Antarctic Ice Discussion

[knocker]

Studies shed new light on Antarctica’s future contribution to sea level rise

A widely reported study in 2016 that suggested Antarctica could add more than a metre to sea levels by 2100 was likely an “overestimate”, new research says.

The original study, published in Nature, grabbed headlines with the finding that Antarctic ice was at risk from “marine ice-cliff instability”, which would see towering cliffs of glacier ice collapse into the ocean under their own weight.

A new Nature study revisits the theory, finding that the “jury’s definitely still out” on ice-cliff instability coming into play this century, the lead author tells Carbon Brief.

A second paper, also in Nature, says that melting of the Greenland and Antarctic ice sheets could have dramatic knock-on impacts for the climate. These include the potential weakening of the Atlantic current that brings warm water up to Europe from the tropics, and a positive feedback loop that reinforces melting of Antarctic ice.

The papers together suggest a likely contribution of around 15cm from melting Antarctic ice by the end of this century, with a 5% likelihood that it will exceed 39cm under a high-emissions scenario.

https://www.carbonbrief.org/studies-shed-new-light-on-antarcticas-future-contribution-to-sea-level-rise

[Snowyowl9]

High geothermal heat beneath West Antarctica glacier responsible for its melting.

In a new study 

High geothermal heat flow beneath Thwaites...

WWW.NATURE.COM

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The Amundsen Sea sector, Antarctica, is underlain by shallow Curie depths – where the magnetic properties of rocks change – according to airborne magnetic data. This suggests high geothermal heat flow in this...

This substantial geothermal heat flow, in turn, are due to the fact that the glacier lies in a tectonic trench, where the Earth’s crust is significantly thinner than it is e.g. in neighbouring East Antarctica.

Heating from below thats what I always said....

[BornFromTheVoid]

On 22/08/2021 at 10:21, Snowyowl9 said:

High geothermal heat beneath West Antarctica glacier responsible for its melting.

In a new study 

High geothermal heat flow beneath Thwaites...

WWW.NATURE.COM

---

The Amundsen Sea sector, Antarctica, is underlain by shallow Curie depths – where the magnetic properties of rocks change – according to airborne magnetic data. This suggests high geothermal heat flow in this...

This substantial geothermal heat flow, in turn, are due to the fact that the glacier lies in a tectonic trench, where the Earth’s crust is significantly thinner than it is e.g. in neighbouring East Antarctica.

Heating from below thats what I always said....

Identifying high heat flow doesn't mean it's responsible for increased melting in recent decades. This high heat flow has been ongoing for millions of years. These refined estimates will be very useful for understanding the flow dynamics of certain glaciers (as the heat will increase basal melting and thus sliding of the ice sheet), but it doesn't explain any recent changes.

[Snowyowl9]

58 minutes ago, BornFromTheVoid said:

Identifying high heat flow doesn't mean it's responsible for increased melting in recent decades. This high heat flow has been ongoing for millions of years. These refined estimates will be very useful for understanding the flow dynamics of certain glaciers (as the heat will increase basal melting and thus sliding of the ice sheet), but it doesn't explain any recent changes.

Thanks for your reply....

[ANYWEATHER]

Nasa back in 2005 showed Antartica cooling and from there on showed a warming trend.! Its clear that there has been a cooling trend for some time.....

[Gowon]

South Pole froze over in coldest winter on record

WWW.MSN.COM

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The south pole had its coldest winter since record keeping began in 1957.

 

[BLAST FROM THE PAST]

On 04/09/2021 at 12:08, ANYWEATHER said:

Nasa back in 2005 showed Antartica cooling and from there on showed a warming trend.! Its clear that there has been a cooling trend for some time.....

Official, Antarctica and particularly the South Pole region has just had the COLDEST 6 months on record.  No warming, smashed the 1976 record.  It isn’t warming down there…this on the back of recent Record ice extent years. There’s a spanner in the AGW works…make no doubt about that  

[Mapantz]

On 06/10/2021 at 19:52, BLAST FROM THE PAST said:

 There’s a spanner in the AGW works…make no doubt about that  

No, there isn't.

[Derecho]

The Antarctic Sea Ice winter season has been an interesting one. Near record highs in extent back in August disappeared by September and we are currently well below average for the time of year. Amundsden has indeed seen its coldest 6 months on record extending back to 1957. Antarctica wasn't actually far off from setting an all time cold record later on in September. 

There has been quite varied anomalies over the last 6 months geographically over Antarctica, one side of Antarctica can be way above normal, the other well below at the same time. Overall the Antarctic has been below average in the last 3 months as seen in the graph below.

However I don't believe anything is afoot and I don't see why anything would be. Global temperatures are still near record highs and this is a classic indicator of a very strong polar vortex over the south pole keeping the cold air bottled up at high latitudes. Lets hope the Arctic doesn't behave in a similar manner this winter.

Edited October 6, 2021 by Quicksilver1989

[Derecho]

11 minutes ago, ANYWEATHER said:

Indeed! But some Punters bang on and on and on , about Global Warming making places like the USA I read recently likely to have severe cold has of recent years likely to be the norm ,when we were told just a year or two back that  cold Winters will be a thing of the past. !!! It must be Snowballs in the face of climate alarmists and global warming enthusiasts that things are not going to plan.....

You seem to be unable to separate localised weather from global climate variations. Areas can still have notable cold spells in a warming climate. Do you seriously believe that global warming is over just because the USA has the odd cold winter?

Notable cold spells can still occur but the extent of the warm spells and their frequency outweigh the cold and hence you have a warming trend, with more warm extremes in the future. Does this graph really look like it is snowballs in the face of climate scientists?

[Mixer 85]

9 hours ago, Quicksilver1989 said:

You seem to be unable to separate localised weather from global climate variations. Areas can still have notable cold spells in a warming climate. Do you seriously believe that global warming is over just because the USA has the odd cold winter?

Notable cold spells can still occur but the extent of the warm spells and their frequency outweigh the cold and hence you have a warming trend, with more warm extremes in the future. Does this graph really look like it is snowballs in the face of climate scientists?

To be fair though we should take note of what’s happening in Antarctica and be grateful of what is no doubt a good thing. 6 months of anomalous cold spread over an entire continent is by no means localised weather variation (not suggesting you implied that). 
 

[Methuselah]

58 minutes ago, Mixer 85 said:

To be fair though we should take note of what’s happening in Antarctica and be grateful of what is no doubt a good thing. 6 months of anomalous cold spread over an entire continent is by no means localised weather variation (not suggesting you implied that). 
 

Why is an Antarctican cold spell 'no doubt a good thing'? Is weather, the world over, not made up of 'spells'?

[Mixer 85]

2 hours ago, Ed Stone said:

Why is an Antarctican cold spell 'no doubt a good thing'? Is weather, the world over, not made up of 'spells'?

Perhaps it’s a good thing if one hasn’t subscribed to the Armageddon narrative. Perhaps it’s a good thing if one is hoping for the mainstream science to be proven wrong.
 

Most importantly, it’s much easier to see it as a good thing if it’s seen for what it actually is rather than a mere ‘cold spell’. A whole continent largely below average for the past 6 months. Coldest September ever recorded and a ‘mere’ 0.6 degrees away from a lowest temperature ever recorded. How on earth can this be construed as a‘cold spell’?

An Assessment of ERA5 Reanalysis for Antarctic Near-Surface Air Temperature

WWW.MDPI.COM

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The European Center for Medium-Range Weather Forecasts (ECMWF) released its latest reanalysis dataset named ERA5 in 2017. To assess the performance of ERA5 in...

This reports 40yrs of good things, or a 40yr ‘cold spell’ depending on your political orientation. 

[Methuselah]

8 minutes ago, Mixer 85 said:

Perhaps it’s a good thing if one hasn’t subscribed to the Armageddon narrative. Perhaps it’s a good thing if one is hoping for the mainstream science to be proven wrong.
 

Most importantly, it’s much easier to see it as a good thing if it’s seen for what it actually is rather than a mere ‘cold spell’. A whole continent largely below average for the past 6 months. Coldest September ever recorded and a ‘mere’ 0.6 degrees away from a lowest temperature ever recorded. How on earth can this be construed as a‘cold spell’?

An Assessment of ERA5 Reanalysis for Antarctic Near-Surface Air Temperature

WWW.MDPI.COM

---

The European Center for Medium-Range Weather Forecasts (ECMWF) released its latest reanalysis dataset named ERA5 in 2017. To assess the performance of ERA5 in...

This reports 40yrs of good things, or a 40yr ‘cold spell’ depending on your political orientation. 

I can assure you that, as a reformed Climate Change Denier, politics have nothing at all to do with it. Science, on the other hand, has everything to do with it!

The world is getting warmer, whether you like it or not. Or, are you now going to tell me that modern thermometers have an inbuilt bias?

[Derecho]

31 minutes ago, Mixer 85 said:

Perhaps it’s a good thing if one hasn’t subscribed to the Armageddon narrative. Perhaps it’s a good thing if one is hoping for the mainstream science to be proven wrong.
 

Most importantly, it’s much easier to see it as a good thing if it’s seen for what it actually is rather than a mere ‘cold spell’. A whole continent largely below average for the past 6 months. Coldest September ever recorded and a ‘mere’ 0.6 degrees away from a lowest temperature ever recorded. How on earth can this be construed as a‘cold spell’?

An Assessment of ERA5 Reanalysis for Antarctic Near-Surface Air Temperature

WWW.MDPI.COM

---

The European Center for Medium-Range Weather Forecasts (ECMWF) released its latest reanalysis dataset named ERA5 in 2017. To assess the performance of ERA5 in...

This reports 40yrs of good things, or a 40yr ‘cold spell’ depending on your political orientation. 

I don't see how you can come to such a dramatic conclusion given global temperatures aren't doing anything irregular. It is not unusual for areas of the globe in winter months to have a period of below average temperatures, just look at the cold wave that impacted Texas this February. Even the cold winter months of 2010 occurred on what was at the time the warmest year on record.

2015 saw the warmest February on record globally at the time, yet the eastern US had record breaking cold. The cold weather over Antarctica this summer also shows up nicely.

Climate change isn't an event where someone suddenly flicks a switch and an apocalyptic event takes us all out at any one moment, it is something that is seen over longer timescales with an increasing number of risks occurring that humans will have to adapt to.

[knocker]

Interannual SAM modulation of Antarctic sea ice extent does not account for its long-term trends, pointing to a limited role for ozone depletion

Abstract

The expansion of Antarctic sea ice since 1979 in the presence of increasing greenhouse gases remains one of the most puzzling features of current climate change. Some studies have proposed that the formation of the ozone hole, via the Southern Annular Mode, might explain that expansion, and a recent study highlighted a robust causal link between summertime Southern Annular Mode (SAM) anomalies and sea ice anomalies in the subsequent autumn. Here we show that many models are able to capture this relationship between the SAM and sea ice, but also emphasize that the SAM only explains a small fraction of the year-to-year variability. Finally, examining multidecadal trends, in models and observations, we confirm the findings of several previous studies and conclude that the SAM – and thus the ozone hole – are not the primary drivers of the sea ice expansion around Antarctica in recent decades.

Plain Language Summary

Unlike its Arctic counterpart, sea ice around Antarctica has been growing since 1979, even as the levels of carbon dioxide in the atmosphere have increased. Given that the ozone hole formed over the South Pole around the same time, one is led to ask whether the ozone hole may be responsible for the growth of Antarctic sea ice (recall that there is no ozone hole over the North Pole). In this study, looking at both models and observations, we show that the ozone hole is capable of affecting the surface winds and these, in turn, can make sea ice expand. However, the magnitude of this effect is small. Also since the ozone hole started healing after the year 2000, while Antarctic sea ice kept expanding, we conclude that ozone depletion is not the main reason for the expansion of Antarctic sea ice in recent decades.

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021GL094871

[knocker]

13 hours ago, Polar. said:

EDIT: This post was removed by the Moderating Team.

I appreciate that Polar and also that all the points raised by deniers have been comprehensively dealt with in here, and elsewhere, over the years. But as far as I'm aware this still reputes to be a scientic based website, particularly this area,  that welcomes differing opinions provided they are supported by logical scientific argument with references or links. We now appear to be back to the old days of opinionated drivel. Being told I do not fit into the NW community seems rather a blessing these days.

Edited October 22, 2021 by Blessed Weather
Post in quote box was removed.

[Wheezer]

Fairly new here, but would like to know the definition of the words "Climate Denier" as it is used so often . Forgive me if this has been explained in detail at an earlier stage

[Blessed Weather]

I have just removed or edited many posts that were either off topic and/or climate change denial discussions. This thread is for serious discussion about Antarctic Ice levels/growth/retreat.

Posts in here should be based on information from a reputable source so please make sure you can back up your claims/details with links to relevant papers and articles. Links to blogs are acceptable provided they contain actual scientific detail and not just a personal view.

Thank you.

[Ultrafour]

NSIDC 15% Antarctic sea ice graph shows a marked drop since the high levels in Mid August. Can anybody provide a viable explanation.

[knocker]

41 minutes ago, Ultrafour said:

NSIDC 15% Antarctic sea ice graph shows a marked drop since the high levels in Mid August. Can anybody provide a viable explanation.

To the best of my knowledge, which is quite limited, there is no definitive answer, as yet, to the variation of Antarctic sea ice in the satellite era. It is an area of ongoing research and numerous papers have been written, such as the one above.

[knocker]

https://www.youtube.com/watch?v=XQ8QCCdevLI

[knocker]

Ice shelf holding back keystone Antarctic glacier within years of failure

An alarming crackup has begun at the foot of Antarctica’s vulnerable Thwaites Glacier, whose meltwater is already responsible for about 4% of global sea level rise. An ice sheet the size of Florida, Thwaites ends its slide into the ocean as a floating ledge of ice 45 kilometers wide. But now, this ice shelf, riven by newly detected fissures on its surface and underside, is likely to break apart in the next 5 years or so, scientists reported today at a meeting of the American Geophysical Union.

The most dramatic sign of impending failure is a set of diagonal fractures that nearly span the entire shelf. Last month, satellites spotted accelerating movement of ice along the fractures, says Erin Pettit, a glaciologist at Oregon State University, Corvallis, who is part of a multiyear expedition studying the glacier. The shelf is a bit like a windshield with a series of slowly opening cracks, she says. “You’re like, I should get a new windshield. And one day, bang—there are a million other cracks there.”

https://www.science.org/content/article/ice-shelf-holding-back-keystone-antarctic-glacier-within-years-failure

 

[Kirkcaldy Weather]

 

[Raindrops]

I'm surprised this hasn't been posted.

First look at giant A81 iceberg from Antarctica's Brunt Ice Shelf | British Antarctic Survey