Cryospheric Sciences

Sophie Berger

Sophie Berger is a PhD student of the glaciology unit, at the Université Libre de Bruxelles (ULB), Brussels Belgium. She is using various remote sensing data and techniques to investigate the dynamics and stability of the ice shelves in Dronning Maud Land (East Antarctica). She tweets as @SoBrgr.

Image of the Week – Monitoring icy rivers from space!

Image of the Week – Monitoring icy rivers from space!
Ice and floodwater inundate a town in Alaska because an ice jam formed downstream (credit: U.S. National Park Service on Wikimedia Commons)

Ice and floodwater inundate a town in Alaska because an ice jam formed downstream (credit: U.S. National Park Service)


When a river freezes over, it changes the amount of water that flows through the river system. River ice affects many of the world’s largest rivers, and in the Northern Hemisphere, approximately 60% of rivers experience significant seasonal effects. The formation and evolution of river ice changes river discharge and is not only of interest to local ice skating enthusiasts. The variations in river discharge can lead to severe situations, such as ice jams/dams (with an accompanying risk of flooding), or issues that affect the management of hydroelectric power plant infrastructures.


Satellite data have a huge potential for river ice monitoring thanks to the capability of imaging large areas. Synthetic Aperture Radar (SAR) systems are particularly promising as they can acquire data day or night without regard to cloud cover. In this way the extent of river ice can be mapped in great detail. The image of this week was produced applying one specific SAR technique : the polarimetry.


The image of this week is a false color composite with the different polarimetric channels (red = HH, green = HV and blue = VV) of RADARSAT-2 images. The nature of the ground/ice surface will influence the way the waves sent by the radar interact with it and thus the value of the backscattered signal in different polarisation. The pattern on the left image was then introduced in an algorithm to automatically retrieve different types of ice (right image). Recognising ice types from space is an essential step to monitor and then predict processes such as ice dam collapses.


Photo-interpretation key of the different types of ice, after Pawłowski et al (2015)


Pawłowski B., Łoś H., Osińska-Skotak K. (2015) The first approach of ice filling and river ice cover types classification for the lower Vistula River based on satellite SAR data. Monografie Komisji Hydrologicznej PTG ; t. 3, pp. 313-324.

Also check out:

This previous image of the week on SAR polarimetry applied to sea ice

The image of last week about another type of ice dam, at the terminus of a glacier

Image of the Week — Last Glacial Maximum in Europe

Image of the Week — Last Glacial Maximum in Europe

During the last ice age*, ~70,000 to 20,000 years ago, the climate was much colder in Europe.

As a result, the northern part of Europe was fully covered by the Fennoscandian (a.k.a the Scandinavian ) ice sheet, which extended up to the British Isles and some parts of Poland and Germany. In central Europe, the Alps were also almost fully glaciated.

The storage of all this ice on the continent lowered the sea level (seedark green), which substantially reduced the extent of the North Sea.

*This period is referred to as the Weichselian glaciation and the Würm glaciation in Northern Europe and the Alps, respectively.


More information

A more complete and accurate dataset (including GIS maps) of Europe during the last glacial maximum is freely available :

Becker, D., Verheul, J., Zickel, M., Willmes, C. (2015): LGM paleoenvironment of Europe – Map. CRC806-Database, DOI:



Image of the Week – Antarctic fieldwork 50 years ago!

Image of the Week – Antarctic fieldwork 50 years ago!

So far this blog has published many pictures of current polar field work campaigns. Today, we would like to take you back to Antarctic expeditions during the 1960s. The photos presented in this post date back from the Belgian-Dutch Antarctic field campaigns of 1964-1966.

The first picture shows Ken Blaiklock (red overalls) with a Belgian surveyor. Ken was part of the 1955–58 Commonwealth Trans-Antarctic Expedition – completing the first overland Antarctic crossing via the south pole. This shot was taken during the 1964-1965 summer campaign, as they were surveying the displacement of glaciers in the Sør Rondane Mountains, East Antarctica.  At that time, the men had to leave the base station for three weeks with two dog-sled pulled by a small skidoo-like vehicle. Remarkably, this shot doesn’t look too dissimilar to many field campaigns today, where the same type of sledges are still used and the clothing worn is also very similar. However, logistical support was very different, with no technicians or field guides those who were part of the polar expeditions of 50 years ago had to be experts at everything!

The second picture illustrates how precise positions (and relative displacements) were measured at that time. No fancy GPS technology, but a network of markers and theodolites. The shot was taken on a pinning point, close to the front of the Roi Baudouin Ice shelf, during the overwintering campaign of 1965 (where people had to stay in Antarctica for 15 months).

A geodesist measuring the precision position of a marker with his theodolite, overwintering campaign in Antarctica, 1965. (Credit: Jean-Jacques Derwael)

[Read More]

Image of the Week — Happy ValentICE’s day

Image of the Week — Happy ValentICE’s day

On the eve of 14 February, love and little hearts are everywhere, even trapped in lake ice!
The EGU Cryosphere blog team wishes you a happy Valentine’s Day 🙂

Behind this nice picture, there is also science

This picture was taken during a laboratory experiment that aimed to reproduce the bubbles observed in Arctic lake ice in the winter.

In this shot, we can see two types of gas bubbles in the ice. The elongated vertical bubbles are formed after the exsolution of gas at the water-ice interface. The gas present in “heart-shaped” bubbles originates from ebullition (i.e. it has been emitted as bubbles from the sediment) and it contains a large amount of methane, a significant greenhouse gas. In both cases, the gas is trapped in the ice during the downward evolution* of the freezing front but the shape and gas content of the bubbles largely depends on the velocity of the freezing front development.

The goal of this research is to better understand the origin of the methane emitted by Artic lakes and unravel the role of lake ice cover on the methane atmospheric burden.

*During the winter, the cold atmosphere cools down the water of the lake, when the freezing point is reached, a thin layer of layer of lake ice starts to form at the surface and extends downward.

Further reading/Reference

Boereboom, T., Depoorter, M., Coppens, S., and Tison, J.-L.: Gas properties of winter lake ice in Northern Sweden: implication for carbon gas release, Biogeosciences, 9, 827-838, doi:10.5194/bg-9-827-2012, 2012.

Sapart, C. J et al (in preparation).

Image of the Week — slush on top of sea ice

Image of the Week — slush on top of sea ice

Many glaciologists look forward to going on fieldtrips and then, once they are back, they make us dream by posting breathtaking photos (like THIS or THIS or THIS). However, the reality of the field can sometimes be very different….

The picture illustrates how difficult it can be to work on sea ice when the snow on top of it starts to melt and forms slush (a mixture of snow and liquid water that looks very much like an Italian granita).

Here, the sled carrying the field equipment is half drowned in the slush while the technician who came to the rescue (with his skidoo in the back) is also sunk.

On this blog post you can read about another expedition of M. Kotovitch on sea ice.

Edited by Emma Smith


Image of the Week — Greenland ice sheet and clouds

Image of the Week — Greenland ice sheet and clouds

A new study combining satellite observations and model simulations shows that clouds increase meltwater runoff in Greenland by one-third compared to a cloud-free scenario.

Precipitation effects not considered, clouds above the Greenland ice sheet reduce its Surface Mass Balance (SMB) [red in figure] compared to clear-sky conditions [blue in figure]. Because clouds trap the outgoing radiation from the ice-sheet surface, they locally warm the atmosphere below, which reduces Greenland’s meltwater refreezing at night. Hence, clouds increase runoff from the ice sheet by 56 billion tons of water each year.

Reference/further reading:

  • Van Tricht, K., S. Lhermitte, J. T. M. Lenaerts, I. V. Gorodetskaya, T. S. L’Ecuyer, B. Noël, M. R. van den Broeke, D. D. Turner, and N. P. M. van Lipzig. 2016. “Clouds Enhance Greenland Ice Sheet Meltwater Runoff.” Nature Communications 7 (January). Nature Publishing Group: 10266. doi:10.1038/ncomms10266.
  • Article in the Washington Post about the paper.
  • You can follow Kristof Van Tricht the study’s lead author on twitter @kristofvt.

Image of the Week — Happy New Year

Image of the Week — Happy New Year

December 2014, 11:50 p.m., the sun licks the horizon on Derwael ice rise; It’s time to go back to the tent …

The shot was taken during the 2014 IceCon Field campaign in East Antarctica (read Brice’s blog post  telllling about his first journey to Antarctica).

Here, you can also read about the 2016 field season of the IceCon project, which started just a few days ago.

Image of the Week — Greetings from Antarctica

Image of the Week — Greetings from Antarctica

Christmas greetings from people at Rothera Research Station, Adelaide Island, Antarctica.

Rothera, which is the British Antarctic Survey’s largest base in Antarctica, is a centre for marine biology and gateway for getting scientists into their deep field camps.

Christmas Day is a regular working day for the staff of around 90. However the chefs will be getting everyone into the festive spirit with a traditional turkey dinner with all the trimmings

Image of the Week — AGU Fall Meeting 2015

Image of the Week — AGU Fall Meeting 2015

The American Geophysical Union (AGU) Fall Meeting, which takes place every December in  San Francisco is ending today.

With more than 24 000 attendees, 14 000 poster presentations and 7 000 talks, the AGU meeting is the largest conference on geophysical sciences in the World.

The cryosphere is one the topics covered by the meeting and we hope that this year edition was a fruitful for every participant.

Busy poster session on the Cryosphere. (Credit: Konstantinos Petrakopoulos)

Busy poster session on the Cryosphere. (Credit: Konstantinos Petrakopoulos)


Image of the Week — Future Decline of sea-ice extent in the Arctic (from IPCC)

Image of the Week — Future Decline of sea-ice extent in the Arctic (from IPCC)

The Arctic sea-ice extent has declined in the past 20 years and its future is uncertain. In the end, greenhouse gas emissions will determine the impact on the sea-ice from man-made climate change through radiative forcing (i.e. Representative Concentration Pathways or RCPs). The COP21 can determine the path we will follow and which course we will take to reduce emissions.

Reduction in sea-ice cover ranges from 43% (RCP 2.6) to 94% (RCP 8.5) in the period 2081-2100 compared to 1986-2005.

Why is sea important?

Decrease in sea-ice extent would:
– decrease the albedo of the Arctic ocean, therefore more heat would be absorbed by the ocean which would enhance the warming in this region.
– affect the global oceanic circulation as sea-ice formation influences the density of ice masses, which drives oceanic circulation.
– completely alter the ecosystem in the Arctic.


Further Reading

Stocker, T F, D Qin, G.-K. Plattner, L V Alexander, S K Allen, N L Bindoff, F.-M. Bréon, et al. 2013. “Technical Summary.” In Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, edited by T F Stocker, D Qin, G.-K. Plattner, M Tignor, S K Allen, J Boschung, A Nauels, Y Xia, V Bex, and P M Midgley, 33–115. Cambridge, United Kingdom and New York, NY, USA: Cambridge University Press. doi:10.1017/CBO9781107415324.005.

Read about sea ice and its importance on the NSIDC website


Previous blog posts featuring sea-ice science:

Do beers go stale in the Arctic?

Cruising for mud sediments from the ocean floor

Camping on the Svalbard coast

Image of the Week: Under the sea


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