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 Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie

nachricht Modeling magma to find copper
13.01.2017 | Université de Genève

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>