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
Novel method for investigating pore geometry in rocks
18.06.2018 | Kyushu University, I2CNER
Decades of satellite monitoring reveal Antarctic ice loss
14.06.2018 | University of Maryland
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...
Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.
From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
18.06.2018 | Earth Sciences
18.06.2018 | Process Engineering
18.06.2018 | Life Sciences