US Climate Change Science Program

Updated 11 October, 2003

Strategic Plan for the
Climate Change
Science Program
Final Report, July 2003

Figure 3-3
from Annex C
(Graphics and Photography Source Information)

Figure 3-3: Schematic of the processes that cause the formation and transformation of aerosol particles in the atmosphere. Aerosols can be emitted directly into the atmosphere or be formed there from the emissions of gaseous precursors. Particles grow by condensation of gases and by coagulation with other particles. Sizes of important atmospheric particles vary over several orders of magnitude. Reactions can occur on the surfaces of particles that can alter the composition of the particle or the surrounding atmosphere. Particles can also grow to become cloud droplets or ice crystals. Particle number and composition can influence the formation and radiative characteristics of clouds. Particles scavenge a variety of gases from the atmosphere and are eventually removed from the atmosphere by wet or dry deposition to Earth's surface. Graphic adapted from: Heintzenberg, J., F. Raes, and S.E. Schwartz, 2003: Tropospheric aerosols. In: Atmospheric Chemistry in a Changing World: An Integration and Synthesis of a Decade of Tropospheric Chemistry Research [Brasseur, G.P., R.G. Prinn, and A.A.P. Pszenny (eds)]. Springer-Verlag, New York, NY, USA, pp. 125-156.


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