Antarctic ice sheet

Recipe to quantify calibration errors in a time-dependent ice sheet model

Beatriz Recinos, Dan Goldberg and James Maddison October 27, 2023

Figure 1: Upper diagram: schematics of baking a pie, representing an idealized 1D Bayesian inverse problem. Lower diagram: schematics of a multi-dimension ice sheet inverse problem solved using FEniCS_ice error propagation framework, created from a compilation of figures from Recinos et al. (2023). FEniCS_ice is designed to solve these problems over a finite element mesh containing (in this study case) more than 100,000 elements. These elements are the vertices, faces, and edges that form our triangular mesh (red map, check out ingredients list below for more information). [Credits: Beatriz Recinos, baking icons from https://www.flaticon.com/].

Ice sheet models are awesome tools that help us learn and predict the fate of ice sheets under human-induced climate change. However, all models have errors. What types of uncertainties exist in an ice sheet model and how can we quantify some of them efficiently? Check out our recipe to quantify one type of uncertainty in sea level rise projections: The model calibration error. Not a numerical mod ...[Read More]

Did you know … that liquid water can be held within a glacier?

Annika Horlings January 29, 2021

Hidden below the surface of some glaciers, liquid water can be found within what is called the firn layer – the upper layer of a glacier where snow compacts into glacier ice. Liquid water may persist there for up to many years, forming what scientists call “firn aquifers.” While observations of seasonal firn aquifers have existed since the mid to late 1900s in several mountain glaciers, recent stu ...[Read More]

Hysteresis For Dummies – Why history matters

Julius Garbe December 4, 2020

Simple illustration of the concept of multi-stability and tipping points of an ice sheet: the stability of the large Antarctic Ice Sheet can be seen as a seesaw. It starts off stable on the left side, but as temperatures rise, the ice starts to melt and lose mass, resulting in the left side of the seesaw getting progressively lighter. Up to a certain threshold, the seesaw remains stuck in its initial position, but upon transgressing the critical threshold, the system flips over, the seesaw switches into the right state which is associated with a much smaller ice sheet. Figure credit: J. Garbe.

Perhaps you have stumbled upon the word ‘hysteresis’ before, for example in connection with the stability behavior of our Earth’s large ice sheets and their long-term effect on global sea-level rise, or the long-term stability of the Atlantic Meridional Overturning Circulation, or even in another context outside earth/climate science. Or you might have come across this term during your studies, bu ...[Read More]

How do the ups and downs of the solid Earth influence the future of the West Antarctic ice sheet?

Violaine Coulon October 30, 2020

When the Antarctic ice sheet loses mass, the pressure it exerts on the underlying solid Earth decreases. As the ice sheet becomes less heavy, the Earth’s surface is not pressed down as much as before and therefore slowly rises up. In some regions, this rebound process is much faster than previously thought and could stabilise areas of unstable ice retreat. How come? Keep reading to figure it out… ...[Read More]

©LEt’sGO to Antarctica !

Brice Van Liefferinge and Marie Cavitte May 15, 2020

The camp site deployed to collect radar data with (a) the polar vehicle (in orange in the centre) or (b) snowmobiles (on the right). Other types of measurements are often carried out simultaneously: atmospheric gas composition, snow/ice core drilling, surface photogrammetry, etc. Can you spot them all ? Photo credit: Brice Van Liefferinge

With the current situation, polar fieldwork might be/have been cancelled and we have a suggestion to remedy your field-blues… Why not use ©LEGO to pretend you’re back in the field with the added bonus that you get to be in the warmth and comfort of your home! Here, we’ve re-enacted radar fieldwork that took place a year and a half ago in Antarctica… But first, let’s start with some backgroun ...[Read More]

Radiocarbon rocks! – How rocks can tell us about the history of an ice sheet…

Keir Nichols March 20, 2020

Figure 1: Collecting a bedrock sample from the Lassiter Coast, Antarctica [Credit: Joanne Johnson, British Antarctic Survey].

When most people hear the phrase “radiocarbon dating”, they think of measuring carbon to date organic material. But did you know that carbon is also produced within rocks, and that we can use it to learn about the past behaviour of a glacier? About 20,000 years ago it was colder and large parts of the continents were covered by ice. But what did Antarctica – the largest ice mass ...[Read More]

Did you know? – Ocean bathymetry can control Antarctic mass loss!

Sainan Sun January 10, 2020

Ice shelves (the floating parts of the Antarctic ice sheet) play a fundamental role in the stability of the Antarctic ice sheet (see this post) and, therefore, its contribution to global sea-level rise. They lose mass primarily through melting at their bases, which are in contact with the ocean. This thins them and makes them more vulnerable, reducing their stabilising potential and causing more i ...[Read More]

Image of the Week – Delaying the flood with glacial geoengineering

David Docquier February 1, 2019

As the climate is currently warming, many countries and cities are preparing to cope with one of its major impacts, namely sea-level rise. Up to now, the mitigation of climate change has mainly focused on the reduction of greenhouse gas emissions. Large-scale geoengineering has also been proposed to remove carbon from the atmosphere or inject aerosols into the stratosphere to limit the rise in tem ...[Read More]

Image of the Week — Quantifying Antarctica’s ice loss

Céline Heuzé June 22, 2018

It is this time of the year, where any news outlet is full of tips on how to lose weight rapidly to become beach-body ready. According to the media avalanche following the publication of the ice sheet mass balance inter-comparison exercise (IMBIE) team’s Nature paper, Antarctica is the biggest loser out there. In this Image of the Week, we explain how the international team managed to weight Anta ...[Read More]

Image of the Week – Antarctica: A decade of dynamic change

Stephen Chuter May 25, 2018

Whilst we tend to think of the ice flow in Antarctica as a very slow and steady process, the wonders of satellites have shown over the last two decades it is one of the most dynamic places on Earth! This image of the week maps this dynamical change using all the satellite tools at a scientist’s disposal with novel statistical methods to work out why the change has recently been so rapid. Why do ...[Read More]