The extent of the sea ice in the Arctic will reach its annual minimum in September. Forecasts indicate that it will not be as low as in 2007, the year of the smallest area covered by sea ice since satellites started recording such data.
Nevertheless, sea ice physicists at the Alfred Wegener Institute are concerned about the long-term equilibrium in the Arctic Ocean. They have indications that the mass of sea ice is dwindling because its thickness is declining. To substantiate this, they are currently measuring the ice thickness north and east of Greenland using the research aircraft Polar 5.
The objective of the roughly one-week campaign is to determine the export of sea ice from the Arctic. Around a third to half of the freshwater export from the Arctic Ocean takes place in this way – a major drive factor in the global ocean current system.
The question of when the Arctic will be ice-free in the summer has been preoccupying the sea ice researchers headed by Prof. Dr. Rüdiger Gerdes from the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association for a long time now. Satellites have been recording the extent of the Arctic ice for more than 30 years. In addition to the area covered, the thickness of the ice is a decisive factor in assessing how much sea ice there is. However, the thickness can only be determined locally, for example by means of the so-called EM-Bird, an electromagnetic measuring device which helicopters or planes tow over the ice. For Gerdes this is a very special job because he usually models his forecasts on his home computer. The campaign with the research aircraft Polar 5 of the Alfred Wegener Institute now takes him on an expedition in the Arctic for the first time. “I’m very keen on seeing the results of the sea ice thickness measurements,” says Gerdes. “Only when we know the distribution of ice of varying thickness, can we calculate how much freshwater is carried out of the Arctic Ocean via ice.”
About 3000 cubic kilometres of ice drift out of the Arctic Ocean every year, corresponding to around 2700 billion tons. The ice exports freshwater that reaches the Arctic Ocean via rivers and precipitation. This maintains its salt concentration, which has been constant over the long term. The temperature rise observed worldwide is especially pronounced in the Arctic latitudes. Researchers have been observing that the ice is getting thinner and thinner for several years now. As a result, it stores and exports less freshwater and the salt concentration (also referred to as salinity) of the Arctic Ocean declines. On the one hand, this influences all living things that have adapted to the local conditions. On the other hand, changes in salinity also have an impact on current patterns of global ocean circulation and thus on meridional heat transport. In the TIFAX (Thick Ice Feeding Arctic Export) measurement campaign the researchers are primarily interested in ice that is several years old, several metres thick and occurs predominantly on the northern coast of Greenland. “Taking off on the measurement flights from Station Nord here is a special adventure,” reports Gerdes from one of the northernmost measuring stations in the world. “Flying through virtually unsettled regions of the Arctic in the high-tech research aircraft is a stark contrast to my modelling work on the computer.”
The Alfred Wegener Institute conducts research in the Arctic, Antarctic and oceans of the high and mid latitudes. It coordinates polar research in Germany and provides major infrastructure to the international scientific community, such as the research icebreaker Polarstern and stations in the Arctic and Antarctic. The Alfred Wegener Institute is one of the sixteen research centres of the Helmholtz Association, the largest scientific organisation in Germany.
Margarete Pauls | idw
Multi-year submarine-canyon study challenges textbook theories about turbidity currents
12.12.2017 | Monterey Bay Aquarium Research Institute
How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas
11.12.2017 | Leibniz-Institut für Ostseeforschung Warnemünde
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
13.12.2017 | Health and Medicine
13.12.2017 | Physics and Astronomy
13.12.2017 | Life Sciences