Short-wave aerosol radiative efficiency over the global oceans derived from satellite data

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Christopher, Sundar A. ; Jones, Thomas A. (2011)

Using 5 yr (December 2000–November 2005) of satellite data from the clouds and the earths radiant energy system (CERES) and moderate resolution imaging spectroradiometer (MODIS), we examine the instantaneous short-wave radiative efficiency (Eτ) of aerosols during the morning Terra satellite overpass time over the global oceans (60°N–60°S). We calculate Eτ using two commonly used methods. The first method uses the MODIS aerosol optical thickness (AOT) at 0.55 μm with radiative transfer calculations, whereas the second method utilizes the same AOT values along with a new generation of aerosol angular distribution models to convert the CERES-measured broad-band radiances to fluxes. Over the 5 yr, the global mean instantaneous Eτ between the methods is remarkably consistent and within 5 W m-2τ-1 with a mean value of –70 W m-2τ-1. The largest differences between the methods occur in high-latitude regions, primarily in the Southern Hemisphere, where AOT is low. In dust dominated regions, there is an excellent agreement between the methods with differences of <3 W m-2τ-1. These differences are largely due to assumptions in aerosol models and definition of clear sky backgrounds. Independent assessments of aerosol radiative effects from different satellite sensors and methods are extremely valuable and should be used to verify numerical modelling simulations.DOI: 10.1111/j.1600-0889.2008.00353.x
  • References (8)

    Anderson, T. L., Charlson, R. J., Bellouin, N., Boucher, O., Chin, M. and co-authors. 2005. An 'A-train' strategy for quantifying direct climate forcing by anthropogenic aerosols. Bull. Am. Meteorol. Soc. 1795- 1718.

    Chou, M. D., Chan, P. K. and Wang, M. 2002. Aerosol radiative forcing derived from seawifs-retrieved aerosol optical properties. J. Atmos. Sci. 59, 748-759.

    Hansen, J., Sato, M., Ruedy, R., Nazarenko, L., Lacis, A. and co-authors. 2005. Efficacy of climate forcings. J. Geophys. Res. 110, D18104, doi:10.1029/2005JD005776.

    Kaufman, Y. J., Boucher, O., Tanre, D., Chin, M., Remer, L. A. and co-authors. 2005. Aerosol anthropogenic component estimated from satellite data. Geophys. Res. Lett. 32, L17804, doi:10.1029/2005GL023125.

    Loeb, N. G. and Kato, S. 2002. Top-of-atmosphere direct radiative effect of aerosols from the clouds and the earth's radiant energy system satellite instrument (CERES). J. Climate S15, 1474-1484.

    Remer, L. A. and Kaufman, Y. J. 2005. Aerosol effect on the distribution of solar radiation over the clear-sky global oceans derived from four years of MODIS retrievals. Atmos. Chem. Phys. Disc. 5, 5007-5038.

    Yu, H., Kaufman, Y. J., Chin, M., Feingold, G., Remer, L. A. and coauthors. 2006. A review of measurement-based assessment of aerosol direct radiative effect and forcing. Atmos. Chem. Phys. Disc. 5, 7647- 7768.

    Zhang J., Christopher, S. A., Remer, L. A. and Kaufman, Y. J. 2005. Shortwave aerosol radiative forcing over cloud-free oceans from Terra: 1. Angular models for aerosols. J. Geophys. Res. 110, D10S23, doi:10.1029/2004JD005008.

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