The 2023/2024 Antarctic melting season

[I’M IN LOVE WITH A RAGER]

Due to the increased attention (and discussion) the Antarctic Sea Ice has been drawing over the last year or two, it seems warranted to open a more casual general thread. Although it feels like a break from tradition, so have the outcomes of multiple of the last 5-10 years of Southern Hemisphere sea ice melting.

Hopefully this thread can keep the raw data separate from the wide variety of other topics, and can ultimately allow members to more easily locate season-specific posts in the future. I am very curious whether the next few months will maintain/grow the current extent and area anomalies, or whether we will see somewhat of a return to normalcy. Either way, it is sure to be worth watching.

[oren]

Thanks, IILWR.
It's nice that we get good participation in the AA sea ice discussions, though it would have been better for things to be very stable and for posters to be bored senseless.
To all, please shift discussion and occasional seasonal chatter here, and leave the data thread to data, as is the habit in the Arctic threads.

[HapHazard]

Good idea, thanks Rager. Most of us much prefer to keep the chatter out of the data threads. And I bet there will be a fair bit of chatter here this melt season. Looks like one helluva head start this time around...

[Comradez]

One way of thinking about the antarctic sea ice right now is that the melt is about 1 month ahead of last year.  As per Cryosphere Computing, 2022 did not approach 12.5 million km^2 until late October.  2023 is almost already there.  Unless there is a reversal ASAP, 2023/2024 will surely dip below 1 million km^2.

[kiwichick16]

@  comradez  +1   ..... perhaps it might wobble around near the current levels and reduce the gap a bit , but unfortunately everything is against it at the moment , with high sea and air temps , and heading into an El Nino , on top of the other factors of lower sulpher emissions from shipping , the Tongan volcanic eruption , slowing AABW flow and the ongoing GHG emissions .

On top of that the societal and political inertia .....

[sadmird]

One way of thinking about the antarctic sea ice right now is that the melt is about 1 month ahead of last year.  As per Cryosphere Computing, 2022 did not approach 12.5 million km^2 until late October.  2023 is almost already there.  Unless there is a reversal ASAP, 2023/2024 will surely dip below 1 million km^2.

I am not so sure about the bold part with i.e. Extent almost surely dipping below 1,000,000 km², because Antarctica has significant areas of thick, landfast ice that are so hard to melt (at all). It's a whole different thing when compared to the Arctic, where such areas are insignificant.
I think gero was talking about it on multiple occasions in the past, but am unable to find these posts to verify the estimated area/extent that is technically guaranteed to stay frozen no matter what, due to these specific dynamics. There are large areas of such landfast ice, primarily in Ross and Weddell seas.

It depends on all other ice melting besides those areas in order to get under 1,000,000 km² and I feel it's unlikely for that to happen even with the current preconditioning and record low extent/area, but am open to hear other people's opinion about this matter.

[Darvince]

All I know about this season in the Antarctic, is that the Antarctic has always defied expectations before, and I am sure it will do that again this year.

[kiwichick16]

@  sadmird ....there is a significant difference between sea ice and ice shelves / sheets

https://www.antarcticglaciers.org/glacier-processes/glacier-types/ice-shelves-sea-ice-icebergs/

[oren]

I read sadmird's comment as referring to landfast sea ice, not to ice shelves. Not sure how much such ice exists in the Antarctic. In any case, I think the bottom line is correct. Weddell sea ice is very difficult to melt, and to get below 1Mkm2 of extent will require very extraordinary circumstances.
OTOH, we are living in extraordinary times, so nothing can be ruled out.

[kiwichick16]

@ Oren ...yes extraordinary times ..... Weddell looking cold today  ......areas around West Antarctica reading at plus 20 degrees above average ..... and continental average above 2 SD again .

the one thing we can be sure of, is that more ice is at risk while we keep pumping GHG's into the system

[John_the_Younger]

By the way, welcome sadmird to the ASIF.  You seem familiar with the site - good on you!  We look forward to you continuing to share insights.

[Renerpho]

Welcome sadmird. 

It's a good idea to give Antactica a dedicated melting season thread, like we do for the Arctic. We don't really understand what's happening in the Arctic ocean, but in comparison, Antarctica is still "Terra Australis Incognita".

@oren: I am not entirely sure yet what belongs here and what should go to the "What's new in Antarctica?" thread. Maybe we'll figure it out as we go. Any good advice?

[oren]

In general, things related to Antarctic sea ice should go here. Data thread should be left for data posts and comments about data processing and calculation (but not about the results). The What's new thread fits things that are new, rather than day to day stuff. Light seasonal chatter can go here for the time being, perhaps at some point there will also be a freeform chatter thread if we get too much of that.

[Gray-Wolf]

I get a notion that this thread will see a lot of activity over 23/24?

With the Southern Hemisphere seeming to take over from the mad heat of the North over its Summer then a start point 5 UK's lower than average isn't good eh?

Let's see what the Southern Ocean can do to ALL the ice shelf this melt season eh?

[kassy]

This has been building for a while but now it is clearly on the radar.
The big question is how bad it will be and the bonus question is what those changes will then do to the glaciers.

The big problem is the ice falling of Antarctica which will raise sea levels. The rather unprecedented change in sea ice also makes for a similar change for many of the glaciers that were more protected before. At some point we will have MISI and MICI GIFs and papers.

What is happening on Earth is far faster then most of our projections and this seasons ice loss is not going to help. It is a lot of albedo loss over a short term.

[kiwichick16]

i keep hoping the losses might at least slow down   ....this is not looking good    ....daylight hours at Scott base   12.38 today  and solar radiation peaked at 250  watts/ sq metre today

[gerontocrat]

One to watch this melting season will be Albedo Warming Potential (AWP) from Nico Sun at https://cryospherecomputing.com/NRTawp-south.html

He hasn't opened the 2023-24 melting season yet, so I can show the 2022-23 graphs and map of the AWP anomaly. The graphs show the effect of the 2022-23 low sea ice area.

Given where we are on extreme low sea ice area at moment, the 2023-24 melting season looks like producing AWP anomalies that will force Nico Sun to increase the y-axis values on the graphs.

[Alexander55]

Just a year ago there was a study that Thwaites glacier was holding on , on his fingertips. And the situation did'nt move in the right direction since than.

[Alexander55]

Let's assume Thwaites collapses at some point. And sea level rises 70 cm. That means the sea will lift all Antartica glaciers at the point where they meet the ocean. What kind of effects would that have ?

[kassy]

Hopefully not this season but we can´t rule it out either.
When it collapses much more ice will come off Antarctica. Also it will not be the only place where ice mass loss accelerates. The 70 cm builds over time but as Antarctica loses masses it also exerts less force on the surrounding waters. So that means that local sea levels decrease somewhat while sea levels further away rise more. This is gravitational fingerprinting.

The 70 cm will be slow and steady rises over X years. Whatever happens to glaciers mostly depends on the underlying bathymetry. And depending on how long X is the increase in temperature of the water might be a bigger problem.

[HapHazard]

More interesting things.

[oren]

Let's assume Thwaites collapses at some point. And sea level rises 70 cm. That means the sea will lift all Antartica glaciers at the point where they meet the ocean. What kind of effects would that have ?

Not in this thread.

[oren]

The numbers provided in the data thread (thanks Gero) paint a very worrying picture. Looking at the extent chart, it appears the melting season has begun with the same trajectory but about a month early. However, while searching for straws to clutch, I looked at the single-day area numbers, and it appears the situation is a bit less dire than it seems.

[kiwichick16]

Usually area only starts falling from around this date......the difference being the million sq kms of missing ice, with open water absorbing energy instead of ice reflecting it

[Unaffiliated]

Sorry if I'm asking to much of this forums data providers.
I feel the best way for me to understand and express to other laymen( especially denialist) the absurdity of the Antarctic sea ice condition is to compare it directly to other extreme anomalies
Could I get data points such as maximum and average deviation from previous record expressed as percentage and total area. And of course Consecutive days at record
I suppose we should be looking at Antarctic
2023 freeze season(current)
2022/23 melt season
2016
2014 highs
Arctic
2007
2012
And if proper parameters adjust can be made 2013 2014 highs
(I know 13 and 14 were not records) but their deviation from the long term trend and current 20 year average was remarkable we could use on of those base line or reduce the data set to start in 2006 to force them as record highs.

[Renerpho]

Sorry if I'm asking to much of this forums data providers.
I feel the best way for me to understand and express to other laymen( especially denialist) the absurdity of the Antarctic sea ice condition is to compare it directly to other extreme anomalies
Could I get data points such as maximum and average deviation from previous record expressed as percentage and total area. And of course Consecutive days at record
I suppose we should be looking at Antarctic
2023 freeze season(current)
2022/23 melt season
2016
2014 highs
Arctic
2007
2012
And if proper parameters adjust can be made 2013 2014 highs
(I know 13 and 14 were not records) but their deviation from the long term trend and current 20 year average was remarkable we could use on of those base line or reduce the data set to start in 2006 to force them as record highs.

I don't quite understand what you're asking for. There is Gero's https://forum.arctic-sea-ice.net/index.php/topic,1759.msg382504.html#msg382504, of course. Does this go in the right direction? Please also have a look at the tables in Gero's recent posts, maybe you find the information you're looking for. If you can point to a specific row/column in a table, it will be much easier to create a graph that may illustrate that data.

EDIT: As a kind of ethical point, I suggest to never artificially shorten your data set to make a point. It will only backfire.

[Unaffiliated]

Raw data and large numbers have a tendency to wash over people. By presenting information solely focused on the most extreme conditions I believe is the best way to spread understanding of how crazy things are now. If we can make a data set of an "average extreme " and show now as the outlier in a data set of outliers.
 Artic in 2012 was considered so extrem that it is sometimes filtered out as an extremely outlier. But this year in Antarctica has about an equal max deviation from the previous record but has presisted for twice as long.
I find the consecutive count to be excellent evidence of a major regimen shift opposed to an isolated event. Over 150day at new years (Imagine day 367)
The consistent and stable downward trend in the Arctic will mask any future extreme highs as they will not be record highs and neither was 2013 but it was still an extrem freeze/nonmelt event that would provide more perspective in a comparison of historically extreme conditions.
 Perhaps global Extent and area for 2013/14 should be include as ice levels were high at both polls.
I have been trolling this form for a few months and get a deeper understand with every post I read and chart I evaluate but I am more science literate(not super science literate) and climate concerned then most my peers who i wish to influence.

A mod should move this conversation out of the data thread

<Moved here, for lack of a better thread. O>

[Ttaski43]

To @Unaffiliated in the data thread, I guess you are asking for a plot with a running value of sigma, the deviation from normal. While this could be done, the scientific value of such a chart is not very good. Usually they are calculated for one specific event in attribution studies, i.e. is the event abnormal considering all previous knowledge. Scientifically a better way to calculate sigma would be to include all data to the baseline, and this would mean the earlier values would change after a very abnormal event. OK, memories of past fade, but not that much. The whole spreadsheet would need to be adjusted just for this, and be recalculated everytime data is added. Some scientists might keep up with the flow of data this way, but probably no one here.

Quick estimate for lines for new spreadsheets for each part of the ocean is 300000. (45 years/daily for 17 areas)

[gerontocrat]

I added the number of consecutive days sea ice has been at lowest for the day on the daily post because it was no big deal to add it on autopilot.

More importantly, a recent paper suggested that persistence of the record daily lows was a signficant factor in leading to their suggestion that Antarctic sea ice was possibly entering a new state, so it is a metric of value.

On the data requests from Unaffiliated, all I can say is that every month I post various monthly summary graphs and tables, and every year annual summaries on which extreme events are clearly seen.

But I have just about reached my limit. There are so many other aspects of climate change and our response to it that fascinate me that none can receive undivided attention. I have to go shopping sometimes.

ps: A spreadsheet of 30,000 lines or an array of linked files, plus a multitude of formulae to analyse it, would kill my home computer which already groans from time to time.

[kiwichick16]

Re   ... el nino ....2016 was an El Nino year  ....and is currently 2nd lowest for area

[kiwichick16]

El Nino could melt more ice

https://eos.org/articles/supercharged-el-nino-could-speed-up-southern-ocean-warming

[kiwichick16]

@  gero  ....hope you get some sleep at some point......after the shopping of course

[oren]

An AMSR2 animation of sea ice concentration and movement around Antarctica, courtesy of the Alfred Wegener institute (AWI), based on the SIC-LEADS algorithm.
Many thanks to seaice.de for making this available.
Click to animate and click again for maximum resolution.
Source is mirrored on https://seaice.de/AMSR2_Antarctic_SIC-LEADS.gif

[FredBear]

Interesting watching the icebergs off the tip of the Antarctic Peninsular on the AMSR2 animation.
D28 is already clear of the pack ice and a smaller iceberg chases after it.
Then D30A also escapes from the edge of the pack ice, then visits Elephant Island before chasing after D28 northwards (with the smaller 'berg switching around and ending up trailing both).
Meanwhile the huge A23A continues to plough through the pack ice (with varying clearances) as it travels northwards across 65⁰S during this sequence.

I did try looking at the iceberg tracking facility on Worldview but this has not been working recently.

[John_the_Younger]

Meanwhile the huge A23A continues to plough through the pack ice (with varying clearances) as it travels northwards across 650S during this sequence.

Just to help others spot it, A23A is a little to the right of 60W (and the Antarctic Peninsula) - worth watching!

[gerontocrat]

Nico Sun has started the 2023-24 AWP season graphs & maps at https://cryospherecomputing.com/NRTawp-south.html

As you can see from the attached graphs and map, Albedo Warming Potential (AWP) starts the season at a very high level due to the absence of sea ice area - with the exception being the BellinghausenAmundsen sea.

[oren]

Interesting watching the icebergs off the tip of the Antarctic Peninsular on the AMSR2 animation.
D28 is already clear of the pack ice and a smaller iceberg chases after it.
Then D30A also escapes from the edge of the pack ice, then visits Elephant Island before chasing after D28 northwards (with the smaller 'berg switching around and ending up trailing both).
Meanwhile the huge A23A continues to plough through the pack ice (with varying clearances) as it travels northwards across 65⁰S during this sequence.

I did try looking at the iceberg tracking facility on Worldview but this has not been working recently.

I think I am also seeing B22-A strolling around the Amundsen Sea, well within the pack.

[kiwichick16]

article on Stuff  .....nz  news website....

https://www.stuff.co.nz/environment/climate-news/132682032/10-new-zealands-of-antarctic-ice-lost-in-alarming-drop-off-a-cliff

[vox_mundi]

Over 40% of Antarctica's Ice Shelves Reduced In Volume Over 25 Years, Scientists Say
https://phys.org/news/2023-10-antarctica-ice-shelves-volume-years.html



....Some of the biggest ice losses were observed on the Getz Ice Shelf, where 1.9 trillion metric tons of ice were lost over the 25-year study period. Just 5% of that was due to calving, where large chunks of ice breakaway from the shelf and move into the ocean. The rest was due to melting at the base of the ice shelf.

Similarly on the Pine Island Ice Shelf, 1.3 trillion metric tons of ice were lost. Around a third of that loss—450 billion metric tons—was due to calving. The rest due to melting from the underside of the ice shelf.

In contrast, the Amery Ice Shelf—on the other side of Antarctica—gained 1.2 trillion metric tons of ice. It is surrounded by much colder waters.

Benjamin Davison et al, Annual mass budget of Antarctic ice shelves from 1997 to 2021, Science Advances (2023).
https://www.science.org/doi/10.1126/sciadv.adi0186

[Renerpho]

Benjamin Davison et al, Annual mass budget of Antarctic ice shelves from 1997 to 2021, Science Advances (2023).
https://www.science.org/doi/10.1126/sciadv.adi0186

Yet another result that I'd love to see extended to the present. What happened in Antarctica in 2022 and 2023 was crazy, and must have had an impact on those numbers.

[gerontocrat]

Antarctic Albedo Warming Potential (AWP)

From Nico Sun's 2023-24 AWP season graphs & maps at https://cryospherecomputing.com/NRTawp-south.html

As you can see from the attached graphs and map, Albedo Warming Potential (AWP) is very high from the start of the season and is increasing rapidly - with the exception being the BellinghausenAmundsen sea.

Entirely due to the absence of sea ice.

[VeliAlbertKallio]

Perhaps it would be useful to look at the most landfast sea ice areas and exclude them from melting projections, perhaps higher latitude Weddell Sea and other areas where sea ice doesn't easily break off. In other areas, we at Sea Research Society expect new records losses being made once again at the next sea ice area minimum point. The extent outside, loose ice, will face torch also this year..

[kiwichick16]

20 hours daylight time at Scott Base today ......24 hours daylight from the 23rd October

[kassy]

I guess we will test the limits this year.

[Phil.]

I guess we will test the limits this year.

I'm sure we will, last year was the record minimum and currently the area is 3 weeks and ~1million sqkm ahead.

[Chris83]

  There is an immense ozone hole this year.
In theory, it will keep the continent much colder ..But will it impact the sea ice?

https://www.livescience.com/planet-earth/weather/one-of-the-biggest-on-record-ozone-hole-bigger-than-north-america-opens-above-antarctica

[oren]

An AMSR2 animation of sea ice concentration and movement around Antarctica, courtesy of the Alfred Wegener institute (AWI), based on the SIC-LEADS algorithm.
Many thanks to seaice.de for making this available.
Click to animate and click again for maximum resolution.
Source is mirrored on https://seaice.de/AMSR2_Antarctic_SIC-LEADS.gif

[Phil.]

  There is an immense ozone hole this year.
In theory, it will keep the continent much colder ..But will it impact the sea ice?

Actually it grew early but now is dropping fast and is about average.

https://ozonewatch.gsfc.nasa.gov/meteorology/figures/ozone/to3areas_2023_toms+omi+omps.pdf

[kiwichick16]

24 hours daylight at scott base now

https://dateandtime.info/citysunrisesunset.php?id=6620787

[kassy]

In the meantime the extent and area numbers are lingering before taking a dive.