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The East Siberian Sea is a Natural Laboratory for Studying Climate Change
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The East Siberian Sea is a Natural Laboratory for Studying Climate Change
February 3, 2005
Ocean water chemistry is an important indicator of climate change in arctic environments. Ocean water is strongly affected by several factors. Among them are temperature, amount of freshwater introduced by rivers, and sediment that is transported by coastal erosion and runoff. Changes in water chemistry can ultimately result in dramatic global climate effects. Since 2003, United States and Russian scientists have collaborated on a joint research program in the Laptev and East Siberian Sea (ESS) to study these northern waters (Fig.1).
During September of 2004, International Arctic Research Center (IARC) Researcher and Chief Scientist of the 2004 cruise Dr. Igor Semiletov and visiting IARC researcher Natalia Shakhova participated in the 2nd U.S.-Russian joint cruise in the ESS on the Russian vessel Ivan Kireev . The cruise was organized and led by the IARC and the Pacific Oceanological Institute (POI) of the Far Eastern Branch of Russian Academy of Sciences (FEBRAS) and was funded by Russian and U.S. agencies including IARC, and FEBRAS, and NSF.
The IARC participants traveled from Fairbanks to Vladivostok, Russia, then north to Tiksi, where they departed for the Laptev and East Siberian Seas. Their research was focused on the shelf zone of the ESS, where river and ocean waters merge.
Fig. 1. Laptev and East Siberian Seas. Shelf zone study area in red (water depth is less than 200m) .
The 2004 research cruise continues the study of the transport of fresh water and carbon from estuaries of the Lena, Kolyma, and Indigirka Rivers, north to the ice edge. This relatively unexplored region contains the widest and shallowest continental shelf in the world's oceans. Here scientists have an opportunity to study three great rivers and the important role they play in the transport of material to the Arctic Ocean.
During the cruise researchers collected water samples from various depths at 118 sites along the route (Fig.2). They are looking for annual and long-term changes. The researchers will compare these new samples with historical data (1932-1999) and earlier study results from 1999-2003. Frozen water, sediment, and particulate matter samples give information that researchers can use to evaluate the "thawing permafrost signal" in this region. Higher quantities of sediments and particulates can be a sign that the area is undergoing increased thawing and erosion. They also performed onboard studies of dissolved methane and the carbonate system, including carbon dioxide exchange between the atmosphere and ocean. Researchers also found an area of high biological activity surrounding Wrangel Island. These cold waters are producing enough biomass to feed thousands of walruses (Fig. 3).
This international collaboration will help to increase our understanding of the ocean's role in global climate change and the effects of greenhouse gas emission from carbon dioxide and methane on the region. Their research also provides needed information for computer models of climate prediction. On future cruises, the scientists plan to deploy moorings equipped with water and chemical sensors at key sites in the study area.
Information about the first joint U.S.-Russian East Siberian Sea cruise, which took place September 10-23, 2003, is available here. In the summary for the 2003 cruise, Dr. Semiletov stated that this largely unexplored region "provides an excellent natural laboratory for improving understanding of the interactions across the atmosphere-land-ocean system..."
Fig. 2. Study area.
Fig. 3. Top left: Temperature and salinity profiles across the Long Strait. Top right: Large quantities of small sea creatures were found on the ocean floor. Bottom right: Area of high biological activity; walrus population near Wrangell Island is highest in the Siberian Arctic.
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