNGFRAUJOCH; SWITZERLAND;

EID: 80051615089     PISSN: 16807316     EISSN: 16807324     Source Type: Journal    
DOI: 10.5194/acp-11-8017-2011     Document Type: Article

References (80)

1. Bader, S. and Croci-Maspoli, M.: The weather in 2007, Interna-tional Foundation HFSJG, Activity Report 2007, MeteoSchweiz, Bundesamt für Meteorologie und Klimatologie, Zürich, 6, 2007.
2. Bader, S. and Schlegel, T.: The weather in 2005, International Foundation HFSJG, Activity Report 2005, MeteoSchweiz, Bundesamt für Meteorologie und Klimatologie, Zürich, 8, 2005.
3. Baltensperger, U., Gäggeler, H. W., Jost, D. T., and Emmeneg-ger, M.: Continuous background aerosol monitoring with the epiphaniometer, Atmos. Environ., 25, 629-634, 1991.
4. Balzani Lööv, J. M. B., Henne, S., Legreid, G., Staehelin, J., Reimann, S., Prevot, A. S. H., Steinbacher, M., and Vollmer, M. K.: Estimation ofbackground concentrations oftrace gases at the Swiss Alpine site Jungfraujoch (3580ma.s.l.), J. Geophys. Res.-Atmos., 113,D22305, doi:10.1029/2007JD009751, 2008.
5. 2 and <5 C, Science, 287, 2467-2470,2000 (Pubitemid 30185438)
6. Bender, M., Ellis, T., Tans, P., Francey, R., and Lowe, D.: Variability in the O2/N2 ratio of Southern Hemisphere air, 1991-1994: implications for the carbon cycle, Global Biogeochem. Cy., 10, 9-21, 1996.
7. Bender, M. L., Ho, D. T., Hendricks, M. B., Mika, R., Battle, M. O., Tans, P. P., Conway, T. J., Sturtevant, B., and Cassar, N.: Atmospheric O2/N2 changes, 1993-2002: implications for the partitioning of fossil fuel CO2 sequestration, Global Biogeochem. Cy., 19, GB4017, doi:10.1029/2004GB002410, 2005. (Pubitemid 43280680)
8. Campana, M., Li, Y. S., Staehelin, J., Prevot, A. S. H., Bonasoni, P., Loetscher, H., and Peter, T.: The influence of south foehn on the ozone mixing ratios at the high alpine site Arosa, Atmos. Environ., 39,2945-2955,2005. (Pubitemid 40725913)
9. 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., 33,2771-2781, 1999. (Pubitemid 29227234)
10. Collaud Coen, M., Weingartner, E., Schaub, D., Hueglin, C., Corrigan, C., Henning, S., Schwikowski, M., and Baltensperger, U.: Saharan dust events at the Jungfraujoch: detection by wavelength dependence of the single scattering albedo and first climatology analysis, Atmos. Chem. Phys., 4, 2465-2480, doi:10.5194/acp-4-2465-2004,2004. (Pubitemid 40191224)
11. Cozic, J., Verheggen, B., Mertes, S., Connolly, P., Bower, K., Petzold, A., Baltensperger, U., and Weingartner, E.: Scavenging of black carbon in mixed phase clouds at the high alpine site Jungfraujoch, Atmos. Chem. Phys., 7, 1797-1807, doi:10.5194/acp-7-1797-2007,2007. (Pubitemid 46841608)
12. Cozic, J., Verheggen, B., Weingartner, E., Crosier, J., Bower, K. N., Flynn, M., Coe, H., Henning, S., Steinbacher, M., Henne, S., Collaud Coen, M., Petzold, A., and Baltensperger, U.: Chemical composition of free tropospheric aerosol for PM1 and coarse mode at the high alpine site Jungfraujoch, Atmos. Chem. Phys., 8,407-423, doi:10.5194/acp-8-407-2008,2008.
13. Cui, J., Sprenger, M., Staehelin, J., Siegrist, A., Kunz, M., Henne, S., and Steinbacher, M.: Impact of stratospheric intrusions and tercontinental transport on ozone at Jungfraujoch in 2005: comparison and validation of two Lagrangian approaches, At-mos. Chem. Phys., 9,3371-3383, doi:10.5194/acp-9-3371- 2009, 2009.
14. Cuna, S., Pendall, E., Miller, J. B., Tans, P. P., Dlugokencky, E., and White, J. W. C.: Separating contributions from natural and anthropogenic sources in atmospheric methane from the Black Sea region, Romania, Appl. Geochem., 23, 2871-2879, 2008.
15. Folini, D., Ubl, S., and Kaufmann, P.: Lagrangian particle dispersion modeling for the high Alpine site Jungfraujoch. J. Geophys. Res., 113,D18111,doi:10.1029/2007JD009558,2008.
16. Forrer, J., Ruttimann, R., Schneiter, D., Fischer, A., Buchmann, B., and Hofer, P.: Variability oftrace gases at the high-Alpine site Jungfraujoch caused by meteorological transport processes, J. Geophys. Res.-Atmos., 105, 12241-12251,2000.
17. Forster, P., Ramaswamy, V., Artaxo, P., Berntsen, T., Betts, R., Fahey, D. W., Haywood, J., Lean, J., Lowe, D. G., Myhre, G., Nganga, J.,Prinn, R., Raga, G., Schulz, M., and VanDorland, R.: Changes in Atmospheric Constituents and in Radiative Forcing., Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K. B., Tignor, M., and Miller, H. L., Cambridge University Press, Cambridge, UK and New York, NY, USA, 106 pp., 2007.
18. Gurk, Ch.,Fischer, H., Hoor, P,Lawrence, M. G.,Lelieveld, J., and Wernli, H.: Airborne in-situ measurements ofvertical, seasonal and latitudinal distributions of carbon dioxide over Europe, At-mos. Chem. Phys., 8,6395-6403, doi:10.5194/acp-8-6395-2008, 2008.
19. Henne, S., Dommen, J., Neininger, B., Reimann, S., Staehelin, J., and Prevot, A. S. H.: Influence of mountain venting in the Alps on the ozone chemistry of the lower free troposphere and the European pollution export, J. Geophys. Res.-Atmos., 110, D22307 doi:10.1029/2005JD005936,2005a. (Pubitemid 43051326)
20. Henne, S., Furger, M., and Prevot, A. S. H.: Climatology of mountain venting-induced elevated moisture layers in the lee of the Alps, J. Appl. Meteorol., 44, 620-633, 2005b. (Pubitemid 41030142)
21. Henne, S., Klausen, J., Junkermann, W., Kariuki, J. M., Aseyo, J. O., and Buchmann, B.: Representativeness and climatology of carbon monoxide and ozone at the global GAW station Mt. Kenya in equatorial Africa, Atmos. Chem. Phys., 8, 3119-3139, doi:10.5194/acp-8-3119-2008,2008.
22. Hirdman, D., Burkhart, J. F., Sodemann, H., Eckhardt, S., Jefferson, A., Quinn, P. K., Sharma, S., Strm, J., and Stohl, A.: Long-term trends of black carbon and sulphate aerosol in the Arctic: changes in atmospheric transport and source region emissions, Atmos. Chem. Phys., 10, 9351-9368, doi:10.5194/acp-10- 9351-2010,2010.
23. 2, Ar/N2 observed in the lowermost part of the stratosphere at northern middle and high latitudes in the early spring of 2002, Geophys. Res. Lett., 35, L03812, doi:10.1029/2007GL031526,2008 (Pubitemid 351492953)
24. Keeling, R. F.: Measuring correlations between atmospheric oxygen and carbon-dioxide mole fractions - a preliminary-study in urban air, J. Atmos. Chem., 7, 153-176, 1988. (Pubitemid 19301801)
25. Keeling, R. F. and Shertz, S. R.: Seasonal and Interannual Variations in Atmospheric Oxygen and Implications for the Global Carbon Cycle, Nature, 358, 723-727, 1992. (Pubitemid 23372396)
26. Keeling, R. F., Najjar, R. P., Bender, M. L., and Tans, P. P.: What atmospheric oxygen measurements can tell us about the global carbon-cycle, Global Biogeochem. Cy., 7, 37-67, 1993. (Pubitemid 23380933)
27. Keeling, R. F., Manning, A. C., McEvoy, E. M., and S. R. Shertz, S. R.: Methods for measuring changes in atmospheric O2 concentration and their application in Southern Hemisphere air, J. Geophys. Res., 103, 3381-3397, 1998. (Pubitemid 28400472)
28. Keeling, R. F., Blaine, T., Paplawsky, B., Katz, L.,Atwood, C., and Brockwell, T.: Measurement ofchanges in atmospheric Ar/N2 ratio using a rapid-switching, single-capillary mass spectrometer system, Tellus B, 56, 322-338, 2004. (Pubitemid 39250789)
29. Keeling, R. F., Manning, A. C., Paplawsky, B., and Cox, A.: On the long-term stability of O2/N2 reference gases, in: Proc. 12th WMO/IAEA Meeting of Experts on Carbon Dioxide Concentration and Related Tracers Measurement Techniques, WMO Tech. Doc. 1275, Toronto, ON, Canada, WMO 131-140, 2005.
30. Kozlova, E. A., Manning, A. C., Kisilyakhov, Y., Seifert, T., and Heimann, M.: Seasonal, synoptic, and diurnal-scale variability of biogeochemical trace gases and O2 from a 300-m tall tower in Central Siberia, Global Biogeochem. Cy., 22, GB4020, doi:10.1029/2008GB003209,2008.
31. Kress, N. and Herut, B.: Deep Sea Research Part I, Oceanogr. Res. Pap., 48,2347-2372,2001.
32. Langenfelds, R. L., van der Schoot, M. V., Francey, R. J., Steele, L. P., Schmidt, M., and Mukai, H.: Modification of air standard composition by diffusive and surface processes., J. Geophys. Res., 110, D13307, doi:10.1029/2004JD005482,2005. (Pubitemid 44651228)
33. Lanz, V. A., Henne, S., Staehelin, J., Hueglin, C., Vollmer, M. K., Steinbacher, M., Buchmann, B., and Reimann, S.: Statistical analysis of anthropogenic non-methane VOC variability at a European background location (Jungfraujoch, Switzerland), At-mos. Chem. Phys., 9, 3445-3459, doi:10.5194/acp-9-3445-2009, 2009.
34. Lewis, A. C., Evans, M. J., Methven, J., Watson, N., Lee, J. D., Hopkins, J. R., Purvis, R. M., Arnold, S. R., McQuaid, J. B., Whalley, L. K., Pilling, M. J., Heard, D. E., Monks, P. S., Parker, A. E., Reeves, C. E., Oram, D. E., Mills, G., Bandy, B. J., Stewart, D., Coe, H., Williams, P., and Crosier, J.: Chemical composition observed over the mid-Atlantic and the detection of pollution signatures far from source regions, J. Geophys. Res., 112, D10S39, doi:10.1029/2006JD007584,2007. (Pubitemid 47193696)
35. Li, Y. S., Campana, M., Reimann, S., Schaub, D., Stemmler, K., Staehelin, J., and Thomas, P. T.: Hydrocarbon concentrations at the Alpine mountain sites Jungfraujoch and Arosa, Atmos. Environ., 39, 1113-1127,2005.
36. Lin, C., Brunner, D., and Gerbig, C.: Studying atmospheric transport through Lagrangian models, Eos. Trans. Am., 92(21), 177-178,2011.
37. Lugauer, M., Baltensperger, U., Furger, M., Gaggeler, H. W., Jost, D. T., Schwikowski, M., and Wanner, H.: Aerosol transport to the high Alpine sites Jungfraujoch (3454m a.s.l.) and Colle Gnifetti (4452m a.s.l.), Tellus B, 50, 76-92, 1998.
38. Manning, A. C.: Temporal variability of atmospheric oxygen from both continuous measurements and a flask sampling network: tools for studying the global carbon cycle, Ph.D. thesis, University of California, San Diego, California, USA, 2001.
39. Manning, A. C. and Keeling, R. F.: Global oceanic and land biotic carbon sinks from the Scripps atmospheric oxygen flask sampling network, Tellus B, 58, 95-116,2006. (Pubitemid 43372757)
40. Marland,G.,Boden, T.A.,andAndres,R. J.: Global,Regional,and National Fossil-Fuel CO2 Emissions. In Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, US Department of Energy, Oak Ridge, Tenn., USA, 2009.
41. Moody, J. L. and Galloway, J. N.: Quantifying the relationship between atmospheric transport and the chemical composition of precipitation on Bermuda, Tellus B 40(5) 463-479 (1988).
42. Morimoto, S., Nakazawa, T., Aoki, S., Hashida, G., and Yamanouchi, T.: Concentration variations ofatmospheric CO2 observed at Syowa Station, Antarctica from 1984 to 2000, Tellus B, 55, 170-177,2003. (Pubitemid 36610962)
43. Nakazawa, T., Ishizawa, M., Higuchi, K., and Trivett,N. B. A.: Two curve fitting methods applied to CO2 flask data, Environmetrics, 8(3), 197-218, 1997.
44. Paris, J.-D., Stohl, A., Ciais, P., Ndlec, P., Belan, B. D., Arshinov, M. Yu., and Ramonet, M.: Sourcereceptor relationships for airborne measurements of CO2, CO and O3 above Siberia: a cluster-based approach, Atmos. Chem. Phys., 10, 1671-1687, doi:10.5194/acp-10-1671-2010,2010.
45. Petzold, A., Weinzierl, B., Huntrieser, H., Stohl, A., Real, E., Cozic, J., Fiebig, M., Hendricks, J., Lauer, A., Law, K., Roiger, A., Schlager, H., and Weingartner, E.: Perturbation of the European free troposphere aerosol by North American forest fire plumes during the ICARTT-ITOP experiment in summer 2004, Atmos. Chem. Phys., 7, 5105-5127, doi:10.5194/acp-7-5105-2007, 2007. (Pubitemid 47549078)
46. Pezeshki, S. R. and DeLaune, R. D.: Effects of soil oxidation-reduction conditions on internal oxygen transport, root aeration, and growth of wetland plants, Proceedings of a conference on sustainability of wetlands and water resources: how well can riverine wetlands continue to support society into the 21st century?, Gen. Tech. Rep. SRS-50. Asheville, NC:US Department of Agriculture, Forest Service, Southern Research Station, 2002.
47. Popa, M. E., Gloor, M., Manning, A. C., Jordan, A., Schultz, U., Haensel, F., Seifert, T., and Heimann, M.: Measurements of greenhouse gases and related tracers at Bialystok tall tower station in Poland, Atmos. Meas. Tech., 3, 407-427, doi:10.5194/amt-3-407-2010,2010.
48. Reimann, S., Schaub, D., Stemmler, K., Folini, D., Hill, M., Hofer, P., and Buchmann, B.: Halogenated greenhouse gases at the Swiss High Alpine Site of Jungfraujoch (3580m a.s.l.): Continuous measurements and their use for regional European source allocation, J. Geophys. Res., 109, D05307, doi:10.1029/ 2003JD003923,2004.
49. Reimann, S., Vollmer, M. K., Folini, D., Steinbacher, M., Hill, M., Buchmann, B., Zander, R., and Mahieu, E.: Observations of long-lived anthropogenic halocarbons at the high-Alpine site of Jungfraujoch (Switzerland) for assessment of trends and European sources, Sci. Total Environ., 391, 224-231, 2008.
50. Rotty, R. M.: Estimates of seasonal variation in fossil fuel CO2 emissions, Tellus B, 39, 184-202, 1987. (Pubitemid 17077211)
51. Sabine, C. L., Feely, R. A., Gruber, N., Key, R. M., Lee, K., Bullister, J. L., Wanninkhof, R., Wong, C. S., Wallace, D. W. R., Tilbrook, B., Millero, F. J., Peng, T. H., Kozyr, A., Ono, T., and Rios, A. F.: The oceanic sink for anthropogenic CO2, Science, 305(5682), 367-371,2004.
52. Scheifinger, H. and Kaiser, A.: Validation oftrajectory statistical methods,Atmos. Environ., 41, 8846-8856, 2007.
53. Schulze, E. D., Luyssaert, S., Ciais, P. A. F., Janssens, I. A., Sous-sana, J. F., Smith, P., Grace, J., Levin, I., Thiruchittampalam, B., Heimann, M., Dolman, A. J., Valentini, R., Bousquet, P., Peylin, P., Peters, W., Rödenbeck, C., Etiope, G., Vuichard, N., Wattenbach, M., Nabuurs, G. J., Poussi, Z., Nieschulze, J., Gash, J. H., and CarboEurope Team: Europe's Greenhouse-Gas Balance: Methane and nitrous oxide emissions compensate CO2 sinks, Nat. Geosci., 2, 842-850, 2009.
54. Schwikowski, M., Seibert, P., Baltensperger, U., and Gaggeler, H. W.: A Study of an Outstanding Saharan Dust Event at the High Alpine Site Jungfraujoch, Switzerland, Atmos. Environ.,29, 1829-1842, 1995. (Pubitemid 26436813)
55. Seibert, P.: South foehn studies since the Alpex experiment, Meteorol. Atmos. Phys., 43, 91-103, 1990.
56. Seibert, P. and Frank, A.: Source-receptor matrix calculation with a Lagrangian particle dispersion model in backward mode, Atmos. Chem. Phys., 4, 51-63, doi:10.5194/acp-4-51-2004, 2004. (Pubitemid 39073750)
57. Seibert, P., Kromp-Kolb, H., Baltensperger, U., Jost, D. T., Schwikowski, M., Kasper,A., and Puxbaum,H.: Trajectory anal-ysis of aerosol measurements at high alpine sites, Proceedings of the EUROTRAC Symposium '94 SPB Academic Publishing, Hague, edited by: Borrell, P. M., Borrell, P., Cvitas, T., and Seiler, W., 1283 pp., 689-693, 1994.
58. Seibert, P., Kromp-Kolb, H., Kasper, A., Kalina, M., Puxbaum, H., Jost, D. T., Schwikowski, M., and Baltensperger, U.: Transport of polluted boundary layer air from the Po Valley to high alpine sites,Atmos. Environ., 32, 3953-3965, 1998. (Pubitemid 28539193)
59. Severinghaus, J. P.: Studies of the terrestrial O2 and carbon cycle in sand dunes gases and in biosphere PhD thesis, Columbia University, New York, USA, 1995.
60. Siegel, D. A., Doney, S. C., and Yoder, J. A.: The North Atlantic spring phytoplankton bloom and Sverdrup's critical depth hypothesis, Science, 296, 730-733, 2002. (Pubitemid 34441999)
61. Stephens, B. B., Keeling, R. F., Heimann, M., Six, K. D., Munane, R., and Caldeira, K.: Testing global ocean carbon cycle models using measurements of atmospheric O2 and CO2 concentration, Global Biogeochem. Cy., 12, 213-230, 1998. (Pubitemid 28482189)
62. Stoffyn, E. P., Potter, T. M., Leonard, J. D., and Pocklington, R.: The identification of black carbon particles with the analytical scanning electron microscope: methods and initial results, Sci. Total Environ., 198, 211-223, 1997.
63. Stohl, A.: The FLEXTRA and FLEXTRAPART homepage: http: //zardoz.nilu.no/~andreas/flextra+flexpart.html,2006.
64. Stohl, A. and Seibert, P.: Accuracy oftrajectories as determined from the conservation of meteorological tracers, Q. J. Roy. Meteorol. Soc., 124, 1465-1484, 1998. (Pubitemid 28497175)
65. 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, 2149-2165, 1995. (Pubitemid 26444658)
66. Stohl, A., Haimberger, L., Scheele, M. P., and Wernli, H.: An intercomparison of results from three trajectory models, Meteorol. Appl., 8, 127-135, 1999.
67. 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, 2461-2474, doi:10.5194/acp-5-2461-2005,2005. (Pubitemid 41479781)
68. Sturm, P.: Atmospheric oxygen and associated tracers from flask sampling and continuous measurements: tools for studying the global carbon cycle, Ph.D. thesis, University of Bern, Bern, Switzerland, 2005.
69. Sverdrup, H. U.: On conditions for the vernal blooming of phytoplankton, J. Conseil/Conseil International pour P Exploration de laMer, 18, 287-295, 1953.
70. Takahashi, T., Broecker, W. S., and Langer, S.: Redfield ratio based on chemical data from isopycnal surfaces, J. Geophys. Res., 90, 6907-6924, 1985.
71. Thompson, R. L., Manning, A. C., Gloor, E., Schultz, U., Seifert, T., Hänsel, F., Jordan, A., and Heimann, M.: In-situ measurements of oxygen, carbon monoxide and greenhouse gases from Ochsenkopf tall tower in Germany, Atmos. Meas. Tech., 2, 573-591, doi:10.5194/amt-2-573-2009, 2009.
72. Tohjima, Y., Mukai, H., Nojiri, Y., Yamagishi, H., and Machida, T.: Atmospheric O2/N2 measurements at two Japanese sites: estimation of global oceanic and land biotic carbon sinks and analysis of the variations in atmospheric potential oxygen (APO), Tellus B, 60, 213-225, 2008.
73. Tuzson, B., Henne, S., Brunner, D., Steinbacher, M., Mohn, J., Buchmann, B., and Emmenegger, L.: Continuous isotopic composition measurements of tropospheric CO2 at Jungfrau-joch (3580ma.s.l.), Switzerland: real-time observation of regional pollution events, Atmos. Chem. Phys., 11, 1685-1696, doi:10.5194/acp-11-1685-2011,2011.
74. Uglietti, C., Leuenberger, M., and Valentino, F. L.: Comparison between real time and flask measurements of atmospheric O2 and CO2 performed at the High Altitude Research Station Jungfraujoch, Switzerland, Sci. Total Environ., 391, 196-202, 2008.
75. Uglietti, C., Leuenberger, M., and Brunner, D.: Large-scale European source and flow patterns retrieved from back-trajectory interpretations of CO2 at the high alpine research station Jungfraujoch, Atmos. Chem. Phys. Discuss., 11, 813-857, doi:10.5194/acpd-11-813-2011,2011.
76. Valentino, F. L., Leuenberger, M., Nyfeler, P., Moret, H. P., Sturm, P., Slemr, F., and Brenninkmeijer, C. A. M.: Description of an airborne instrument for continuous O2 and CO2 analysis, Environ. Sci. Technol., 2007.
77. 2, CO2 and <5 C of CO2 from the high altitude research station Junfgraujoch, Switzerland - a comparison with the observations from the remote site Puy de Dome, France, Sci. Total Environ., 391, 203-210,2008
78. van der Laan-Luijkx, I. T., Neubert, R. E. M., van der Laan, S., and Meijer, H. A. J.: Continuous measurements ofatmospheric oxygen and carbon dioxide on a North Sea gas platform, Atmos. Meas. Tech., 3, 113-125, doi:10.5194/amt-3-113-2010, 2010.
79. Weingartner, E., Nyeki, S., and Baltensperger, U.: Seasonal and diurnal variation ofaerosol size distributions (10
80. Zeng, Y. and Hopke, P. K.: A study of the sources of acid precipitation in Ontario, Canada, Atmos. Environ., 23, 1499-1509, 1989.