Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Higher Water Temperatures and Reduced Ice Cover In the Arctic Ocean

27.08.2004


Over the past six weeks, scientists aboard the research vessel "Polarstern" of the Alfred Wegener Institute for Polar and Marine Research have been investigating changes in ocean temperature and sea ice cover in the area of Fram Strait between Spitsbergen and Greenland.

In this area significant exchange of water masses between the Arctic Ocean and the Atlantic Ocean takes place. The ongoing process of global warming throughout the past years has also altered conditions in Fram Strait and the North Polar Sea.

Recordings of temperature measurements in Fram Strait at various water depths indicate a rise in temperature since 1990 in the West Spitsbergen Current, which carries warm Atlantic Ocean water into the Arctic Ocean. The recent measurements by oceanographers aboard "Polarstern" point towards a further warming tendency. Compared to the previous year, temperatures recorded in the upper 500 metres of ocean current were up to 0.6 °C higher this year. The rise in temperature was detectable to a water depth of 2000 metres, representing an exceptionally strong signal by ocean standards. Consequently, the influx of warmer water causes a change in sea ice cover. Satellite images have documented a clear recession of sea ice edges in the Fram Strait region and in the Barents Sea over the last three years.



Climate processes are not only affected by the horizontal extent of sea ice, but also by its thickness. In order to determine ice thickness, the sea ice research group of the Alfred Wegener Institute has, over the past years, developed an airborne ice thickness sensor. It is towed by helicopter approximately 30 metres above ground and can cover up to 100 kilometres distance within one hour. This method allows construction of a representative picture of sea ice thickness. The thickness sensor is validated by flying the helicopter over a series of drilled ice holes (of known depth) arrayed along a transect line. In this way the precision of the sensor can be confirmed.

An exceptional type of comparison between measurements was carried out on Wednesday off the East Greenland coast, where "Polarstern" met the British research icebreaker "James Clark Ross": for the very first time in the history of sea ice research, sea ice topography was measured simultaneously from above and below. For this purpose, a British autonomous underwater vehicle (AUV) scanned the underside of the sea ice using sonar, while the sea ice physicists of the Alfred Wegener Institute evaluated the ice surface as well as its thickness from above, using the helicopter-towed ice thickness sensor.

These activities served as preparation for the calibration of the satellite "CryoSat". Starting in March 2005, "CryoSat" will measure sea ice thickness continually from a height of 700 kilometres in both polar regions. The quantification of sea ice thickness and its changes are of great importance in international climate research. Sea ice has a key role in climate systems and is considered a sensitive indicator of climate fluctuations. "CryoSat" will be used to investigate whether regional changes occur in all polar regions as a consequence of global warming.

Presently, "Polarstern" is on her 20th Arctic expedition. Since July 16th, scientists of the Alfred Wegener Institute for Polar and Marine Research have been working as part of an international team carrying out atmospheric chemical measurements, gathering data from the ocean and sea ice and collecting rock samples from the sea floor. On Sunday, "Polarstern" will reach Tromsø.

Torsten Fischer | alfa
Further information:
http://www.awi-bremerhaven.de

More articles from Earth Sciences:

nachricht How much biomass grows in the savannah?
16.02.2017 | Friedrich-Schiller-Universität Jena

nachricht Canadian glaciers now major contributor to sea level change, UCI study shows
15.02.2017 | University of California - Irvine

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Biocompatible 3-D tracking system has potential to improve robot-assisted surgery

17.02.2017 | Medical Engineering

Real-time MRI analysis powered by supercomputers

17.02.2017 | Medical Engineering

Antibiotic effective against drug-resistant bacteria in pediatric skin infections

17.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>