When it comes to climate change, the Arctic and the Antarctic are poles apart. At the north of the planet, temperatures are increasing twice as fast as in the rest of the globe, while warming in Antarctica has been milder. A recent study published in Earth System Dynamics shows that the high elevation of Antarctica might help explain why the two poles are warming at different speeds. The Arctic vs ...[Read More]
Image of the Week – Heat waves during Polar Night!
The winter 2016-2017 has been one of the hottest on record in the Arctic. In our Image of the Week, you can see that air temperatures were positive in the middle of the winter! Let’s talk about the reasons and implications of this warm Arctic winter. But first, let’s take a tour in Svalbard, the gateway to the Arctic… A breach in the one of the world’s largest seed vaults The Global S ...[Read More]
Image of the Week – How geometry limits thinning in the interior of the Greenland Ice Sheet
Figure 1: (a) Mass change of the Greenland ice sheet measured by NASA’s GRACE mission in cm/yr water equivalent from January 2003 to December 2013 [Credit: modified from Velicogna et al., 2014]. (b) Dynamic surface elevation change and mass loss along the margin of West Greenland as measured by DEM differencing. The map shows surface elevation change from 1985 to present for 16 outlet glaciers. Circles represent mass change (estimated using 917 kg m-3 as ice density) with circle areas proportional to magnitude of mass change. [Credit: Denis Felikson]
The Greenland ice sheet flows from the interior out to the margins, forming fast flowing, channelized rivers of ice that end in fjords along the coast. Glaciologists call these “outlet glaciers” and a large portion of the mass loss from the Greenland ice sheet is occurring because of changes to these glaciers. The end of the glacier that sits in the fjord is exposed to warm ocean water that can me ...[Read More]
Image of the Week – A high-resolution picture of Greenland’s surface mass balance
Fig. 1: Surface mass balance (SMB) of the Greenland ice sheet and peripheral ice caps at 1 km resolution averaged for 1958-2015. The interior of the ice sheet (blue) accumulates mass from snowfall whereas the narrow margins (red) lose mass from runoff of meltwater. Yellow dots locate on-site measurements. At this resolution, the small ice caps and marginal glaciers are accurately resolved [Credit: Brice Noël]. Click here here to enlarge the image.
The Greenland ice sheet – the world’s second largest ice mass – stores about one tenth of the Earth’s freshwater. If totally melted, this would rise global sea level by 7.4 m, affecting low-lying regions worldwide. Since the 1990s, the warmer atmosphere and ocean have increased the melt at the surface of the Greenland ice sheet, accelerating the ice loss through increased runoff of meltwater and i ...[Read More]
Image of The Week – Ice Flows!
By changing factors such as snowfall and temperature players can alter the ice flow and make sure that icebergs starts to form just where the penguins want to dive down and catch fish, but get it wrong and there’s a seal waiting! [Credit: Still image from the Ice Flows game]
Portraying ice sheets and shelves to the general public can be tricky. They are in remote locations, meaning the majority of people will never have seen them. They also change over timescales that are often hard to represent without showing dramatic images of more unusual events such as the collapse of the Larsen B Ice Shelf. However, an app launched in the summer at the SCAR (Scientific Committe ...[Read More]
Image of the Week — Hidden lakes in East Antarctica !
Underwater picture of englacial lake 4m
below the surface [Credit: S.
Lhermitte].
Who would have guessed that such a beautiful picture could get you interviewed for the national news?! Certainly not me! And yet, the photo of this englacial lake (a lake trapped within the ice in Antarctica), or rather science behind it, managed to capture the media attention and brought me, one of the happy co-author of this study, on the Belgian television… But what do we see on the pic ...[Read More]
Image of The Week – The Pulsating Ice Sheet!
Figure 1: (a) Ice sheet at its most advanced state, the terminus is grounded 300 m beneath sea level (b) An ocean-warming event triggers retreat (c) Retreat is amplified by enhanced calving as the ice sheet retreats into deeper water (d) After the collapse, the ice sheet is in its most retreated position. Isostatic adjustment uplifts the bed (and sill) which will allow the ice sheet to advance again. Insets show a close-up around the sill. [Credit:
Bassis et al., 2017]
During the last glacial period (~110,000-12,500 years ago) the Laurentide Ice Sheet (North America) experienced rapid, episodic, mass loss events – known as Heinrich events. These events are particularly curious as they occurred during the colder portions of the last glacial period, when we would intuitively expect large-scale mass loss during warmer times. In order to understand mass loss m ...[Read More]
Image of the Week – For each tonne of CO2 emitted, Arctic sea ice shrinks by 3m² in summer
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]
Image of the Week — Allez Halley!
On the Brunt Ice Shelf, Antarctica, a never-observed-before migration has just begun. As the pale summer sun allows the slow ballet of the supply vessels to restart, men and machines alike must make the most of the short clement season. It is time. At last, the Halley VI research station is on the move! Halley, sixth of its name Since 1956, the British Antarctic Survey (BAS) has maintained a resea ...[Read More]
Ice Cores “For Dummies”
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]