September 1, 2009

Scientists study global weather patterns

U.S.-led scientists say the solar cycle, Earth's stratosphere and oceans work in sync to produce global weather patterns.

The researchers, headed by the U.S. National Center for Atmospheric Research, said their findings will help in predicting the intensity of certain climate phenomena, such as the Indian monsoon and tropical Pacific rainfall, years in advance.

An international team led by the National Center for Atmospheric Research in Boulder, Colo., used more than a century of weather observations and three powerful computer models to tackle one of the more difficult questions in meteorology: if the total energy reaching Earth from the sun varies by only 0.1 percent during the approximately 11-year solar cycle, how can it drive major changes in weather patterns on Earth?

The answer, the study fond, has to do with the sun's impact on two seemingly unrelated factors -- chemicals in the stratosphere and the Pacific Ocean's surface temperatures. The interaction, said the scientists, can intensify winds and rainfall, change sea surface temperatures and ultimately influence global weather.

With the help of increased computing power and improved models, as well as observational discoveries, we are uncovering more of how the mechanisms combine to connect solar variability to our weather and climate, Gerald Meehl, a NCAR scientist and the study's lead author, said.

The research appears in the journal Science.