Size Matters More than Chemistry for Cloud-Nucleating Ability of Aerosol Particles

• Published in: Science (American Association for the Advancement of Science) Vol. 312; no. 5778; pp. 1375 - 1378
• Main Authors: Dusek, U., Frank, G. P., Hildebrandt, L., Curtius, J., Schneider, J., Walter, S., Chand, D., Drewnick, F., Hings, S., Jung, D., Borrmann, S., Andreae, M. O.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 02-06-2006; The American Association for the Advancement of Science
• Subjects: Aerosols; Air masses; Atmospheric aerosols; Atmospheric chemistry; Average linear density; Chemical composition; Cloud physics; Clouds; Composite particles; Earth, ocean, space; Exact sciences and technology; External geophysics; Meteorology; Particle size distribution; Physics; Polls; Size distribution; Supersaturation; Time series; Central Europe; Germany; Cloud physics; aerosols; Europe; Size effect; Observation data; Composition effect; Condensation nucleus; troposphere
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1125261

Size-resolved cloud condensation nuclei (CCN) spectra measured for various aerosol types at a non-urban site in Germany showed that CCN concentrations are mainly determined by the aerosol number size distribution. Distinct variations of CCN activation with particle chemical composition were observed but played a secondary role. When the temporal variation of chemical effects on CCN activation is neglected, variation in the size distribution alone explains 84 to 96% of the variation in CCN concentrations. Understanding that particles' ability to act as CCN is largely controlled by aerosol size rather than composition greatly facilitates the treatment of aerosol effects on cloud physics in regional and global models.