ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-10-10949-2010 A decadal regional and global trend analysis of the aerosol optical depth using a data-assimilation grade over-water MODIS and Level 2 MISR aerosol products Zhang J. 1 Reid J. S. 2 Department of Atmospheric Science, University of North Dakota, Grand Folks, ND, USA Marine Meteorology Division, Naval Research Laboratory, Monterey, CA, USA 24 11 2010 10 22 10949 10963 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/10/10949/2010/acp-10-10949-2010.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/10/10949/2010/acp-10-10949-2010.pdf

Using the ten-year (2000–2009) Data-Assimilation (DA) quality Terra MODIS and MISR aerosol products, as well as 7 years of Aqua MODIS, we studied both regional and global aerosol trends over oceans. This included both operational and data assimilation grade versions of the products. After correcting for what appears to be aerosol signal drift from the radiometric calibration of both MODIS instruments, we found MODIS and MISR agreed on a statistically negligible global trend of ±0.003/per decade. Our study also suggests that AODs over the Indian Bay of Bengal, east coast of Asia, and Arabian Sea show increasing trends of 0.07, 0.06, and 0.06 per decade for MODIS, respectively. These regional trends are considered as significant with a confidence level above 95%. Similar increasing trends were found from MISR, but with less relative magnitude. These trends reflect respective increases in the optical intensity of aerosol events in each region: anthropogenic aerosols over the east coast of China and Indian Bay of Bengal; and a stronger influence from dust events over the Arabian Sea. Negative AOD trends, low in confidence levels, are found off Central America, the east coast of North America, and the west coast of Africa, which indicate that longer periods of observation are necessary to be conclusive.

 References Cermak, J., Wild, M., Knutti, R., Mishchenko, M. I., and Heidinger, A. K.: Consistency of global satellite-derived aerosol and cloud data sets with recent brightening observations, Geophys. Res. Lett., L21704, doi:10.1029/2010GL044632, 2010. Giglio, L., Csiszar, I., and Justice, C. O.: Global distribution and seasonality of active fires as observed with the Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) sensors, J. Geophys. Res., 111, G02016, doi:10.1029/2005JG000142, 2006. Herman, J. R., Labow, G., Hsu, N. C., and Larko, D.: Changes in cloud and aerosol cover (1980–2006) from reflectivity time series using SeaWiFS, N7-TOMS, EP-TOMS, SBUV-2, and OMI radiance data, J. Geophys. Res., 114, D01201, doi:10.1029/2007JD009508, 2009. 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. Kahn, R. A., Garay, M. J., Nelson, D. L., Yau, K. K., Bull, M. A., Gaitley, B. J., Martonchik, J. V., and Levy, R. C.: Satellite-derived aerosol optical depth over dark water from MISR and MODIS: Comparisons with AERONET and implications for climatological studies, J. Geophys. Res., 112, D18205, doi:10.1029/2006JD008175, 2007. Kahn, R. A., Nelson, D. L., Garay, M., Levy, R. C., Bull, M. A., Diner, D. J., Martonchik, J. V., Paradise, S. R., and Hansen, E. G., and Remer, L. A.: MISR Aerosol product attributes, and statistical comparisons with MODIS. IEEE Trans. Geosci. Remt. Sens, 4095–4114, 2009. Kahn, R. A., Gaitley, B. J., Garay, M. J., Diner, D. J., Eck, T., Smirnov, A., and Holben, B. N.: MISR aerosol product assessment by comparison with AERONET. J. Geophys. Res., in press, 2010. Intergovernmental Panel on Climate Change (IPCC): The scientific basis, Cambridge University Press, Cambridge, UK and New York, NY, USA, 996 pp., 2007. Kahn, R. A., Gaitley, B., Martonchik, J., Diner, D., Crean, K., and Holben, B.: MISR Global Aerosol Optical Depth Validation based on Two Years of Coincident AERONET observations, J. Geophys. Res., doi:10:1029/2004JD004706, 2005. Kaufman, Y. J., Koren, I., Remer, L. A., Tanré, D., Ginoux, P., and Fan, S.: Dust transport and deposition observed from the Terra-Moderate Resolution Imaging Spectroradiometer (MODIS) spacecraft over the Atlantic Ocean, J. Geophys. Res., 110, D10S12, doi:10.1029/2003JD004436, 2005. Kishcha, P., Starobinets, B., and Alpert, P.: Latitudinal variations of cloud and aerosol optical thickness trends based on MODIS satellite data, Geophys. Res. Lett., 34, L05810, doi:10.1029/2006GL028796, 2007. Lallart, P., Kahn, R., and Tanré, D.: POLDER2/ADEOSII, MISR, and MODIS/Terra reflectance comparisons. J. Geophys. Res., 113, D14S02, doi:10.1029/2007JD009656, 2008. Lau K.-M., K.-M. Kim, Observational relationships between aerosol and Asian monsoon rainfall, and circulation, Geophys. Res. Lett., $33$, L21810, doi:10.1029/2006GL027546, 2006. Levy, R. C., Leptoukh, G. G., R. Kahn, V. Zubko, A. Gopalan, and L.A. Remer, A Critical Look at Deriving Monthly Aerosol Optical Depth From Satellite Data. IEEE Transacations on Geoscience and Remote Sensing, 47(8), 2942–2956, 2009. Levy R. C., Remer, L. A., Kleidman, R. G., Mattoo, S., Ichoku, C., Kahn, R., and Eck, T. F.: Global evaluation of the Collection 5 MODIS dark-target aerosol products over Land, Atmos. Chem. Phys. Discuss., 10, 14815–14873, doi:10.5194/acpd-10-14815-2010, 2010. Li, J., Carlson, B. E., and Lacis, A. A.: A study on the temporal and spatial variability of absorbing aerosols using Total Ozone Mapping Spectrometer and Ozone Monitoring Instrument Aerosol Index data, J. Geophys. Res., 114, D09213, doi:10.1029/2008JD011278, 2009a. Li, Z., Zhao, X., Kahn, R., Mishchenko, M., Remer, L., Lee, K.-H., Wang, M., Laszlo, I., Nakajima, T., and Maring, H.: Uncertainties in satellite remote sensing of aerosols and impact on monitoring its long-term trend: a review and perspective, Ann. Geophys., 27, 2755–2770, 2009b. Lyapustin, A., Wang, Y., Kahn, R., Xiong, J., Ignatov, A., Wolfe, R., Wu, A., Holben, B., and Bruegge, C.: Analysis of MODIS–MISR calibration differences using surface albedo around AERONET sites and cloud reflectance, Remote Sens. Environ.,107, 12–21, 2007. Massie, S. T., Torres, O., and Smith, S. J.: Total Ozone Mapping Spectrometer (TOMS) observations of increases in Asian aerosol in winter from 1979 to 2000, J. Geophys. Res., 109, D18211, doi:10.1029/2004JD004620, 2004. Mishchenko, M. I., Geogdzhaev, I. V., Rossow, W. B., Cairns, B., Carlson, B. E., Lacis, A. A., Liu, L., and Travis, L. D.: Long-term satellite record reveals likely recent aerosol trend, Science, 315, 1543, doi:10.1126/science.1136709, 2007a. Mishchenko, M. I. and Geogdzhayev, I. V.: Satellite remote sensing reveals regional tropospheric aerosol trends, Opt. Exp. 15, 7423–7438, 2007b. Mishchenko, M. I., Geogdzhayev, I. V., Liu, L., Lacis, A. A., Cairns, B., and Travis, L. D.: Toward unified satellite climatology of aerosol properties: what do fully compatible MODIS and MISR aerosol pixels tell us?, J. Quant. Spectrosc. Radiat. Transfer, 110, 402–408, 2009. Montgomery, H., Che, N., Parker K.,, and Bowser, J.: The algorithm or MODIS wavelength on-orbit calibration suing the SRCA, IEEE Trans. Geosci. Remote Sens., 38, 877–884, 2000. O'Neill, N. T., Eck, T. F., Smirnov, A., Holben, B. N., and Thulasiraman, S.: Spectral discrimination of coarse and fine mode optical depth, J. Geophys. Res., 108(D17), 4559, doi:1029/2002JD002975, 2003. Rao, C. R. N. and Chen, J.: Post launch calibration of the visible and near-infrared channels of the Advanced Very High Resolution Radiometer on the NOAA-14 spacecraft, Int. J. Remote Sens., 17, 2743–2747, 1996. 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. Remer, L. A., Kaufman, Y. J., and Kleidman, R. G.: Comparison of three years of Terra and Aqua MODIS Aerosol Optical Thickness Over the Global Oceans. IEEE, Geosci. Remote Sens. Lett., 3(4), 537–540, 2006. Remer, L. A., Kleidman, R. G., Levy, R. C., Kaufman, Y. J., Tanré, D., Mattoo, S, Martins, J. V., Ichoku, C., Koren, I., Yu, H., and Holben, B.: Global aerosol climatology from the MODIS satellite sensors, J. Geophys. Res., 113, D14S07, doi:10.1029/2007JD009661, 2008. Shi, Y., Zhang, J., Reid, J. S., Holben, B. N., Hyer, E. J., and Curtis, C.: An analysis of the collection 5 MODIS over-ocean aerosol optical depth product for its implication in aerosol assimilation, Atmos. Chem. Phys., submitted, 2010. Streets, D. G., Yan, F., Chin, M., Diehl, T., Mahowald, N., Schultz, M., Wild, M., Wu, Y., and Yu, C.: Anthropogenic and natural contributions to regional trends in aerosol optical depth, 1980–2006, J. Geophys. Res., 114, D00D18, doi:10.1029/2008JD011624, 2009. Sun, J.-Q., Xiong, X., Barnes, W. L., and Guenther, B.: MODIS reflective solar bands on-orbit lunar calibration, IEEE Trans. Geosci. Remote Sense, 45, 2383–2393, 2007. Van Donkelaar, A., Martin, R. V., Brauer, M., Kahn, R., Levy, R., Verduzco, C., and Villeneuve, P. J., : Global Estimates of Ambient Fine Particulate Matter Concentrations from Satellite-Based Aerosol Optical Depth: Development and Application, Environ. Health Pers., 118, 847–855, doi:10.1289/ehp.0901623, 2010. Weatherhead, E. C., Reinsel, G. C., Tiao, G. C., Meng, X.-L., Choi, D., Cheang, W.-K., Keller, T., DeLuisi, J., Wuebbles, D. J., Kerr, J. B., Miller, A. J., Oltmans, S. J., and Frederick, J. E.: Factors affecting the detection of trends: Statistical considerations and applications to environmental data, J. Geophys. Res., 103(D14), 17149–17161, 1998. Young, P. C. Pedregal D. J., and Tych, W.: Dynamic Harmonic Regression, J. of Forecast., 18, 369–394, 1999. Yu, H., Chin, M., Remer, L. A., Kleidman, R. G., Bellouin, N., Bian, H., and Diehl, T.: Variability of marine aerosol fine-mode fraction and estimates of anthropogenic aerosol component over cloud-free oceans from the Moderate Resolution Imaging Spectroradiometer (MODIS), J. Geophys. Res., 114, D10206, doi:10.1029/2008JD010648, 2009. Zhang, J. and Reid, J. S.: MODIS Aerosol Product Analysis for Data Assimilation: Assessment of Level 2 Aerosol Optical Thickness Retrievals, J. Geophys. Res, 111, D22207, doi:10.1029/2005JD006898, 2006. Zhang, J. and Reid, J. S.: An analysis of clear sky and contextual biases using an operational over ocean MODIS aerosol product, Geophys. Res. Lett., 36, L15824, doi:10.1029/2009GL038723, 2009. Zhang, J., Reid, J. S., and Holben, B. N.: An analysis of potential cloud artifacts in MODIS over ocean aerosol optical thickness products, Geophys. Res. Lett., 32, L15803, doi:10.1029/2005GL023254, 2005. Zhang, J., Christopher, S. A., and Holben, B. N.: Intercomparison of aerosol optical thickness derived from GOES-8 Imager and Ground-Based Sun Photometers, J. Geophys. Res, 106, 7387–7398, 2001. Zhao, T. X.-P., Laszlo, I., Guo, W., Heidinger, A., Cao, C., Jelenak, A., Tarpley, D., and Sullivan, J.: Study of decadal trend in aerosol optical thickness observed from operational AVHRR satellite instrument, J. Geophys. Res., 113, D07201, doi:10.1029/2007JD009061, 2008.