New discoveries could improve climate projections

Dec 11, 2009

New discoveries about the deep ocean's temperature variability and circulation system could help improve projections of future climate conditions.

The deep ocean is affected more by surface warming than previously thought, and this understanding allows for more accurate predictions of factors such as and ice volume changes.

High ocean surface temperatures have also been found to result in a more vigorous deep ocean circulation system. This increase results in a faster transport of large quantities of warm water, with possible impacts including reduction of sea ice extent and overall warming of the Arctic.

"The deep ocean is relatively unexplored, and we need a true understanding of its many complex processes," said U.S. Geological Survey Director Marcia McNutt. "An understanding of climate change and its impacts based on sound, objective data is a keystone to the type of long-term strategies and solutions that are being discussed now at the United Nations conference in Copenhagen."

USGS scientists created the first ever 3-D reconstruction of an ocean during a past warm period, focusing on the mid-Pliocene warm period 3.3 to 3 million years ago.

"Our findings are significant because they improve our previous understanding that the deep ocean stayed at relatively constant, and that the circulation system would slow down as surface temperatures increased," said USGS scientist Harry Dowsett. "By looking at conditions in the past, we acquire real data that allow us to see the global climate system as it actually functioned."

"The average temperature of the entire during the mid-Pliocene was approximately one degree warmer than current conditions, showing that warming wasn't just at the surface but occurred at all depths" said USGS scientist Marci Robinson. "Temperatures were determined by analyzing marine plankton fossils, which are organisms that inhabited the water's surface, as well as fossils of bottom-dwelling organisms, known as ostracodes."

Global average surface temperatures during the mid-Pliocene were about 3°C (5.5°F) greater than today and within the range projected for the 21st century by the Intergovernmental Panel on Climate Change. Therefore it may be one of the closest analogs in helping to understand Earth's current and future conditions. USGS research on the mid-Pliocene is also the most comprehensive global reconstruction for any .

More information: Read the full article, published in Climate of the Past at www.clim-past.net/5/769/2009/cp-5-769-2009.html

Source: United States Geological Survey (news : web)

Explore further: NASA satellites measure increase of Sun's energy absorbed in the Arctic

add to favorites email to friend print save as pdf

Related Stories

Climate projections underestimate CO2 impact

Dec 10, 2009

The climate may be 30-50 percent more sensitive to atmospheric carbon dioxide in the long term than previously thought, according to a recent study published in Nature Geoscience.

Ocean height indicator of climate

Oct 07, 2005

U.S. and Canadian authors say an index of sea surface heights gathered by satellites could be a useful indicator of long-term climate cycles.

Recommended for you

Improving forecasts for rain-on-snow flooding

9 hours ago

Many of the worst West Coast winter floods pack a double punch. Heavy rains and melting snow wash down the mountains together to breach riverbanks, wash out roads and flood buildings.

The Greenland Ice Sheet: Now in HD

9 hours ago

The Greenland Ice Sheet is ready for its close-up. The highest-resolution satellite images ever taken of that region are making their debut. And while each individual pixel represents only one moment in time, ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.