Poll: 2023 Antarctic JAXA extent minimum

[Steven]

It's about 5 or 6 weeks or so until the minimum, seems a good time for a small poll.

Current conditions: JAXA extent for 13 January 2023 is 3.52 million km2, which is record low for the date.

Minima for the last 10 years:   

2022   2.128 million km2
2021   2.788
2020   2.759
2019   2.425
2018   2.209
2017   2.147
2016   2.657
2015   3.594
2014   3.542
2013   3.685

[oren]

Due to the low area situation, which I expect to result in a new area minimum, I find it hard to believe 2023 can avoid a new extent minimum as well. Voted for <2M km2.

[Stephan]

My best guess is with the 2-2.25 M km² bin as since New Year the extent losses have been consequently lower than average. I think this behaviour will continue until the minimum. Even a "not 1^st place" seems possible for me.

[Phil.]

Can't see any of the FYI surviving so sure that will be below 2.0.

[Juan C. García]

Above 2 million (2-2.25 range).

I think there has to be some melting of the Antarctic ice sheets, which will somehow cool the ocean and slow the melting of the Antarctic sea ice. And I think it is worst to have some melting of the Antarctic ice sheets, than to have a new low record on the  Antarctic sea ice.

[gerontocrat]

If Juan is right that the reported (by Steven) high snow melt in parts of the West Antarctica and the Peninsula will cool the ocean and thus reduce sea ice melt, then the current well below average daily sea ice extent loss will continue and maybe reduce further and perhaps result in an earlier that average minimum date.

This would likely mean that the minimum could be well over 2 million km2, say 2.3 million km2, 3rd lowest in the satellite record. Nevertheless, I am plumping for 2023 sea ice extent daily losses to continue lower but still end with a minimum below 2 million (just) at around 1.9 million km2.

I attach the graph of the 7 day trailing average of daily sea ice extent losses, which shows the remorseless reduction in daily sea ice losses, currently around 50,000km2 per day less than the 10 year average.

[Steven]

Zack Labe's NSIDC extent anomaly graph also shows the slowdown of the losses in the last 2 weeks.  I would guess a record low minimum is still the most likely outcome, but obviously it looks a lot less certain than a few weeks ago.

Much of the remaining ice is now in Weddell Sea, which is currently on par with last year and 2017.  In the other seas, 2023 is generally ahead of the previous years.

[Juan C. García]

If Juan is right that the reported (by Steven) high snow melt in parts of the West Antarctica and the Peninsula will cool the ocean and thus reduce sea ice melt, then the current well below average daily sea ice extent loss will continue...

It is right that I am concerned of the melt on the surface above, but the true is that I am more concern on the melt below the ice sheets. This paragraph could explain what I am thinking of:

Now that same canyon was channeling warm ocean water under the Pine Island Ice Shelf. Somewhere tens of miles inland, the warm water was finding the “grounding line”: the place where the glacier lifts off the seafloor and becomes a floating ice shelf. Hitting that wall of ice, the warm water was eroding it, producing a steady stream of melt-laden seawater. Because it was cooler and fresher, it was less dense, and so it was rising above the warmer, incoming water and flowing back out to sea just under the shelf.
https://www.nationalgeographic.com/magazine/article/antarctica-sea-level-rise-climate-change

In Greenland and in Antarctica, we have warm water coming from the oceans, they hit the ice shelfs from below, they melt the ice and then, we have a flow of fresh water, with less salt and cooler than the ocean water. My point is that this fresh water should delay the melt of the Antarctic sea ice, close to the coast (and at the end of the melting season).

There is a video on the National Geographic link (with the title "ANTARCTICA IS MELTING AT A DANGEROUS PACE—HERE'S WHY"), that explains the process with more detail. I was looking for another NG link, but I didn't find it.

[Steven]

24 hours left to vote in this poll, or to change your vote.

My guess is 1.85 million km2 (I voted 1.75-2).  This is based on a linear regression using NSIDC sea ice area as predictor variable.

[gerontocrat]

I attach Nico Sun's Albedo Warming Potential (AWP) images to show the potential high level of solar radiation that could have warmed the Antarctic Ocean this melting season. It is a record breaker. Howver, we do not know how cloudy and/or sunny the melting season has been.

The anomaly is especially high offshore the Western coast of the Antarctic Peninsula and below average offshore of the Eastern side where the most stubborn ice in the Weddell sea lives.

I would have thought that these images would indicate that remaining sea ice is vulnerable, The attached image from NOAA of SST anomalies gives a very mixed picture of SST anomalies at high southern latitudes. As usual, the Antarctic remains inscrutable.

link: https://cryospherecomputing.com/NRTawp-south.html

click images to enlarge

[Steven]

JAXA extent dropped below 2.5 million km² today: it's now 2.48 million km².  We'll see whether it drops below 2.25 and 2.0 million km² in the next few weeks.

[WildFit]

Make the numbers overlapping, it will be so close to 2 that one should be able to vote 1.9-2.1

[oren]

The poll is already closed. Maybe next time.

[oren]

JAXA ANTARCTIC SEA ICE EXTENT:  1,995,759 KM2 as at 14-Feb-2023

And 1.75-2.00 M seems to be the winner (unless extent manages to drop another 245k somehow).