Antarctic Thwaites glacier sitting on above freezing water

[FrumiousBandersnatch]

On a side note almost all of the palm trees in my region froze to death this year. Everyone I've talked to about it has said that this has never happened before. Well I say "never say never." It might have happened at the peak of the last ice age. I hope that those scientists from the 70's were wrong. I hope that we're not heading for another ice age. It would make the potato famine look like we were simply denied our after dinner mints.

As I understand it, many of these unprecedented cold and hot spells are indirectly due to the effects of global warming on the circumpolar airstream or 'vortex'. Roughly speaking, this circulation is driven by the temperature difference between polar and temperate attitudes. This airstream corrals the polar air, partially separating it from temperate weather patterns, so that north of this airstream is very cold polar air and south of it is relatively warm temperate air.

As the pole is warming faster than the rest of the planet, the temperature difference driving this airstream is reducing. Consequently, the airstream is slowing, and as it does so, it is meandering more widely. As a result, these meanders bring polar air further south and for longer periods than previously. Similarly, northward meanders bring warm temperate air further towards the pole for longer periods - hence the unusually warm weather within the Arctic circle recently.

 

[durangodawood]

...On a side note almost all of the palm trees in my region froze to death this year. Everyone I've talked to about it has said that this has never happened before. Well I say "never say never." It might have happened at the peak of the last ice age. I hope that those scientists from the 70's were wrong. I hope that we're not heading for another ice age. It would make the potato famine look like we were simply denied our after dinner mints.

Dont worry. Despite the wilder temp swings here and there, the earths atmosphere as a whole is not experiencing any net cooling. Or perhaps i should say: worry about something else.

 

[Halbhh]

As I understand it, many of these unprecedented cold and hot spells are indirectly due to the effects of global warming on the circumpolar airstream or 'vortex'. Roughly speaking, this circulation is driven by the temperature difference between polar and temperate attitudes. This airstream corrals the polar air, partially separating it from temperate weather patterns, so that north of this airstream is very cold polar air and south of it is relatively warm temperate air.

As the pole is warming faster than the rest of the planet, the temperature difference driving this airstream is reducing. Consequently, the airstream is slowing, and as it does so, it is meandering more widely. As a result, these meanders bring polar air further south and for longer periods than previously. Similarly, northward meanders bring warm temperate air further towards the pole for longer periods - hence the unusually warm weather within the Arctic circle recently.

Nice explanation. I kinda vaguely remembered something like that from some little bit of quick glance reading (of dozens I glance at any day) one day from years ago, but it's good to have laid out usefully for folks.

 

[FrumiousBandersnatch]

Nice explanation. I kinda vaguely remembered something like that from some little bit of quick glance reading (of dozens I glance at any day) one day from years ago, but it's good to have laid out usefully for folks.

Thanks - I think it's a pretty crude description of a complex system, but it seems a reasonably effective way to visualise it.

 

[essentialsaltes]

Crucial Antarctic ice shelf could fail within five years, scientists say
Until recently, the ice shelf was seen as the most stable part of Thwaites Glacier, a Florida-sized frozen expanse that already contributes about 4 percent of annual global sea level rise. Because of this brace, the eastern portion of Thwaites flowed more slowly than the rest of the notorious “doomsday glacier.”

But new data show that the warming ocean is eroding the eastern ice shelf from below. Satellite images taken as recently as last month and presented Monday at the annual meeting of the American Geophysical Union show several large, diagonal cracks extending across the floating ice wedge.

“This eastern ice shelf is likely to shatter into hundreds of icebergs,” she said. “Suddenly the whole thing would collapse.”

The failure of the shelf would not immediately accelerate global sea level rise. The shelf already floats on the ocean surface, taking up the same amount of space whether it is solid or liquid.

But when the shelf fails, the eastern third of Thwaites Glacier will triple in speed, spitting formerly landlocked ice into the sea. Total collapse of Thwaites could result in several feet of sea level rise, scientists say, endangering millions of people in coastal areas.

 

[durangodawood]

Was it like 20 years ago when "conservatives" were arguing with all their might that warming wasnt even happening at all?

They were hoodwinked by internet propaganda like temp sensors in the wrong places and every other kind of lies and misdirections.

 

[essentialsaltes]

Was it like 20 years ago when "conservatives" were arguing with all their might that warming wasnt even happening at all?

They were hoodwinked by internet propaganda like temp sensors in the wrong places and every other kind of lies and misdirections.

Were? Many of them put their heads in the sand long ago, and still have not emerged. Florida and Texas and other states are now spending hundreds of millions on 'climate resiliency' so their Republican governors and legislatures don't have to say the forbidden phrase. But mitigating the effects of 'extreme weather events' is still being paid for with people's taxes. Declaring that the problem doesn't exist hasn't made the problem go away. But it will make it more expensive in the long run to pay for pounds of cure rather than ounces of prevention.

 

[Halbhh]

Crucial Antarctic ice shelf could fail within five years, scientists say
Until recently, the ice shelf was seen as the most stable part of Thwaites Glacier, a Florida-sized frozen expanse that already contributes about 4 percent of annual global sea level rise. Because of this brace, the eastern portion of Thwaites flowed more slowly than the rest of the notorious “doomsday glacier.”

But new data show that the warming ocean is eroding the eastern ice shelf from below. Satellite images taken as recently as last month and presented Monday at the annual meeting of the American Geophysical Union show several large, diagonal cracks extending across the floating ice wedge.

“This eastern ice shelf is likely to shatter into hundreds of icebergs,” she said. “Suddenly the whole thing would collapse.”

The failure of the shelf would not immediately accelerate global sea level rise. The shelf already floats on the ocean surface, taking up the same amount of space whether it is solid or liquid.

But when the shelf fails, the eastern third of Thwaites Glacier will triple in speed, spitting formerly landlocked ice into the sea. Total collapse of Thwaites could result in several feet of sea level rise, scientists say, endangering millions of people in coastal areas.

Yeah, after reading various articles on that ice shelf for a few years now, we've been getting the feeling/intuition we'd be seeing that process accelerating, and it's interesting to have a time estimate.

 

[Halbhh]

Were? Many of them put their heads in the sand long ago, and still have not emerged. Florida and Texas and other states are now spending hundreds of millions on 'climate resiliency' so their Republican governors and legislatures don't have to say the forbidden phrase. But mitigating the effects of 'extreme weather events' is still being paid for with people's taxes. Declaring that the problem doesn't exist hasn't made the problem go away. But it will make it more expensive in the long run to pay for pounds of cure rather than ounces of prevention.

Speaking of Texas and 'resiliency' it will be interesting to see whether or not the companies have 'hardened' their gas and electric infrastructure much, if another serious test happens like the jet stream sets up just right again and so on.

 

[essentialsaltes]

The Thwaites Glacier, capable of raising sea level by several feet, is eroding along its underwater base as the planet warms. In a study published Monday in the journal Nature Geoscience, scientists mapped the glacier's historical retreat, hoping to learn from its past what the glacier will likely do in the future.

'Doomsday glacier,' which could raise sea level by several feet, is holding on 'by its fingernails,' scientists say

 

[essentialsaltes]

Ocean water is rushing miles underneath the ‘Doomsday Glacier’ with potentially dire impacts on sea level rise​

Thwaites, which already contributes 4% to global sea level rise, holds enough ice to raise sea levels by more than 2 feet. But because it also acts as a natural dam to the surrounding ice in West Antarctica, scientists have estimated its complete collapse could ultimately lead to around 10 feet of sea level rise — a catastrophe for the world’s coastal communities.

Many studies have pointed to the immense vulnerabilities of Thwaites. Global warming, driven by humans burning fossil fuels, has left it hanging on “by its fingernails,” according to a 2022 study. [i.e. previous post]

This latest research adds a new and alarming factor into projections of its fate.

A team of glaciologists — led by scientists from the University of California, Irvine — used high resolution satellite radar data, collected between March and June last year, to create an X-ray of the glacier. This allowed them to build a picture of changes to Thwaites’ “grounding line,” the point at which the glacier rises from the seabed and becomes a floating ice shelf. Grounding lines are vital to the stability of ice sheets, and a key point of vulnerability for Thwaites, but have been difficult to study.

They observed seawater pushing beneath the glacier over many miles, and then moving out again, following the daily rhythm of the tides. When the water flows in, it’s enough to “jack up” the surface of the glacier by centimeters, Rignot told CNN.

One uncertainty to be unraveled is whether the rush of seawater beneath Thwaites is a new phenomenon or whether it’s been significant but unknown for a long time, said James Smith, a marine geologist at the British Antarctic Survey, who was not involved in the study.

“Either way, it’s clearly an important process that needs to be incorporated into ice sheet models,” he told CNN.

--

Connecting this to the OP, if I'm making a valid conclusion: the glacier is not just partly sitting on warmer water, but that water is flushing in and out with the tides. That would seem to accelerate the melting. If the water were just trapped there, well when the water melts the ice, the ice makes the water colder, so there's less temperature difference left to melt further ice. But if the water keeps getting flushed in and out and replenished from the ocean, that's transferring more thermal energy into the ice every day.

 

[AV1611VET]

Thwaites, which already contributes 4% to global sea level rise, holds enough ice to raise sea levels by more than 2 feet. But because it also acts as a natural dam to the surrounding ice in West Antarctica, scientists have estimated its complete collapse could ultimately lead to around 10 feet of sea level rise — a catastrophe for the world’s coastal communities.

We live in exciting times, don't we!?

Psalm 98:7 Let the sea roar, and the fulness thereof; the world, and they that dwell therein.
8 Let the floods clap their hands: let the hills be joyful together
9 Before the LORD; for he cometh to judge the earth: with righteousness shall he judge the world, and the people with equity.

 

[Astrid]

I am counting on all the global ice melting. That way I end up with beach front property and a delightful little creek that will take a nice ketch. I also get to snub my nose at all the global warming deniers, so it is a win-win situation.

Not all!! Do you know how HOT
it is in Hong Kong at this time of year???

 

[AV1611VET]

Do you know how HOT it is in Hong Kong at this time of year???

As hot as it was in Hong Kong the same time last year?

 

[essentialsaltes]

Antarctica’s ‘Doomsday Glacier’ Isn't as Vulnerable to Collapse as We Thought​

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

Thwaites Glacier holds enough ice to raise global sea level by more than 2 feet(0.65 meters). Once Thwaites starts to destabilize, it also will destabilize neighboring glaciers. So, what happens to Thwaites affects all of the West Antarctic Ice Sheet, and that affects sea-level rise along coastlines everywhere.

If Thwaites’ ice shelf were to collapse, it would expose a very tall ice cliff facing the ocean along its 75-mile (120-kilometer) front. There is only so much force that ice can sustain, so if the cliff is too tall, it will collapse into the ocean.

[which would expose a new cliff, which would collapse, and a domino effect might set in]

When the theory of marine ice cliff instabilitywas first introduced, it used a rough approximation of how ice cliffs might collapse once the ice shelf was gone.

Studies since then have determined that ice cliffs won’t fail systematicallyuntil the ice is about 442 feet (135 meters) high. Even at that point, they would fail more slowly than projected until they became much taller.

Our results show that if Thwaites’ entire ice shelf collapsed today, its ice front would not rapidly retreat inland due to marine ice cliff instability alone.

We found that Thwaites would remain fairly stable at least through 2100.

The results call into question some recent estimates of just how fast Thwaites might collapse. That includes a worst-case scenario that the Intergovernmental Panel on Climate Change mentioned in its latest assessment reportbut labeled as “low likelihood.”

 

[AV1611VET]

Thwaites Glacier holds enough ice to raise global sea level by more than 2 feet(0.65 meters). Once Thwaites starts to destabilize, it also will destabilize neighboring glaciers. So, what happens to Thwaites affects all of the West Antarctic Ice Sheet, and that affects sea-level rise along coastlines everywhere.

Ya -- um -- no.

Here's why:

 

[essentialsaltes]

Ya -- um -- no.

Here's why:

Ya um yes.

The glacier is not floating on water. It is on land.

If it melts, it runs into the water, raising the level.

 

[sjastro]

Ya um yes.

The glacier is not floating on water. It is on land.

If it melts, it runs into the water, raising the level.

If only Archimedes was mentioned in the Bible.

 

[AV1611VET]

The glacier is not floating on water. It is on land.

If it melts, it runs into the water, raising the level.

Did you specify that in your post?

ETA: Okay, I just checked the definition of "glacier." It originates on land, then slides into the water from its own weight.

My bad.