Aerosol climate effect

The climate effects of atmospheric aerosol particles are a matter of continuous interest in the research community. The aerosol-climate effects are divided into two groups The direct effect represents the ability of the particle population to absorb and scatter short-wave radiation - directly affecting the radiation balance. These direct effects depend primarily on the aerosol optical properties and particle number size distribution, as the particle size significantly affects the scattering efficiency of... 

In addition to homogeneous reactions in the stratosphere and troposphere, characteristics, fluid dynamics, thermodynamics, nucleation, deposition processes, organic aerosols, climate effect regarding aerosols are expounded. In particular, efforts are made to explain each process starting from basic principles. 

Buseck, P. R., and M. Posfai, Airborne Minerals and Related Aerosol Particles Effects on Climate and the Environment, Proc. Natl. Acad. Sci. USA, 96, 3372-3379 (1999). 

Hansen, J. E., W. C. Wang, and A. A. Lacis, 1979. Climatic effects of atmospheric aerosols, Proc. Conf. on Aerosols Urban and Rural Characteristics, Source and Transport Studies, New York Academy of Sciences, New York. 

Abstract The aerosol particle number size distribution is a key component in aerosol indirect climate effects, and is also a key factor on potential nanoparticle health effects. This chapter will give background on particle number size distributions, their monitoring and on potential climate and health effects of submicron aerosol particles. The main interest is on the current variability and concentration levels in European background air. 

The submicron particle number size distribution controls many of the main climate effects of submicron aerosol populations. The data from harmonized particle number size distribution measurements from European field monitoring stations are presented and discussed. The results give a comprehensive overview of the European near surface aerosol particle number concentrations and number size distributions between 30 and 500 nm of dry particle diameter. Spatial and temporal distributions of aerosols in the particle sizes most important for climate applications are presented. Annual, weekly, and diurnal cycles of the aerosol number concentrations are shown and discussed. Emphasis is placed on the usability of results within the aerosol modeling community and several key points of model-measurement comparison of submicron aerosol particles are discussed along with typical concentration levels around European background. 

The first indirect climatic effect of aerosol (the Twomey effect) is based on the assumption that with a constant equivalent liquid water content (LWC) of clouds an increase in atmospheric aerosol number density (and, hence, concentration of CCN)... 

Brenguier J.-L. (2003). Introduction to special section An experimental study of the aerosol indirect effect for validation of climate model parameterizations. J. Geophys. Res., 108(D15), CMP1/1-CMP1/3. 

Kondratyev K.Ya. (1999a). Climatic Effects of Aerosols and Clouds. Springer/Praxis, Chichester, U.K., 264 pp. 

Eckman et al. 1996 Barth et al. 2000) and aerosol indirect effects (e.g., Liao et al. 2003), with a few exceptions after mid. 1990s when truly-coupled systems were developed to enable a full range of feedbacks between meteorology/climate variables and a myriad of gases and size-resolved aerosols (e.g., Jacobson 1995, 2000 Ghan et al. 2001a, b, c). 

Weickmann H.K. and Pueschel R.F., Atmospheric aerosols-, residence times, retain-ment factor and climatic effects. Beitr. Phys. Atmos. , Bd. 46, s. 112-118 (1973). 

Andreae M. O. (1995) Climatic effects of changing atmospheric aerosol levels. In Future Climates of the World A Modeling Perspective, World Survey of Climatology (ed. A. Henderson-Sellers). Elsevier, Amsterdam, vol. 16, pp. 341-392. 

Buseck P. R. and Pdsfai M. (1999) Airborne minerals and related aerosol particles effects on climate and the environment. Proc. Natl Acad. Sci. USA 96, 3372-3379. 

Buseck PR, P6 sfai M (1999) Airborne minerals andrelated aerosol particles Effects on climate and the enviromnent. Proc Nat Acad Sci USA 96 3372-3379... 

The reverse effects are related to the formation of aerosols during forest fires in tropical areas. Aerosol lifetimes are on the order of days and their climate effects are initially on the regional scale. They form nuclei for the formation of cloud droplets, which then form clouds. The large number of aerosols in biomass-burning plumes results in the formation of many small cloud droplets, which are effective in reflecting solar radiation. Significant daytime temperature drops have been observed during haze episodes in Southeast Asia. 

Indirect climate effects of aerosols are more complex and more difficult to assess than direct effects because they depend on a chain of phenomena that connect aerosol levels to concentrations of cloud condensation nuclei, cloud condensation nuclei concentrations to cloud droplet number concentrations (and size), and these, in turn, to cloud albedo and cloud lifetime. Changes in the number concentration of aerosols are observed to cause variations in the population and sizes of cloud droplets, which are expected to cause... 

The quantity / c(l — Rc) achieves its maximum value of when Rc = 0.5. At this point ARc attains its maximum value of AN/N. The approximation ARc — 0.075 A In is accurate to within 10% for cloud albedos in the range 0.28 < Rc < 0.72. A 10% relative increase in N, AN/N =0.1, leads to an increase in cloud albedo of 0.75%. This high sensitivity of Rc to changes in N, together with the global importance of cloud albedo, is, in a nutshell, the source of the indirect climatic effects of aerosols. 

Andreae, M. O. (1991) Biomass burning Its history, use, and distribution and its impact on environmental quality and global climate. In Levine (1991) pp. 3-27 Andreae, M. O. and W. Jaeschke (1992) Exchange of sulphur between biosphere and atmosphere over temperate and tropical regions. In Sulphur cycling on the continents (Eds. R. W. Howarth, J. W. B. Stewart and M. V. Ivanov). John WUey Sons, New York, pp. 27-61 Andreae, M. O. (1995) Climatic effects of changing atmospheric aerosol levels. In World survey of climatology. Vol. 16 Future climates of the world (Ed. A. Henderson-Sellers). Elsevier, Amsterdam, pp. 341-392... 

The 1982 eruption of the southern Mexico volcano El Chicon showed the importance of the type of particulate matter in determining effects on climate. The matter given off by this eruption was imusually rich in sulfur, so that an aerosol of sulfuric acid formed and persisted in the atmosphere for about 3 years, during which time the mean global temperature was lowered by several tenths of a degree due to the presence of atmospheric sulfuric acid. By way of contrast, the eruption of Mt. St. Helens in Washington State in the U.S. 2 years earlier had little perceptible effect on climate, although the amount of material blasted into the atmosphere was about the same as that from El Chicon. The material from the Mt. St. Helens eruption had comparatively little sulfur in it, so the climatic effects were minimal. 

The climatic effect of the smoke aerosols is beyond current understanding because of the complex nature of the interactions involved. Aerosols can influence climate directly by changing Earth s radiation balance. They reflect sunlight back into space. Smoke particles also contain black (elemental) C, which may strongly absorb sunlight and thus cause a heating of the atmosphere and less penetration of... 

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