Amplifying the Pacific Climate System Response to a Small 11-Year Solar Cycle Forcing
Abstract
The radiative output of the Sun varies distinctly with the 11-year cycle of sunspots, although the change in energy output is small—less than a tenth of a percent in magnitude. Nevertheless, that small variation produces changes in sea surface temperatures two or three times as large as it should, and the mechanism by which this occurs has remained unclear. Meehl et al. (p. 1114 ; see the news story by Kerr ) employ three global, coupled climate models to simulate this phenomenon. Two mechanisms appear to act in conjunction to cause this ocean response: a change in the abundance of stratospheric ozone owing to fluctuations of shortwave solar forcing; and a coupled surface ocean-atmosphere response. This combination of effects enhances precipitation maxima, reduces low-latitude cloud cover, and lowers the temperature of surface waters in the tropical Pacific Ocean, resulting in the larger warm-to-cold variation.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 28, 2009
- Source ID
- 10.1126/science.1172872
Entities
People
- Fabrizio Sassi
- Gerald Meehl
- Harry Van Loon
- Julie M. Arblaster
- Katja Matthes
Organizations
- Bureau of Meteorology
- Freie Universität Berlin
- National Center for Atmospheric Research
- United States Naval Research Laboratory