General Circulation Model Calculations of the Direct Radiative Forcing by Anthropogenic Sulfate and Fossil-Fuel Soot Aerosol

J. M. Haywood Atmospheric and Oceanic Sciences Program, Princeton University, Princeton, New Jersey

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D. L. Roberts Hadley Centre for Climate Prediction and Research, U.K. Meteorological Office, Bracknell, United Kingdom

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A. Slingo Hadley Centre for Climate Prediction and Research, U.K. Meteorological Office, Bracknell, United Kingdom

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J. M. Edwards Hadley Centre for Climate Prediction and Research, U.K. Meteorological Office, Bracknell, United Kingdom

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K. P. Shine Department of Meteorology, University of Reading, Reading, United Kingdom

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Abstract

A new radiation code within a general circulation model is used to assess the direct solar and thermal radiative forcing by sulfate aerosol of anthropogenic origin and soot aerosol from fossil-fuel burning. The radiative effects of different aerosol profiles, relative humidity parameterizations, chemical compositions, and internal and external mixtures of the two aerosol types are investigated. The contribution to the radiative forcing from cloudy sky regions is found to be negligible for sulfate aerosol; this is in contrast to recent studies where the cloudy sky contribution was estimated using a method in which the spatial correlation between cloud amount and sulfate burden was ignored. However, the radiative forcing due to fossil-fuel soot aerosol is enhanced in cloudy regions if soot aerosol exists within or above the cloud. The global solar radiative forcing due to sulfate aerosol is estimated to be −0.38 W m−2 and the global thermal radiative forcing is estimated to be +0.01 W m−2. The hemispheric mean radiative forcings vary by only about 10% for reasonable assumptions about the chemical form of the sulfate aerosol and the relative humidity dependence; the uncertainties in the aerosol loading are far more significant. If a soot/sulfate mass ratio of 0.075 is assumed, then the global solar radiative forcing weakens to −0.18 W m−2 for an external mixture and weakens further for an internal mixture. Additionally, the spatial distribution of the radiative forcing shows strong negative/positive forcing contrasts that may influence the dynamical response of the atmosphere. Although these results are extremely sensitive to the adopted soot/sulfate ratio and the assumed vertical profile, they indicate that fossil-fuel soot aerosol may exert a nonnegligible radiative forcing and emphasize the need to consider each anthropogenic aerosol species.

Corresponding author address: Dr. J. M. Haywood, GFDL/NOAA, Princeton University, Forrestal Campus, Route 1, Princeton, NJ 08542.

Abstract

A new radiation code within a general circulation model is used to assess the direct solar and thermal radiative forcing by sulfate aerosol of anthropogenic origin and soot aerosol from fossil-fuel burning. The radiative effects of different aerosol profiles, relative humidity parameterizations, chemical compositions, and internal and external mixtures of the two aerosol types are investigated. The contribution to the radiative forcing from cloudy sky regions is found to be negligible for sulfate aerosol; this is in contrast to recent studies where the cloudy sky contribution was estimated using a method in which the spatial correlation between cloud amount and sulfate burden was ignored. However, the radiative forcing due to fossil-fuel soot aerosol is enhanced in cloudy regions if soot aerosol exists within or above the cloud. The global solar radiative forcing due to sulfate aerosol is estimated to be −0.38 W m−2 and the global thermal radiative forcing is estimated to be +0.01 W m−2. The hemispheric mean radiative forcings vary by only about 10% for reasonable assumptions about the chemical form of the sulfate aerosol and the relative humidity dependence; the uncertainties in the aerosol loading are far more significant. If a soot/sulfate mass ratio of 0.075 is assumed, then the global solar radiative forcing weakens to −0.18 W m−2 for an external mixture and weakens further for an internal mixture. Additionally, the spatial distribution of the radiative forcing shows strong negative/positive forcing contrasts that may influence the dynamical response of the atmosphere. Although these results are extremely sensitive to the adopted soot/sulfate ratio and the assumed vertical profile, they indicate that fossil-fuel soot aerosol may exert a nonnegligible radiative forcing and emphasize the need to consider each anthropogenic aerosol species.

Corresponding author address: Dr. J. M. Haywood, GFDL/NOAA, Princeton University, Forrestal Campus, Route 1, Princeton, NJ 08542.

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  • Ackerman, S., and M. Baker, 1977: Shortwave radiative effects of unactivated aerosol particles in clouds. J. Appl. Meteor.,16, 63–68.

  • Ackerman, T. P., and O. B. Toon, 1981: Absorption of visible radiation in atmosphere containing mixtures of absorbing and nonabsorbing particles. Appl. Opt.,20, 3661–3668.

  • Andreae, M. O., 1995: Climatic Effects of Changing Atmospheric Aerosol Levels. Vol. 16, World Survey of Climatology, A. Deepak Publishing, 468 pp.

  • Blanchet, J. P., 1982: Application of the Chandrasekhar mean to aerosol optical parameters. Atmos.–Ocean,20, 189–206.

  • Boucher, O., and T. L. Anderson, 1995: General circulation model assessment of the sensitivity of direct climate forcing by anthropogenic sulfate aerosols to aerosol size and chemistry. J. Geophys. Res.,100, 26 117–26 134.

  • Cess, R. D., G. L. Potter, S. J. Ghan, and W. L. Gates, 1985: The climate effects of large injections of atmospheric smoke and dust: A study of climate feedback mechanisms with one and three dimensional climate models. J. Geophys. Res.,90, 12 937–12 950.

  • Charlson, R. J., J. Langner, H. Rodhe, C. B. Leovy, and S. G. Warren, 1991: Perturbation of the Northern Hemisphere radiative balance by backscattering from anthropogenic sulfate aerosols. Tellus,43AB, 152–163.

  • ——, S. E. Schwartz, J. M. Hales, R. D. Cess, J. A. Coakley, J. E. Hansen, and D. J. Hofmann, 1992: Climate forcing by anthropogenic aerosols. Science,255, 423–430.

  • Chen, C.-T., and V. Ramaswamy, 1996: Sensitivity of simulated global climate to perturbations in low cloud microphysical properties. Part II: Spatially localized perturbations. J. Climate,9, 1385–1402.

  • Chylek, P., V. Ramaswamy, and R. J. Cheng, 1984: Effect of graphitic carbon on the albedo of clouds. J. Atmos. Sci.,41, 3076–3084.

  • ——, V. Srivastava, R. G. Pinnick, and R. T. Wang, 1988: Scattering of electromagnetic waves by composite spherical particles: Experiments and effective medium approximations. Appl. Opt.,27, 2936–2404.

  • ——, G. Videen, D. Ngo, R. G. Pinnick, and J. D. Klett, 1995: Effect of black carbon on the optical properties and climate forcing of sulfate aerosols. J. Geophys. Res.,100, 16 325–16 332.

  • Cooke, W. F., and J. J. N. Wilson, 1996: A global black carbon model. J. Geophys. Res.,101, 19 395–19 409.

  • Cox, S. J., W.-C. Wang, and S. E. Schwartz, 1995: Climate response to radiative forcings by sulfate aerosols and greenhouse gases. Geophys. Res. Lett.,22, 2509–2512.

  • Cullen, M. J. P., 1993: The unified forecast/climate model. Meteor. Mag.,122, 81–94.

  • ——, and T. Davies, 1991: A conservative split–explicit integration scheme with fourth-order horizontal advection. Quart. J. Roy. Meteor. Soc.,117, 993–1002.

  • d’Almeida, G. A., P. Koepke, and E. P. Shettle, 1991: Atmospheric Aerosols. Global Climatology and Radiative Characteristics. A. Deepak Publishing, 561 pp.

  • Dobbins, R. A., G. W. Mulholland, and N. P. Bryner, 1994: Comparison of a fractal smoke optics model with light extinction measurements. Atmos. Environ.,28, 889–897.

  • Dolman, A. J., and D. Gregory, 1992: The parametrization of rainfall interception in GCMs. Quart. J. Roy. Meteor. Soc.,118, 455–467.

  • Edwards, J. M., and A. Slingo, 1996: Studies with a flexible new radiation code. I: Choosing a configuration for a large-scale model. Quart. J. Roy. Meteor. Soc.,122, 689–719.

  • Fitzgerald, J. W., 1975: Approximation formulas for the equilibrium size of an aerosol particle as a function of its dry size and composition and the ambient relative humidity. J. Appl. Meteor.,14, 1044–1049.

  • Gregory, D., and P. R. Rowntree, 1990: A mass flux convection scheme with representation of cloud ensemble characteristics and stability dependent closure. Mon. Wea. Rev.,118, 1483–1506.

  • Hansen, J. E., A. Lacis, D. Rind, G. Russell, P. Stone, R. Fung, D. Ruedy, and J. Lerner, 1984: Climate sensitivity: Analysis of feedback mechanisms. Geophys. Monogr., No. 29, 130–163.

  • Haywood, J. M., and K. P. Shine, 1995: The effect of anthropogenic sulfate and soot aerosol on the clear sky planetary radiation budget. Geophys. Res. Lett.,22, 603–606.

  • ——, and ——, 1997: Multi-spectral calculations of the radiative forcing of tropospheric sulphate and soot aerosols using a column model. Quart. J. Roy. Meteor. Soc., in press.

  • ——, V. Ramaswamy, and L. J. Donner, 1997: A limited-area model case study of the effects of sub-grid scale variations in relative humidity and cloud upon the direct radiative forcing of sulfate aerosol. Geophys. Res. Lett.,24, 143–146.

  • Heintzenberg J., 1989: Fine particles in the global troposphere. Tellus,41B, 149–160.

  • ——, and A. Meszaros, 1985: Elemental carbon, sulfur and metals in aerosol samples at a Hungarian regional air pollution station. J. Hung. Meteor. Service,89, 313–319.

  • Hofmann, D. J., 1993: Twenty years of balloon-borne tropospheric aerosols measurements at Laramie, Wyoming. J. Geophys. Res.,98, 753–766.

  • Horvath, H., 1993: Atmospheric light absorption—A review. Atmos. Environ.,27A, 293–317.

  • Intergovernmental Panel on Climate Change (IPCC), 1996: Climate Change 1995. The Science of Climate Change. J. T. Houghton, L. G. Meira Filho, B. A. Callander, N. Harris, A. Kattenberg, and K. Maskell, Eds., Cambridge University Press, 572 pp.

  • Jones, A., D. L. Roberts, and A. Slingo, 1994: A climate model study of the indirect radiative forcing by anthropogenic sulphate aerosols. Nature,370, 450–453.

  • Kasibhatla, P., W. L. Chameides, and J. St. John, 1997: A three-dimensional global model investigation of the seasonal variation in the atmospheric burden of anthropogenic sulfate aerosols. J. Geophys. Res., in press.

  • Kiehl, J. T., and B. P. Briegleb, 1993: The relative roles of sulfate aerosols and greenhouse gases in climate forcing. Science,260, 311–314.

  • Langner, J., and H. Rodhe, 1991: A global three-dimensional model of the tropospheric sulfur cycle. J. Atmos. Chem.,13, 225–263.

  • Liousse, C., J. E. Penner, C. Chuang, J. J. Walton, and H. Eddleman, 1996: A global three-dimensional model study of carbonaceous aerosols. J. Geophys. Res.,101, 19 411–19 432.

  • Mitchell, J. F. B., R. A. Davis, W. J. Ingram, and C. A. Senior, 1995: On surface temperature, greenhouse gases, and aerosols: Models and observations. J. Climate,8, 2364–2386.

  • Nemesure, S., R. Wagener, and S. E. Schwartz, 1995: Direct shortwave forcing of climate by anthropogenic sulfate aerosol: Sensitivity to particle size, composition, and relative humidity. J. Geophys. Res.,100, 26 105–26 116.

  • Ogren, J. A., and R. J. Charlson, 1984: Wet deposition of elemental carbon and sulfate in Sweden. Tellus,36B, 262–271.

  • Palmer, T. N., G. J. Shutts, and R. Swinbank, 1986: Alleviation of a systematic westerly bias in general circulation and numerical weather prediction models through an orographic gravity wave drag parametrization. Quart. J. Roy. Meteor. Soc.,112, 1001–1039.

  • Penner, J. E., R. E. Dickinson, and C. A. O’Neill, 1992: Effects of aerosol from biomass burning on the global radiation budget. Science,256, 1432–1433.

  • ——, C. S. Atherton, and T. E. Graedel, 1994: Global emissions and models of photochemically active compounds. 37th OHOLO Conference Series, R. Prinn, Ed., Plenum Publishing, 223–248.

  • Pilinis, C., S. N. Pandis, and J. H. Seinfeld, 1995: Sensitivity of direct climate forcing by atmospheric aerosols to aerosol size and composition. J. Geophys. Res.,100, 18 739–18 754.

  • Quinn, P. K., S. F. Marshall, T. S. Bates, D. S. Covert, and V. N. Kapustin, 1995: Comparison of measured and calculated aerosol properties relevant to the direct radiative forcing of tropospheric sulfate aerosol on climate. J. Geophys. Res.,100, 8977–8991.

  • Simmons, A. J., and D. M. Burridge, 1981: An energy and angular-momentum conserving vertical finite-difference scheme and hybrid vertical coordinates. Mon. Wea. Rev.,109, 758–766.

  • Sisler, J. F., and W. C. Malm, 1994: The relative importance of soluble aerosols to spatial and seasonal trends of impaired visibility in the United States. Atmos. Environ.,28, 850–862.

  • Smith, R. N. B., 1990: A scheme for predicting layer clouds and their water content in a general circulation model. Quart. J. Roy. Meteor. Soc.,116, 435–460.

  • Sundqvist, H., 1978: A parameterization scheme for non-convective condensation including prediction of cloud water content. Quart. J. Roy. Meteor. Soc.,104, 677–690.

  • ——, 1981: Prediction of stratiform clouds: Results from a 5-day forecast with a global model. Tellus,33, 242–253.

  • Tang, I. N., W. T. Wong, and H. R. Munkelwitz, 1981: The relative importance of atmospheric sulfates and nitrates in visibility reduction. Atmos. Environ.,15, 2463–2471.

  • Taylor, K., and J. E. Penner, 1994: Response of the climate system to atmospheric aerosols and greenhouse gases. Nature,369, 734–737.

  • Tegen, I., and I. Fung, 1995: Contribution to the atmospheric mineral aerosol load from land surface modification. J. Geophys. Res.,100, 18 707–18 726.

  • ——, A. A. Lacis, and I. Fung, 1996: The influence on climate forcing of mineral aerosols from disturbed soils. Nature,380, 419–422.

  • Toon, O. B., J. B. Pollack, and B. N. Khare, 1976: The optical constants of several atmospheric aerosol species: Ammonium sulphate, aluminium oxide and sodium chloride. J. Geophys. Res.,81, 5733–5748.

  • Twomey, S. A., 1977: The influence of pollution on the short-wave albedo of clouds. J. Atmos. Sci.,34, 1149–1152.

  • Waggoner, A. P., R. E. Weiss, N. C. Ahlquist, D. S. Covert, S. Will, and R. J. Charlson, 1981: Optical characteristics of atmospheric aerosols. Atmos. Environ.,15, 1891–1909.

  • WCP, 1986: A preliminary cloudless standard atmosphere for radiation computation. World Climate Programme Rep. WCP-112, 54 pp.

  • Weast, R. C., 1987: Physical constants of inorganic compounds. CRC Handbook of Chemistry and Physics, 68th ed., R. C. Weast, Ed., CRC Press, B67–146.

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