Cloud condensation nuclei in the Amazon Basin: “marine” conditions over a continent?
Article first published online: 7 DEC 2012
Copyright 2001 by the American Geophysical Union.
Geophysical Research Letters
Volume 28, Issue 14, pages 2807–2810, 15 July 2001
How to Cite
- Issue published online: 7 DEC 2012
- Article first published online: 7 DEC 2012
- Manuscript Accepted: 3 APR 2001
- Manuscript Received: 6 NOV 2000
Cloud condensation nuclei (CCN) are linked to radiative forcing, precipitation, and cloud structure; yet, their role in tropical climates remains largely unknown. CCN concentrations (NCCN) measured during the wet season in the Amazon Basin were surprisingly low (mean NCCN at 1% supersaturation: 267±132 cm−3) and resembled concentrations more typical of marine locations than most continental sites. At low background CCN concentrations, cloud properties are more sensitive to an increase in NCCN. Therefore, enhanced aerosol emissions due to human activity in the Amazon Basin may have a stronger impact on climate than emissions in other continental regions. In spite of the large organic fraction in the Amazonian aerosol, a detailed analysis of number distributions and size-dependent chemical composition indicates that sulfate plays an important role in CCN activity.