EGU Guest blogger

Image of the Week – Apocalypse snow? … No, it’s sea ice!

Jean-Louis Tison February 10, 2017

Sea-ice brine sampling is sometimes challenging [Credit: Stefan Hendricks]

Sea ice brine sampling is always great fun, but sometimes somewhat challenging ! As sea water freezes to form sea ice, salts in the water are rejected from the ice and concentrate in pockets of very salty water, which are entrapped within the sea ice. These pockets are known as “brines”. Scientists sample these brines to measure the physical and bio-geochemical properties, such as: tem ...[Read More]

Image of the Week – Supraglacial debris variations in space and time!

Morgan Gibson February 3, 2017

Figure 1: A schematic diagram of debris distribution on a debris-covered glacier, showing spatial variation in debris distribution with regards to rock type and layer thickness. Modelled on Baltoro Glacier, Karakoram. Surface velocity, sediment flux and debris thicknesses would vary between glaciers. Click here for a larger version. [Credit: Gibson et al., unpublished]

There is still a huge amount we don’t know about how glaciers respond to climate change. One of the most challenging areas is determining the response of debris-covered glaciers. Previously, we have reported on a number of fieldwork expeditions to debris-covered glaciers but with this Image of The Week we want to show you another way to investigate these complex glaciers – numerical modelling! Deb ...[Read More]

Katabatic winds – A load of hot (or cold) air?

Thomas Shaw January 25, 2017

Figure 1: A schematic of the potential wind flow and interplay of local effects on Tsanteleina Glacier in the Italian Alps. The diagram represents wind modelling, measured data and observations from the field. (1) The interactions of down-glacier katabatic winds (blue) and up-valley winds/local heat sources (red); (2) the potential heat emitted from the warm valley surroundings (pink) and; (3) localised surface depressions representing glacier 'cold spots' during calm, high pressure conditions. Arrows correspond to synoptic westerlies (purple), southerly airflow (orange), katabatic winds (blue) and valley winds (red) [Credit: T Shaw, unpublished] - Click here for a larger version.

It might seem obvious that a warming world will lead to a reduction in glacial ice cover, but predicting the response of glaciers to climatic change is no simple task (even within the short term). One way to approach this problem is to come up with relationships which describe how glaciers interact with the world around them, for example, how the ice interacts with the air above it. Our post today ...[Read More]

Image of the Week – For each tonne of CO2 emitted, Arctic sea ice shrinks by 3m² in summer

David Docquier January 20, 2017

Mean area of Arctic September sea ice lost by CO₂ emissions of each citizen for each country of the world in 2013. These results are based on the observed trend of 3 m² sea-ice area loss per tonne of CO₂ emitted [Credit: adapted from Notz and Stroeve (2016), Fig.S1]

Declining sea ice in the Arctic is definitely one of the most iconic consequences of climate change. In a study recently published in Science, Dirk Notz and Julienne Stroeve find a linear relationship between carbon dioxide (CO2) emissions and loss of Arctic sea-ice area in summer. Our image of this week is based on these results and shows the area of September Arctic sea ice lost per inhabitant d ...[Read More]

Polar Exploration: Perseverance and Pea Sausages

Nanna B. Karlsson January 15, 2017

"Pølse” it says on the tin i.e. “sausage”. On the other side the word “ærte” (“pea”) is printed, in other words “pea sausage”. This is one of the tins brought to Greenland on the ill-fated Danish expedition 1904-1906 led by Ludvig Mylius-Erichsen. Credit: Danish Arctic Institute.

Born on this Day On this day in 1872 – 145 years ago –Ludvig Mylius-Erichsen, Danish author and polar explorer, was born. He led two expeditions to Greenland and successfully mapped the then unknown northeastern part of the country. The second expedition was his last. The expedition was surprised by an early onset of spring and could no longer use their dog sledges. The two Danes, Mylius-Eri ...[Read More]

Image of the Week – The Sound of an Ice Age

Nanna B. Karlsson December 30, 2016

The blue curves show the δOxygen-18 values for NorthGRIP in Greenland (top) and WAIS in Antarctica (bottom) for the last 20,000 years. The black dots are 1,000 years values, and the far left hand side of the curves are present day values.

New Year’s Eve is just around the corner and the last “image of the week” of 2016 will get you in the mood for a party. If your celebration needs a soundtrack with a suitably geeky touch then look no further. Here is the music for climate enthusiasts: The sound of the past 60,000 years of climate. Scientist Aslak Grinsted (Centre for Ice and Climate, University of Copenhagen, Denmark) has transfor ...[Read More]

Ice Cores “For Dummies”

Ashleigh Massam December 14, 2016

Ice cores are important tools for investigating past climate as they are effectively a continuous record of snowfall, which preserves historical information about climate conditions and atmospheric gas composition. In this new “For Dummies” post, we discuss the history and importance of ice-core science, and look at the way we can use ice core chemistry to reconstruct past climate. Ice sheets, arc ...[Read More]

Image of the Week – Sea Ice Floes!

Chris Horvat December 2, 2016

Left: Floes in the Southern Ocean surrounding the Nathaniel Palmer, taken by a multi-rotor drone. The length of the Nathaniel Palmer, about 100 m, is shown for comparison [Credit: EOS]. Right: Floes in the Bering Strait in May, 2000 from the MODIS satellite. Arrow shows the width of the Bering Strait, 85 km, for comparison [Credit: NASA Earth Observatory].

The polar regions are covered by a thin sheet of sea ice – frozen water that forms out of the same ocean water it floats on. Often, portrayals of Earth’s sea ice cover show it as a great, white, sheet. Looking more closely, however reveals the sea ice cover to be a varied and jumbled collection of floating pieces of ice, known as floes. The distribution and size of these floes is vitally imp ...[Read More]

Ice-Hot News : The “Oldest Ice” quest has begun

Oldest Ice PhD Students November 14, 2016

There is million-year old ice somewhere deep under the surface of the Antarctic ice sheet! [Credit: Brice Van Liefferinge]

This is it! The new European horizon 2020 project on Oldest Ice has been launched and the teams are already heading out to the field, but what does “Old Ice” really mean? Where can we find it and why should we even care? This is what we (Marie, Olivier and Brice) will try to explain somewhat. Why do we care about old ice, ice cores and past climate? Unravelling past climate and how it responded to ...[Read More]

Image of the Week – Inside a Patagonian Glacier

Tommaso Santagata November 4, 2016

Figure 1: A speleologist descending inside a glacier cave of the Grey Glacier [Credit: Tommaso Santagata/ La Venta]

Chilean Patagonia hosts many of the most inhospitable glaciers on the planet – in areas of extreme rainfall and strong winds. These glaciers are also home to some of the most spectacular glacier caves on Earth, with dazzlingly blue ice and huge vertical shafts (moulins). These caves give us access to the heart of the glaciers and provide an opportunity to study the microbiology and water drainage ...[Read More]