The CryoSat-2 mission, due for launch in 2009, will provide highly accurate information on changing marine and land ice thicknesses over the entire north and south polar regions, and in doing so will help address key questions regarding the impact of climate change on the polar environment. The mission is a technical tour-de-force if you take a step back and consider that the satellite will be travelling at over 23,000 kilometres per hour at 717 kilometres above the surface of the Earth and yet still measure changes in the ice thickness down to a few centimetres per year using its sophisticated radar altimeter SIRAL. Given these objectives and the importance of accurate measurements in assessing environmental change, it is not surprising that ESA goes to great lengths to ensure that the data from CryoSat-2 will be as accurate as possible.
Enter the Arctic Arc Expedition, part of the International Polar Year. The expedition’s two Belgian explorers, Alain Hubert and Dixie Dansercoer, 'stepped' onto the sea ice off the coast of Siberia on the 1 March 2007 and have so far covered a staggering 2,500 km each pulling a 130-kg sledge holding supplies and equipment. Along the way these two intrepid explorers are contributing to the preparation of the CryoSat-2 mission by measuring snow depths at regular intervals. These data in turn will be used by scientists to assess how well snow conditions can be predicted using existing climate models as well as inputs to methods for improving the accuracy of CryoSat-2 maps of sea-ice thickness.
"We are making good progress," said Alain Hubert when contacted in his tent on the ice with his satellite phone a few days ago. "We are now only 160 km from the North Pole and taking snow-thickness measurements at regular intervals along the way. Sometimes conditions are very difficult because of the cold and wind. However, we feel the effort is worthwhile and we will keep going."
As Alain and Dixie trek across the North Pole, a parallel campaign by scientists from Germany, Norway and the UK is unfolding in the extreme northern archipelago of Svalbard, Norway. On Thursday12 April, a group of eight scientists were transported by helicopter to the remote Austfonna ice cap. As part of the CryoVex 2007 campaign, they will spend one month making measurements of snow and ice properties along long transects that criss-cross the ice sheet surface. Conditions on the ground are often difficult, with high winds and low temperatures. The result is that sometimes the instruments and equipment fail as the leader of the ground team, Jon Ove Hagen from the University of Oslo, pointed out.
"We are currently moving our team from the depot at the bottom of the Austfonna ice cap to the summit so that we can start our ground measurements and support the airborne acquisition," said Jon Ove Hagen when contacted on Monday 16 April. "Bad weather and a broken skidoo are simply things we need to work around as we start our measurement programme."
As the ground experiments are carried out, measurements are also being taken from the air by the Alfred Wegner Institute (AWI). The Dornier-228 aircraft carries the ASIRAS instrument, which is an airborne version of the radar altimeter instrument onboard CryoSat-2. By comparing the airborne data with ground measurements scientists will test and verify novel methods for retrieving ice-thickness change from the CryoSat-2 satellite mission ahead of the launch.
"The first flight with ASIRAS looks good," says Veit Helm from AWI. "As soon as the weather conditions are good and the ground teams are in place, we look forward to our scientific flights and getting our hands dirty processing and analysing the airborne radar altimeter data over Austfonna. One fascinating aspect of such work is that the campaign actually allows us to look into the future and see what the CryoSat-2 mission will see and measure when it is launched."
The airborne work will continue until 24 April and the ground teams will stay on the ice cap until the beginning of May. When the campaign draws to an end, the challenge will then be to analyse the large volumes of data in order to characterise and improve the CryoSat-2 measurements of changing ice surfaces. In is only through such painstaking work that the challenge of measuring ice thickness down to centimetre level from space can be achieved, and in turn lead to a better understanding of the impact that changing climate is having on the polar ice fields.
Mariangela D'Acunto | alfa
Climate satellite: Tracking methane with robust laser technology
22.06.2017 | Fraunhofer-Gesellschaft
How reliable are shells as climate archives?
21.06.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
23.06.2017 | Physics and Astronomy
23.06.2017 | Physics and Astronomy
23.06.2017 | Information Technology