The 2019 melting season

[DrTskoul]

As salt gets rejected the ice is not homogeneous ( includes regions with defects and brine channels etc) and thus weaker than ice that was rejected most salt.

Sources: Met Office, Anderson DL '58 A Theoretical Analysis of Sea-Ice Strength

A very interesting paper on brine pockets and the tensile strength of sea ice, but I wonder how often the ice is in pure tension rather than compression or shear. It seems that the crack north of Greenland is probably caused by wind blowing off Greenland and across the ice towards the North Pole. It is also presumably relevant to ice breakers that put the ice in local tension by driving a wedge shape into the ice at the bow.

Whenever the ice floe flexes due to waves, wind etc ( let's assume it creates a convex shape , like a bowl) then the top portion experiences compression forces but the lower portion experiences tensile forces.

[slow wing]

Here's Neven's year-to-year comparison maps for Arctic sea ice on 1 August.


2019 definitely appears to be one of the worst years on this date. How bad will this melt season end up compared to previous worst years? Too early to tell?

[sja45uk]

PS this discussion seems to getting a bit OT, perhaps it could be continued here https://forum.arctic-sea-ice.net/index.php/topic,854.0.html or even better here https://forum.arctic-sea-ice.net/index.php/topic,2274.0.html

Thanks, always a useful tactic for regulars to suggest to newcomers where a OT subject is best covered to help keep focus on the primary subject.

[philopek]

....but I've always assumed that ice breakers sailed up onto the ice and broke it by pressing downwards. ....

That's how it is, you're 100% correct, common knowledge

[gerontocrat]

....but I've always assumed that ice breakers sailed up onto the ice and broke it by pressing downwards. ....

That's how it is, you're 100% correct, common knowledge

That's how it was - until

The latest Russian icebreakers cut through ice up to at least 2 metres thick without reducing cruising speed and shove the ice sideways. Nuclear powered with many thousand of tonnes forward motion. And bigger ones coming. Even the new fleet of LNG tankers can go through ice at least 1 metre thick (backwards) in their stride.

Wander around the Northern Sea Route thread and you will find loads of stuff.

https://forum.arctic-sea-ice.net/index.php/topic,854.msg169242.html#msg169242
https://forum.arctic-sea-ice.net/index.php/topic,854.msg141126.html#msg141126

[pauldry600]

Greenlands roof is disturbing

But hopefully heatwave will go away from it soon

[binntho]

....but I've always assumed that ice breakers sailed up onto the ice and broke it by pressing downwards. ....

That's how it is, you're 100% correct, common knowledge

That's how it was - until

The latest Russian icebreakers cut through ice up to at least 2 metres thick without reducing cruising speed and shove the ice sideways. Nuclear powered with many thousand of tonnes forward motion. And bigger ones coming. Even the new fleet of LNG tankers can go through ice at least 1 metre thick (backwards) in their stride.

Wander around the Northern Sea Route thread and you will find loads of stuff.

https://forum.arctic-sea-ice.net/index.php/topic,854.msg169242.html#msg169242
https://forum.arctic-sea-ice.net/index.php/topic,854.msg141126.html#msg141126

Yes, as can be seen in that Yamal video.

[philopek]

....but I've always assumed that ice breakers sailed up onto the ice and broke it by pressing downwards. ....

That's how it is, you're 100% correct, common knowledge

That's how it was - until

The latest Russian icebreakers cut through ice up to at least 2 metres thick without reducing cruising speed and shove the ice sideways. Nuclear powered with many thousand of tonnes forward motion. And bigger ones coming. Even the new fleet of LNG tankers can go through ice at least 1 metre thick (backwards) in their stride.

Wander around the Northern Sea Route thread and you will find loads of stuff.

https://forum.arctic-sea-ice.net/index.php/topic,854.msg169242.html#msg169242
https://forum.arctic-sea-ice.net/index.php/topic,854.msg141126.html#msg141126

The Amal brakes the ice from above as it always has been and the Eduard Toll's bow section implies a similar, perhaps mixed approach. The ice shown in the video was not super thick and the impression of splitting the ice is due to the speed and hence the power of vessel that is outstanding. In fact the vessel does not stay level in the water but bumps up and down still. The bow section clearly shows the purpose the heave the ship above the ice while at those speeds the movement is not that distinguishable like with the slow  common ice-breakers

Only real exception are new vessels that crash the ice with their propellers but that limits their suitability when it comes to ice thickness.

If there is real disagreement and you can provide pictures of any vessel's bow section that does not serve to heave said vessel above the ice and does not crush ice with propellers, send me P.M. or take it elsewhere.

I'm totally interested to learn new things but the examples and the related images you provided do neither serve that purpose nor convince me that those vessels indeed split really thik ice like a sword.

[Shared Humanity]

Can we stay focused on the melt season?

[Davidsf]

"Can we stay focused on the melt season?"

+1

[blumenkraft]

You are right SH, it's kind of OT. But philopeks reaction to Gerontocrats post makes me want to post this:

Oden is extraordinarily manoeuvrable in heavy ice, thanks to the special design, with its square bow, specific hull shape, ice knife, propellers with nozzles and oversized rudders. Thrusters at the bow sprays jets of water to reduce the vessel’s friction on the ice, and a healing system for wiggling the vessel side-to-side further enhances the ability to navigate the ice.

https://polar.se/en/about-polar-research/icebreaker-oden/

[F.Tnioli]

...
2019 definitely appears to be one of the worst years on this date. How bad will this melt season end up compared to previous worst years? Too early to tell?

Yes, too early. I see that unusually large amount of ice is now in the state which allows quick and massive melt under GAC-like conditions, by either low thickness, high fragmentation or both. In the same time i see large amounts of ice which are just barely enough thickness to survive if it'll be not too much wind and not too much insolation. I.e., the season arrived to the point where weather decides unusually much. And since "usual" is already pretty much - yep, too early to tell.

[blumenkraft]

Crossposting this great thread in the most-read thread on the forum:

https://forum.arctic-sea-ice.net/index.php/topic,2850.0.html

Everyone give NotaDenier some love for posting a stunning video collection and great info regarding Greenland moulins.

[petm]

petm, can you post you uni bremen median graph for today? and maybe as comparison 2012 for the same date? i find them most useful. thanks

Glad you find them useful. Here they are.

Left, 5-day median ; Right, original

Top, 2019; Bottom, 2012

[petm]

Beaufort continuing to get hammered now, and forecast to get hammered again on Monday, probably even worse. If the clouds clear later next week, it would be something to see. One-day difference of the part that's been cloud-free (and therefore probably not even the worst affected):
 
https://go.nasa.gov/2GDFtNZ

ESS still dropping at an unprecedented rate and CAA a little bit late but dropping now.

ECMWF and CMC but not GFS forecasting a wide, sub-980 low for d+7 (still teasing us).

[blumenkraft]

Playing around with the Slider long term options. Here are a few days of weather (M10 band) in the Arctic.

Is this kind of thing any useful for anyone?

[Shared Humanity]

You are right SH, it's kind of OT. But philopeks reaction to Gerontocrats post makes me want to post

Not kind of off topic. Completely off topic.

[cognitivebias2]

@blumenkraft - I love all the animations.  The only thing is this one is a bit too choppy.  Any way to increase the frame rate?

[blumenkraft]

@blumenkraft - I love all the animations.  The only thing is this one is a bit too choppy.  Any way to increase the frame rate?

EZgif doesn't allow a fading when it's more than 30 frames which would improve choppyness, but let me see what i can do.

[sailor]

Playing around with the Slider long term options. Here are a few days of weather (M10 band) in the Arctic.

Is this kind of thing any useful for anyone?

Yes!

[gerontocrat]

Meanwhile, them pesky forecasters are suggesting things about the longer-term future weather on the Arctic shores.
Must give some clue about the end-of-season melt / early season re-freeze? Or maybe not?

Environment Canada says a high chance of above average temperatures in the Canadian North including the CAA August to October - apart from a cold blob centered in the south of Hudson Bay.
https://weather.gc.ca/saisons/index_e.html

The USA CPC says Alaska likely to be warmer than Average in August.

Russia says most of the Arctic shore of Western Siberia may be colder than normal while the far East - Kamchatka could be warmer from Sept to November.
https://meteoinfo.ru/en/climate/seasonal-forecasts

Make of it what you will. Some will poo-poo the data, some will not.

[El Cid]

thanks petm!

I still can't make up my mind which one looks worse: 2012 or 2019, but 2019 is more fearsome.

The attack from towards the Laptev bite could reach the North Pole but even more worrysome is the CAA-Greenland megacrack and all that red north of Greenland: those regions were thought to be the last refuge of ice and now they ars dissipating?!

[RoxTheGeologist]

Here's Neven's year-to-year comparison maps for Arctic sea ice on 1 August.


2019 definitely appears to be one of the worst years on this date. How bad will this melt season end up compared to previous worst years? Too early to tell?

What's really noticeable is the difference on the CAA and Greenland side of the Arctic, compared to all other years (except, perhaps, 2016). There appears to be thinner ice extending hundreds of KMs offshore where the store of MYI used to be.

[petm]

What's really noticeable is the difference on the CAA and Greenland side of the Arctic, compared to all other years (except, perhaps, 2016). There appears to be thinner ice extending hundreds of KMs offshore where the store of MYI used to be.

The western part of that has been steadily advecting into the Beaufort and melting. Given the right conditions (e.g. a big storm), there's the potential for a big bite in an area where it's never been seen before.

[petm]

I still can't make up my mind which one looks worse: 2012 or 2019, but 2019 is more fearsome.

To my eye (and most graphs), on this day 2019 looks worse. But given that the 2012 GAC was this week, it won't be for long. Unless...

[sailor]

Inspired by Blumenkraft display of the clouds around the ridge and the following wave of clouds from CAA and Greenland (warm and cloudy stuff!!) I took 10 days of GFS forecast and played with the wheel. Showing SLP anomaly, it strikes immediately the stability of Greenland High and quite some action over the Pacific side, with a very unquiet weather. Not that good for ice I would say.

The last frame shows a deep low over the Aleutians and quite high pressure over Chukchi, which mean Bering inflow enhanced if this is maintained.

[RoxTheGeologist]

I still can't make up my mind which one looks worse: 2012 or 2019, but 2019 is more fearsome.

To my eye (and most graphs), on this day 2019 looks worse. But given that the 2012 GAC was this week, it won't be for long. Unless...

My hunch is because the 2012 GAC did a lot to release heat that was entrained in deeper waters, 2013 and 2014 had less melt. 2019 looks like it is on trend, and that 'normal' conditions are getting close to 2012. I wont hold my breath for 'recovery' years in 2020 and 2021.

[petm]

My hunch is because the 2012 GAC did a lot to release heat that was entrained in deeper waters, 2013 and 2014 had less melt.

Very interesting point that I hadn't considered before.

and that 'normal' conditions are getting close to 2012

Sounds about right. 2012 was an unusually high deviation from the trend -- perfect storm conditions, as it were. The color palettes on brand new NSIDC interactive interface show this very nicely. The next perfect storm year may take us below 3 or god forbid lower.

[Sterks]

... Showing SLP anomaly, it strikes immediately the stability of Greenland High and quite some action over the Pacific side, with a very unquiet weather. Not that good for ice I would say.

Perhaps it is related with the chaotic state of the jet stream and of the airmasses after the ridge over Europe connected with the ridge over the Arctic. Just a wild guess.

BTW today’s wild forecast day 9 is a mega garlic press. Stay tuned for a completely changed wild forecast every day.

[philopek]

Beaufort continuing to get hammered now, and forecast to get hammered again on Monday, probably even worse. If the clouds clear later next week, it would be something to see. One-day difference of the part that's been cloud-free (and therefore probably not even the worst affected):
 
https://go.nasa.gov/2GDFtNZ

ESS still dropping at an unprecedented rate and CAA a little bit late but dropping now.

ECMWF and CMC but not GFS forecasting a wide, sub-980 low for d+7 (still teasing us).

All true and winds will blow straight out of McLure Straight, perhaps some ice in the luggage.

[petm]

Found a new comparison mode: "spy". Here's a part of the Beaufort melt edge, July 27 vs. 29 (chosen due to lack of cloud).

Move the cursor around. Click A or B to invert. Drag A or B to switch days. Click on "Compare Mode" under "Layers" to change between 3 available modes or to turn compare on or off.

https://go.nasa.gov/2YEom4D

[petm]

winds will blow straight out of McLure Straight, perhaps some ice in the luggage.

Hope so... it'll be fun to watch such ice melt!

[RoxTheGeologist]

My hunch is because the 2012 GAC did a lot to release heat that was entrained in deeper waters, 2013 and 2014 had less melt.

Very interesting point that I hadn't considered before.

The thin ice on the Greenland coast may also be indicative of heat building in deep waters. It's far north, and we have had plenty of Pacific to Atlantic drift this year, so why isn't it thick as usual? The only reason I can see for it being thinner is that the water is warmer! It strikes me that it's likely to be representative of the increasing heat build up in the intermediate waters. I'd say it would take a long time for extra heat to impact the surface, as it has to conduct through the halocline. If it is driven by conduction we wont be able to observe it with SST or salinity changes, so to test the theory we would have to have consistent buoy records going back a decade at least.

[pearscot]

My hunch is because the 2012 GAC did a lot to release heat that was entrained in deeper waters, 2013 and 2014 had less melt.

Very interesting point that I hadn't considered before.

The thin ice on the Greenland coast may also be indicative of heat building in deep waters. It's far north, and we have had plenty of Pacific to Atlantic drift this year, so why isn't it thick as usual? The only reason I can see for it being thinner is that the water is warmer! It strikes me that it's likely to be representative of the increasing heat build up in the intermediate waters. I'd say it would take a long extra heat to impact the surface, as it has to conduct through the halocline. If it is driven by conduction we wont be able to observe it with SST or salinity changes, so to test the theory we would have to have consistent buoy records going back a decade at least.

That's pretty much what my hunch is as well. I mean as much 'fun' the drama of huge storms like the GAC are, I think the actual beast lurking in the darkness are the ever growing/warming waters on the Pacific and Atlantic side. As far as I'm concerned, Atlantification is going to be the death spell of the ice and contains far more energy. The fact that the cold blob (which persisted for a while) below Greenland has disappeared, while at the same time a HUGE crack is slowly breaking the entire floating mass from land is scary to me. I'm not claiming both of those events are related (far beyond my knowledge) but it DOES point to the fact that I think ocean currents are changing.

My biggest fear are both the Pacific and Atlantic waters more or less meeting/combining in the CAB and then upwelling. To me, any strong indication of substantial changes to ocean currents inundating the Arctic Oceans seems like the nail in the coffin.

[VeganPeaceForAll]

Something to remember also about the Arctic sea ice melt, e.g. the ice North of Greenland:
""Over the last couple of days, you could see the warm wave passing over Greenland," she said. "That peak of warm air has passed over the summit of the ice sheet, but the clear skies are almost as important, or maybe even more important, for the total melt of the ice sheet."

She added that clear skies are likely to continue in Greenland "so we can still get a lot of ice melt even if the temperature is not spectacularly high."

From: https://m.phys.org/news/2019-08-walloped-greenland-massive-ice.html?fbclid=IwAR0xOyN8KHe2A7z3C5q6sZafhhZbErARvcrIk2Hdz_hU1p5MqiQt8_7Fguo

[petm]

Cyclone currently centered over the remaining Beaufort ice.

https://go.nasa.gov/2GH34x2

[Sterks]

The storm at Beaufort is ~990 hPa, nothing spectacular, but is sustaining impressive winds and currently pushing the floes against Banks Island, see one day change. This storm must have been doing a number, over the ice edge, and now will be passing directly over these floes.

[pearscot]

Cyclone currently centered over the remaining Beaufort ice.

https://go.nasa.gov/2GH34x2

wow...that really looks like a hurricane! I was reading Barrow's extended forecast details and strong winds were predicted there, which is a fair distance from the center. I'll be very interested to see the implications of that given high large the waves were from the last system to move thru.

[Sterks]

Cyclone currently centered over the remaining Beaufort ice.

https://go.nasa.gov/2GH34x2

Wow. I was looking at the same thing, but focusing on the small open window thru the clouds. That explains...

[philopek]

Make this a double cyclone, side by side.

Key is that current wind direction and air temps exactly over the part of the ice that was not there in 2012, means for me we gonna see par in that area in around 2 days.

https://earth.nullschool.net/#current/wind/surface/level/overlay=temp/orthographic=-0.90,87.31,1336/loc=-135.027,74.329

[petm]

Yeah, up to 4m wind waves near the ice edge according to windy (ECMWF WAM). I'm starting to think the pressure value of a cyclone is far from the whole story...

[Sterks]

Yeah, up to 4m wind waves near the ice edge according to windy (ECMWF WAM). I'm starting to think the pressure value of a cyclone is far from the whole story...

Yes, it’s also surrounded from high pressure “walls” do to speak so it’s small but powerful. How it gets the energy, above my head.
Wow the effect is gonna be big

[Sterks]

From the EC forecast I count three storms messing with Beaufort in 10 days.
The second one, coming in the next two or three days, will be sweeping the entire pacific edge, and also seem small but packed with winds due to its interaction with ~1020 hPa high dominating the Pacific side eventually.

[petm]

July 23 - Aug 1 (2 weeks)

3-day trailing median (left) vs. original Bremen map (right)

Click.

[Sterks]

The injection of heat from the Pacific and a prominent ridge now shows from day+5 of the EC ensembles.

[iceman]

I enjoy your analysis.  I don’t care where it gets posted, but I hope you continue to post it.  I don’t know why there has been push back.  Lots of people speculate on here and it is fun to look at the guesses and see how they turn out.

Posting location matters for future reference (as well as current streamlining). When we're trying to compare, say, 2023 to 2019, it will be useful to have the 2019 vs. 2012 analysis compiled mostly in one thread.

[GoSouthYoungins]

This insolation graph gets posted from time to time, but I think it is missing a cruicial component for best understanding. So I added it. At approx 350, the insolation/radiation balance seems to be achieved.

As we enter the final month of melt, we can see that pretty much all the sun energy excess is in the past, and now a good stirring is what the melt doctor should write a prescription for.

(Once the ESS finishes melting out in a week or two, conditions for cyclone creation will be as ideal as possible in the Arctic.)

[Shared Humanity]

July 23 - Aug 1 (2 weeks)

3-day trailing median (left) vs. original Bremen map (right)

Click.

The state of the ice along the coast of the CAA and Greenland is unprecedented IMHO. It does not guarantee a new record for 2019 but it does not bode well for future melt seasons.

[petm]

NW Passage has been clearing out quickly in the last few days. Only remaining obstacle is the ice south of Prince of Wales Island (Larsen Sound), correct? That ice is clearing out fast. Maybe it will open in about a week.

[Freegrass]

Found a new comparison mode: "spy".

I like to use that mode this way. It makes it easier to see all the ice, and it's not looking good north of the fram strait.

https://go.nasa.gov/2GIEqMM