CR
Cryospheric Sciences

Sea Level Rise

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

October 27, 2023
Recipe to quantify calibration errors in a time-dependent ice sheet model
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]

CryoNews – The WMO is making the cryosphere a global priority

June 9, 2023
A plane and several researchers on the ice in Antarctica.
The collection and sharing of climate data especially from Antarctic is now more than ever supported by the World Meteorological Organisation (WMO). (Photo credit: Andrew Elvidge, distributed via imaggeo.egu.eu)

To us, the cryosphere has always been a priority. It is our field of interest, research, maybe passion, it is the stuff that gets us excited. Now, the cryosphere also became a priority to the World Meteorological Organisation (WMO). In today’s post we cover a recent news item introducing this very decision made during WMO’s recent congress. Read along to find out  why they emphasize the importance ...[Read More]

Hysteresis For Dummies – Why history matters

December 4, 2020
Hysteresis For Dummies – Why history matters
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 small changes can make a big difference: tipping points in Antarctica

November 13, 2020

As Antarctica’s mass loss increases, the threat of crossing tipping points both in the ice sheet and the surrounding Southern Ocean is increasing. But what actually is a tipping point? Have tipping points already been crossed in the past? And what might the future hold? What do we mean by a “tipping point”? Scientifically speaking, a tipping point is generally understood to be a threshold that, on ...[Read More]

What’s up on Thwaites Glacier?

March 13, 2020
What’s up on Thwaites Glacier?
Figure 1: Map showing the location of Thwaites Glacier in West Antarctica, as well as the main geographic focus of the 8 projects involved in the International Thwaites Glacier Collaboration (ITGC). Credit: ITGC website.

With the West Antarctic Ice Sheet currently losing ice at a fast pace, leading to sea-level rise, it is very important to better understand the processes by which this ice melting occurs. In this context, Thwaites Glacier is a very good case study of an accelerating glacier, which contributes substantially to sea-level rise, and for which a huge scientific collaboration effort has recently been se ...[Read More]

Water plumes are tickling the Greenland Ice Sheet

January 31, 2020
Water plumes are tickling the Greenland Ice Sheet
Figure 1. Cross section of a schematic representation of a glacier. Surface water is penetrating into the glacier through crevasses at its surface, reaching its base where it flows towards the ocean. Once this freshwater has entered the ocean, it rises up creating a so-called water plume. Credit: Stefan Hollenbach.

7 meters of sea-level rise – what you would get if the whole Greenland Ice Sheet melted. But the tricky question is: how much of this ice will be melted in the next decades, and how fast will it occur? This piece of information is critical in order to plan for present and future populations living in coastline areas, all around the world. How much and how fast can the Greenland Ice Sheet melt ? In ...[Read More]

Image of the Week – The solid Earth: softer than you might think!

March 15, 2019

  Global sea level is rising and will continue to do so over the next century, as has once again been shown in the recent IPCC special report on 1.5°C. But did you know that, in some places of our planet, local sea level is actually falling, and this due to rising of the continent itself?! Where is this happening? In places where huge ice sheets used to cover the land surface during the last ...[Read More]

Image of the Week – Delaying the flood with glacial geoengineering

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 – Learning from our past!

September 1, 2017
Image of the week – Learning from our past!
Figure 1: Peak global mean temperature, atmospheric CO2, maximum global mean sea level (GMSL) and source(s) of meltwater over the past 3 million years. The light blue area on each bar indicates the uncertainty associated with the maximum global mean sea level , and the pie charts denote the fraction (not location) of ice retreat in Greenland and Antarctica [Credit: Dutton et al. (2015)].

Understanding the climate evolution of our planet is not an easy task, but it is essential to understand the past if we are to predict the future! Historic climate cycles provide us with a glimpse into a period of time when the Earth was warmer than it was today. Our image of the week looks at these warmer periods of time to see what they can tell us about the future! For example, during the Plioc ...[Read More]

Image of the Week – Storing water in Antarctica to delay sea-level rise

April 29, 2016
Image of the Week – Storing water in Antarctica to delay sea-level rise
Difference in ice thickness from the initial equilibrium state after 100 years of ice addition (upper panels) and 1000 years after the end of the forcing (lower panels). Two scenarios are shown, 200 km (left panels) and 800 km (right panels) from the coastline, both corresponding to a sea-level mitigation of 10 mm per year (credit: Frieler et al., 2016, fig 3) .

  Sea level rise Sea-level rise is one of the main impacts of the current global warming and its rate has dramatically increased in the last decades (the current rate is about 3 mm per year). Even if greenhouse gas emissions were stopped today, sea level would continue to rise due to the slow Earth climate system response (IPCC, 2013, chap. 13). It is therefore a considerable threat for popul ...[Read More]