Journal of Atmospheric Chemistry

, Volume 53, Issue 1, pp 63–90 | Cite as

Air masses and aerosols chemical components in the free troposphere at the subtropical northeast atlantic region

  • A. M. DíazEmail author
  • J. P. Díaz
  • F. J. Expósito
  • P. A. Hernández-Leal
  • D. Savoie
  • X. Querol


The dynamics and the aerosol chemistry of the air masses reaching the free troposphere of the subtropical Northeast Atlantic region during the period 1995–98 have been studied. Seven days backward trajectories were calculated daily with HYSPLIT-4 model for Izaña Global Atmospheric Watch (GAW) Observatory (28.3°N 16.5°W, 2367 m a.s.l.). These back-trajectories were classified by means of a k-means clustering strategy. The daily air masses have been coded using 16 variables to detect the aerosol load of each one of them. Four clusters were found: Cluster 1, representative of Atlantic oceanic middle troposphere air masses, (OMT), has an average frequency of occurrence of 50.6%. Cluster 2, which includes air masses originated in the African continent (AfD), has been recorded in a 19.8% of time. Cluster 3 represents a mixture at least of two of the next sources: Europe, Africa and Ocean, (EAM), with a frequency of 12.7%. Finally, Cluster 4 includes air masses with a high load of maritime aerosols, (MaA), and it has been detected in a 16.9%. An analysis of four aerosol components: NO3, NH4+, non-sea-salt-SO42−, and mineral dust and its relation with the origin and transport of the air masses have been done. The highest quantities of mineral dust and nss-SO42− are linked with African air masses with a mean value of 86.5 and 1.9 μg/m3 respectively. Whereas the highest levels of NO3, 1.0 μg/m3, and NH4+, 0.4 μg/m3, were obtained for AfD and EAM. The lowest levels were associated with OMT and MaA air masses types: 12.7, 0.6, 0.2, and 0.5 μg/m3 for dust, NO3, NH4+, and nss-SO42− in average for the four studied years. However, it is remarkable that the values of the median for dust are 2.2 and 3.5 μg/m3 in clusters MaA and OMT respectively. Using non-parametric statistical tests the distributions of concentrations in each cluster by year have been compared in order to detect similarities. The results show that the aerosol loads of OMT and MaA air masses are quite similar and the same occurs for AfD and EAM air masses. However, the correlation analysis between the levels of anions and ammonium evidenced important differences among the air mass types. In AfD air masses is clear a low correlation between levels of nss-SO42− and NH4+ (r2 = 0.08) suggesting that the sulfate speciation was dominated by sulfate species others than ammonium sulfate, such as calcium sulfate. CaSO4 2H2O (gypsum) is mainly present in the coarse mode, where the radiative effects of sulfate are less important that in the accumulative mode. For OMT air masses is noticeable an important increasing on the correlation between the levels of anions and those of NH4+ for the two last years of the study period (1997–1998, r2 = 0.61 –0.85%) with respect to the first ones (1995–1996, r2 = 0.25–0.49%), coinciding with the second strongest ENSO (El Niño Southern Oscillation) event recorded. This behavior indicates a change in the speciation of the aerosol component.


air mass transport aerosol ammonium dust nitrate sulfate radiative properties 


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  1. Alastuey, A., Querol, X., Castillo, S., Avila, A., Cuevas, E., Estarellas, C., Torres, C., Exposito, F., García, O., Diaz, J. P, Van Dingenen, R., and Putaud, J. P., 2003: Characterisation of TSP and PM2.5 at Izaña and Sta. Cruz de Tenerife (Canary Islands, Spain) during a Saharan dust episode. 2nd Workshop on Mineral Dust. LISA, Laboratoire Interuniversitaire des Systèmes Atmosphériques. CNRS., 10-12 September, Paris.Google Scholar
  2. Charlson, R. J., Lovelock, J. E., Andrea, M. O., and Warren, S. G., 1987: Oceanic phytoplankton, atmospheric sulfur, cloud albedo and climate, Nature 326, 655–661.CrossRefGoogle Scholar
  3. Charlson, R. J., Schwartz, S. E., Hales, J. M., Cess, R. D., Coakley, J. A. Jr., Hansen, J. E., and Hoffman, D. J., 1992: Climate forcing by anthropogenic aerosols, Science 255, 423–430.Google Scholar
  4. Chylek, P. and Wong, J., 1995: Effect of absorbing aerosols on global radiation budget, Geophys. Res. Lett. 22, 929–931.CrossRefGoogle Scholar
  5. Cuevas, E., 1995: Study of the behaviour of the tropospheric ozone at the Izaña Observatory (Tenerife) and its relation with atmospheric dynamic. Ph.D. thesis, Universidad Complutense de Madrid, Madrid, 251pp.Google Scholar
  6. DeMott, P. J., Sassen, K., Poellot, M. R., Baumgardner, D., Rogers, D. C., Brooks, S. D., Prenni, A. J., and Kreidenweis, S. M., 2003: African dust aerosols as atmospheric ice nuclei, Geophys. Res. Lett. 30(14), 1732, doi:10.1029/2003GL017410.Google Scholar
  7. Díaz, J. P., Expósito, F. J., Torres, C. J., Herrera, F., Prospero, J. M., and Romero, M. C., 2001: Radiative properties of aerosols in Saharan dust outbreaks using ground-based and satellite data: Applications to radiative forcing, J. Geophys. Res. 106, 18,403–18,416.CrossRefGoogle Scholar
  8. Draxler, R. R. and Hess, G. D., 1997: Description of the Hysplit 4 modeling system. NOAA Tech Memo ERL ARL-224, U.S.A., 24p.Google Scholar
  9. Draxler, R. R. and Rolph, G. D., 2003: HYSPLIT (HYbrid Single-Particle Lagrangian Integrated Trajectory) Model access via NOAA ARL READY Website ( NOAA Air Resources Laboratory, Silver Spring, MD, U.S.A.
  10. Font, I., 1956: “El tiempo atmosférico en las Islas Canarias”. Servicio Meteorológico Nacional (INM), Serie A, No. 26.Google Scholar
  11. Harrison, R. M. and Kito, A. M. N., 1990: Field intercomparison of filter pack and denuder sampling methods for reactive gaseous and particulate pollutants, Atmos. Environ. 24, 2633–2640.Google Scholar
  12. Harrison, R. M. and Pio, C., 1983: Size differentiated composition of inorganic aerosol of both marine and continental polluted origin, Atmos. Environ. 17, 1733–1738.Google Scholar
  13. Haywood, J. M., Francis, P., Osborne, S. R., Glew, M., Loeb, H., Highwood, E., Tanre, D., Myhre, G., Formenti, P., and Hirst, E., 2003: Radiative properties and direct radiative effect of Saharan dust measured by the C-130 aircraft during SHADE: 1. Solar spectrum, J. Geophys. Res., SHADE Special Issue, No. 8577 July 18.Google Scholar
  14. Highwood, E. J., Haywood, J. M., Silverstone, M. D., Newman, S. M., and Taylor, J. P., 2003: Radiative properties and direct effect of Saharan dust measured by the C-130 aircraft during SHADE: 2. Terrestrial spectrum. J. Geophys. Res., accepted for SHADE Special Issue, Art. No. 8578 July 24.Google Scholar
  15. HYSPLIT4 (Hybrid Single-Particle Lagrangian Integrated Trajectory) 1997: Model. Website:, NOAA Air Resources Laboratory, Silver Spring, MD, U.S.A.
  16. IPCC, 2001: Contribution of working group I to the third assessment report of the intergovernmental panel on climate change, in J. T. Houghton et al. (eds.), Climate Change, 2001: The Scientific Basis, Cambridge University Press, Cambridge, United Kingdom and New York, NY, U.S.A., 881 pp.Google Scholar
  17. Karyampudi, M. V., Palm, S. P., Reagen, J. A., Fang, H., Grant, W. B., Hoff, R. M., Moulin, C., Pierce, H. F., Torres, O., Browell, E. V., and Melfi, S. H., 1999: Validation of the Saharan Dust Plume conceptual model using Lidar, Meteosat, and ECMWF data, Bulletin of the American Meteorological Society 80(6), 1045–1076.CrossRefGoogle Scholar
  18. Kaufman, L. and Rousseeuw, P. J., 1990: Finding Groups in Data: An Introduction to Cluster Analysis. John Wiley & Sons, NY, U.S.A. ISBN: 0471878766.Google Scholar
  19. Kiehl, J. T. and Briegleb, B. P., 1993: The relative roles of surface aerosol and greenhouse gases in climate forcing, Science 260, 311–314.Google Scholar
  20. McGovern, F. M., Raes, F., and Van Dingenen, R., 1999: Anthropogenic influences on the chemical and physical properties of aerosols in the Atlantic subtropical region during July 1994 and July 1995, J. Geophys. Res. 104, 14-309–14.319.CrossRefGoogle Scholar
  21. McPhaden, M. J., 1999: Genesis and evolution of the 1997–1998 El Niño, Science 283, 950–954.CrossRefGoogle Scholar
  22. Merrill, J. T., 1994: Isentropic airflow probability analysis, J. Geophys. Res. 99, 22,881–25,889.Google Scholar
  23. Mészáros, E. and Horváth, L., 1984: Concentration and dry deposition of atmospheric sulphur and nitrogen compounds in Hungary, Atmos. Environ. 18, 1725–1730.Google Scholar
  24. Pio, C. A. and Lopes, D. A., 1998: Chlorine loss from marine aerosol in a coastal atmosphere, J. Geophys. Res. 103, 25263–25272.CrossRefGoogle Scholar
  25. Prospero, J. M. and Lamb, P. J., 2003, African droughts and dust transport to the Caribbean: Climate change implications, Science 302, 1024–1027.CrossRefGoogle Scholar
  26. Pszenny, A., Fischer, D., Mendez, A., and Zetwo, M., 1993: Direct comparison of cellulose and quartz fiber filters for sampling submicrometer aerosols in the marine boundary layer, Atmos. Environ. 27A, 281–284.Google Scholar
  27. Querol, X., Alastuey, A., Lopez-Soler, A., Plana, F., Puicercus, J. A., Ruiz, C. R., Mantilla, E., and Juan, R., 1998: Seasonal evolution of atmospheric suspended particles around a coal-fired power station: Chemical Characterization, Atmos. Environ. 32(4), 719–731.CrossRefGoogle Scholar
  28. Raes, F., van Dingenen, R., Cuevas, E., van Velthoven, P. F. J., and Prospero, J. M., 1997: Observations of aerosols in the free troposphere and marine boundary layer of the subtropical Northeast Atlantic: Discussion of processes determining their size distribution, J. Geophys. Res. 102 21,315–21,328.Google Scholar
  29. Raes, F., Bates, T., McGovern, F., and Van Liedekerke, M., 2000: The second aerosol characterization experiment (ACE-2): General overview and main results, Tellus 52B, 111–125.Google Scholar
  30. Ramaswamy, V., et al., 2001: Radiative forcing of climate change, in J. T. Houghton et al. (eds.), Climate Change 2001: The Scientific Basis, Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 349–416, 881 pp.Google Scholar
  31. Rolph, G. D., 2003: Real-time Environmental Applications and Display System (READY) Website ( NOAA Air Resources Laboratory, Silver Spring, MD, U.S.A.
  32. Rosenfeld, D., Rudich, Y., and Lahav, R., 2001: Desert dust suppressing precipitation a possible desertification feedback loop, Proceedings of the National Academy of Sciences 98(11), 5975–5980.Google Scholar
  33. Sancho, P. and de la Cruz, J., 1992: A five-year climatology of back–trajectories for the Izaña baseline station, Tenerife, Canary Islands, Atmos. Environ. 26, 1081–1096.Google Scholar
  34. Sassen, K., DeMott, P. J., Prospero, J. M., and Poellot, M. R., 2003: Saharan dust storms and indirect aerosol effects on clouds: CRYSTAL-FACE results, Geophys. Res. Lett. 30(12), 1633, doi:10.1029/2003GL017371.Google Scholar
  35. Savoie, D. L., 1984: Nitrate and non-sea-salt sulfate aerosols over major regions of the World Ocean: Concentration, sources and fluxes, Ph.D. thesis, University of Miami. Miami, Florida, U.S.A., 432 pp.Google Scholar
  36. Seidl, W., Brunnemann, G., Kins, E., Kölher, E., Reusswig, K., Ruoss, K., Seiler, T., and Dlugi, R., 1996: Nitrate in the accumulation mode; data from measurement campaigns in eastern Germany, in M. Kulmala and P. E. Wagner (eds.), Nucleation and Atmospheric Aerosols, Pergamon Press, Oxford, United Kingdom, pp. 431–434.Google Scholar
  37. Sokolik, I. N., Winker, D. M., Bergametti, G., Gillette, D. A., Carmichael, G., Kaufman, Y. J., Gomes, L., Schuetz, L., and Penner, J. E., 2001: Introduction to special section: Outstanding problems in quantifying the radiative impacts of mineral dust, J. Geophys. Res. 106, 18015–18027–8826.CrossRefGoogle Scholar
  38. Taylor, K. E. and Penner, J. E., 1994: Response of climate system to atmospheric aerosols and greenhouse gases, Nature 369, 734–737.Google Scholar
  39. Tegen, I., Werner, M., Harrison, S. P., and Kohfeld, K. E., 2004: Relative importance of climate and land use in determining present and future global soil dust emission, Geophys. Res. Lett. 31, L05105, doi:10.1029/2003GL019216.Google Scholar
  40. Torres, C., Cuevas, E., and Guerra, J. C., 2002: Characterization of the marine boundary layer and the free troposphere in the subtropical region over Canary Islands, 3rd Spanish-Portuguese Assembly of Geodesy and Geophysics, Valencia, Spain.Google Scholar
  41. Viana, M., Querol, X., Alastuey, A., Cuevas, E., and Rodríguez, S., 2002: Influence of African dust on the levels of atmospheric particulates in the Canary Islands air quality network, Atmos. Environ. 36/38, 5861–5875.Google Scholar
  42. Wakamatsu, S., Utsunomiya, A., Han, J. S., Mori, A., Uno I., and Uehara, K., 1996: Seasonal variation in atmospheric aerosol concentration covering Northern Kyushu, Japan and Seoul, Korea, Atmos. Environ. 30, 2343–2354.CrossRefGoogle Scholar
  43. Willison, M. J., Clarke, A. G., and Zeki, E. M., 1985: Seasonal variations in atmospheric aerosol concentration and composition at urban and rural sites in northern England, Atmos. Environ. 19, 1081–1089.Google Scholar

Copyright information

© Springer Science + Business Media, Inc. 2006

Authors and Affiliations

  • A. M. Díaz
    • 1
    Email author
  • J. P. Díaz
    • 1
  • F. J. Expósito
    • 1
  • P. A. Hernández-Leal
    • 1
  • D. Savoie
    • 2
  • X. Querol
    • 3
  1. 1.Dpto. de FísicaUniversidad de la LagunaTenerifeSpain
  2. 2.Rosenstiel School of Marine and Atmospheric ScienceUniversity of Miami
  3. 3.Instituto de Ciencias de la Tierra “Jaume Almera”- Consejo Superior de Investigaciones CientíficasBarcelonaSpain

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