Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tracking the amount of sea ice from the Greenland ice sheet

28.09.2016

By analysing ice cores drilled from deep inside the Greenland ice sheet, researchers have started to calculate how much Arctic sea ice there was in the past. Researchers from Denmark, Italy, Spain and Japan have just published the results in the research journal Scientific Reports.

The Greenland ice sheet records information about Arctic temperature and climate going back to more than 120 000 years ago. But new research reveals that the ice doesn’t just tell us about the situation in the air and on the land – it can also tell us about what was happening at sea.


Arctic sea ice max-min


Andrea Spolaor - Svalbard

By analysing ice cores drilled from deep inside the Greenland ice sheet, researchers have started to calculate how much Arctic sea ice there was in the past. Researchers from Denmark, Italy, Spain and Japan have just published the results in the research journal Scientific Reports.

Arctic sea ice is changing. In the past the Arctic Ocean was covered by metres of thick sea ice but now that sea ice is thinning and being replaced by sea ice that melts away over the summer. The rapid decrease of summer sea ice that we currently observe is opening up the region for shipping and exploration but also threatening local ecosystems and cultures. But what was sea ice like in the past?

The amount of sea ice has only been well known since the 1970’s when satellite measurements began, so we don’t know what has been happening far back into the past.

Researchers at the Niels Bohr Institute in Denmark and Ca’Foscari Univeristy of Venice in Italy have discovered that chemical traces of sea ice can be found far away from the ocean within the kilometres-thick Greenland ice sheet.

The ice sheet is covered by snow which falls every year and is compressed into ice over many thousands of years. Every layer of ice tells us about the year that the snow originally fell on the ice sheet – what the temperature was like and what kinds of particles were blowing around in the atmosphere at that time.

”We can measure the amount of a chemical called bromine in the Greenland ice cores. You find bromine in both the ocean and sea ice, but when new sea ice forms in the winter the sea salt is concentrated into salty pockets of brine which contain bromine. In spring and summer, the sunlight that shines down onto the sea ice starts chemical reactions.

In these reactions, ozone in the air reacts with bromine in the ice and the bromine is released in greater and greater amounts from the sea ice. This process is called a bromine explosion. When it is released from the sea ice, the concentrated bromine is carried by the wind up onto the ice sheet and then deposited with the falling snow. That is the source of the bromine we measure in ice cores”, explains Andrea Spolaor, researcher at Ca’ Foscari University of Venice, ”The reactions stop in autumn and winter, when the sun goes below the horizon and new sea ice begins to form again.”.

Reconstructing sea-ice in the past
It’s one thing to measure the amount of bromine in an ice core from Greenland, but it’s another thing to understand the connection between bromine and the amount of sea ice in the Arctic.

In order to link the bromine measurements with the amount of sea ice covering the Arctic, scientists have used satellite observations of sea ice as a measuring stick, which goes back to the 1970’s. The measurements can be used to link the bromine content in the ice cores with the amount of new sea ice produced each year since 1979. A clue about the amount of sea ice in the past has also been revealed by records from Icelandic fishing communities, which go back more than 1000 years. Altogether, these data have allowed researchers to calculate how much sea ice there was in the Arctic tens of thousands of years ago.

”With this technique we can fill the gaps in our understanding of the amount of Arctic sea ice in the past. Since ice cores also reveal a lot of information about the climate, we can combine the sea ice data with the climate data and start to understand how sea ice reacts to climate change” explains Paul Vallelonga, Associate Professor at the Centre for Ice and Climate at the Niels Bohr Insitute, University of Copenhagen.

Sea ice and climate change
Researchers have found that 8000 years ago the Arctic climate was 2 to 3 degrees warmer than now, and that there was also less summertime Arctic sea ice than today.

”We have been in this situation before, with less sea ice and more open ocean during the warm Arctic summer. So right now we have not yet exceeded the natural boundaries for the Arctic region, but the question is: with more warming in the Arctic driven by rising greenhouse gases, how soon will sea ice melting reach and exceed the levels of 8000 years ago? These new research results can help us to answer this question when we combine them with climate models”, says Paul Vallelonga.

http://www.nature.com/articles/srep33925 

For further information, please contact:

Andrea Spolaor

Ca’ Foscari University of Venice

+39 3337464504

andrea.spolaor@unive.it

Andrea Spolaor | AlphaGalileo
Further information:
http://www.unive.it

Further reports about: Arctic sea ice Greenland ice sheet bromine ice cores ice sheet

More articles from Earth Sciences:

nachricht GPM sees deadly tornadic storms moving through US Southeast
01.12.2016 | NASA/Goddard Space Flight Center

nachricht Cyclic change within magma reservoirs significantly affects the explosivity of volcanic eruptions
30.11.2016 | Johannes Gutenberg-Universität Mainz

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

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,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

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

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>