Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Arctic sea ice is getting thinner as well as receding

28.10.2008
Last winter, the thickness of sea ice in large parts of the Arctic fell by nearly half a metre (19 per cent) compared with the average thickness of the previous five winters. This followed the dramatic 2007 summer low when Arctic ice extent dropped to its lowest level since records began.

Up until last winter, the thickness of Arctic sea ice showed a slow downward trend during the previous five winters, but after the summer 2007 record low extent, the thickness of the ice also nose-dived. What is concerning is that sea ice is not just receding but it is also thinning.

Some scientists blamed the record summer 2007 ice extent low on unusually warm weather conditions over the Arctic, but this summer, sea ice extent reached the second lowest level since records began, even though the Arctic had a relatively cool summer. Dr Katharine Giles, who led the study and is based at the Centre for Polar Observation and Modelling at University College London – part of the National Centre for Earth Observation, says: “This summer’s low ice extent doesn’t seem to have been driven by warm weather, so the question is, was last winter’s thinning behind it?”

The team of researchers, including Dr Seymour Laxon and Andy Ridout, used satellites to measure sea ice thickness over the Arctic from 2002 to 2008. Winter sea ice in the Arctic is around two and half metres thick on average. Ice thickness can be calculated from the time it takes a radar pulse to travel from a satellite to the surface of the ice and back again.

The research - reported in Geophysical Research Letters - showed that last winter the average thickness of sea ice over the whole Arctic fell by 26cm (10 per cent) compared with the average thickness of the previous five winters, but sea ice in the western Arctic lost around 49cm of thickness. This region of the Arctic saw the North-West passage become ice free and open to shipping for the first time in 30 years during the summer of 2007.

The team is the first to measure ice thickness throughout the Arctic winter, from October to March, over more than half of the Arctic, using the European Space Agency’s Envisat satellite. Before this, Christian Haas of the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, Germany, had discovered thinner ice in a small region around the North Pole. Whilst the overall loss of older, thicker ice led researchers to speculate that Arctic sea ice had probably thinned, this is the first time scientists have been able to say for definite that the ice thinning was widespread and occurred in areas of both young and old ice.

“The extent of sea ice in the Arctic is down to a number of factors, including warm weather melting it as well as currents and the wind blowing it around, so it’s important to know how ice thickness is changing as well as the extent of the ice,” added Giles.

The team will continue to monitor the thickness of the ice over this coming winter. Laxon says: “We’ll be keeping our eyes on the ice thickness this winter as it’ll be interesting to see what happens after a second summer of low ice extent.”

The Envisat satellite that provided the UCL scientists with their data doesn’t cover the whole of the North Pole. Because of the satellite’s orbit, there’s a hole north of 81.5 degrees, which is about 600 miles shy of the North Pole. But a team, including Laxon, at the Centre for Polar Observation and Modelling has designed a satellite – CryoSat-2 – to plug this hole.

CryoSat-2 is the first radar satellite specifically designed to measure ice thickness. It will do this with greater resolution than is possible with Envisat and so will give scientists a much more detailed picture of what is happening to ice in the Arctic. CryoSat-2 is being prepared for launch at the end of 2009.

Tamera Jones | alfa
Further information:
http://www.nerc.ac.uk

Further reports about: Arctic Arctic sea ice CryoSat-2 North Pole Polar Day sea ice

More articles from Earth Sciences:

nachricht Predicting unpredictability: Information theory offers new way to read ice cores
07.12.2016 | Santa Fe Institute

nachricht Sea ice hit record lows in November
07.12.2016 | University of Colorado at Boulder

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>