Bering Strait influenced ice age climate patterns worldwide 100,000 years ago

January 11th, 2010 - 4:13 pm ICT by ANI  

Washington, January 11 (ANI): A new study has shown that water levels in the Bering Strait helped drive global climate patterns during ice age episodes dating back more than 100,000 years.

The international study, led by scientists at the National Center for Atmospheric Research (NCAR), found that the repeated opening and closing of the narrow strait due to fluctuating sea levels affected currents that transported heat and salinity in the Atlantic and Pacific oceans.

As a result, summer temperatures in parts of North America and Greenland oscillated between warmer and colder phases, causing ice sheets to alternate between expansion and retreat and affecting sea levels worldwide.

During that period, saltier and heavier water led to an intensification of the Atlantic’s meridional overturning circulation, which is a current of rising and sinking water that, like a conveyor belt, pumps warmer water northward from the tropics.

This circulation warmed Greenland and parts of North America by about 3 degrees Fahrenheit (1.5 degrees Celsius)- enough to reverse the advance of ice sheets in those regions and reduce their height by almost 400 feet (112 meters) every thousand years.

The computer simulations showed that North America and Eurasia warmed significantly during the times when the Bering Strait was open, with the tropical and subtropical Indian and Pacific Oceans, as well as Antarctica, warming slightly.

While the findings do not directly bear on current global warming, they highlight the complexity of Earth’s climate system and the fact that seemingly insignificant changes can lead to dramatic tipping points for climate patterns, especially in and around the Arctic.

“The global climate is sensitive to impacts that may seem minor,” said NCAR scientist Aixue Hu, the lead author of the study.

“Even small processes, if they are in the right location, can amplify changes in climate around the world,” Hu added.

“This kind of study is critical for teasing out the nuances of our climate system,” said NCAR scientist Gerald Meehl, a co-author of the study.

“If we can improve our understanding of the forces that affected climate in the past, we can better anticipate how our climate may change in the future,” he added. (ANI)

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