ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-8-7603-2008 Evaluation of the MERIS aerosol product over land with AERONET Vidot J. 1 Santer R. 2 Aznay O. 2 Laboratoire de Météorologie Physique (LaMP), Observatoire de Physique du Globe de Clermont-Ferrand, Université Blaise Pascal, Clermont-Ferrand, France Laboratoire Interdisciplinaire des Sciences de l'Environnement, Maison de la Recherche en Environnement Naturel, Université du Littoral Cote d'Opale, Wimereux, France 17 12 2008 8 24 7603 7617 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/8/7603/2008/acp-8-7603-2008.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/8/7603/2008/acp-8-7603-2008.pdf

The Medium Resolution Imaging Spectrometer (MERIS) launched in February 2002 on-board the ENVISAT spacecraft is making global observations of top-of-atmosphere (TOA) radiances. Aerosol optical properties are retrieved over land using Look-Up Table (LUT) based algorithm and surface reflectances in the blue and the red spectral regions. We compared instantaneous aerosol optical thicknesses retrieved by MERIS in the blue and the red at locations containing sites within the Aerosol Robotic Network (AERONET). Between 2002 and 2005, a set of 500 MERIS images were used in this study. The result shows that, over land, MERIS aerosol optical thicknesses are well retrieved in the blue and poorly retrieved in the red, leading to an underestimation of the Angstrom coefficient. Correlations are improved by applying a simple criterion to avoid scenes probably contaminated by thin clouds. To investigate the weakness of the MERIS algorithm, ground-based radiometer measurements have been used in order to retrieve new aerosol models, based on their Inherent Optical Properties (IOP). These new aerosol models slightly improve the correlation, but the main problem of the MERIS aerosol product over land can be attributed to the surface reflectance model in the red.

 References % vor jede Referenz Abdou, W. A., Diner, D. J., Martonchik, J. V., Bruegge, C. J., Kahn, R. A., Gaitley, B. J., Crean, K. A., Remer, L. A., and Holben, B.: Comparison of coincident Multiangle Imaging Spectroradiometer and Moderate Resolution Imaging Spectroradiometer aerosol optical depths over land and ocean scenes containing Aerosol Robotic Network sites, J. Geophys. Res., 110, D10S07, doi:10.1029/2004JD004693, 2005. % vor jede Referenz Aznay, O. and Santer, R.: Validation of the La Crau aerosol model using the Avignon AERONET site, internal report, LISE-ULCO, 2007. % vor jede Referenz Bokoyé, A. I., Royer, A., O'Neill, N. T., and McArthur, L. J. B.: A North American Arctic Aerosol Climatology using Ground-Based Sunphotometry, Arctic, 5, 215–228, 2002. % vor jede Referenz Chin, M., Ginoux, P., Kinne, S., Torres, O., Holben, B. N., Duncan, B. N., Martin, R. V., Logan, J. A., Higurashi, A., and Nakajima, T.: Tropospheric Aerosol Optical Thickness from the GOCART Model and Comparisons with Satellite and Sun Photometer Measurements, J. Atmos. Sci., 59, 461–483, 2002. % vor jede Referenz Delwart, S., Bourg, L., and Huot, J.-P.: MERIS 1$^st$ year: early calibration results, in: Proceeding of SPIE in Sensors, Systems and Next-Generation Satellite VII, Barcelona (SPAIN), 8–12, September 2003, 5234, 379–390, 2003. % vor jede Referenz Deuzé, J.-L., Herman, M., and Santer, R.: Fourier series expansion of the transfer equation in the atmosphere-ocean system, J. Quant. Spectrosc. Ra., 41, 483–494, 1989. % vor jede Referenz Deuzé, J.-L., Bréon, F.-M., Devaux, C., Goloub, P., Herman, M., Lafrance, B., Maignan, F., Marchand, A., Nadaf, L., Perry, G., and Tanré, D.: Remote sensing of aerosols over land surfaces from POLDER-ADEOS 1 Polarized measurements, J. Geophys. Res., 106(D5), 4913–4926, 2001. % vor jede Referenz 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, doi:10.1029/2000JD900040, 2000. % vor jede Referenz Dubovik, O., Holben, B., 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. % vor jede Referenz Eck, T. F., Holben, B. N., Ward, D. E., Dubovik, O., Reid, J. S., Smirnov, A., Mukelabai, M. M., Hsu, N. C., O'Neill, N. T., and Slutsker, I.: Characterization of the optical properties of biomass burning aerosols in Zambia during the 1997 ZIBBEE field campaign, J. Geophys. Res., 106, 3425–3448, doi:10.1029/2000JD900555, 2001. % vor jede Referenz Eck, T. F., Holben, B. N., Dubovik, O., Smirnov, A., Goloub, P., Chen, H. B., Chatenet, B., Gomes, L., Zhang, X. Y., Tsay, S. C., Ji, Q., Giles, D. and Slutsker, I.: Columnar aerosol optical properties at AERONET sites in central eastern Asia and aerosol transport to the tropical mid-Pacific, J. Geophys. Res., 110, D06202, doi:10.1029/2004JD005274, 2005. % vor jede Referenz Grey, W. M. F., North, P. R. J., Los, S. O., and Mitchell, R. M.: Aerosol optical depth and land surface reflectance from multiangle AATSR measurements: global validation and intersensor comparisons, IEEE T. Geosci. Remote Sens., 44, 2184–2197, doi: 10.1109/TGRS.2006.872079, 2006. % vor jede Referenz 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, Remote Sens. Environ., 66, 1–16, doi:10.1016/S0034-4257(98)00031-5, 1998. % vor jede Referenz Hsu, N. C., Tsay, S. C., King, M. D., and Herman, J. R.: Deep blue retrievals of Asian aerosol properties during ACE-Asia, IEEE Trans. Geosci. Remote Sens., 44, 3180–3195, 2006. % vor jede Referenz Intergovernmental Panel on Climate Change, 2007, Climate Change 2007: The Scientific Basis, 996 pp., available on http://ipcc-wg1.ucar.edu/wg1/wg1-report.html, 2007. % vor jede Referenz Kahn, R. A., Gaitley, B. J., Martonchik, J. V., Diner, D. J., Crean, K. A. and, Holben, B.: Multiangle Imaging Spectroradiometer (MISR) global aerosol optical depth validation based on 2 years of coincident Aerosol Robotic Network (AERONET) observations, J. Geophys. Res., 110, D10S04, doi:10.1029/2004JD004706, 2005. % vor jede Referenz Kaufman, Y. J. and Sendra, C.: Algorithm for automatic atmospheric corrections to visible and near-IR satellite imagery, Int. J. Remote Sens., 9, 1357–1381, 1988. % vor jede Referenz Kaufman, Y. J. and Tanré, D.: Atmospherically resistant vegetation index (ARVI) for EOS-MODIS, IEEE T. Geosci. Remote, 30, 261–270, doi:10.1109/36.134076, 1992. % vor jede Referenz 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, 17051–17068, doi:10.1029/96JD03988, 1997. % vor jede Referenz Kaufman, Y. J., Tanré, D., and Boucher, O.: A satellite view of aerosols in the climate system, Nature, 419, 215–223, 2002. % vor jede Referenz Kneubuehler, M., Schaepman, M. E., Thome, K. J., and Schlapfer, D. R.: MERIS/ENVISAT vicarious calibration over land, in: Proceedings of SPIE, Sensors, Systems, and Next-Generation Satellites VII, edited by: Meynart, R., Neeck, S. P., Shimoda, H., Lurie, J B., and Aten, M. L., 5234, 614–623, 2004. % vor jede Referenz Levy, R. C., Remer, L., Mattoo, S., Vermote, E., and Kaufman, Y. J.: Second-generation algorithm for retrieving aerosol properties over land from MODIS spectral reflectance, J. Geophys. Res., 112, D13211, doi:10.1029/2006JD007811, 2007. % vor jede Referenz Mishchenko, M. I., Cairns, B., Hansen, J. E., Travis, L. D., Burg, R., Kaufman, Y. J., Martins, V., and Shettle, E. P.: Monitoring of aerosol forcing of climate from space: analysis of measurement requirements, J. Quant. Spectrosc. Ra., 88, 149–161, 2004. % vor jede Referenz Moody, E. G., King, M. D., Platnick, S., Schaaf, C. B., and Feng, G.: Spatially complete global spectral surface albedos: value-added datasets derived from Terra MODIS land products, IEEE T. Geosci. Remote, 43, 144–158, doi:10.1109/TGRS.2004.838359, 2005. % vor jede Referenz Preusker, R. and Fischer, J.: Cloud top pressure retrieval within the O2-A band with the satellite sensors MOS and MERIS, in: Proceedings of the International Geoscience and remote sensing Symposium (IGARSS'99), Hamburg, Germany, 28 June–2 July 1999 (Piscataway, New Jersey: IEEE), 1999. % vor jede Referenz Ramon, D. and Santer, R.: Operational Remote Sensing of Aerosols over Land to Account for Directional Effects, Appl. Optics, 40, 3060–3075, 2001. % vor jede Referenz Ramon, D., Santer, R., and Dubuisson, P.: MERIS surface pressure and cloud flag: Present status and improvements, in: Proceedings of the Envisat Validation Workshop 2002, 9–13 December 2002, ESRIN Frascati, Italy, 2002. % vor jede Referenz Ramon, D., Santer, R., Dilligeard, E., Jolivet, D., and Vidot, J.: Validation of MERIS products over land, in: Proccedings of the MERIS Users Workshop, ESA ESRIN, 10–13 November 2003, Frascati, Italy, 2003. % vor jede Referenz Ramon, D. and Santer, R.: Aerosol over Land with MERIS, Present and Future, in: Proceeding of the MERIS and AATSR Workshop 2005, ESA SP-597, 26–30 September 2005, ESRIN, Frascati, Italy, 2005. % vor jede Referenz Rast, M. and Bezy, J. L.: The ESA Medium Resolution Imaging Spectrometer MERIS a review of the instrument and its mission, Int. J. Remote Sens., 20, 1681–1702, doi:10.1080/014311699212416, 1999. % vor jede Referenz 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. % vor jede Referenz Santer, R., Carrère, V., Dubuisson, P., and Roger, J. C.: Atmospheric correction over land for MERIS, Int. J. Remote Sens., 20, 1819–1840, doi:10.1080/014311699212506, 1999. % vor jede Referenz Santer, R. and Martiny, N.: Sky radiance measurements for ocean colour calibration-validation, Appl. Optics, 42, 896–907, 2003. % vor jede Referenz Santer, R. and Lemire, F.: Validation of the MERIS Atmospheric Corrections: Toward a New Aerosol Climatology, in: Proceeding of the ENVISAT workshop, Salzburg, 6–10 September 2004, Austria, 2004. % vor jede Referenz Santer, R., Ramon, D., Vidot, J., and Dilligeard E.: A surface reflectance model for aerosol remote sensing over land, Int. J. Remote Sens., 28, 737–760, doi:10.1080/01431160600821028, 2007a. % vor jede Referenz Santer R., Zagolski F., and Aznay, O.: Iterative process to derive aerosol phase function from CIMEL measurements, Int. J. Remote Sens., submitted, September 2007, 2007b. % vor jede Referenz Schafer, J. S., Eck, T. F., Holben, B. N., Artaxo, P., Yamasoe, M. A., and Procopio, A. S.: Observed reductions of total solar irradiance by biomass-burning aerosols in the Brazilian Amazon and Zambian Savanna, Geophys. Res. Lett., 29, 4–1, doi:10.1029/2001GL014309, 2002. % vor jede Referenz Schroeder, T., Fischer, J., Preusker, R., Schaale, M., and Regner, P.: Retrieval of Surface Reflectance in the Framework of the MERIS Global Land Surface Albedo Maps Project, in: Proceeding of the MERIS and (A)ATSR Workshop 2005 (ESA SP-597), 26–30 September 2005, ESRIN, Frascati, Italy, 2005. % vor jede Referenz Shettle, E. P. and Fenn, R.W.: Models fort he aerosols of the lower atmosphere and the effects of humifity variations on their optical properties, Air Force Geophysical Laboratory, Technical Report AFGL-TR-79-0214, Hanscom Air Force Base (Mass.), 1979. % vor jede Referenz Smirnov, A., Holben, B. N., Eck, T. F., Dubovik, O., and Slutsker, I.: Cloud-Screening and Quality Control Algorithms for the AERONET Database, Remote Sens. Environ., 73, 337–349, doi:10.1016/S0034-4257(00)00109-7, 2000. % vor jede Referenz Toledano, C., Cachorro, V., Berjon, A., Sorribas, M., Vergaz, R., De Frutos, A., Anton, M., and Gausa M.: Aerosol optical depth at ALOMAR Observatory (Andøya, Norway) in summer 2002 and 2003, Tellus B, 58, 218–228, doi:10.1111/j.1600-0889.2006.00184.x, 2006. % vor jede Referenz Wilson, R. and Sprengler, J. D.: Particles in our air: concentrations and health effects, Harvard University Press, 259 pp., 1996. % vor jede Referenz Zagolski F., Santer, R., and Aznay, O.: A new climatology for atmospheric correction based on the aerosol inherent optical properties, J. Geophys. Res., 112, D14208, doi:10.1029/2006JD007496, 2007.