Ice in Arctic Ocean getting thinner day-by-day
Sea ice physicists have predicted that ice thickness in the region will reach its annual minimum in September.
Washington: Concerned about the thinning ice in the Arctic Ocean, sea ice physicists at the Alfred Wegener Institute have predicted that ice thickness in the region will reach its annual minimum in September.
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.
For a long time now, 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.
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. 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,” said Gerdes.
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.