The 2020 melting season

[Rod]

They may cancel each other out, but the point is that it makes it hard to compare year to year values.

That is why extent is the value that is used for the official number.  NSIDC has a discussion on this on their web page. 

Again, area is important to look at, but you have to remember that a foggy day, or clouds with high moisture content, or any of a number of factors could trick the sensors and make comparison from one year to the next difficult.

[Michael Hauber]

72 hours until we see what happens when low pressure system takes over the Arctic.  In my opinion we will see the most dramatic slow down in extent drop in history.  Largely because the recent drop has been unprecedented (so a drop even to normal is a very big drop), and also because such a strongly compacted ice pack will accentuate the slow impacts of a switch to cool and cloudy conditions.

A wrinkle in the forecast is that there is hints of a high pressure system building into the Arctic from the Atlantic side in around 7 days time.  At this stage it looks a long way from a return to the extreme melt conditions we have seen recently.

[VeganPeaceForAll]

Regarding the heatwave over Siberia which is has having a big impact on the melt season:

The results showed with high confidence that the January to June 2020 prolonged heat was made at least 600 times more likely as a result of human-induced climate change.
We note that even with climate change, the prolonged heat was a very rare event expected to occur less than once every 130 years.
The results for the town of Verkhoyansk show that the record breaking June temperatures were also made much more likely (upwards of many thousands of times), though there is less confidence in this result.
Combining the values from the models and weather observations shows that for the large region the same six-months hot spell would have been at least 2 degrees Celsius cooler had it occurred in 1900 instead of 2020. For Verkhoyansk, maximum June temperatures increased due to climate change by at least 1 degree compared to 1900.

https://www.worldweatherattribution.org/siberian-heatwave-of-2020-almost-impossible-without-climate-change/?fbclid=IwAR07PNoPsnmaoygihf5FXFuynKpuMvPeknq9Z1MhBnNl85k5SHwjI9IjII0

[bbr2315]

72 hours until we see what happens when low pressure system takes over the Arctic.  In my opinion we will see the most dramatic slow down in extent drop in history.  Largely because the recent drop has been unprecedented (so a drop even to normal is a very big drop), and also because such a strongly compacted ice pack will accentuate the slow impacts of a switch to cool and cloudy conditions.

A wrinkle in the forecast is that there is hints of a high pressure system building into the Arctic from the Atlantic side in around 7 days time.  At this stage it looks a long way from a return to the extreme melt conditions we have seen recently.

A large chunk of the "strongly compact" ice is under .5-.25M  in thickness, what and where is this illusive strong ice you are discussing?

[Frivolousz21]

Hi Jim, how are you?

At the risk of drifting off topic, I reckon I had a dose of Covid-19 (or something a lot like it!) over Xmas following an evidently rash trip across the River Tamar into Devon.

Suitably brassed off with BoJo's response to both "climate change" and Covid, perhaps great minds think alike?



Except that Elon et al. are allegedly not into AC V2G!

Meanwhile back in the high res Arctic:

So is that the lowest years???  That's exactly how I would expect area to look on a good high res scan.

While NSIDC and it's 25km grid and the algorithm is old School

[Artful Dodger]

Why are extent numbers dropping like a stone, and extent is #1, while area numbers are just bumbling along in #3 position?

Sea Ice Area, as captured by passive radar from satellites, is not an especially reliable metric (read: noisy) for sea ice loss (the underlying variable of interest) during the Summer months:

• melt ponds form slowly (which can appear to reduce area), then drain suddenly (appearing to increase area), all without capturing much of the underlying melt dynamics
• variable clouds can block observations making obscured areas seem more concentrated

These problems (and more I'm sure the researchers know about that I don't), are literally the reason the concept of Sea Ice Extent (SEI) was invented. It's an attempt to give a more reliable measurement of the state of the sea ice.

Once the pack firms up with the refreeze, then area once more becomes a reliable measure, it's just that we want to know about the Summer minimun above all else. Drat!

Cheers!

[Jim Hunt]

So is that the lowest years???  That's exactly how I would expect area to look on a good high res scan.

While NSIDC and it's 25km grid and the algorithm is old School

It's every year since AMSR2 first flew, with the data starting flowing part way through the 2012 melting season.

Based on 3.125 km gridded data using the ARTIST Sea Ice (ASI) algo.

[KenB]

This map posted by Zack Labe today showing the January to June 2020 temperature ranks is pretty incredible!

Notice there are no blue colors anywhere on the map. And, Siberia 🔥🔥🔥!

There is a blip of blue in India adjacent to the Himalayas and I would imagine there would be quite a few blue areas if this was Jan-Mar and Apr-Jun instead of a six month block. With blues appearing in Apr-June across parts of North America and the Himalayas.

The graphic itself doesn't specify the time period over which top/bottom five are being figured, but from the source: http://berkeleyearth.org/june-2020-temperature-update it's since 1850, so 170 years. 

According to this source for the graphic there are no record cold spots (so no blue blips):  "Looking at regions where January to June temperature averages were either the top 5 warmest or the top 5 coldest observed, we note extensive regions with record or near-record warmth during the first half of the year and no regions of near-record cold."  (my emphasis)

Whether there would be many (or indeed, any) places with average temperatures for *any* three months of 2020 in the lowest 5 spots out of the last 170 years I leave to others to look, but I'd be very surprised. 

[bbr2315]

This map posted by Zack Labe today showing the January to June 2020 temperature ranks is pretty incredible!

Notice there are no blue colors anywhere on the map. And, Siberia 🔥🔥🔥!

There is a blip of blue in India adjacent to the Himalayas and I would imagine there would be quite a few blue areas if this was Jan-Mar and Apr-Jun instead of a six month block. With blues appearing in Apr-June across parts of North America and the Himalayas.

The graphic itself doesn't specify the time period over which top/bottom five are being figured, but from the source: http://berkeleyearth.org/june-2020-temperature-update it's since 1850, so 170 years. 

According to this source for the graphic there are no record cold spots (so no blue blips):  "Looking at regions where January to June temperature averages were either the top 5 warmest or the top 5 coldest observed, we note extensive regions with record or near-record warmth during the first half of the year and no regions of near-record cold."  (my emphasis)

Whether there would be many (or indeed, any) places with average temperatures for *any* three months of 2020 in the lowest 5 spots out of the last 170 years I leave to others to look, but I'd be very surprised.

I think you are wrong. In fact, the magnitude of the cold over the Himalayas and Tibetan Plateau this April-June has actually been more severe than the warmth over Northern Eurasia although the latter occurred over a wider area -- the cold pocket in North America has also been substantial. I would wager if the April-June period were isolated the Himalayan situation would be top 3 since 1800s and Canada would be top five (both ranking in your chart).

Both of these discrepancies are crucial pieces of the puzzle to the Arctic's current state.

[VeliAlbertKallio]

The conditions of direct sunlight help us to determine 2020 sea ice area. Should not have been too difficult this summer if one has access to NASA Worldview and spectacles. Cloud free season is luckily exception: sometimes knowing less the ice is better for it - much akin it is to Schrödinger's Cat...!

Area numbers are very difficult to interpret in the summer.  That is why the official numbers are always reported as extent. Extent is certainly not perfect, but at least it is consistent.

People on this forum are very good at interpreting area numbers in the summer. Probably as good as the sea ice scientists. But, it is still impossible to rely on them. Wet clouds, dense fog, wet ice, melt ponds, rain, fresh snow, overnight freeze,  etc ... all cause bumps in area data.

Area is helpful in the summer, but the numbers need to be taken with a grain of salt.

[Rod]

I don’t really get your point Veli.

I was simply trying to explain to Pagophilus why area numbers are sometimes misleading in the summer.

However, I do love a physics conversation! But, we are not allowed to have it in this thread.

If you want to talk about Schrödinger’s cat and quantum mechanics, I’m happy to engage. But we can’t do that in the melting thread.

[bbr2315]

Bbr, you have always been one of my favorite weather guys on this forum even though you are sometimes unpopular. But, you are way the fuck out on a limb on this one. You can not possibly believe that there is some “missing” data that changes what Berkeley Earth reported. That is nuts!

You can disagree with their data, but they are one of the top three weather reporting agencies in the world right now.

? I literally do not know what you are talking about, I didn't say they were missing data, I said that taking a six month snapshot does not show you an accurate picture of what has been going on when certain regions that have shifted from record + to record or severely - may average out as normal when the sensible weather has been anything but.

It is the equivalent of saying "oh NYC had its record warmest year by a degree but we are not going to mention the fact that it happened because it was +15 in DJF and -10 in March and April and May because that is irrelevant" when such a discrepancy would literally result in winter occurring in March and April and May instead of December and January and February and would consequently be devastating to agriculture / normal life / etc. Glossing over what makes up "X anomaly" is literally ignoring the actual weather occurring on the ground and is not sound science.

[Paul]

72 hours until we see what happens when low pressure system takes over the Arctic.  In my opinion we will see the most dramatic slow down in extent drop in history.  Largely because the recent drop has been unprecedented (so a drop even to normal is a very big drop), and also because such a strongly compacted ice pack will accentuate the slow impacts of a switch to cool and cloudy conditions.

A wrinkle in the forecast is that there is hints of a high pressure system building into the Arctic from the Atlantic side in around 7 days time.  At this stage it looks a long way from a return to the extreme melt conditions we have seen recently.

I think ironically, a huge slow down is perhaps worse for the ice long term as it would suggest huge spreading out of the ice and possibly weakening the CAB ice as a result. I would prefer if its a more gradual process of trying to rejoin the pack.

There was perhaps some surprise and even suspicion of the PIOMAS volume charts, I do think we got to remember, alot of the rapid melt occured where ice thicknesses were below normal to start off with so whilst alot of extent has been reduced, there has been less volume loss because that part of the ice was not all that thick.

I know the compactness debate has been talked about alot but the theory would suggest a compact ice cap should be harder to melt than a more diffused one but like last year, I do fear SSTS will overrule any compactness especially on the Atlantic/Laptev edge. I also think Area has some positives of measuring during summer and there does seem to be link that if extent is high but area is low, a rapid drop is due but perhaps its more inconclusive the other way round?

[Pagophilus]

Why are extent numbers dropping like a stone, and extent is #1, while area numbers are just bumbling along in #3 position?

Sea Ice Area, as captured by passive radar from satellites, is not an especially reliable metric (read: noisy) for sea ice loss (the underlying variable of interest) during the Summer months:

• melt ponds form slowly (which can appear to reduce area), then drain suddenly (appearing to increase area), all without capturing much of the underlying melt dynamics
• variable clouds can block observations making obscured areas seem more concentrated

These problems (and more I'm sure the researchers know about that I don't), are literally the reason the concept of Sea Ice Extent (SEI) was invented. It's an attempt to give a more reliable measurement of the state of the sea ice.

Once the pack firms up with the refreeze, then area once more becomes a reliable measure, it's just that we want to know about the Summer minimun above all else. Drat!

Cheers!

Thank you, Mr. Hawkins!   And Paul.  That helps a lot. 

My radar on this is still up though (I realize the scientific world is not trembling), since if the situation of relative positions persists as so much else changes, why would that be so? 

[Frivolousz21]

The most recent day where extent did not have a century drop was July 2nd. If these century drops continue for the rest of July, sea ice extent will drop to 5,551,222 square kilometres or lower. The record low for July 31st is currently taken by 2019 at 5,955,851, which is over 400k higher than this extrapolation.

True that "IF" but they won't 

There is no doubt about that.

We are looking at a big slow down for a few days at least.

Unless the ESS/Chuchki/CAB start melting out insitu like the NORTHERN LAPTEV

[Rod]

Bbr, you have always been one of my favorite weather guys on this forum even though you are sometimes unpopular. But, you are way the fuck out on a limb on this one. You can not possibly believe that there is some “missing” data that changes what Berkeley Earth reported. That is nuts!

You can disagree with their data, but they are one of the top three weather reporting agencies in the world right now.

? I literally do not know what you are talking about, I didn't say they were missing data, I said that taking a six month snapshot does not show you an accurate picture of what has been going on when certain regions that have shifted from record + to record or severely - may average out as normal when the sensible weather has been anything but.

It is the equivalent of saying "oh NYC had its record warmest year by a degree but we are not going to mention the fact that it happened because it was +15 in DJF and -10 in March and April and May because that is irrelevant" when such a discrepancy would literally result in winter occurring in March and April and May instead of December and January and February and would consequently be devastating to agriculture / normal life / etc. Glossing over what makes up "X anomaly" is literally ignoring the actual weather occurring on the ground and is not sound science.

Fair enough.  I don’t want to argue over this. Again, you are one of my favorite weather forecasters on ASIF. If I misinterpreted your comments, I am sorry! Have a great rest of the weekend!

[bbr2315]

Bbr, you have always been one of my favorite weather guys on this forum even though you are sometimes unpopular. But, you are way the fuck out on a limb on this one. You can not possibly believe that there is some “missing” data that changes what Berkeley Earth reported. That is nuts!

You can disagree with their data, but they are one of the top three weather reporting agencies in the world right now.

? I literally do not know what you are talking about, I didn't say they were missing data, I said that taking a six month snapshot does not show you an accurate picture of what has been going on when certain regions that have shifted from record + to record or severely - may average out as normal when the sensible weather has been anything but.

It is the equivalent of saying "oh NYC had its record warmest year by a degree but we are not going to mention the fact that it happened because it was +15 in DJF and -10 in March and April and May because that is irrelevant" when such a discrepancy would literally result in winter occurring in March and April and May instead of December and January and February and would consequently be devastating to agriculture / normal life / etc. Glossing over what makes up "X anomaly" is literally ignoring the actual weather occurring on the ground and is not sound science.

Fair enough.  I don’t want to argue over this. Again, you are one of my favorite weather forecasters on ASIF. If I misinterpreted your comments, I am sorry! Have a great rest of the weekend!

You too!

JAXA @ 6.45M KM^2 btw -100K KM^2 ish

I think what happened in 2016 is about to happen in 2020 except this time it is going to be to the EDGE of the pack and to the WEAK ice and not to the center of a larger extant ice mass.

This means that instead of open floes within solid ice that resolve by September, the areas that are imminently going to be most under the gun are going to be open floes adjacent to open water. In 2016 this was not enough to save the Beaufort but it did save most of the CAB. In 2020 that may not be the case, and current indications are that it will not be the case.

The "order of operations" for a perfect melt storm in the CAB have now been completed, now we watch where the cards fall. Within a few days we could be 1M KM^2 below 2012 and there is a non-zero possibility we maintain or increase that lead to minimum -- or later (!!!)

The same thing that has happened to ESS over last 10 days is about to happen to almost all of the Beaufort and Chukchi btw .... and the Laptev.... I really think we could do under 5M KM^2 by 8/1.... we need -121K KM^2 per day to achieve that and I think we could honestly push 125-150K KM^2 in worst case scenario / given current conditions which sounds insane but idk.

[Tor Bejnar]

...
There was perhaps some surprise and even suspicion of the PIOMAS volume charts, I do think we got to remember, alot of the rapid melt occured where ice thicknesses were below normal to start off with so whilst alot of extent has been reduced, there has been less volume loss because that part of the ice was not all that thick.

I know the compactness debate has been talked about alot but the theory would suggest a compact ice cap should be harder to melt than a more diffused one ....

From a couple of posts up thread "today" [for me at least] (on this page or the previous one):
You're right about there being some expressed suspicion, but more volume melted, according to PIOMAS during the first half of July 2020 than ever before during a half-month span, significantly more (15xx, new record, vs 13xx km³ [2012 record], I recall).  Some of that melt happened where the ice was thin (and is now gone) and some happened where the ice is thicker.  As to compactness, a graph of the CAB's compaction shows it to be in the middle of the pack, historically.  (I don't know how it relates to other years this century, though, and this may be significant.)

[Tor Bejnar]

[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.
July 19^th, 2020:
     6,448,219 km², a century drop of -103,003 km².
...

From the graph Juan just posted, it looks like 2020 is marching to the beat a different drummer!

[HapHazard]

...a graph of the CAB's compaction shows it to be in the middle of the pack, historically.

This is why I'm with Friv; IDK why a few folks are saying it's "compact". It's really quite average. Gero posted a graph a few days back illustrating this.

[pearscot]

I realize there has been a substantial amount of ice in the Beaufort, but I don't think I've ever seen icebergs being raked across the sea. Is this even normal arctic behavior?

[jdallen]

<snippage>
We are looking at a big slow down for a few days at least.

Unless the ESS/Chuchki/CAB start melting out insitu like the NORTHERN LAPTEV

I'm not convinced it is going to slow down.

There is a whole bunch of very powerful in-situ melt taking place.

If extent drop *does* slow down, I expect to see a reciprocal greater drop in area, as FYI from mid-winter gets erased.

[jdallen]

Back in #2688 (July 13th) I commented this:

At some point - in about 15 days, we should start to see a lot of that mid-range ice begin to fail.  This should start to reveal relict MYI - the larger floes - that have been embedded in the pack for years.

And on the 19th, I see this in the Beaufort, NW of Banks Island.

This is melting *in situ*.

(Edit:  Most of the Beaufort is starting to look like this)

[Frivolousz21]

72 hours until we see what happens when low pressure system takes over the Arctic.  In my opinion we will see the most dramatic slow down in extent drop in history.  Largely because the recent drop has been unprecedented (so a drop even to normal is a very big drop), and also because such a strongly compacted ice pack will accentuate the slow impacts of a switch to cool and cloudy conditions.

A wrinkle in the forecast is that there is hints of a high pressure system building into the Arctic from the Atlantic side in around 7 days time.  At this stage it looks a long way from a return to the extreme melt conditions we have seen recently.

I think ironically, a huge slow down is perhaps worse for the ice long term as it would suggest huge spreading out of the ice and possibly weakening the CAB ice as a result. I would prefer if its a more gradual process of trying to rejoin the pack.

There was perhaps some surprise and even suspicion of the PIOMAS volume charts, I do think we got to remember, alot of the rapid melt occured where ice thicknesses were below normal to start off with so whilst alot of extent has been reduced, there has been less volume loss because that part of the ice was not all that thick.

I know the compactness debate has been talked about alot but the theory would suggest a compact ice cap should be harder to melt than a more diffused one but like last year, I do fear SSTS will overrule any compactness especially on the Atlantic/Laptev edge. I also think Area has some positives of measuring during summer and there does seem to be link that if extent is high but area is low, a rapid drop is due but perhaps its more inconclusive the other way round?

What are you talking about?  The SOUTHERN CAB has been blow torched.

This pattern started back in june.

I just can't understand how you can come to that kind of conclusion. 

You are a really INTELLIGENT contributor here. 

You know better than to say that.

You know the Northern half of the CAA has been warm at times.

But the CAB has been decimated everywhere.

ONLY the far far Western reach has gotten slightly less warmth because of more persistent clouds.

Even tho it's still above freezing 24/7 expect a few hours here and there for like 6
50+ days.

The CAA & CAB IN JUNE BLOW TORCHED.

THE CAA HAD 3-4C+ 925mb temp anomalies in June

The Southern CAB had 4-5C+ for the entire month of June.






FOR JULY THROUGH THE 19TH(WHICH IS ALMOST 2/3RDS OF THE MONTH. )  CANADIAN ARCTIC ARPICHELAGO HAD ANOMALY OF 3-4C+ SO FAR IN JULY.


THE SOUTHERN CAB HAS HAD TEMPS ANOMALIES OF 2-7C+.THE CLOSER TO THE POLE YOU REACH THE 6-10C+ RANGE. 

THE NORTHERN 1/2 OF THE CAB HvAS HAD:

9-10C+ TEMP ANOMALIES FOR THE ENTIRE MONTH!!!


ON PIOMAS THE ATLANTIC SIDE WAS WAYYYYY ABOVE NORMAL NOW ITS ALL GONE.

ALL OF IT.

THE SOUTHERN CAB WAS THE ONLY OTHER BIG AREA OF POSITIVE THICKNESS!!

[bbr2315]

The entire Laptev front has collapsed another 25KM+ as revealed by today's EOSDIS. Wow.

https://worldview.earthdata.nasa.gov/?v=-235878.58990397037,870146.3908656848,132761.41009602963,1055234.390865685&p=arctic&t=2020-07-20-T05%3A11%3A17Z&l=Reference_Labels(hidden),Reference_Features(hidden),Coastlines,MODIS_Aqua_CorrectedReflectance_TrueColor,MODIS_Terra_CorrectedReflectance_TrueColor

The LP now moving into the region is annihilating the ice which is largely sub .25M in thickness. I anticipate most of the CAB's Laptev front will melt out in-situ over the next ten days as the edge approaches, with "compaction" of both of these factors resulting in continued massive extent drops.

[ArcTickTock]

Sea ice & bathymetry.

At this point it would seem we are at 0% chance of survival in summer for ice over the shallow peripheral seas except for where there is coastal protection in the CAA and off the northeast Greenland coast (well, Fram export keeps reloading the latter).  Most of these seas are 50m or so deep so not enough depth for proper stratification which implies that stratification or coastal protection are now mandatory for sea ice to have any hope of survival through the melt season.  One other thing, though it will taper off quickly, I believe insolation towards the blue end of the spectrum actually will penetrate to the sea floor in a 50m depth.  So every year that these seas are uncovered the entire water column and sea floor gets a bit more heat.  Am wondering if that deeper insolation is accumulating or dissipative?

[bbr2315]

The LP entering the Laptev / responsible for the now-ongoing massive retreat and in-situ melt is riding in on a front of smoke that is enormous. You can see the wildfires driving this plume exceedingly active in today's MODIS shot. The black carbon / visible melt ongoing indicate this is not a "benign-ing" of the conditions but potentially an accelerant despite relatively meek low pressure.

[Wherestheice]

While I don't see us reaching the 1 million km2 threshold this year, its always interesting to see how far we are from that metric. Using JAXA data, we are 5.448,219 above this threshold. The question becomes, how much will the ice melt from here on out....Well, lets use history as an example

In 2012, the min. was 3.18, and on this date in 2012, the extent was 7.21. So that means from this date (in 2012) to the 2012 min. the ice melted about 4.03.

We only need to lose 5.44 of sea ice to reach 1 million. Perhaps there isn't enough melt season left for it to happen this year, but it sure seems like it will be possible in the next 5 years.

We are observing rapid changes that will bring extreme consequences. Enjoy the days left with ice in the Arctic!

[slow wing]

Here's the year-to-year comparison of the ASI (from AMSR2) maps for 19 July.

This year is unprecedented for the amount of ice cover lost by this date on the Russian side.

[ajouis]

[...]
Just another question - the reason ice skates work so well, in that ice under the pressure of the blade melts reducing friction. in a generally warm arctic environment with long term compaction pressure, is the ice on the edges of individual flows being pushed together actually melting under that pressure? Is the force applied strong enough to actually provide another source of melt?

Someone did the maths a few pages earlier and it is negligible compared to the extent of the Arctic, I think it was 3 mm of melt but it might have only been microns.

[ajouis]

The negative AO seems will last at least until end of July. I think that is enough to weaken the ice. I have to say this summer is bad for the ice. The ice seems to be not disturbed by the storm. No storm, heat is still stored in the ocean. No storm, the ekman pumping does not begin. But the storm will be gradually strong in August. Stronger storm with thin ice, horrible!

When did the negative AO affecting ASI become a thing? I remember being roundly criticized for saying this in past years - though I've been saying so since at least 2011 or 12.

It isn’t, although it has a small impact, it is really not much compared to more major happenings, the arctic atmosphere patterns, NAO included only represent

Correlation analysis reveals that none of these patterns explain more than 10% of the variance in sea ice melt as defined here (explains 5%, 10%, and 10%, respectively)

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014JD022608#jgrd52033-fig-0006

[JayW]

82 hour loop ESS, contrast boosted. Needs a click. 

[Killian]

When did the negative AO affecting ASI become a thing? I remember being roundly criticized for saying this in past years - though I've been saying so since at least 2011 or 12.

It isn’t, although it has a small impact, it is really not much compared to more major happenings, the arctic atmosphere patterns, NAO included only represent

Correlation analysis reveals that none of these patterns explain more than 10% of the variance in sea ice melt as defined here (explains 5%, 10%, and 10%, respectively)

Well, then it's *a* thing, just not *the* thing.

[Freegrass]

While I don't see us reaching the 1 million km2 threshold this year, its always interesting to see how far we are from that metric. Using JAXA data, we are 5.448,219 above this threshold. The question becomes, how much will the ice melt from here on out....Well, lets use history as an example

In 2012, the min. was 3.18, and on this date in 2012, the extent was 7.21. So that means from this date (in 2012) to the 2012 min. the ice melted about 4.03.

We only need to lose 5.44 of sea ice to reach 1 million. Perhaps there isn't enough melt season left for it to happen this year, but it sure seems like it will be possible in the next 5 years.

We are observing rapid changes that will bring extreme consequences. Enjoy the days left with ice in the Arctic!

Don't forget that this is an exceptional year with clean air that has increased insolation. If the economy and air traffic gets back to normal we'll probably have to wait for another strong El Niño before we ever reach this years record melt again.

If the economy completely collapses, next year could be worse...

[liefde]

Don't forget that this is an exceptional year with clean air that has increased insolation. If the economy and air traffic gets back to normal we'll probably have to wait for another strong El Niño before we ever reach this years record melt again.

If the economy completely collapses, next year could be worse...

Naa, this has been studied, it's hardly been a noticeable factor. People overestimate the short term effect of this, CO2 emissions have still risen, even during the entire first half of 2020.

I'm a little shocked people continue being 'surprised' about the warming that's taking place. It's not 'strange' or 'exceptional' at all;
Earth continues to build up heat at a rate of 4 Hiroshima bomb detonations worth of energy *every second*. Because the blanket of heat-trapping gases (H2O, CO2, CH4, N2O) is not getting any thinner, the Sun's energy is not escaping Earth, it's accumulating.

You can turn and twist this process every which way you want, it's not going to change. Ice will melt, globally, because there are still 2 main factors that cause warming;
- The Sun's energy, and it's way too large a source to slow anything down, , just like El Niño being mentioned as a global influence, it just isn't for the energy build-up over time.
- The ever growing blanket of isolation around the planet, which thus far has not diminished even a tiny bit since humans started pulling carbon out of the ground.

[Freegrass]

Latest Five Day Forecast
Wind + Temp @ Surface
Wind @ 250hPa

Large GiFS!

Wind @ Surface + Total Precipitable Water can be found in the Nullschool Forecasts thread

[gerontocrat]

At this point it would seem we are at 0% chance of survival in summer for ice over the shallow peripheral seas except for where there is coastal protection in the CAA and off the northeast Greenland coast (well, Fram export keeps reloading the latter).

Methinks that the coastal protection given to the CAA since Northern Canada got really warm is negative, and looks like staying that way.

The snow free islands and Canadian Shore are getting warm to hot every afternoon. I attach the min & max temperatures images for the next 5 days from GFS.
______________________________________
ps: Looks to me as if the ice in Hudson Bay is toast - even the ice in Foxe Basin. Look how hot Baffin Island gets.

[marcel_g]

Don't forget that this is an exceptional year with clean air that has increased insolation. If the economy and air traffic gets back to normal we'll probably have to wait for another strong El Niño before we ever reach this years record melt again.

If the economy completely collapses, next year could be worse...

Naa, this has been studied, it's hardly been a noticeable factor. People overestimate the short term effect of this, CO2 emissions have still risen, even during the entire first half of 2020.
I'm a little shocked people continue being 'surprised' about the warming that's taking place. It's not 'strange' or 'exceptional' at all;

I think Freegrass is referring to the effect of lack of airplane vapour trails and lower sulphate pollutants that reflect a small but significant percentage of sunlight, rather than CO2 pollution. I'm sure most of us here are aware that CO2 is still rising and that it's effects are cumulative rather than instantaneous.

[Pagophilus]

Don't forget that this is an exceptional year with clean air that has increased insolation. If the economy and air traffic gets back to normal we'll probably have to wait for another strong El Niño before we ever reach this years record melt again.

If the economy completely collapses, next year could be worse...

Naa, this has been studied, it's hardly been a noticeable factor. People overestimate the short term effect of this, CO2 emissions have still risen, even during the entire first half of 2020.
I'm a little shocked people continue being 'surprised' about the warming that's taking place. It's not 'strange' or 'exceptional' at all;

I think Freegrass is referring to the effect of lack of airplane vapour trails and lower sulphate pollutants that reflect a small but significant percentage of sunlight, rather than CO2 pollution. I'm sure most of us here are aware that CO2 is still rising and that it's effects are cumulative rather than instantaneous.

The scientific consensus is that contrails cause net heating.  It used to be thought that contrails raised net albedo and cooled the planet.  So the logic would indeed be clearer air and therefore more solar energy reaching the surface under that former understanding.  Now the research indicates that there is another, larger effect, and that contrails produce a net heating by trapping and reradiating long wavelength radiation, as do high altitude cirrus clouds in general.

So, somewhat counterintuitively, the absence of contrails could be cooling the Arctic. 
 
https://e360.yale.edu/features/how-airplane-contrails-are-helping-make-the-planet-warmer
https://www.sciencedirect.com/science/article/abs/pii/S0094576596000987#:~:text=Cirrus%20clouds%3A%20Their%20role%20in%20climate%20and%20global%20change%E2%98%86&text=Thin%20cirrus%20clouds%20cause%20a,radiation%20from%20the%20surface%20below.

[Freegrass]

Don't forget that this is an exceptional year with clean air that has increased insolation. If the economy and air traffic gets back to normal we'll probably have to wait for another strong El Niño before we ever reach this years record melt again.

If the economy completely collapses, next year could be worse...

Naa, this has been studied, it's hardly been a noticeable factor. People overestimate the short term effect of this, CO2 emissions have still risen, even during the entire first half of 2020.
I'm a little shocked people continue being 'surprised' about the warming that's taking place. It's not 'strange' or 'exceptional' at all;

I think Freegrass is referring to the effect of lack of airplane vapour trails and lower sulphate pollutants that reflect a small but significant percentage of sunlight, rather than CO2 pollution. I'm sure most of us here are aware that CO2 is still rising and that it's effects are cumulative rather than instantaneous.

The scientific community is still resolving whether contrails cause net heating or cooling.  It used to be thought that contrails raised net albedo and cooled the planet.  So the logic would indeed be clearer air and more insolation under that former understanding.  Now the research indicates that contrails produce a net heating by trapping and reradiating long wavelength radiation, as do high altitude cirrus clouds in general. 
 
https://e360.yale.edu/features/how-airplane-contrails-are-helping-make-the-planet-warmer
https://www.sciencedirect.com/science/article/abs/pii/S0094576596000987#:~:text=Cirrus%20clouds%3A%20Their%20role%20in%20climate%20and%20global%20change%E2%98%86&text=Thin%20cirrus%20clouds%20cause%20a,radiation%20from%20the%20surface%20below.

I think we're going off topic here, and we'll soon get our asses kicked by Oren, but I think it's obvious - with the record temperatures this year - that clean air caused a record melting season.

Just look at how much ice there is in Antarctica, and then it's really obvious that this season is special.

But let's not debate this here any further. I thought it was settled that clean air caused this incredible melt season. I didn't want to stoke a debate about it.

[BeeKnees]

So, somewhat counterintuitively, the absence of contrails could be cooling the Arctic. 

From your link
"Like regular cirrus clouds, contrail cirrus clouds have two competing effects on climate. They shade us by reflecting incoming sunlight back into space. But they also trap heat radiating from the earth’s surface, so causing warming in the air below.
During the day, cooling compensates part of the warming. But at night, with no sunlight, only the warming effect operates. "

Suggests that in the Arctic, contrails would cool the summer and warm the winter, with the net effect being warming.

[ArcticMelt2]

If had a strong cooling effect from anthropogenic aerosols, then satellites in recent months should have seen a strong heating of the atmosphere. But in fact, in the last months after February, the cooling of the lower atmosphere is more likely to be observed, and not at all heating.

http://images.remss.com/msu/msu_time_series.html

So I think that the melting of the ice this spring and summer could be even stronger.

[oren]

Folks, this thread is for discussing the melting season itself. When the thread hits a point of scientific contention about whether something affects or not affects this specific melting season or the ice in general, that is the time to move that discussion to an existing or new thread.
Recently a thread was started discussing the effect of flights on the Arctic, though it then deteriorated a bit.  I recommend moving along to that thread or another of your choice, to discuss whether in fact clean skies made the melting season more extraordinary or not.

[MrGreeny]

From now until the 31st of July in order to reach 5,000,000km2 we'll need a majority of these days with losses over 132,000km2 in extent, unlikely but not impossible, however we might end up just above 5mil by the months end if we're to get losses under this amount.

Though I am not quite versed in forecasts I wonder how bad the forecast is four days out.

This has been quite interesting for me lately and I have been closely watching this for a while now.

[guygee]

Apologies for the OT on clouds, but I've seen the same error here repeatedly regarding the effect of high altitude clouds. These clouds raise temperatures both day and night, since  they are relatively transparent to incoming short wave radiation but tend to reflect outgoing long wave radiation. So their effect on warming is positive both in the day, and, like all clouds, at night. See, for example,
https://earthobservatory.nasa.gov/features/Clouds/clouds3.php

[marcel_g]

Folks, this thread is for discussing the melting season itself. When the thread hits a point of scientific contention about whether something affects or not affects this specific melting season or the ice in general, that is the time to move that discussion to an existing or new thread.
Recently a thread was started discussing the effect of flights on the Arctic, though it then deteriorated a bit.  I recommend moving along to that thread or another of your choice, to discuss whether in fact clean skies made the melting season more extraordinary or not.

I've created a new topic here: https://forum.arctic-sea-ice.net/index.php/topic,3202.0.html

[Tigertown]

(Snip)
Though I am not quite versed in forecasts I wonder how bad the forecast is four days out.

We also might want to ask at this point; How much melt momentum we have going? A change in forecast might have delayed reaction as far as melt slowing down. I would not look for any relief soon. When it comes, it will probably be in the way of a storm, which will be for the worse.

[FishOutofWater]

There was an important an insightful comment way up the thread by Lodger/Dodger. The exceptional amounts of insolation early this summer has apparently caused early drainage of melt ponds. This explains why area has not kept up with extent loss in terms of the rankings of 2020 and other strong melt seasons. It may also explain why PIOMAS thickness is lagging extent because, as another comment noted, PIOMAS uses area in its calculation of extent.

As to teleconnections to the Arctic, China has not had this much rain and flooding since 1998. The flooding is tied to the push of ocean heat from eastern tropical Pacific a few years ago to the western tropical Pacific and Indian oceans. That excessive ocean heat probably ties in with the trough ridge pattern in this summer's jet stream and the advection of heat into the Arctic that caused the crazy heat on the Siberian side this spring and early summer. I remember that there were papers about the 2012 melting season that found teleconnections with the Asian monsoon and high heat levels in the Indian ocean.

Here's the first paper that comes up on Google about the teleconnection of Arctic sea ice extent to the Asian monsoon:
https://journals.ametsoc.org/jcli/article/29/24/9097/34372/Arctic-Sea-Ice-Patterns-Driven-by-the-Asian-Summer

The cool temperature anomaly in the Tibet region may be tied to rainfall and clouds. Nepal is seeing excessive rain and destructive floods. https://www.theguardian.com/world/2020/jul/20/flooding-assam-nepal-displaces-millions-coronavirus

[F.Tnioli]

Today's Yale piece on this melting season, comes with a few lively pictures and a few quite funny statements among the others.

Like their graph which is a bit "softened" in terms of how bad it looks (15th last date, running average - small ways to "tone it down a little" eh). Or like while some of us discuss chances for BOE this very season, the piece notes that "most of the models now produce a blue ocean event prior to 2050, even if major emission cuts are put into place". 2050? Seriously? Wow. Sigh. They'll probably keep saying that even after BOE happens. It'd be extremely funny if it wouldn't be extremely sad.

[Pagophilus]

There was an important an insightful comment way up the thread by Lodger/Dodger. The exceptional amounts of insolation early this summer has apparently caused early drainage of melt ponds. This explains why area has not kept up with extent loss in terms of the rankings of 2020 and other strong melt seasons. It may also explain why PIOMAS thickness is lagging extent because, as another comment noted, PIOMAS uses area in its calculation of extent.

Thanks FooW.  This is the first explanation for area's persistent lagging extent that makes full sense to me.   

(my bolding on your comment).