ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-10-5797-2010 Modelling the chemically aged and mixed aerosols over the eastern central Atlantic Ocean – potential impacts Astitha M. 1 Kallos G. 2 Spyrou C. 2 O'Hirok W. 1 Lelieveld J. 1 3 Denier van der Gon H. A. C. 4 Energy, Environment and Water Research Centre, The Cyprus Institute, Nicosia, Cyprus University of Athens, School of Physics, Division of Environmental Physics-Meteorology, Bldg PHYS-V, 15784, Athens, Greece Max Planck Institute for Chemistry, Becherweg 27, 55128 Mainz, Germany TNO Built Environment and Geosciences, Princetonlaan 6, P.O. Box 80015, 3584 CB Utrecht, The Netherlands 01 07 2010 10 13 5797 5822 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. This article is available from http://www.atmos-chem-phys.net/10/5797/2010/acp-10-5797-2010.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/10/5797/2010/acp-10-5797-2010.pdf

Detailed information on the chemical and physical properties of aerosols is important for assessing their role in air quality and climate. This work explores the origin and fate of continental aerosols transported over the Central Atlantic Ocean, in terms of chemical composition, number and size distribution, using chemistry-transport models, satellite data and in situ measurements. We focus on August 2005, a period with intense hurricane and tropical storm activity over the Atlantic Ocean. A mixture of anthropogenic (sulphates, nitrates), natural (desert dust, sea salt) and chemically aged (sulphate and nitrate on dust) aerosols is found entering the hurricane genesis region, most likely interacting with clouds in the area. Results from our modelling study suggest rather small amounts of accumulation mode desert dust, sea salt and chemically aged dust aerosols in this Atlantic Ocean region. Aerosols of smaller size (Aitken mode) are more abundant in the area and in some occasions sulphates of anthropogenic origin and desert dust are of the same magnitude in terms of number concentrations. Typical aerosol number concentrations are derived for the vertical layers near shallow cloud formation regimes, indicating that the aerosol number concentration can reach several thousand particles per cubic centimetre. The vertical distribution of the aerosols shows that the desert dust particles are often transported near the top of the marine cloud layer as they enter into the region where deep convection is initiated. The anthropogenic sulphate aerosol can be transported within a thick layer and enter the cloud deck through multiple ways (from the top, the base of the cloud, and by entrainment). The sodium (sea salt related) aerosol is mostly found below the cloud base. The results of this work may provide insights relevant for studies that consider aerosol influences on cloud processes and storm development in the Central Atlantic region.

 References Alpert, P., Kaufman, Y. J., Shay-El, Y., Tanre, D., da Silva, A., Schubert, S., and Joseph, J. H.: Quantification of dust-forced heating of the lower troposphere, Nature, 395, 367–370, 1998. Andreae, M. O., Charlson, R. J., Bruynseels, F., Storms, H., Van Grieken, R., and Maenhaut, W.: Internal Mixture of Sea Salt, Silicates, and Excess Sulfate in Marine Aerosols, Science, 232, 1620–1623, doi:10.1126/science.232.4758.1620, 1986. Andreae, M. O., Hegg, D. A., and Baltensperger, U.: Sources and Nature of Atmospheric Aerosols, Chapter 3 in Aerosol Pollution Impact on Precipitation-A Scientific Review, edited by: Levin, Z. and Cotton, W. R., Springer, ISBN: 978-1-4020-8689-2, 2009. Astitha, M. and Kallos, G.: Gas-phase and aerosol chemistry interactions in South Europe and the Mediterranean Region, Environmental Fluid Mechanics, 9(1), 3–22, doi:10.1007/s10652-008-9110-7, 2009. Astitha, M., Kallos, G., and Katsafados, P.: Air Pollution Modeling in the Mediterranean Region: From Analysis of Episodes to Forecasting, Atmos. Res., 89, 358–364, 2008. Bauer, S. E., Balkanski, Y., Schulz, M., Hauglustaine, D. A., and Dentener F.: Global modeling of heterogeneous chemistry on mineral aerosol surfaces: Influence on tropospheric ozone chemistry and comparison to observations, J. Geophys. Res., 109, D02304, doi:10.1029/2003JD003868, 2004. Bauer, S. E. and Koch, D.: Impact of heterogeneous sulfate formation at mineral dust surfaces on aerosol loads and radiative forcing in the Goddard Institute for Space Studies general circulation model, J. Geophys. Res., 110(D17), D17202, doi:10.1029/2005JD005870, 2005. Birmili, W., Ries, L., Sohmer, R., Anastou, A., Sonntag, A., König, K., and Levin, I.: Fine and ultrafine aerosol particles at the GAW station Schneefernerhaus/Zugspitze, Gefahrst. Reinh. Luft, 69(1/2), 31–35, 2009a. Birmili, W., Weinhold, K., Nordmann, S., Wiedensohler, A., Spindler, G., Müller, K., Herrmann, H., Gnauk, T., Pitz, M., Cyrys, J., Flentje, H., Nickel, C., Kuhlbusch, T. A. J., Löschau, G., Haase, D., Meinhardt, F., Schwerin, A., Ries, L., and Wirtz, K.: Atmospheric aerosol measurements in the German Ultrafine Aerosol Network (GUAN): Part 1 – soot and particle number size distributions, Gefahrst. Reinh. Luft, 69(4), 137–145, 2009b. 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 PM$_1$ and coarse mode at the high alpine site Jungfraujoch, Atmos. Chem. Phys., 8, 407–423, doi:10.5194/acp-8-407-2008, 2008. Denman, K. L., Brasseur, G., Chidthaisong, A., Ciais, P., Cox, P. M., Dickinson, R. E., Hauglustaine, D., Heinze, C., Holland, E., Jacob, D., Lohmann, U., Ramachandran, S., da Silva Dias, P. L., Wofsy S. C. and Zhang, X.: Couplings Between Changes in the Climate System and Biogeochemistry. In: 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, United Kingdom and New York, NY, USA, 2007. de Reus, M., Fischer, H., Sander, R., Gros, V., Kormann, R., Salisbury, G., Van Dingenen, R., Williams, J., Zöllner, M., and Lelieveld, J.: Observations and model calculations of trace gas scavenging in a dense Saharan dust plume during MINATROC, Atmos. Chem. Phys., 5, 1787–1803, doi:10.5194/acp-5-1787-2005, 2005. Dentener, F. J., Carmichael, G. R., Zhang, Y., Lelieveld, J., Crutzen, P.: Role of mineral aerosol as a reactive surface in the global troposphere, J. Geophys. Res., 101(D17), 22869–22889, 1996. Dusek, U., Frank, G. P., Hildebrandt, L., Curtius, J., Schneider, J., Walter, S., Chand, D., Drewnick, F., Hings, S., Jung, D., Borrmann, S., and Andreae M. O.: Size Matters More Than Chemistry for Cloud-Nucleating Ability of Aerosol Particles, Science, 312(5778), 1375, doi:10.1126/science.1125261, 2006. Engler, C., Rose, D., Wehner, B., Wiedensohler, A., Brüggemann, E., Gnauk, T., Spindler, G., Tuch, T., and Birmili, W.: Size distributions of non-volatile particle residuals (D$_\rm p<$800 nm) at a rural site in Germany and relation to air mass origin, Atmos. Chem. Phys., 7, 5785–5802, doi:10.5194/acp-7-5785-2007, 2007. Environ: User's Guide to the Comprehensive Air Quality Model with Extensions (CAMx), Version 4. 31, prepared by ENVIRON Inter Corp., Novato, CA, 2006. EPA: Guidance on the Use of Models and Other Analyses for Demonstrating Attainment of Air Quality Goals for Ozone, PM$_2.5$, and Regional Haze, US Environmental Protection Agency, Office of Air Quality Planning and Standards, Air Quality Analysis Division, Research Triangle Park, North Carolina, EPA-454/B-07-002, April 2007. Evan, A. T., Dunion, J., Foley, J. A., Heidinger, A. K., and Velden, C. S.: New evidence for a relationship between Atlantic tropical cyclone activity and African dust outbreaks, Geophys. Res. Lett., 33, L19813, doi:10.1029/2006GL026408, 2006. Evan, A., Vimont, D., Heidinger, A., Kossin, J., and Bennartz, R.: The role of aerosols in the evolution of Tropical North Atlantic Ocean Temperature Anomalies, Science, 324, 778–781, 2009. Feingold, G., Cotton, W. R., Kreidenweiss, S. M., and Davis, J. T.: The impact of giant cloud condensation nuclei on drizzle formation in stratocumulus: Implications for cloud radiative properties, J. Atmos. Sci., 56, 4100–4117, 1999. Formenti, P., Elbert, W., Maenhaut, W., Haywood, J., and Andreae, M. O.: Chemical composition of mineral dust aerosol during the Saharan Dust Experiment (SHADE) airborne campaign in the Cape Verde region, September 2000, J. Geophys. Res., 108(D18), 8576, doi:10.1029/2002JD002648, 2003. Forster, P., Ramaswamy, V., Artaxo, P., Berntsen, T., Betts, R., Fahey, D. W., Haywood, J., Lean, J., Lowe, D. C., Myhre, G., Nganga, J., Prinn, R., Raga, G., Schulz, M., and Van Dorland R.: Changes in Atmospheric Constituents and in Radiative Forcing. In: 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, United Kingdom and New York, NY, USA, 2007. Fuchs, N. A. and Sutugin, A. G.: Highly dispersed aerosols, Ann Arbor Science Publishers, Ann Arbor, MI, 1970. Gangoiti, G., Alonso, L., Navazo, M., Garc\'ia, J. A., and Millan, M. M.: North African soil dust and European pollution transport to America during the warm season: Hidden links shown by a passive tracer simulation, J. Geophys. Res., 111, D10109, doi:10.1029/2005JD005941, 2006. Garrett, T. J. and Hobbs, P. V.: Long range transport of continental aerosols over the Atlantic Ocean and their effects on cloud structures, J. Atmos. Sciences, 52(16), 2977–2984, 1995. Goodman, A. L., Li, P., Usher, C. R., and Grassian, V. H.: Heterogeneous uptake of sulfur dioxide on aluminum and magnesium oxide particles, J. Phys. Chem. A, 105, 6109–6120, 2001. Husar, R. B., Prospero, J., and Stowe, L.: Characterization of tropospheric aerosols over the oceans with the NOAA advanced very high resolution radiometer optical thickness operational product, J. Geophys Res., 102(D14), 16889–16909, 1997. Kallos, G., Nickovic, S., Papadopoulos, A., Jovic, D., Kakaliagou, O., Misirlis, N., Boukas, L., Mimikou, N., Sakellaridis, G., Papageorgiou, J., Anadranistakis, E., and Manousakis, M.: The regional weather forecasting system SKIRON: An overview, Proceedings of the International Symposium on Regional Weather Prediction on Parallel Computer Environments, ISBN: 960-8468-22-1, University of Athens, Greece, 109–122, 1997. Kallos, G., Kotroni, V., Lagouvardos, K., and Papadopoulos A.: On the long-range transport of air pollutants from Europe to Africa, Geophys. Res. Lett., 25(5), 619–622, 1998. Kallos, G., Papadopoulos, A., Katsafados, P., and Nickovic, S.: Trans-Atlantic Saharan dust transport: Model simulation and results, J. Geophys. Res., 111, D09204, doi:10.1029/2005JD006207, 2006. Kallos, G., Astitha, M., Katsafados, P., and Spyrou, C.: Long-Range Transport of Anthropogenically and Naturally Produced Particulate Matter in the Mediterranean and North Atlantic-Current State of Knowledge, J. Applied Meteor. Climat., 46(8), 1230–1251, 2007. Kallos, G., Spyrou, C., Astitha, M., Mitsakou, C., Solomos, S., Kushta, J., Pytharoulis, I., Katsafados, P., Mavromatidis, E., and Papantoniou, N.: Ten-year operational dust forecasting – Recent model development and future plans, IOP Conf. Ser.: Earth Environ. Sci., 7, 012012, doi:10.1088/1755-1307/7/1/012012, 2009. Karyampudi, V. M.: A detailed synoptic-scale study of the structure, dynamics, and radiative effects of the Saharan air layer over the eastern tropical Atlantic during GARP Atlantic Tropical Experiment, MS~thesis, Department of Meteorology, The Pennsylvania State University, 136 pp., 1979. Karyampudi, V. M., Palm, S. P., Reagen, J. A., and Coauthors: Validation of the Saharan dust plume conceptual model using lidar, Meteosat, and ECMWF data, B. Am. Meteor. Soc., 80, 1045–1075, 1999. Kaufman, Y. J., Tanre, D., Mattoo, S., Eck, T. F., Vaughan, J., Chatenet, B., Holben, B. N., Remer, L. A.: Aerosol radiative impact on spectral solar flux at the surface, derived from principal-plane sky measurements, J. Atmos. Sci., 59, 635–646, 2002a. Kaufman, Y. J., Tanre, D., and Boucher, O.: A satellite view of aerosols in the climate system, Nature, 419, 215–223, 2002b. Lau, W. K. M. and Kim, K. M.: How Nature Foiled the 2006 Hurricane Forecasts, Eos Trans AGU, 88(9), 105–107, 2007. Lelieveld, J., Berresheim, H., Borrmann, S., Crutzen P. J., and Coauthors: Global air pollution crossroads over the Mediterranean, Science, 298, 794–799, 2002. Levin, Z., Ganor, E., and Gladstein, V.: The Effects of Desert Particles Coated with Sulfate on Rain Formation in the Eastern Mediterranean, J. Appl. Meteor., 35, 1511–1523, 1996. Levin, Z., Teller, A, Ganor, E., and Yin, Y.: On the interactions of mineral dust, sea-salt particles and clouds: a measurement and modelling study from the Mediterranean Israeli Dust Experiment campaign, J. Geophys. Res., 110, D20202, doi:10.1029/2005JD005810, 2005. Levin, Z. and Cotton, W. R.: Aerosol Pollution Impact on Precipitation-A Scientific Review, Springer, 386 pp., ISBN: 978-1-4020-8689-2, 2009. Millan, M. M., Salvador, R., Mantilla, E., and Kallos, G.: Photooxidant dynamics in the western Mediterranean in summer: Results from European research projects, J. Geophys. Res., 102(D7), 8811–8823, 1997. Nenes, A., Pilinis, C., and Pandis, S. N.: ISORROPIA: A new thermodynamic model for multiphase multicomponent inorganic aerosols, Aquat. Geochem., 4, 123–152, 1998. Nickovic, S., Kallos, G., Papadopoulos, A., and Kakaliagou, O.: A model for prediction of desert dust cycle in the atmosphere, J. Geophys. Res., 106, 18113–18129, 2001. Perez, C., Nickovic, S., Pejanovic, G., Baldasano, J. M., and Özsoy E.: Interactive dust radiation modeling: A step to improve weather forecasts, J. Geophys. Res., 111, D16206, doi:10.1029/2005JD006717, 2006. Perry, K. D., Cahill, T. A., Eldred, R. A., and Dutcher, D. D.: Long-range transport of North African dust to the eastern Union States, J. Geophys. Res., 102, 11225–11238, 1997. Prospero, J. M., Olmez, I., and Ames, M.: Al and Fe in PM$_2.5$ and PM$_10$ suspended particles in South-Central Florida: The impact of the long range transport of African mineral dust, Water Air Soil Pollut., 125, 291–317, 2001. Ramanathan, V., Crutzen, P. J., Kiehl, J. T., Rosenfeld, D.: Aerosols, Climate and the Hydrological Cycle, Science, 294, 2119, doi:10.1126/science.1064034, 2001. Redelsperger, J.-L., Thorncroft, C. D., Diedhiou, A., Lebel, T., Parker, D. J., and Polcher J.: African Monsoon Multidisciplinary Analysis: An international research project and field campaign, B. Am. Meteor. Soc., 87, 1739–1746, 2006. Remer, L. A., Tanré, D., and Kaufman, Y.: Algorithm for remote sensing of tropospheric aerosol from MODIS: collection 5. MODIS Algorithm Theoretical Basis Document. 87 pp Available at: http://modis-atmos.gsfc.nasa.gov/MOD04_L2/atbd.html, 2006. Saylor, R. D.: An estimate of the potential significance of heterogeneous loss to aerosols as an additional sink for HO radicals in the troposphere, Atmos. Environ., 21, 3653–3658, 1997. Seinfeld, J. and Pandis, S.: Atmospheric Chemistry and Physics (From Air Pollution to Climate Change), John Wiley and Sons, Inc., 2nd edition, 2006. Spyrou, C., Mitsakou, C., Kallos, G., Louka, P., and Vlastou, G.: An improved limited-area model for describing the dust cycle in the atmosphere, J. Geophys. Res., doi:10.1029/2009JD013682, in press, 2010. Tang, Y., Carmichael, G. R., Kurata, G., Uno, I., Weber, R. J., Song, C., Guttikunda, S. K., Woo, J. H., Streets, D. G., Wei, C., Clarke, A. D., Huebert, B., and Anderson, T. L.: Impacts of dust on regional tropospheric chemistry during the ACE-Asia experiment: A model study with observations. J. Geophys. Res., 109, D19S21, doi:10.1029/2003JD003806, 2004. Teller, A. and Levin, Z.: The effects of aerosols on precipitation and dimensions of subtropical clouds: a sensitivity study using a numerical cloud model, Atmos. Chem. Phys., 6, 67–80, doi:10.5194/acp-6-67-2006, 2006. Usher, C. R., Al-Hosney, H., Carlos-Cuellar, S., and Grassian, V. H.: A laboratory study of the heterogeneous uptake and oxidation of sulfur dioxide on mineral dust particles, J. Geophys. Res.-A, 107, 4713, doi:10.1029/2002JD002051, 2002. Vestreng, V.: EMEP/MSC-W Technical report. Review and Revision. Emission data reported to CLRTAP. MSC-W Status Report 2003, EMEP/MSC-W Note 1/2003, ISSN 0804-2446, 2003. Visschedijk, A. H. J. and Denier van der Gon, H. A. C.: Gridded European anthropogenic emission data for NO<sub>x</sub>, SO<sub>2</sub>, NMVOC, NH<sub>3</sub>, CO, PM$_10$, PM$_2. 5$ and CH<sub>4</sub> for the year 2000, TNO B&O-A Rapport 2005/106, 2$^nd$ version November, 2005. Wurzler, S., Reisin, T., and Levin, Z.: Modification of mineral dust particles by cloud processing and subsequent effects on drop size distributions, J. Geophys. Res., 105(D4), 4501–4512, doi:10.1029/1999JD900980, 2000. Yin, Y., Levin, Z., Reisin, T. G., and Tzivion, S.: The effects of giant cloud condensation nuclei on the development of precipitation in convective clouds-a numerical study, Atmos. Res., 53, 91–116, 2000. Zhang, Y. and Carmichael, G. R.: The role of mineral aerosol in tropospheric chemistry in East Asia-A model study, J. App. Met., 38, 353–366, 1999. Zhang, Y., Sunwoo, Y., Kotamarthi, V., and Carmichael, G. R.: Photochemical oxidant pro-processes in the presence of dust: An evaluation of the impact of dust on particulate nitrate and processes ozone formation, J. Appl. Met., 33, 813–824, 1994. Zipser, E. J, Twohy, C. H., Tsay, S., Thornhill, K. L., Tanelli, S., Ross, R., Krishnamurti, T. N., Ji, Q., Jenkins, G., Ismail, S., Hsu, N. C., Hood, R., Heymsfield, G. M., Heymsfield, A., Halverson, J., Goodman, H. M., Ferrare, R., Dunion, J. P., Douglas, M., Cifelli, R., Chen, G., Browell, E. V., and Anderson, B.: The Saharan Air Layer and the Fate of African Easterly Waves – NASA's AMMA Field Study of Tropical Cyclogenesis, B. Am. Meteor. Soc., 90(8), 1137–1156, 2009.