The 2022/2023 freezing season

[oren]

Meanwhile, looking at other regions of potential interest for this time of year we see Hudson relatively low, Baffin consistently high (thanks to Nares?), Chukchi rather high and Bering negligible.
Note: all of the above charts are of sea ice area.

[nadir]

This might remind a bit to 2016/2017. If we started to observe anemic ice thickness growths from c2cmos and piomas…
However FDD metric (Nico Sun) has stalled at the same time of the ice extent stalling, meaning normal cold temperatures over the Central Arctic. Not really 2016/2017.

https://cryospherecomputing.com/#FDD

[morganism]

Uniquorn, is that the polar bridging they were expecting in the polar vortex?  Connection at higher altitudes keeps the split at lower alt energized?

Or does the bridge damp out the bipolar tendencies ?

[uniquorn]

Severe weather.eu covers it in some detail here.
https://www.severe-weather.eu/global-weather/winter-pattern-december-blocking-cold-air-polar-vortex-split-united-states-europe-fa/

https://www.severe-weather.eu/global-weather/winter-pattern-december-blocking-cold-air-polar-vortex-split-united-states-europe-fa/

POLAR VORTEX RECOVERY

Despite having a very disrupted low-level weather circulation, the upward pressure is expected to (at least temporarily) ease off. This will allow the lower stratospheric Polar Vortex to regain some composure but will remain elongated, reaching down into North America.


The forecast is the same for the mid-stratosphere, having an elongated and rather healthy Polar Vortex. But the next disruption is likely not far off, as we are monitoring a developing trend of possible warming events emerging in the Stratosphere later in the month.


Yet again, the 3D structure helps to reveal the shape of the Polar Vortex across the many levels of the atmosphere. It is still being split in the core at the lower levels, but the strong momentum from above will (temporarily) reshape the structure and merge the cores back in higher altitudes.

---------------------------

GFS shows a sudden stratospheric warming peaking Dec 9-Dec 15. No split in the vortex is seen yet. In my (admittedly pretty short) experience SSW and p.vortex split is more important for NH midlatitude winter weather (especially N. America) than the Arctic though...

...however the current extent numbers are quite amazing: 2022 climbed to 4th place, behind 2016,2020 and 2006 only (a few days ago it was still below the 2010s average value)

Yes, it's only a partial split that's forecast to recover longer term. It might delay refreeze on the Pacific side for a couple more days.

1. https://stratobserve.com/misc_vort3d dec2 forecast for dec6 dec13
2. nullschool wind at 70hPa

[Neven]

I still update my Arctic surface air temperature graphs, and noticed that this year saw the warmest/least cold November on record in the Atlantic sector of the Arctic, a whopping 1.5 °C warmer/less cold than November 2016:

[El Cid]

I still update my Arctic surface air temperature graphs, and noticed that this year saw the warmest/least cold November on record in the Atlantic sector of the Arctic, a whopping 1.5 °C warmer/less cold than November 2016:

I've been theorizing that for a BOE to happen we would need yearlong open water in the Barents / Kara and Chukchi/Bering. This year ocean heat anomalies were extremely high in the Barents region and maybe Atlantification is progressing fast and more and more warm waters arrive there and that's why we saw such high T anomalies in the Atlantic sector. Or maybe it is just noise. If this happened in 2-3 consecutive years then we could be almost sure that Atlantification took another step and a BOE is closer...

[vox_mundi]

The First Complete Picture of Arctic Sea Ice Freeze-Thaw Cycle Highlights Sea Ice Response to Climate Change
https://phys.org/news/2022-12-picture-arctic-sea-ice-freeze-thaw.html



Until now, most studies calculated the Arctic melt and freeze onsets using remote sensing observations from the surface, but rarely investigated the freeze-thaw process at ice bottom.

In a new study published today in the European Geosciences Union journal The Cryosphere, an international team of scientists synthesized multisource data from 2001 to 2018 to explore the spatiotemporal variations of both surface and basal melt/freeze onsets and uncover the mechanism behind them. These findings could improve our understanding of changes in the atmosphere–ice–ocean system and the mass balance of sea ice in a changing Arctic.

"Thinner ice thickness and thinner snow cover favors earlier basal freeze onset. The ocean plays a cross-seasonal role in regulating the growth or decay of sea ice," explains lead author Long Lin from the Polar Research Institute of China.

The researchers found that the overall average basal freeze onset of Arctic multiyear ice was almost 3 months later than the surface. "Based on synchronous ice and underlying ocean observations, we found the ice basal freeze-up delay relative to the surface, which can be attributed to the regulation of heat capacity of sea ice itself and the oceanic heat release from the ocean mixed layer and subsurface layer," Lin says.

According to Lin, although thinner ice generally experiences a longer freezing season, the total ice growth still cannot offset the sea ice loss in summer. "From another point of view, the self-regulation of the Arctic sea ice-ocean system will delay the loss of Arctic sea ice."

The research also found that the most significant temporal difference of melt onsets between surface and bottom occurred in the Beaufort Gyre region, where basal melt onsets showed more than a half month earlier than surface. Besides, both multiyear ice and first-year ice in this region exhibit a trend towards earlier basal melt onset, which can be attributed to the earlier warming of the surface ocean caused by thinning of sea ice thickness and increasing of sea ice mobility.

These results present the first complete picture of Arctic sea ice freeze-thaw cycle, and its coupling with atmosphere atop and ocean underlying. It also highlights the importance of synchronous comprehensive monitoring of air-ice-ocean system, which helps explain the physical nature of the coupling process.

Long Lin et al, Changes in the annual sea ice freeze–thaw cycle in the Arctic Ocean from 2001 to 2018, The Cryosphere (2022)
https://tc.copernicus.org/articles/16/4779/2022/

[uniquorn]

Some interesting numbers in the paper

https://tc.copernicus.org/articles/16/4779/2022/
Changes in the annual sea ice freeze–thaw cycle in the Arctic Ocean from 2001 to 2018
Long Lin, Ruibo Lei, Mario Hoppmann, Donald K. Perovich, and Hailun He

For all IMBs that experienced the complete melting or freezing seasons, the average ice melt was 0.56 m at the surface and 0.65 m at the ice bottom, while the average ice growth was 0.74 m. Thus, the average annual ice thickness budget derived from all IMB observations during 2000–2018 amounts to −0.47 m, which clearly confirms the ongoing decline of the Arctic sea ice thickness.

One remarkably similar result was for example presented by Petty et al. (2020), who used the February–March ice thickness retrieved from the satellite altimeter measurement of ICE-Sat (Ice, Cloud, ad land Elevation Satellite) to show a decrease of ∼ 0.37 m or ∼ 20 % thinning across an inner Arctic Ocean domain from 2008 to 2019. We infer that the growth of multiyear sea ice in winter is not sufficient to compensate for the melt in summer, even though the negative conductive feedback enhances the ice growth during the freezing season.

BMO basal melt onset
BFO basal freeze onset

Supplementary data has all the dates.
https://tc.copernicus.org/articles/16/4779/2022/tc-16-4779-2022-supplement.pdf

Figure 8
Decadal changes in BMO (a) and BFO (b) obtained from Lagrangian IMB observations in the Beaufort Gyre. The solid square is the mean, the horizontal line is the median, the box represents ±1 SD (standard deviation), and the whiskers are the maximum and minimum values.

[nadir]

https://twitter.com/alaskawx/status/1599805298558263297?s=61&t=SF2wHjcPnU7Op-nD4TeiYA

[uniquorn]

nov30-dec5

[uniquorn]

A closer look at the Alaskan coast using rammb shows possible upwelling west of the Mackenzie river.
https://col.st/hjxnT  dec5-6

[binntho]

A closer look at the Alaskan coast using rammb shows possible upwelling west of the Mackenzie river.
https://col.st/hjxnT  dec5-6

I am assuming you are talking about the area slightly to the right of center along the coast. I agree, this certainly looks as if the ice is thinning in this area, most likely due to upwelling.

[uniquorn]

A closer look at the Alaskan coast using rammb shows possible upwelling west of the Mackenzie river.
https://col.st/hjxnT  dec5-6

I am assuming you are talking about the area slightly to the right of center along the coast. I agree, this certainly looks as if the ice is thinning in this area, most likely due to upwelling.

Yes, it could just be the wind whipping around Herschel Island but heavy contrast on gmrt bathy reveals a gentle trough in that area.

[vox_mundi]

On Sunday, the Arctic as a whole averaged 11.5 degrees (6.4 degrees Celsius) warmer than the 1979-2000 average temperature and on Monday, computer models showed that average to likely be 10.5 degrees (5.9 degrees Celsius) warmer than normal, according to the University of Maine's Climate Reanalyzer.

In Nuuk, Greenland, on Friday it was shirt-sleeve weather in December, when the temperature peaked at 54 degrees (12.2 degrees Celsius), 26 degrees (14.4 degrees Celsius) above the normal high mark. In Kangerlussuaq, Greenland, on Friday it hit 48 degrees (8.9 degrees Celsius), which was 34 degrees (18.9 degrees Celsius) warmer than normal.

https://phys.org/news/2022-12-december-alaska-arctic.html

[Glen Koehler]

    Interesting to see that the highest anomaly is in areas that have ice cover.

[Darvince]

Where are the current massive extent gains? Is it all in the Hudson?

[oren]

Where are the current massive extent gains? Is it all in the Hudson?

Maybe the animation will help. But looking at regional charts there are also some gains in the Greenland Sea and in the Chukchi, in addition to the Hudson.

An AMSR2 animation of sea ice concentration and movement in the central Arctic, courtesy of the Alfred Wegener institute (AWI). More information available in the AWI thread mostly updated by uniquorn.
Click to animate and click again for maximum resolution.
Source is mirrored on https://seaice.de/AMSR2_Central_Arctic_SIC-LEADS.gif

Adding a chart of total AMSR2 area according to AWI, source https://sites.google.com/view/sea-ice/startseite

And DMI temps N of 80, for what it's worth.

[gerontocrat]

The AMSR2 graph shows only modest gains in sea ice area in the last few days. large increase in sea This suggests to me that the very large increase in sea ice extent in the last 2 days may be due to sudden increase in low concentration ice somewhere. The AWI animation then suggests to me that maybe the Beaufort Sea is at least part of that "somewhere".

[uniquorn]

Hudson, Chukchi, Kara and Greenland extent increased significantly yesterday according to awi amsr2 v110

Area:
Hudson     98821 km²
Chukchi     49806
Kara          21066
Beaufort    20758
CAB           15191
Barents     13552
Greenland 11466
Baffin         7893
Okhotsk     4997
ESS           -3025
CAA           -3976

Total         260431 (includes other small areas)

[nadir]

Crazy atmospheric ridge predicted closer to Christmas day leading to a 1072 hPa High at surface.

Probably this won’t happen but the intrusion of warmer atmospheric airmass from the Pacific will, to greater or lower degree

[Glen Koehler]

NSIDC 5-day Sea Ice Area - the Beaufort Sea

The Beaufort had an unseasonal fall in sea ice area starting in mid-November. Since then sea ice area has stayed well below norms (by about 75k), and has notched up 18 days lowest in the satellite record since the 19th November.

Not earth-shattering, but odd.

As I understand it, the rapid loss of MYI in early 2000s was largely due to changes in Beaufort that changed the "Beaufort Gyre" (quotes in deference to A-Team) ice nursery into a killing ground.  That makes me wonder if weakening in the Beaufort in winter 22-23 hints at another step change of some sort in the upcoming melt season, though repeating something as dramatic as the MYI decimation seems unlikely.

[oren]

An AMSR2 animation of sea ice concentration and movement in the central Arctic, courtesy of the Alfred Wegener institute (AWI). More information available in the AWI thread mostly updated by uniquorn.
Click to animate and click again for maximum resolution.
Source is mirrored on https://seaice.de/AMSR2_Central_Arctic_SIC-LEADS.gif

Adding a chart of total AMSR2 area according to AWI, source https://sites.google.com/view/sea-ice/startseite

And DMI temps N of 80, for what it's worth.

[be cause]

a bit of a novelty .
      ECM shows +4'C uppers today and several days of positive values above the ESS over the winter solstice .
     The summer solstice saw uppers of -10'C .
 
 meanwhile moving into the USA ... brrrr .

[Brigantine]

And DMI temps N of 80, for what it's worth.

and its anomaly, currently right on the 2010's average

[VeliAlbertKallio]

AWI's AMSR2 just shows nicely the restlessness and ice fracturization of the Beaufort Sea but the freezing of Chuckchi Sea and Bering Strait now underway might stabilise it a bit as ice congestion grows and open sea areas vanish. If ice thickens and stays there, its will be better for Beaufort too.

NSIDC 5-day Sea Ice Area - the Beaufort Sea

The Beaufort had an unseasonal fall in sea ice area starting in mid-November. Since then sea ice area has stayed well below norms (by about 75k), and has notched up 18 days lowest in the satellite record since the 19th November.

Not earth-shattering, but odd.

As I understand it, the rapid loss of MYI in early 2000s was largely due to changes in Beaufort that changed the "Beaufort Gyre" (quotes in deference to A-Team) ice nursery into a killing ground.  That makes me wonder if weakening in the Beaufort in winter 22-23 hints at another step change of some sort in the upcoming melt season, though repeating something as dramatic as the MYI decimation seems unlikely.

[uniquorn]

Bering sea ice looks weak this freezing season
awi sic-leads v110, dec16-21
https://sites.google.com/view/sea-ice/startseite

[nadir]

The weather pattern has been extremely unfavorable in the Bering area, first with Southerlies and now with a extremely strong surface pressure gradient (note in the animation above the jet-like structure formed by Pacific water entering Chukchi Sea).

It seems Arctic will get much colder toward the New Year.

[gerontocrat]

Meanwhile, at the moment quite an impressive spike in temps Norh of 80.

[uniquorn]

-14C air temps temporarily reversing the heat flux through the snow layer again.
simb3-566570 data, 2cm temp difference

[The Walrus]

Meanwhile, at the moment quite an impressive spike in temps Norh of 80.

That typically happens whenever Arctic air dives far south.  Once the jet stream realigns, watch for temps to drop again north if 80.

[uniquorn]

Polar vortex keeps lifting over the Pacific side recently and is forecast to continue. Atl side may be better.
https://stratobserve.com/misc_vort3d

[uniquorn]

Atl side may be better.

or maybe not

[oren]

An AMSR2 animation of sea ice concentration and movement in the central Arctic, courtesy of the Alfred Wegener institute (AWI). More information available in the AWI thread mostly updated by uniquorn.
Click to animate and click again for maximum resolution.
Source is mirrored on https://seaice.de/AMSR2_Central_Arctic_SIC-LEADS.gif

Adding a chart of total AMSR2 area according to AWI, source https://sites.google.com/view/sea-ice/startseite

And DMI temps N of 80, for what it's worth.

[icy voyeur2]

An AMSR2 animation of sea ice concentration and movement in the central Arctic, courtesy of the Alfred Wegener institute (AWI). More information available in the AWI thread mostly updated by uniquorn.
Click to animate and click again for maximum resolution.
Source is mirrored on https://seaice.de/AMSR2_Central_Arctic_SIC-LEADS.gif

Adding a chart of total AMSR2 area according to AWI, source https://sites.google.com/view/sea-ice/startseite

And DMI temps N of 80, for what it's worth.

That Fram expert looks like part of a nightmare scenario.

[A-Team]

That Fram export looks like part of a nightmare scenario.

Not to worry. The ice may all be going out the door but academic experts have told us repeatedly in peer-reviewed journals that this will be part of the Last Ice Area in 2050.

the ice chart challenge data download website has a bad gateway YET AGAIN on top of all the earlier GROSS INCOMPETENCE !@#!

Not to worry. We can count on authorities hosting AI contests to safely direct Arctic tourism, trophy hunts, midnight winter shrimp harvests, oil exploration and coal shipping far into the future.

Op-Ed today LA Times:
Climate change efforts won’t work if they exclude people with disabilities
https://www.latimes.com/opinion/story/2022-12-27/climate-change-disability-rights-policy

Let's all hitch our favorite cause to the climate change bandwagon and disrupt efforts to curb emissions until we've achieved global social justice, inclusion, diversity, wealth equality, organic vegan food security, affordable Mars tourism, democracy, low rents, universal medical, self-driving cars, green desalination, cheap fusion and found forever homes for feral cats.

[gerontocrat]

That Fram expert looks like part of a nightmare scenario.

Not really

Fram Export data to 15 Dec posted on the Piomas Latest Volume Update thread.

[nadir]

Let's all hitch our favorite cause to the climate change bandwagon and disrupt efforts to curb emissions until we've achieved global social justice, inclusion, diversity, wealth equality, organic vegan food security, affordable Mars tourism, democracy, low rents, universal medical, self-driving cars, green desalination, cheap fusion and found forever homes for feral cats.

Hahah that was good!

Universal medical should be out of the question though. What’s the point of saving human race if anyone’s life depends on their economic status?

[oren]

While I echo A-Team's comment on the climate change bandwagon, let's get back to the freezing season.

As for Fram export, this is one the charts Gero kindly posted in the PIOMAS thread, based on a more northerly cutoff line from Greenland to FJL (reddish line). What bothers me with Fram export comparisons is they depend on the volume in export staging area. However it would seem export this freezing season was indeed on the low side, although based on the LEADS animation it picked up some more in the days after the end of the chart.

[uniquorn]

some calculated distances of 2 buoys drifting north and north east of Greenland, dec1-25. One of them is snowbuoy S116 deployed at the pole on jul14 and already at the Fram Strait

300234066034140     335.0000   84.10600   -17.15640
                    361.6250   81.29260   -6.81020
> distHaversine(c(-17.15640,84.10600),c(-6.81020,81.29260),r=6378137)
[1] 344470.9m

snowboy
300534061353000   335.0000   84.23700   -3.77220
                  361.6250   80.83420   -1.14080
> distHaversine(c(-3.77220,84.23700),c(-1.14080,80.83420),r=6378137)
[1] 380606m

The area their drifts encompass is roughly 40,795km², say average thickness of 1.5m is 61,000km³. Guestimate of the full ice covered width of Fram export from dec1-25 would be 150,000km² but thinner towards the ice edge.

1, rough worldview visualisation
2. buoy names circled
3. some thickness data
4. buoy animation form iabp data, dec1-25
One went down the Nares lol

[A-Team]

The ice exiting out the Fram has not been just TransArctic Drift; perhaps half has been western CAA/north pole/Lincoln/Wandel ice over the last six months. The latter type export is really devastating to build-up of multi-year ice taken as fairly stationary over the years.

That snowboy S116 buoy, installed at the pole on 14 July 2022 and already reaching the Fram, helps interpret the Hycom ice thickness over the last six months. (Hycom is useful for the shape-shifting, not necessarily for literal ice thickness accuracy.)

The gray line on the AMSR2 cutout defines the confluence of the two ice streams for five days in late December. It would be good to string together AMSR2 at the same scale for the same time frame.

We don't know whether this new pattern is a transient episode or a persistent change in flow. Regardless, it illustrates something that could happen a lot sooner than what decadal trends set as upper bound to ice collapse.

The imagery below is all in 'Greenland down' orientation to facilitate comparison. Scales differ slightly but could be uniformatized using the pole to 80º latitude pixel distances. Choice of map projection varies but has little effect for the small region shown.

[Jim Hunt]

The ice exiting out the Fram has not been just TransArctic Drift.

CryoSat-2 suggests some thicker patches currently heading Framwards:

[gerontocrat]

NSIDC Sea Ice Area Data - a cuople of graphs

The contrast between rapid complete freezing over in the Central Seas (High Arctic currently 15th lowest in the satellite record) and the low to a stall is sea ice area gain in the Peripheral Seas (currently 2nd lowest in the satellite record) continues to grow.

click images to enlarge

[uniquorn]

hycom drift compared to buoys is pretty good north of Greenland, jul14-dec27
2 more buoys may be heading for Nares Strait

[uniquorn]

iabp buoys and ascat, jul14-dec27, the summer low concentration area drifting into view top right

[johnm33]

The present mslp set up is conducive to a massive exchange of waters through Fram, even though we're at a low point in the tidal cycle. Since the full moon in early oct. when I think there was a step change in outgoing currents nothing has happened to seriously reverse that heft. Since the near surface waters take less energy to move there has to be a slow increase in temperature of deeper waters and a slow thinning of the layers above. More water is entering from the Pacific side and I think this is due to the opposite phase of tidal pressure establishing an harmonic across the ocean, that in turn is adding pressure to the flows through Nares and Fram. I guess the best proxy for testing this is a growing difference [higher] between predicted and actual low and high tides in Delaware and points south.

[kassy]

Since the near surface waters take less energy to move there has to be a slow increase in temperature of deeper waters

Why? What causes this?

[A-Team]

A lot of thick ice is going out the door - oren

Indeed the semi-stochastic Fram export mechanism may be ramping up.

Despite being incompressible, the ice pack slops back and forth almost like a viscous liquid as seen in AMSR2 and Ascat animations.

Pack motion is driven by atmospheric pressure patterns (wind) and to a lesser extent by tides, currents and internal waves.

Greenland, CAA and AK buttressing lands provide a stationary boundary condition, along with a lesser counterpart on shallow Russian side far to the south.

Semi-coherent wind episodes driving CW Transatlantic Drift on the Eurasian side derive from the ‘default' Arctic pressure pattern.

That motion pressures the ice ahead but it is pinned against the unmovable projection of Cape Morris Jesup in northern Greenland.

If a lobe of multi-year ice happens to be west of the northern tip of Greenland, it gets squeezed in the direction of Ellesmere.

If a lobe of multi-year ice happens to be past of this northern tip of Greenland, it gets squeezed west into the upper Fram catchment and exported.



A significant percentage of hycom-thicker ice can be irrevocably exported in a month-long event.

However hycom-thicker ice increases over winter and, though trending down, can more or less recover from these export events.

The ice is trending to thinner overall and becoming more susceptible to wind-induced motion.

Thus lobes over Greenland may be becoming more common and prolonged, increasing vulnerability to an onset of Transatlantic Drift and thus export.

However by the time sufficient statistics have accrued, it will be too late.

[oren]

An AMSR2 animation of sea ice concentration and movement in the central Arctic, courtesy of the Alfred Wegener institute (AWI). More information available in the AWI thread mostly updated by uniquorn.
Click to animate and click again for maximum resolution.
Source is mirrored on https://seaice.de/AMSR2_Central_Arctic_SIC-LEADS.gif

Adding a chart of total AMSR2 area according to AWI, source https://sites.google.com/view/sea-ice/startseite

And DMI temps N of 80, for what it's worth.

[oren]

That motion pressures the ice ahead but it is pinned against the unmovable projection of Cape Morris Jesup in northern Greenland.

If a lobe of multi-year ice happens to be west of the northern tip of Greenland, it gets squeezed in the direction of Ellesmere.

If a lobe of multi-year ice happens to be past of this northern tip of Greenland, it gets squeezed west into the upper Fram catchment and exported.

Indeed. And the worst events are when the ice shifts from west to east along Greenland's tip, as happened in the past week (see animation above). This moves a large chunk of what is surely very thick ice, from the "last ice refuge" category" to the "marked for export" category.
Obviously, with Nares open for the past year, the Lincoln Sea is anything but a last ice refuge, but ice there at least has the potential to randomly shift in the direction of Ellesmere and possibly even reach the true last ice refuge, which is probably somewhere around Ellef Ringness and the region of ocean to its north, if it's anywhere at all.

[gerontocrat]

Edit : It seems my brain went AWOL earlier

Until I looked properly at the AMSR2 animation posted by oren I had not noticed that EDIT BAFFIN Bay  Hudson Bay Bay is fed ice not just from the Nares Strait (continuing unabated), but also from NW via the Parry Channel (which ends as Lancaster Sound), and by the looks of it ice that has headed north from the Gulf of Bothnia via the Prince Regent Channel and then turns East into Lancaster Sound joining the Parry Channel export.

EDIT:- & some ice from Jones Sound just north of Lancaster Sound

What a lively place a frozen Arctic is.

See map attached. Click to enlarge