Julius GarbeAug 22, 2024

Thwaites Glacier won’t collapse like dominoes as feared, study finds, but that doesn’t mean the ‘Doomsday Glacier’ is stable
https://theconversation.com/thwaites-glacier-wont-collapse-like-dominoes-as-feared-study-finds-but-that-doesnt-mean-the-doomsday-glacier-is-stable-236480 via @TheConversationClimate

#Antarctica #Ice #SeaLevel #Thwaites #DoomsdayGlacier #AntarcticIceSheet #WAIS 🇦🇶🧊🌊

Thwaites Glacier won’t collapse like dominoes as feared, study finds, but that doesn’t mean the ‘Doomsday Glacier’ is stable

Antarctica’s riskiest glacier is a disaster in slow motion, a polar scientist writes. But in a rare bit of good news, the worst-case scenario may be off the table.

The Conversation
Ruth Mottram Aug 7, 2024
And on to that other great unknown: @fsmccormack.bsky.social taking us through geothermal heatflux and it's role in basal melting under the #AntarcticIceSheet at #IGSnorthumbria2024
Ruth MottramAug 7, 2024
And on to that other great unknown: @fsmccormack.bsky.social taking us through geothermal heatflux and it's role in basal melting under the #AntarcticIceSheet at #IGSnorthumbria2024
Show threadRuth MottramJun 29, 2024

Related: one of the things I love about my fellow scientists is their sense of humour. There are 2 ways to reconstruct the bed of the #AntarcticIceSheet; interpolate between those very sparse observations or use an ice flow model that has surface observations in it and invert to work out how the bed is changing the flow field.

Colleagues in Leeds/Sheffield have blended the 2 approaches and they have called it: "Frankenbed". Because why not? 😆

formuchdeliberationMay 24, 2024
Miles of seawater are flowing under Thwaites Glacier, undermining an Antarctic ice sheet and threatening rapid sea level rise... #arctic #westantarctica #ThwaitesGlacier #melting #icesheet #antarctica #antarcticicesheet #climatechange #climate #globalwarming #sealevelrise #EarthScience #geography https://grist.org/oceans/scientists-find-miles-of-seawater-beneath-doomsday-glacier/
The ‘Doomsday Glacier’ is melting faster than scientists thought

Miles of seawater are flowing under Thwaites Glacier, undermining an Antarctic ice sheet and threatening rapid sea level rise.

Grist
formuchdeliberationMar 2, 2024
Sea ice levels in Antarctica have registered historic lows for three consecutive years, portending grave consequences for life on Earth as we know it...
#climatechange #antarctica #SeaIceLoss #IceSheets #melting #polarregions #climate #ClimateCrisis #climatescience #antarctic #temperature #climateemergency #icemelting #geography #glaciology #EarthScience #climatenews #antarcticicesheet #antarcticicemelt https://phys.org/news/2024-03-scientists-fret-antarctic-sea-ice.html
'Very worried': Scientists fret as Antarctic sea ice dwindles

Sea ice levels in Antarctica have registered historic lows for three consecutive years, portending grave consequences for life on Earth as we know it.

Phys.org
8Petros [MOVING!!]Nov 29, 2023

COP28: Earth's frozen zones are in trouble – we're already seeing the consequences
#sealevelrise #Permafrost #glaciers #NewZealandstories #ScienceEnvironment #Antarcticicesheet #Polarice
COP28: Earth's frozen zones are in trouble – we're already seeing the consequences

The world is on track to exceed 2°C warming within the next five years, with dire consequences for polar ice, mountain glaciers and permafrost – and human society.

The Conversation
Julius GarbeNov 2, 2023
Extremely happy that my new paper on the future of #AntarcticIceSheet surface melting is finally published! 🎉
We use a new melt module in our ice-flow model #PISM which in addition to temperature also takes into account the effect of solar radiation & thus the melt–albedo feedback. Check it out! #OpenAccess #OpenScience
https://doi.org/10.5194/tc-17-4571-2023
The evolution of future Antarctic surface melt using PISM-dEBM-simple

Abstract. It is virtually certain that Antarctica's contribution to sea-level rise will increase with future warming, although competing mass balance processes hamper accurate quantification of the exact magnitudes. Today, ocean-induced melting underneath the floating ice shelves dominates mass losses, but melting at the surface will gain importance as global warming continues. Meltwater at the ice surface has crucial implications for the ice sheet's stability, as it increases the risk of hydrofracturing and ice-shelf collapse that could cause enhanced glacier outflow into the ocean. Simultaneously, positive feedbacks between ice and atmosphere can accelerate mass losses and increase the ice sheet's sensitivity to warming. However, due to long response times, it may take hundreds to thousands of years until the ice sheet fully adjusts to the environmental changes. Therefore, ice-sheet model simulations must be computationally fast and capture the relevant feedbacks, including the ones at the ice–atmosphere interface. Here we use the novel surface melt module dEBM-simple (a slightly modified version of the “simple” diurnal Energy Balance Model) coupled to the Parallel Ice Sheet Model (PISM, together referred to as PISM-dEBM-simple) to estimate the impact of 21st-century atmospheric warming on Antarctic surface melt and ice dynamics. As an enhancement compared to the widely adopted positive degree-day (PDD) scheme, dEBM-simple includes an implicit diurnal cycle and computes melt not only from the temperature, but also from the influence of solar radiation and changes in ice albedo, thus accounting for the melt–albedo feedback. We calibrate PISM-dEBM-simple to reproduce historical and present-day Antarctic surface melt rates given by the regional atmospheric climate model RACMO2.3p2 and use the calibrated model to assess the range of possible future surface melt trajectories under Shared Socioeconomic Pathway SSP5-8.5 warming projections until the year 2100. To investigate the committed impacts of the enhanced surface melting on the ice-sheet dynamics, we extend the simulations under fixed climatological conditions until the ice sheet has reached a state close to equilibrium with its environment. Our findings reveal a substantial surface-melt-induced speed-up in ice flow associated with large-scale elevation reductions in sensitive ice-sheet regions, underscoring the critical role of self-reinforcing ice-sheet–atmosphere feedbacks in future mass losses and sea-level contribution from the Antarctic Ice Sheet on centennial to millennial timescales.

Dave RobinsonOct 24, 2023
In the past couple of months I've seen several reports that suggest that the dramatic reduction of sea ice around Antarctica will accelerate the collapse of the West Antarctic ice sheet, which will melt and slide into the sea, raising sea level by 5 metres. This is probably inevitable even if we hit net zero next week - it's locked in and will happen this century, but possible a lot sooner in the worst case scenario. Who would bet against the worst case scenario, given the current year)? If we immediately start drastically reducing emissions, we might avert the collapse of the East Antarctic ice sheet... if that goes completely, the sea level rise could be 50 metres. Then there's the Greenland ice sheet, which could contribute a few more metres in the mix.

At what point will governments actually start to do something? The UK government is going in the opposite direction!

#climatechange
#antarcticicesheet
#toriesdestroyingtheplanet
OCEAN ICE EUOct 20, 2023

🧊 What is Objective 4 of OCEAN:ICE? 🧊

In this #OCEANICEBreaker we explore objective 4 aiming to quantify #AntarcticIceSheet melt sensitivity to climate forcing and reduce the 'deep uncertainty' in freshwater flux and #SeaLevelRise projections to 2300 💙

Watch this OCEAN:ICE Breaker on our Youtube channel ▶️ https://youtu.be/gklDYdIp58Q

#HorizonEurope #OCEANICEImpact

OCEAN:ICE Objective 4 - OCEAN:ICE Breakers

YouTube