numerical modelling

Did you know that cracks play a large role in the Arctic sea ice production?

Guillaume Boutin April 7, 2023

Figure 1. New sea ice forming in an opening in the Arctic sea ice cover (what we call a lead), as seen during the MOSAIC expedition. This type of newly formed ice is generally called “frost flowers”. Credit: [Alfred-Wegener-Institut/Michael Gutsche (CC-BY 4.0)]

What do you need to form sea ice? Well, you can start with some sea water, an ocean will do, and cold air above it. Once a layer of ice starts forming, break it to make some cracks. You would have not thought of that? Yet, our recent study suggests cracks in the ice contribute significantly to Arctic winter sea ice production. A relationship between sea ice formation and breakup? We have known for ...[Read More]

Image of the Week – (Un)boxing the melting under the ice shelves

Ronja Reese November 30, 2018

Figure 1: Melting underneath Antarctic ice shelves as modelled with the Potsdam Ice-shelf Cavity mOdel (PICO) for present-day ice geometries and ocean conditions. Extending a simple ocean box model approach (Olbers and Hellmer, 2010), it efficiently calculates the wide range of melting in Antarctica [Credit: adapted from Fig. 5 of Reese et al. (2018)]

The Antarctic ice sheet stores a large amount of water that could potentially add to sea level rise in a warming world (see this post and this post). It is currently losing ice, and the ice loss has been accelerating in the past decades. All this is linked to the melting of ice – not at the surface but at the base, underneath the so-called ice shelves which form the continuation of the Antarctic i ...[Read More]

Image of the Week – Karthaus Summer School 2018

Rohi Muthyala November 16, 2018

Nearly every year since the late 90s, during the summer, the picturesque Karthaus has hosted 10-day glaciology course. This school is a platform for glaciologists to explore, learn and expand their knowledge base. This helps researchers become multi-faceted: to view glaciology from the perspective of those specializing in other backgrounds such as hydrology, geomorphology, oceanography, etc. which ...[Read More]

Image of the Week – The shape of (frozen sea) water

Adam Bateson September 7, 2018

Polar sea ice exists as isolated units of ice that we describe as floes. These floes do not have a constant shape (see here for instance); they can vary from almost circular to being jagged and rectangular. However, sea ice models currently assume that all floes have the same shape. Much focus has been paid to the size of floes recently, but do we also need to reconsider how floe shape is t ...[Read More]

Image of the Week – A high-resolution picture of Greenland’s surface mass balance

Brice Noël April 14, 2017

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 – 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]