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S.ravi
Advanced Member
India
4205 Posts |
 Posted - 07/18/2009 : 22:19:57
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Solar activity has big impact on earth's climate
Washington (IANS): A high in solar activity impacts the earth in a way that resembles the devastating El Nino, releasing more energy than a million Hiroshima bombs, according to a new study.
The study shows that as the sun reaches maximum activity, it heats cloud-free parts of the Pacific Ocean enough to increase evaporation, intensify tropical rainfall and the trade winds, and cool the eastern tropical Pacific.
The giant El Nino Southern Oscillation (ENSO) of 1997-98, rising out of the tropical Pacific Ocean, "deranged weather patterns around the world, killed an estimated 2,100 people, and caused at least $33 billion in property damage," wrote Curt Suplee in the National Geographic magazine.
The study may pave the way toward predictions of temperature and rainfall patterns at certain times during the approximately 11-year solar cycle.
"These results 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," says Jay Fein, programme director in National Science Foundation's (NSF) 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 adds.
The total energy reaching us from the sun varies by only 0.1 percent across the solar cycle. Scientists have sought for decades to link these ups and downs to climate variations and distinguish their subtle effects from the larger pattern of human-caused global warming.
Building on previous work, National Centre for Atmospheric Research (NCAR) researchers used computer models of global climate and more than a century of ocean temperature data to answer longstanding questions about the connection between solar activity and global climate.
"We have fleshed out the effects of a new mechanism to understand what happens in the tropical Pacific when there is a maximum of solar activity," says NCAR scientist Gerald Meehl, the study's co-author.
"When the sun's output peaks, it has far-ranging and often subtle impacts on tropical precipitation and on weather systems around much of the world," he added, according to an NSF release.
The research was published in July in the Journal of Climate.
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Solar activity has big impact on earth's climate
