Global Ice Age Climate Patterns Influenced by Bering Strait: Small Geographic Feature has Large Effects on Climate

Bering Sea images

Image Credit: NASA
The Bering Sea in Summer and Winter. The 90km-wide waterway
separates the U.S. and Russia.

1/12/2010

In a vivid example of how a small geographic feature may have far-reaching impacts on climate, new research shows 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) in Boulder, Colo., 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 comparatively warm and cold phases, causing ice sheets to alternate between expansion and retreat and affecting sea levels worldwide.

While the findings do not directly bear on current global warming, according to Steve Nelson, National Science Foundation (NSF) program director for NCAR.

But they do 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, he added.

The global climate is sensitive to impacts that may seem minor," says NCAR scientist Aixue Hu, the project's lead scientist. "Even small processes, if they are in the right location, can amplify changes in climate around the world."

Read the rest of the story here.