The influence of organic compounds on cloud droplet growth
- Univ. of Washington, Seattle, WA (United States)
Under atmospheric conditions, some submicrometer aerosol particles provide vapor-pressure depressing solute which allows cloud droplets to form at low supersaturations . The ubiquitous and hygroscopic sulfate compounds are thought to be dominant . However, many organic compounds are common in the atmosphere and are likely to partition mostly into the aerosol phase due to their low vapor pressures. We present a simple calculation which describes the influence of organic compounds on droplet growth based on newly measured bulk solubilities of representative model organic compounds (OC`s) in aqueous solutions. The calculations indicate that some OC`s may exist in an undissolved phase in droplets at sizes critical to droplet growth. Additionally, an important thermodynamic parameter to droplet growth is surface tension. Based on recent measurements, it appears that some model OC`s reduce droplet surface tension relative to pure water. Sparingly soluble OC`s are likely to affect both the equilibrium thermodynamics and kinetics of a nucleating cloud droplet.
- OSTI ID:
- 126290
- Report Number(s):
- CONF-950402--
- Country of Publication:
- United States
- Language:
- English
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