Solar cycle affecting global climate, say scientists

Research led by scientists at the National Science Foundation-funded National Center for Atmospheric Research (NCAR) in Boulder, Colorado, has shown that maximum solar activity and its aftermath have impacts on Earth similar to that caused by ocean currents La Niña and El Niño in the tropical Pacific Ocean.

The research, while establishing a key link between the solar cycle and global climate, may pave the way toward predictions of temperature and precipitation patterns at certain times during the approximately 11-year solar cycle.

Scientists find link between solar cycle and global climate similar to El Nino/La Nina. Credit: NCAR

"These results are striking in that they point to a scientifically feasible series of events that link the 11-year solar cycle with ENSO, the tropical Pacific phenomenon that so strongly influences climate variability around the world," said Jay Fein, program director in NSF's Division of Atmospheric Sciences. "The next step is to confirm or dispute these intriguing model results with observational data analyses and targeted new observations," he added.

The total energy reaching Earth from the sun varies by only 0.1 per cent across the solar cycle and scientists now think these ups and downs cause natural weather and climate variations other than the their subtle effects from the larger pattern of human-caused global warming.

Building on previous work, the NCAR researchers used computer models of global climate and more than a century of ocean temperature to answer longstanding questions about the connection between solar activity and global climate.

The research, published this month in a paper in the Journal of Climate, was funded by NSF, NCAR's sponsor, and by the US Department of Energy.