Paris, Dec 3 : Observations by the European Space Agency's (ESA's) ERS and Envisat satellites have revealed that the Arctic is undergoing rapid transformation due to climate change, pollution and human activity.
From their unique positions in space, Earth-observing satellites provide effective means of continuously monitoring these regions.
The Advanced Synthetic Aperture Radar (ASAR) sensor aboard Envisat is especially suitable for monitoring the Arctic because it can acquire images through clouds and darkness - conditions often found there.
In 2007, ASAR data showed that the Arctic area covered by sea ice had shrunk to its lowest level since satellites began monitoring the area nearly 30 years ago.
In 2008, ASAR data revealed that the Northern Sea Route, also known as the Northeast Passage, and the Northwest Passage were both open simultaneously for the first time since satellite measurements began.
Using another instrument aboard Envisat, the radar altimeter, scientists measured sea ice thickness over the Arctic from 2002 to 2008.
Based on these data, they found that sea ice thickness in large parts of the Arctic had declined by as much as 19 percent in 2007 compared to the previous five winters.
The Arctic is experiencing an increase in shipping, primarily for oil and gas development and tourism, with further increases expected due to diminishing ice extent. The ice loss has also lead to an increasing number of icebergs in the area.
Research is difficult to carry out in Polar Regions because of the remoteness and harshness of the area. But, from their unique positions in space, Earth-observing satellites provide effective means of continuously monitoring these regions.
According to Ulf Gullne, a Polar View user responsible for ice-breaking services in Sweden, "It is vital for the safety of winter navigation to know where the ice is and where it is going to be. The use of satellite images has also reduced our ice-breakers' fuel consumption by half."