ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-11-12647-2011 Aerosol shortwave direct radiative effect and forcing based on MODIS Level 2 data in the Eastern Mediterranean (Crete) Benas N. 1 Hatzianastassiou N. 2 Matsoukas C. 3 Fotiadi A. 2 Mihalopoulos N. 4 Vardavas I. 1 Department of Physics, University of Crete, Greece Department of Physics, University of Ioannina, Greece Department of Environment, University of the Aegean, Greece Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, Greece 15 12 2011 11 24 12647 12662 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/11/12647/2011/acp-11-12647-2011.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/11/12647/2011/acp-11-12647-2011.pdf

The shortwave (SW) radiation budget was computed on a 10 km × 10 km resolution above FORTH-CRETE AERONET station in Crete, Greece, for the 11-year period from 2000 to 2010. The area is representative of the Eastern Mediterranean region, where air pollution and diminishing water resources are exacerbated by high aerosol loads and climate change. The present study aims to quantify the aerosol direct effect and forcing on the local surface and atmospheric energy budget. A radiative transfer model was used, with climatological data from the Moderate Resolution Imaging Spectroradiometer (MODIS), on board NASA's Terra and Aqua satellites. The instantaneous radiative fluxes were computed for satellite overpass times at the surface, within the atmosphere and at the top of atmosphere (TOA). Downward surface fluxes and aerosol input data were validated against ground measurements. Output fluxes reveal the direct radiative effects of dust events, with instantaneous values reaching up to −215, 139 and −46 Wm<sup>−2</sup> at the surface (cooling), within the atmosphere (warming) and at TOA (cooling), respectively. Mean monthly values show a decreasing trend of the aerosol direct radiative effect, in agreement with a similar trend in AOT. The analysis of the contribution of anthropogenic and natural aerosol show major peaks of natural aerosol direct effect occurring mainly in spring, while a summer maximum is attributed to anthropogenic aerosol. During their peaks, anthropogenic aerosol forcing can reach values of −24 Wm<sup>−2</sup> at the surface, 19 Wm<sup>−2</sup> in the atmosphere and over −4 Wm<sup>−2</sup> at TOA (monthly mean instantaneous values). The corresponding monthly peak values for natural aerosol are over −20 Wm<sup>−2</sup>, 12 Wm<sup>−2</sup> and −9 Wm<sup>−2</sup>.

 References Andreae, T. W., Andreae, M. O., Ichoku, C., Maenhaut, W., Cafmeyer, J., Karnieli, A., and Orlovsky, L.: Light scattering by dust and anthropogenic aerosol at a remote site in the Negev desert, Israel, J. Geophys. Res., 107(D2), 4008, http://dx.doi.org/10.1029/2001JD900252doi:10.1029/2001JD900252, 2002. Allen, C. W.: Astrophysical Quantities, 3rd Edn., The Athlone Press, University of London, 1976. Barnaba, F. and Gobbi, G. P.: Aerosol seasonal variability over the Mediterranean region and relative impact of maritime, continental and Saharan dust particles over the basin from MODIS data in the year 2001, Atmos. Chem. Phys., 4, 2367–2391, http://dx.doi.org/10.5194/acp-4-2367-2004doi:10.5194/acp-4-2367-2004, 2004. Bergamo, A., Tafuro, A. M., Kinne, S., De Tomasi, F., and Perrone, M. R.: Monthly-averaged anthropogenic aerosol direct radiative forcing over the Mediterranean based on AERONET aerosol properties, Atmos. Chem. Phys., 8, 6995–7014, http://dx.doi.org/10.5194/acp-8-6995-2008doi:10.5194/acp-8-6995-2008, 2008. Bryant, C., Eleftheriadis, K., Smolik, J., Zdimal, V., Mihalopoulos, N., and Colbeck, I.: Optical properties of aerosols over the eastern Mediterranean, Atmospheric Environment,~40,~6229–6244, 2006. Christopher, S. A. and Zhang, J.: Shortwave aerosol radiative forcing from MODIS and CERES observations over the oceans, Geophys. Res. Lett., 29, 1859, http://dx.doi.org/10.1029/2002GL014803doi:10.1029/2002GL014803, 2002. Chu, D. A., Kaufman, Y. J., Zibordi, G., Chern, J. D., Mao, J., Li, C., and Holben, B. N.: Global monitoring of air pollution over land from the Earth Observing System-Terra Moderate Resolution Imaging Spectroradiometer (MODIS), J. Geophys. Res., 108, 4661, http://dx.doi.org/10.1029/2002JD003179doi:10.1029/2002JD003179, 2003. Draxler, R. R. and Hess, G. D.: An overview of the HYSPLIT_4 modelling system for trajectories, dispersion and deposition, Aust. Meteorol. Mag., 47, 295–308, 1998. Dubovik, O. and King, M. D.: A flexible inversion algorithm for retrieval of aerosol optical properties from Sun and sky radiance measurements, J. Geophys. Res., 105, 20673–20696, http://dx.doi.org/10.1029/2000JD900282doi:10.1029/2000JD900282, 2000. Dubovik, O., Smirnov, A., Holben, B. N., King, M. D., Kaufman, Y. J., Eck, T. F., and Slutsker, I.: Accuracy assessments of aerosol optical properties retrieved from Aerosol Robotic Network (AERONET) Sun and sky radiance measurements, J. Geophys. Res., 105, 9791–9806, http://dx.doi.org/10.1029/2000JD900040doi:10.1029/2000JD900040, 2000. Dubovik, O., Holben, B. N., Eck, T. F., Smirnov, A., Kaufman, Y. J., King, M. D., Tanré, D., and Slutsker, I.: Variability of absorption and optical properties of key aerosol types observed in worldwide locations, J. Atmos. Sci., 59, 590–608, 2002. Formenti, P., Andreae, M. O., Andreae, T. W., Galani, E., Vasaras, A., Zerefos, C., Amiridis, V., Orlovsky, L., Karnieli, A., Wendisch, M., Wex, H., Holben, B. N., Maenhaut, W., and Lelieveld, J.: Aerosol optical properties and large-scale transport of air masses: Observations at a coastal and a semiarid site in the eastern Mediterranean during summer 1998, J. Geophys. Res., 106, 9807–9826, http://dx.doi.org/10.1029/2000JD900609doi:10.1029/2000JD900609, 2001. 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. Fotiadi, A., Hatzianastassiou, N., Drakakis, E., Matsoukas, C., Pavlakis, K. G., Hatzidimitriou, D., Gerasopoulos, E., Mihalopoulos, N., and Vardavas, I.: Aerosol physical and optical properties in the Eastern Mediterranean Basin, Crete, from Aerosol Robotic Network data, Atmos. Chem. Phys., 6, 5399–5413, http://dx.doi.org/10.5194/acp-6-5399-2006doi:10.5194/acp-6-5399-2006, 2006. Gómez-Amo, J. L., Pinti, V., Di Iorio, T., Di Sarra, A., Meloni, D., Becagli, S., Bellantone, V., Cacciani, M., Fuà, D., and Perrone, M. R.: The June 2007 Saharan dust event in the central Mediterranean: Observations and radiative effects in marine, urban, and sub-urban environments, Atmospheric Environment, 45, 5385–5393, http://dx.doi.org/10.1016/j.atmosenv.2011.06.045doi:10.1016/j.atmosenv.2011.06.045, 2011. Gueymard, C.: The Sun's total and spectral irradiance for solar energy applications and solar radiation models, Solar Energy, 76, 423–453, 2004. Hartman, D. L.: Global Physical Climatology, Academic Press, 411~pp., 1994. Hatzianastassiou, N. and Vardavas, I.: Shortwave radiation budget of the Northern Hemisphere using International Satellite Cloud Climatology Project and NCEP/NCAR climatological data, J. Geophys. Res., 104, 24401–24421, 1999. Hatzianastassiou, N. and Vardavas, I.: Shortwave radiation budget of the Southern Hemisphere using ISCCP C2 and NCEP/NCAR climatological data, J. Climate, 14, 4319–4329, 2001. Hatzianastassiou, N., Fotiadi, A., Matsoukas, Ch., Pavlakis, K., Drakakis, E., Hatzidimitriou, D., and Vardavas, I.: Long-term global distribution of earth's shortwave radiation budget at the top of atmosphere, Atmos. Chem. Phys., 4, 1217–1235, http://dx.doi.org/10.5194/acp-4-1217-2004doi:10.5194/acp-4-1217-2004, 2004a. Hatzianastassiou, N., Katsoulis, B., and Vardavas, I.: Global distribution of aerosol direct radiative forcing in the ultraviolet and visible arising under clear skies, Tellus, 56B, 51–71, 2004b. Hatzianastassiou, N., Matsoukas, C., Fotiadi, A., Pavlakis, K. G., Drakakis, E., Hatzidimitriou, D., and Vardavas, I.: Global distribution of Earth's surface shortwave radiation budget, Atmos. Chem. Phys., 5, 2847–2867, http://dx.doi.org/10.5194/acp-5-2847-2005doi:10.5194/acp-5-2847-2005, 2005. Hatzianastassiou, N., Matsoukas, C., Fotiadi, A., P. W. Stackhouse Jr., Koepke, P., Pavlakis, K. G., and Vardavas, I.: Modelling the direct effect of aerosols in the solar near-infrared on a planetary scale, Atmos. Chem. Phys., 7, 3211–3229, http://dx.doi.org/10.5194/acp-7-3211-2007doi:10.5194/acp-7-3211-2007, 2007. Haywood, J., Francis, P., Osborne, S., Glew, M., Loeb, N., Highwood, E., Tanré, D., Myhre, G., Formenti, P., and Hirst, E.: Radiative properties and direct radiative effect of Saharan dust measured by the C-130 aircraft during SHADE: 1. Solar spectrum, J. Geophys. Res., 108, 8577, http://dx.doi.org/10.1029/2002JD002687doi:10.1029/2002JD002687, 2003. Holben, B. N., Eck, T. F., Slutsker, I., Tanré, D., Buis, J. P., Setzer, A., Vermote, E., Reagan, J. A., Kaufman, Y. J., Nakajima, T., Lavenu, F., Jankowiak, I., and Smirnov, A.: AERONET – A federated instrument network and data archive for aerosol characterization, Remote Sens. Environ., 66, 1–16, 1998. Holben, B. N., Tanré, D., Smirnov, A., Eck, T. F., Slutsker, I., Abuhassan, N., Newcomb, W. W., Schafer, J., Chatenet, B., Lavenue, F., Kaufman, Y. J., Vande Castle, J., Setzer, A., Markham, B., Clark, D., Frouin, R., Halthore, R., Karnieli, A., O'Neill, N. T., Pietras, C., Pinker, R. T., Voss, K., and Zibordi, G.: An emerging ground-based aerosol climatology: Aerosol Optical Depth from AERONET, J. Geophys. Res., 106, 12067–12097, 2001. Ichoku, C., Chu, D. A., Mattoo, S., Kaufman, Y. J., Remer, L. A., Tanré, V., Slutsker, I., and Holben, B. N.: A spatio-temporal approach for global validation and analysis of MODIS aerosol products, Geophys. Res. Lett., 29, 8006, http://dx.doi.org/10.1029/2001GL013206doi:10.1029/2001GL013206, 2002. IPCC, 2007: 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, 996~pp., 2007. Joseph, J. H., Wiscombe, W. J., and Weinmann, J. A.: The Delta-Eddington approximation of radiative flux transfer, J. Atmos. Sci., 33, 2452–2459, 1976. Kalivitis, N., Gerasopoulos, E., Vrekoussis, M., Kouvarakis, G., Kubilay, N., Hatzianastassiou, N., Vardavas, I., and Mihalopoulos, N.:~Dust transport over the eastern Mediterranean derived from Total Ozone Mapping Spectrometer, Aerosol Robotic Network, and surface measurements,~J. Geophys. Res.,~112, D03202, http://dx.doi.org/10.1029/2006JD007577doi:10.1029/2006JD007577, 2007. Kaskaoutis, D. G., Kambezidis, H. D., Nastos, P. T., and Kosmopoulos, P. G.: Study on an intense dust storm over Greece, Atmospheric Environment, 42, 6884–6896, http://dx.doi.org/10.1016/j.atmosenv.2008.05.017doi:10.1016/j.atmosenv.2008.05.017, 2008. Kaufman, Y. J., Tanré, D., Remer, L. A., Vermote, E. F., Chu, A., and Holben, B. N.: Operational remote sensing of tropospheric aerosol over land from EOS moderate resolution imaging spectroradiometer, J. Geophys. Res., 102, 17051–17067, 1997. Kaufman, Y. J., Tanré, D., and Boucher, O.: A satellite view of aerosols in the climate system, Nature, 419, 215–223, 2002. King, M. D., Menzel, W. P., Kaufman, Y. J., Tanré, D., Gao, B. C., Platnick, S., Ackerman, S. A., Remer, L. A., Pincus, R., and Hubanks, P. A.: Cloud and aerosol properties, precipitable water, and profiles of temperature and humidity from MODIS. IEEE Trans., Geosci. Remote Sens., 41, 442–458, 2003. Keil, A. and Haywood, J.: Solar radiative forcing by biomass burning aerosol particles during SAFARI-2000: A case study based on measured aerosol and cloud properties, J. Geophys. Res., 108, 8467, http://dx.doi.org/10.1029/2002JD002315doi:10.1029/2002JD002315, 2003. Kleidman, R. G., O'Neill, N. T., Remer, L. A., Kaufman, Y. J., Eck, T. F., Tanré, D., Dubovik, O., and Holben, B. N.: Comparison of Moderate Resolution Imaging Spectroradiometer (MODIS) and Aerosol Robotic Network (AERONET) remote-sensing retrievals of aerosol fine mode fraction over ocean,~J. Geophys. Res.,~110, D22205, http://dx.doi.org/10.1029/2005JD005760doi:10.1029/2005JD005760, 2005 Kondratyev, K. Y.: Radiation Characteristics of the Atmosphere and the Earth's surface, Amerind, New Delhi, 580~pp., 1973. Lelieveld, J., Berresheim, H., Borrmann, S., Crutzen, P. J., Dentener, F. J., Fischer, H., Feichter, J., Flatau, P. J., Heland, J., Holzinger, R., Korrmann, R., Lawrence, M. G., Levin, Z., Markowicz, K. M., Mihalopoulos, N., Minikin, A., Ramanathan, V., de Reus, M., Roelofs, G. J., Scheeren, H. A., Sciare, J., Schlager, H., Schultz, M., Siegmund, P., Steil, B., Stephanou, E. G., Stier, P., Traub, M., Warneke, C., Williams, J., and Ziereis, H.: Global Air Pollution Crossroads over the Mediterranean, Science, 298, 5594, 794–799, 2002. Mallet, M., Tulet, P., Serça, D., Solmon, F., Dubovik, O., Pelon, J., Pont, V., and Thouron, O.: Impact of dust aerosols on the radiative budget, surface heat fluxes, heating rate profiles and convective activity over West Africa during March 2006, Atmos. Chem. Phys., 9, 7143–7160, http://dx.doi.org/10.5194/acp-9-7143-2009doi:10.5194/acp-9-7143-2009, 2009. Matsoukas, C., Benas, N., Hatzianastassiou, N., Pavlakis, K. G., Kanakidou, M., and Vardavas, I.: Potential evaporation trends over land between 1983–2008: driven by radiative or turbulent fluxes?, Atmos. Chem. Phys. Discuss., 11, 10935–10972, http://dx.doi.org/10.5194/acpd-11-10935-2011doi:10.5194/acpd-11-10935-2011, 2011. Meloni, D., di Sarra, A., Di Iorio, T., and Fiocco, G.: Influence of the vertical profile of Saharan dust on the visible direct radiative forcing, J. Quant. Spectrosc. Ra., 93, 347–413, 2005. Mihalopoulos, N., Stephanou, E., Pilitsidis, S., Kanakidou, M., and Bousquet, P.: Atmospheric aerosol composition above the Eastern Mediterranean region, Tellus, 49B, 314–326, 1997. Papadimas, C. D., Hatzianastassiou, N., Mihalopoulos, N., Querol, X., and Vardavas, I.: Spatial and temporal variability in aerosol properties over the Mediterranean basin based on 6-year (2000–2006) MODIS data, J. Geophys. Res., 113, D11205, http://dx.doi.org/10.1029/2007JD009189doi:10.1029/2007JD009189, 2008. Peng, L. I., Chou, M.-D., and Arking, A.: Climate studies with a multi-layer energy balance model, Part I: Model description and sensitivity to the solar constant, J. Atmos. Sci., 39, 2639–2656, 1982. Remer, L. A., Tanré, D., Kaufman, Y. J., Ichoku, C., Mattoo, S., Levy, R., Chu, D. A., Holben, B. N., Dubovik, O., Smirnov, A., Martins, J. V., Li, R.-R., and Ahmad, Z.: Validation of MODIS aerosol retrieval over ocean, Geophys. Res. Lett., 29, MOD03, http://dx.doi.org/10.1029/2001GL013204doi:10.1029/2001GL013204, 2002. Remer, L. A., Kaufman, Y. J., Tanré, D., Mattoo, S., Chu, D. A., Martins, J. V., Li, R. R., Ichoku, C., Levy, R. C., Kleidman, R. G., Eck, T. F., Vermote, E., and Holben, B. N.: The MODIS aerosol algorithm, products and validation, J. Atmos. Sci., 62, 947–973, 2005. Sander, S. P., Friedl, R. R., Ravishankara, A. R., Golden, D. M., Kolb, C. E., Kurylo, M. J., Molina, J., Moortgat, G. K., Keller-Rudek, H., Finlayson-Pitts, B. J., Wine, P. H., Huie, R. E., and Orkin, V. L.: Chemical Kinetics and Photochemical Data for Use in Atmospheric Studies, Evaluation Number 15, Jet Propulsion Laboratory Publication 06-2, California Institute of Technology, Pasadena, 2006. Santese, M., De Tomasi, F., and Perrone, M. R.: Moderate Resolution Imaging Spectroradiometer (MODIS) and Aerosol Robotic Network (AERONET) retrievals during dust outbreaks over the Mediterranean, J. Geophys. Res., 112, D18201, http://dx.doi.org/10.1029/2007JD008482doi:10.1029/2007JD008482, 2007. Shettle, E. P. and Weinmann, J. A.: The transfer of solar irradiance through inhomogeneous turbid atmospheres evaluated by Eddington's approximation, J. Atmos. Sci., 27, 1048–1055, 1970. Tafuro, A. M., Barnaba, F., De Tomasi, F., Perrone, M. R., and Gobbi, G. P.: Saharan dust particle properties over the central Mediterranean, Atmos. Res., 81, 67–93, http://dx.doi.org/10.1016/j.atmosres.2005.11.008doi:10.1016/j.atmosres.2005.11.008, 2006. Tanré, D., Kaufman, Y. J., Herman, M., and Mattoo, S.: Remote sensing of aerosol properties over oceans using the MODIS/EOS spectral radiances, J. Geophys. Res., 102, 16971–16988, 1997. Vardavas, I. and Carver, J. H.: Solar and terrestrial parameterizations for radiative convective models, Planet. Space Sci., 32, 1307–1325, 1984. Vardavas, I. M. and Koutoulaki, K.: A model for the solar radiation budget of the Northern Hemisphere: Comparison with Earth Radiation Budget Experiment data, J. Geophys. Res., 100, 7303–7314, 1995. Vardavas, I. M. and Taylor, F. W.: Radiation and Climate: Atmospheric energy budget from satellite remote sensing, International Series of Monographs on Physics, 138, Oxford University Press, Oxford, UK, 2011. Willson, R. C.: Total solar irradiance trend during solar cycles 21 and 22, Science, 277, 1963–1965, 1997.