Amplifying the Pacific Climate System Response to a Small 11-Year Solar Cycle Forcing

• DOI: 10.1126/science.1172872
• Publication Date: 2009-08-27T20:43:38Z
• Authors: Gerald A. Meehl; Julie M. Arblaster; Katja Matthes; Fabrizio Sassi; Harry van Loon
• Keywords: Shortwave; Forcing (mathematics); Sunspot; Middle latitudes

More Than the Sum of Parts The radiative output Sun varies distinctly with 11-year cycle sunspots, although change in energy is small—less than a tenth percent magnitude. Nevertheless, that small variation produces changes sea surface temperatures two or three times as large it should, and mechanism by which this occurs has remained unclear. Meehl et al. (p. 1114 ; see news story Kerr ) employ global, coupled climate models to simulate phenomenon. Two mechanisms appear act conjunction cause ocean response: abundance stratospheric ozone owing fluctuations shortwave solar forcing; ocean-atmosphere response. This combination effects enhances precipitation maxima, reduces low-latitude cloud cover, lowers temperature waters tropical Pacific Ocean, resulting larger warm-to-cold variation.