Aerosol climate forcing

The influence of aerosols on radiative forcing depends on the balance between three essential quantities single-scattering albedo, upscatter fraction, and optical depth—all are sensitive functions of the aerosol chemical composition and size distribution in the 0.1 to 1.0 pm range [1,14]. Aerosol climate forcing, AF, depends on geophysical and aerosol parameters and can be expressed as... 

It is clear that human action can affect seven of eight of the major gi eenhouse forcings carbon dioxide, methane, nitrous oxide, ozone, CFCs, aerosols, and water vapor. As studies of solar variation have shown, it is also clear that human action is not the only factor involved in determining the impact of these forcings. There is still substantial uncertainty regarding the actual climate impact of the climate forcings. 

Fig. 17-7 Calculated geographical distribution of the direct climate forcing (W/m ) by one anthropogenic aerosol component, sulfates, from pre-industrial periods to ca. 1990. (Reprinted with permission from IPCC, 1995.)...

Kiehl, J. T. and Briegleb, B. P. (1993). The relative roles of sulfate aerosols and greenhouse gases in climate forcing. Science 260 (16 April), 311-314. 

Boucher, O., and T. L. Anderson, General Circulation Model Assessment of the Sensitivity of Direct Climate Forcing by Anthropogenic Sulfate Aerosols to Aerosol Size and Chemistry, ]. Geophys. Res., 100, 26117-26134 (1995). 

Kiehl, J. T., and B. P. Briegleb, The Relative Roles of Sulfate Aerosols and Greenhouse Gases in Climate Forcing, Science, 260, 311-314 (1993). 

Lacis, A., J. Hansen, and M. Sato, Climate Forcing by Stratospheric Aerosols, Geophys. Res. Lett., 19, 1607-1610 (1992). 

Lacis, A. A., and M. I. Mishchenko, Climate Forcing, Climate Sensitivity, and Climate Response A Radiative Modeling Perspective on Atmospheric Aerosols, in Aerosol Forcing of Climate (R. J. Charlson and J. Heintzenberg, Eds.), Wiley, New York, 1995. 

Liao, H., and J. H. Seinfeld, Effect of Clouds on Direct Aerosol Radiative Forcing of Climate, J. Geophys. Res., 103, 3781-3788... 

National Research Council, Aerosol Radiative Forcing and Climate Change, National Academy Press, Washington, DC, 1996. 

Schwartz, S. E., Climate Forcing by Gases and Aerosols, Pure Appl. Chem., 66, 178-187 (1994). 

Tegen, I., A. A. Lacis, and I. Fung, The Influence on Climate Forcing of Mineral Aerosols from Disturbed Soils, Nature, 380, 419-422(1996). 

West, J. J., C. Pilinis, A. Nenes, and S. N. Pandis, Marginal Direct Climate Forcing by Atmospheric Aerosols, Atmos. Environ., 32, 2531-2542 (1998). 

As Mitra (2004) pointed out, the Indian oceanic experiment (INDOEX) was the first complex problem-oriented observational international program aimed mainly at studies of the aerosol-induced radiative and climatic forcing of regional and global climate that take respective feedbacks into account. The preliminary stage of the accomplishment of INDOEX began in 1996-1997, and the basic part of complex observations was accomplished in 1998-1999 with the participation of specialists from different countries (India, U.S.A., Western Europe, Mauritius, and the Maldives). The obtained results were based on the use of surface, ship, aircraft, and satellite observational means. 

Fortmann (2004) discussed in detail the microphysical and optical characteristics of atmospheric aerosol which determine the formation of aerosol radiative forcing (ARF) (i.e., the climatic impact of aerosol in the Arctic). In particular, the following problems were considered ... 

Feczko T. Molnar A. Meszaros E. and Major G. (2002). Regional climate forcing of aerosol estimated by a box model for a rural site in Central Europe during summer. Atmospheric Environment, 36, 4125-4131. 

Maria S.F. Russel L.M. Gilles M.K. and Myneni S.C.B. (2004). Organic aerosol growth mechanisms and their climate-forcing implications. Science, 306(5703), 1921-1924. 

Tegen, I., Lacis, A.A. and Fung, I. (1996) The influence on climate forcing of mineral aerosols from disturbed soils. Nature, 380, 419-422. 

An understanding of the influence that aerosols have on climate has become increasingly important over the last several decades [3]. Primary and secondary aerosols can affect the Earth s radiative balance by scattering and absorbing light directly and can act indirectly as cloud condensation nuclei and therefore influence the distribution, duration, precipitation processes, and radiative properties of clouds. Thus, developing the ability to understand, model, and predict aerosol formation with confidence is essential to determine the impact of aerosol radiative forcing in climate models. 

The on-line integration of meso-scale meteorological models and atmospheric aerosol and chemical transport models enables the utilization of all meteorological 3D fields in ACTMs at each time step and the consideration of the feedbacks of air pollution (e.g. urban aerosols) on meteorological processes and climate forcing. 

Penner JE et al (1998) Climate forcing by carbonaceous and sulphate aerosols. Cllm Dyn 14 839-851... 

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