The 2020 melting season

[wdmn]

I'm really surprised at how long it can take for what appears as slush on worldview to melt out. For example this patch of "ice" in Hudson's Bay, which -- according to nullschool -- is in water well above -1.8C. Why wouldn't this go poof? Is it the lack of movement, which creates a cool pocket? Surely if there was wind this would disappear over the course of a day?

GIF of the last three days.

[Freegrass]

I get that, but can you actually see it? or measure it? I picked one floe that was easy. Normally we see 'goodbye waves' but I assume some other process happens in open water in the 'crack'.

edit: ok. It was easy to fine 'glue ice' melting too.

I keep wondering how much of that ice is still MYI, and how much is FYI. MYI ice melts away from the top, and refreezes at the bottom. So how much of that MYI is really still MYI, and not FYI that was added through winter?

[oren]

The main area where 2019 has more ice is in the ESS

MH, I am surprised you do not mention the big advantage 2020 has over 2019 along the Atlantic front and in the Laptev.

[Anne]

I get that, but can you actually see it? or measure it? I picked one floe that was easy. Normally we see 'goodbye waves' but I assume some other process happens in open water in the 'crack'.

edit: ok. It was easy to fine 'glue ice' melting too.

I keep wondering how much of that ice is still MYI, and how much is FYI. MYI ice melts away from the top, and refreezes at the bottom. So how much of that MYI is really still MYI, and not FYI that was added through winter?

PMFBI and stating the obvious - I wonder this too. You can't always eyeball the 90% below the waterline.

[Michael Hauber]

The main area where 2019 has more ice is in the ESS

MH, I am surprised you do not mention the big advantage 2020 has over 2019 along the Atlantic front and in the Laptev.

I started with mentioning that extra ice in Atlantic last year looked roughly equivalent to extra ice in Beaufort this year and then decided to go for simplicity and deleted that part.

[thejazzmarauder]

I'm really surprised at how long it can take for what appears as slush on worldview to melt out. For example this patch of "ice" in Hudson's Bay, which -- according to nullschool -- is in water well above -1.8C. Why wouldn't this go poof? Is it the lack of movement, which creates a cool pocket? Surely if there was wind this would disappear over the course of a day?

GIF of the last three days.

This example only strengthens my belief that, at least until late summer, bottom-melt isn't often the primary culprit of notable melt. I wonder if mechanical factors don't deserve much of the credit that bottom-melt gets for melting sea ice in July.

[Neven]

I started with mentioning that extra ice in Atlantic last year looked roughly equivalent to extra ice in Beaufort this year and then decided to go for simplicity and deleted that part.

And then you decided to go for even more simplicity and not mention the weather. 

But of course, it's always possible that 2020 still comes in third. It's just going to take exceptionally cold and windless weather.

[UCMiami]

I'm really surprised at how long it can take for what appears as slush on worldview to melt out. For example this patch of "ice" in Hudson's Bay, which -- according to nullschool -- is in water well above -1.8C. Why wouldn't this go poof? Is it the lack of movement, which creates a cool pocket? Surely if there was wind this would disappear over the course of a day?

GIF of the last three days.

Without serious movement/current, the energy required to melt the ice cools the water and creates a lens of cold water around it - the north of the basin is around 10C SST, the area where the ice remains is close to zero.

There isn't much surface current and the wind hasn't moved the remnants far, but the numbers in the extent and area thread are still recording multiple sq km of ice disappearing every day. 13 km since the 24th.

[ArcticMelt2]

I'm really surprised at how long it can take for what appears as slush on worldview to melt out. For example this patch of "ice" in Hudson's Bay, which -- according to nullschool -- is in water well above -1.8C. Why wouldn't this go poof? Is it the lack of movement, which creates a cool pocket? Surely if there was wind this would disappear over the course of a day?

GIF of the last three days.

Without serious movement/current, the energy required to melt the ice cools the water and creates a lens of cold water around it - the north of the basin is around 10C SST, the area where the ice remains is close to zero.

There isn't much surface current and the wind hasn't moved the remnants far, but the numbers in the extent and area thread are still recording multiple sq km of ice disappearing every day. 13 km since the 24th.

It could be a pressure ridge, so the ice is very thick here. In the Central Arctic, the wind drives the ice in about the same direction.

https://en.wikipedia.org/wiki/Pressure_ridge_(ice)

One of the largest pressure ridges on record had a sail extending 12 metres (39 ft) above the water surface, and a keel depth of 45 metres (148 ft).[6] The total thickness for a multiyear ridge was reported to be 40 metres (130 ft).[11] On average, total thickness ranges between 5 metres (16 ft) and 30 metres (98 ft),[2] with a mean sail height that remains below 2 metres (6.6 ft).[7]

[wdmn]

@UCMiami

Yes, I can see the ice remnants, if mostly stationary, creating a microclimate through their melt, causing a negative feedback that slows further melt.

@thejazzmarauder
I think bottom melt can be extremely significant from early in the season, but it has more to do with how much the water is moving. Moving water has friction as well as getting rid of delays in thermal conductivity as adjacent water has to warm the lens of meltwater around the ice when there is no movement. (This is layman's physics, I could be wrong).

@arcticmelt
It doesn't look thick right now, though it may have been at the start of the melt season. It looks like very decayed ice/slush.

[Paul]

The main area where 2019 has more ice is in the ESS

MH, I am surprised you do not mention the big advantage 2020 has over 2019 along the Atlantic front and in the Laptev.

But then 2020 has a big advantage in the Beaufort and ice in that area will melt out more between now and September thus reducing the chances of finishing 3rd. Of course we must remember the Atlantic ice retreated quite a bit in September 2019 which meant it dropped below 4million and we are already near those levels now on the Atlantic side.

Really what the ice needs in the 2nd half of August is a cold slack Arctic high to lower the temperatures over the ice and perhaps start filling any holes in the interior of the ice pack.

In general though, the current weather outlook should favour the sea ice but whether it will or not this year remains to be seen.

[Pagophilus]

I believe this is the ice through a gap in the clouds in the Chukchi-Beaufort area, the place where the low has centered over the past few days.  This is the first time the clouds have really cleared in this area

The ice looks like it has taken a tremendous beating...  I must confess I was rather shocked when I saw it.

First image closeup, second more zoomed out, third image is for geographical context.

The area of 'low concentration' on the Bremen AMSR2 map for July 29 (one of those surprising 'hey we can see the storm on AMSR2' images) kinda sorta lines up with this low concentration ice.  Uniquorn called the low concentration of this ice in Reply 4160.

[Pagophilus]

I pushed contrast on the Worldview image below to try to 'see' the ice below some of the lighter clouds.

Click on the image, magnify to see more.  For me, it is hard to avoid the impression that almost all the icepack on the Alaskan side is now Swiss cheese as far as 80 degrees N.

By all means pull me back if I am over-interpreting.

[Frivolousz21]

The Pacific side is going to melt out to at least 80 degrees north everywhere except for maybe the far Southern Beaufort where there's multi-year ice


Modis shows the ice has been rocked on the Pacific side.

It has the flat darkish gray look everywhere. This is the end before melt out.

I have been really busy so I haven't been able to read through this thread.

But I called it a couple days ago that if the Pacific side didn't melt immediately underneath this vortex that people would come out and claim that this year was going to finish like third or higher.


There is no chance of it finishing third or higher regardless of the weather no chance the Arctic is loaded with heat everywhere.


It is possible that 2020 will finish second if the weather is extremely favorable the rest of the way. 

A and even then it's pretty sketchy that that will happen

[Rod]

In general though, the current weather outlook should favour the sea ice but whether it will or not this year remains to be seen.

You said the same thing last night, and I asked you about it and you did not respond.

I’m not trying to be rude. I just want to understand what you see that I am missing.

What is it in the current weather pattern that you think favors the sea ice?

[wallen]

Tend agree with Friv, about 2020 not finishing 3rd or higher. Given the state of the ice and the considerable extent lead it still has over the previous years. Gerontocrat's assessment that as at 29/7 (For the minimum to be above 4.0 million km2,  remaining melt needs to be  20.0% or more below the previous 10 years average remaining melt.), I believe gives credence to this.

This aside, I am curious as to what would be the worst specific scenario(Weather wise) for the ice from now to the end of the melt season.

[Juan C. García]

The quick view of today Bremen ASI Concentration.

I think that there is almost no ASI frontier in which there is no melting going on.
Of course, Chukchi and Beaufort don't look good.
If this were the image of August 10th, I would feel more confortable. But it is the end on July.

[UCMiami]

The fact that 2020 has just gone through a week of significant slow down and is still 220k ahead of 2019 which is about to start its own 4 day slow down and 350k ahead of 2012 which is about to enter a 4 day pause in decline is pretty impressive. That so far 2020 area decline has accelerated during this same week is even more impressive. The ice that can be seen is no longer 'compacted', the heater is still blowing across the arctic, and the weather forecast calls for this same stirring to move to the CAA another area where the ice is already breaking up.

None of that suggests this is a good omen for ice retention. Maybe 2020 needs more stormy weather in August  to continue the current record breaking destruction, but anything less than second place seems like wishful thinking. And first place is still on the table.

[Frivolousz21]

In general though, the current weather outlook should favour the sea ice but whether it will or not this year remains to be seen.

You said the same thing last night, and I asked you about it and you did not respond.

I’m not trying to be rude. I just want to understand what you see that I am missing.

What is it in the current weather pattern that you think favors the sea ice?

He recently made the statement that the huge losses/highly anomolous temps were only over areas with low thickness according to piomas. 

I responded asking how that is so when the Southern CAB and Atlantic side have been torched which are the only two areas where piomas had abnormally thick ice. 

I essentially said that's a pretty disingenuous statement from an intelligent poster.

Didn't get a response.

That kind of wrangling the discussion thread is not the most honorable way for a man to participate here trying to be of total integrity regardless of if they end up wrong

I might end up wrong.  Has happened a lot.


Anyways regardless of whether he responds he is right. The current weather is generally good for the ice.  Or is trending that way slowly as the anomolous heat backs off over the Eastern half of the CAB.

The cooler overcast over the Pacific side is good for slowing melt

Although it won't prevent most of that ice from melting since it's so thin now which can be inferred  through modis and amsr2 products.






The general wind pattern is currently a reverse dipole which is spreading the ice out.

The ice isn't going to move very much so only the edges get displaced into the inferno waters

While outgoing winds dampen waves within the ice pack and blow's the torching water away from the ice.

In this case the Chuckchi, ESS, Laptev are all in the exit zone of the reverse dipole.

But it' varys from day to day.



The bigger question is what is being protected?  The Pacific ice South of 80N is toast.

Some ice in the Beaufort but mostly the Western CAB will survive.

But almost all of the ice that Bremen has categorized as 35-60 percent Concentration (the greenish hues) is toast.

Thats been like the entire Pacific side South of 80 the last 3 days.  The rest of the CAB has been smoked. The Southern CAB we will find out soon how bad.

So yeah what's left in parts of the CAB will benefit from melt being slowed.

Whoi bouys show sustained bottom melt in the Beaufort at least to 75N.  They also show a quick spike in salinity the last couple days.  A sign of near surface overturning of the fresh water layer.

If that is the case the layer below it is torching.

[binntho]

I'm really surprised at how long it can take for what appears as slush on worldview to melt out. For example this patch of "ice" in Hudson's Bay, which -- according to nullschool -- is in water well above -1.8C. Why wouldn't this go poof? Is it the lack of movement, which creates a cool pocket? Surely if there was wind this would disappear over the course of a day?

This is definitely not MYI - the Hudson melted out completely last year (if you want to verify this, look at EOSDIS Worldview starting c.a. 10th September last year. The following days have clear skies over different parts of the Hudson proper, no ice in sight.

ArcticMelt2 pointed out that these could be pressure ridges. I'd like to extend that to this being remnants of pressure ridges and stacks that have been pushing and piling up against the shore all winter. These thick chunks have now drifted away from the coast and are slowly but surely melting away.

But this shows how unduly optimistic/pessimistic (take your pick)  the "this ice looks like slush, should melt out in a couple of days" statements that one sees frequently in the forum are.

[Frivolousz21]

Tend agree with Friv, about 2020 not finishing 3rd or higher. Given the state of the ice and the considerable extent lead it still has over the previous years. Gerontocrat's assessment that as at 29/7 (For the minimum to be above 4.0 million km2,  remaining melt needs to be  20.0% or more below the previous 10 years average remaining melt.), I believe gives credence to this.

This aside, I am curious as to what would be the worst specific scenario(Weather wise) for the ice from now to the end of the melt season.

the worst pattern would be something like this:
I pulled this from August  2007.

Its very unlikely this happens this August.


But a dipole like this would drop extent and area down into the 2.0-2.5 mil range if it lasted for a couple weeks

[Frivolousz21]

The quick view of today Bremen ASI Concentration.

I think that there is almost no ASI frontier in which there is no melting going on.
Of course, Chukchi and Beaufort don't look good.
If this were the image of August 10th, I would feel more confortable. But it is the end on July.

Really the entire Pacific is in the green range. 

Just mostly covered in clouds.

Check this out. 

Its from AMSR2.

I used the 26th and  30th.

It shows three Pacific  side ice took a total beating.

Absolutely massive  change.   Also the melting graphic shows how wet the ice is.

[Rod]

I'm really surprised at how long it can take for what appears as slush on worldview to melt out. For example this patch of "ice" in Hudson's Bay, which -- according to nullschool -- is in water well above -1.8C. Why wouldn't this go poof? Is it the lack of movement, which creates a cool pocket? Surely if there was wind this would disappear over the course of a day?

This is definitely not MYI - the Hudson melted out completely last year (if you want to verify this, look at EOSDIS Worldview starting c.a. 10th September last year. The following days have clear skies over different parts of the Hudson proper, no ice in sight.

ArcticMelt2 pointed out that these could be pressure ridges. I'd like to extend that to this being remnants of pressure ridges and stacks that have been pushing and piling up against the shore all winter. These thick chunks have now drifted away from the coast and are slowly but surely melting away.

But this shows how unduly optimistic/pessimistic (take your pick)  the "this ice looks like slush, should melt out in a couple of days" statements that one sees frequently in the forum are.

I’m sorry, but I followed this discussion back as far as I could and no one said anything about MYI. The people involved in this discussion raised reasonable questions, and had reasonable responses.

[wallen]

Thank you for that reply Friv.

[Freegrass]

Latest Five Day Forecast
Wind + Temp @ Surface
Large GiF!

[binntho]

I’m sorry, but I followed this discussion back as far as I could and no one said anything about MYI. The people involved in this discussion raised reasonable questions, and had reasonable responses.

You are absolutely right. I misread another posters comment that had nothing to do with Hudson ice. But through my misunderstanding I became curious whether there was some small possibility of MYI in the Hudson, hence the Worldview check (not that I expected to find any).

[Frivolousz21]

For anyone interested here is 2020 versus 2019, 2016, 2012....

[Frivolousz21]

Seriously  tho.  Click this if you want to see what the STORM DID...

WRECKED THE PACIFIC SIDE....


The second one is over the Southern Chukchi

[S.Pansa]

Wrecked the pacific side - very much so. Worldview's view on the wracking shown by the two first GIFs below: Chukchi and Beaufort seas between 21/07 and 31/07 (click to see the rocky horror picture show)

The GIF of TOPAZ4 31/07-08/08 indicates, that the 'real damage' is still to come (bottom melt from all the up-welling?).

In other news: While all the action seems to be on the Pacific side,  the Atlantic side is dying a slow death me thinks - obscured in the last few days by low clouds.

[BornFromTheVoid]

An update on the side by side comparison. Those apparent concentration drops are looking more real than not.
Slightly higher res version on twitter, for those without data limits: https://twitter.com/Icy_Samuel/status/1289080922617372672

(Large file, click to play)

[Aluminium]

July 26-30.

2019.

[Gizmo]

An update on the side by side comparison. Those apparent concentration drops are looking more real than not.
Slightly higher res version on twitter, for those without data limits: https://twitter.com/Icy_Samuel/status/1289080922617372672

(Large file, click to play)

That is amazing.  Fingerprint of the storm.

[blumenkraft]

I'm really surprised at how long it can take for what appears as slush on worldview to melt out.

...

Is it the lack of movement, which creates a cool pocket?

SST shows a -ve anomaly. Therefore my bet is on the cool pocket (i.e. micro-climate).

[uniquorn]

Whoi bouys show sustained bottom melt in the Beaufort at least to 75N.  They also show a quick spike in salinity the last couple days.  A sign of near surface overturning of the fresh water layer.
If that is the case the layer below it is torching.

Best not to read too much into the recent itp114 profile, both itp113 and 114 profilers have been stuck below 250m for the last few days due to high drift speed. More details here

[Mark Tough]

Amazing Aluminium,

Always click your work and get the best overview of what's happening with the ice. This time it's scary but oh so real.

[Paul]

In general though, the current weather outlook should favour the sea ice but whether it will or not this year remains to be seen.

You said the same thing last night, and I asked you about it and you did not respond.

I’m not trying to be rude. I just want to understand what you see that I am missing.

What is it in the current weather pattern that you think favors the sea ice?

I just want to say I genuinely did not see your post so apologies for that.

In answer to your post because traditionally reverse dipoles tends to favour slower ice melt as it usually means cooler temperatures and ice spread. Of course I've always maintain the caveats that it's in theory and this year could be different because of what happened so far but put it this way, the current set ups look less threatening than a huge dipole for example.

I've always maintained that I think we will finish 2nd lowest but avoid the record of 2012 but I said also its irrelevant if we are lowest or not as this season continues the trend of faster ice melt regardless where we finish up.

[Tammukka]

What is the change that hurricane isaias will affect arctic? Or atleast southern Greenland?https://www.nhc.noaa.gov/graphics_at4.shtml?start#contents

[Freegrass]

Latest Five Day Forecast
Wind @ Surface
Large GiF!

[oren]

Latest Five Day Forecast
Wind @ Surface

Seems the Atlantic inflow/WAA will be finally coming to an end.

[Pagophilus]

NSIDC sea ice extent comparison, July 30 2020 vs same day, 2012, 2016, 2019.

2020 used to lag on the Atlantic side.  No longer.

[Paul]

In general though, the current weather outlook should favour the sea ice but whether it will or not this year remains to be seen.

You said the same thing last night, and I asked you about it and you did not respond.

I’m not trying to be rude. I just want to understand what you see that I am missing.

What is it in the current weather pattern that you think favors the sea ice?

He recently made the statement that the huge losses/highly anomolous temps were only over areas with low thickness according to piomas. 

I responded asking how that is so when the Southern CAB and Atlantic side have been torched which are the only two areas where piomas had abnormally thick ice. 

I essentially said that's a pretty disingenuous statement from an intelligent poster.

Didn't get a response.

I thought I responded to this or at least to another poster on this issue.

It is correct to say the extreme losses was caused in areas which had thinner than average ice cover. Ive said from the very start the ESS this year looks very vulnable and we could see very fast melting like we did in 2007 and 2017. The Laptev retreat caught me out a bit but PIOMAS also had this area largely in the blue anaomoly so this area was also vulnable.

People wondered why did ice volume has not went down as much as they expected, its because most of the ice losses occurred in areas where ice volume/thicknesses was below normal and the supposed thicker ice area like the Beaufort sea has not melted out yet but no doubt with ice thinning, we would be losing volume regardless.

I've also mentioned that we got to be careful reading too much into the red on the Atlantic side because it does not necessary means the ice is thick. Why that might be? Because its an anaomoly chart between 2011 and 2018  and there's been times where that area has been ice free especially around Svalbard so any ice that is recorded there even if its thin ice would likely show as a red anaomoly. I've no doubt some of the Atlantic front would add upto the volume but its the one area where even if its red showing, it does not mean its thick ice.

To give a clearer example. If Scandinavia had the coldest winter on record and the Baltic sea virtually all froze over, that area would show up as a positive(red) anaomoly even if the ice cover is very thin because the Baltic sea has struggled to gain much ice during the 2011-2018 period.

Hope this makes some sence and I don't intend to mislead people. It's just how I see it from reading those charts.

[glennbuck]

Arctic sea ice area for July 30th,  3,746.526 km^2. NSIDC Daily Area.

lowests minimum: 2.241 (2012), 2.477 (2016)

Graph by Nico Sun, https://cryospherecomputing.tk/

Will be posted on the off topic thread in future.

[Pagophilus]

Latest Five Day Forecast
Wind @ Surface

Thanks, Freegrass.
So the low is threatening to morph into another low on day 5?

[FishOutofWater]

The remnants of hurricane Isaias will ultimately be taken up into the large north Atlantic low southeast of Greenland and will likely contribute to building a blocking high over Scandinavia and the Barents sea. This evolving forecast may bring more Atlantic heat to the Arctic. This year's active hurricane season and this summer's melt pattern is related to a build up of heat in the north Atlantic ocean and advection of that heat into the Arctic. Of course, there is also a crazy amount of heat that has been advected from the Eurasian continent towards the Arctic. The hurricane will be a bit player in this story.

Note, according to the Climate Reanalyzer, northern hemisphere sea surface temperatures are 1.0 Celsius above the old normal, I believe 1970 to 2000. (There are problems with the normals shifting on different SST anomaly maps.)

Global tropical convection, the MJO, has been stuck over the African/Eurasian sector since June. This ties in with the situation in the Arctic via Rossby waves. Several excellent papers have been cited in comments above related to the crazy weather we have been watching. It's all tied together, but the hurricane won't be an issue for the ice. How the stratospheric polar vortex develops will be a major issue over the rest of the melting season because it may bring on more cyclonic activity like the not so great Arctic cyclone we just observed.

[Pagophilus]

July 26-30.

Thanks again, Aluminium.  They should hire you at Bremen University.

That last frame is extra-significant, I think, because it does not just show the black 'low concentration markings' that are sometimes somewhat transient, but a honeycomb of blue open water that is confirmed by the Worldview image (below).  When AMSR2 shows this, it is further confirmation that matters have gone to the next level for me.

[kassy]

Sea ice Concentration July 30th.

There is no need to regularly post redundant graphics like this or #4241 in this thread.

[oren]

Sea ice Concentration July 30th.

There is no need to regularly post redundant graphics like this or #4241 in this thread.

I agree. Post them every few days, not daily, unless you have some special reason or special analysis to go with them.
Even better, group them together to reduce post load on the thread, rather than one image per post.

[Freegrass]

Latest Five Day Forecast
Wind @ Surface

Seems the Atlantic inflow/WAA will be finally coming to an end.

It looks like it, but not before a big gap could open up on the north-east corner of Greenland. The ice there isn't that strong I think.

Curious to see if a new storm will materialize like the long-term forecast sometimes predicts. IMO there's enough energy available for another big August storm or two. Time will tell...

[gandul]

An update on the side by side comparison. Those apparent concentration drops are looking more real than not.
Slightly higher res version on twitter, for those without data limits: https://twitter.com/Icy_Samuel/status/1289080922617372672

(Large file, click to play)

Nice hole
The effects of the storm are in a very vulnerable region, expect gradual meltout including the rest of Chukchi and Beaufort seas until october

[glennbuck]

It looks like it, but not before a big gap could open up on the north-east corner of Greenland. The ice there isn't that strong I think.

I was looking at that area on the north-east corner of Greenland and agree a big gap could open for ice above it to escape into the Greenland Sea. Taking chunks out of the Arctic North Pole area from the south, while the Laptev/Kara Sea suck out/blown sections from the North East side melting in the warmer seas..

<Image already posted today, removed. O>