The 2020 melting season

[Lord M Vader]

The last couple of days have seen a decline in the sea ice extent in Arctic, mostly confined to peripheral areas. Whether this downward trend is signaling the "onset" of the melting is an open question. However, we are in the middle of March and this year the upcoming weeks will probably be terribly slow for most of us. So, if Neven is OK with maning an exception for this year I hope we can start the discussions about the 2020 melting season.

The strong polar vortex that bottled up the cold air over the central Arctic basin should have strengthened the ice enough to make the 2020 minimum end up higher than the last few years. At least if we Have a moderately bad summer.

I hope everyone in here will be with us through the whole season and many more years ahead. Stay safe out there!

//LMV

<edit Neven: I don't have time to follow current events in the Arctic, so I can't assess whether it's too early for this thread or not, which means I'll leave it open. I did adjust the title though. If there's a second max, this is on you, LMV.  >

[PragmaticAntithesis]

Alright, I finally found the actual thread. Sorry about creating a clone! >_<

[kassy]

Thanks! Also there are usually several MS threads so you have just made your contribution to the tradition. 

[kassy]

Also

Has anyone notices that there is a large "valley" in the Fram strait in the DMI thickness map? If that's accurate then the ice near the pole could be unusually weak this year.

That does not look like a great set up. Very weak on the siberian side.

[Stephan]

This melting season starts with a higher extent than most of the years before. The last year with a higher extent value than 2020 (see Juan's post in the Sea Ice Area and Extent thread) was 2014.
So let's see what 2020 brings...


PS: My Post # 1.000

[blumenkraft]

Congrats, Stephan!

2012 was higher BTW and had a later maximum than in 2020.

[HapHazard]

Congrats, Stephan!

2012 was higher BTW and had a later maximum than in 2020.

Indeed! Predicting the minimum extent based on current maximum isn't really feasible. There's a bunch of other indicators I'd consider much more valuable to glean info from. But this far out, there's just too many dice rolls between now & then.

That said, based on my own top-secret formula I predict we'll finish top-3 in lowest min extent. 

[blumenkraft]

Well, what's your top-secret formula then? I will tell no one else, i promise.

[HapHazard]

I will only divulge that it involves Green Spot Irish Whiskey.

[Freegrass]

Did you guys really start a new melting thread without posting the Slater prediction? 

We're coming in very low...

https://cires1.colorado.edu/~aslater/SEAICE/

[Tom_Mazanec]

Will possible aerosol reduction from covid-19 economic decline affect this year’s minimum?

[PragmaticAntithesis]

Will possible aerosol reduction from covid-19 economic decline affect this year’s minimum?

I wouldn't be surprised if it causes an increase. The lack of soot in the air will give the ice higher albedo, especially in the upcoming freezing season. [sarcasm]Time to start the 2020/2021 freezing thread?[/sarcasm] This may cause the ice to be much more resilient, especially next year, and could delay the eventual BOE.

Also, look at where the temperature increase caused by removing aerosols is coming from: it's increasing the effective power of the sun by unblocking light instead of decreasing the amount of heat escaping from Earth like the usual greenhouse effect. This probably means all the additional heat is going to end up at the equator (which sea ice doesn't care about), not the poles.

[NotaDenier]

Will possible aerosol reduction from covid-19 economic decline affect this year’s minimum?

I wouldn't be surprised if it causes an increase. The lack of soot in the air will give the ice higher albedo, especially in the upcoming freezing season. [sarcasm]Time to start the 2020/2021 freezing thread?[/sarcasm] This may cause the ice to be much more resilient, especially next year, and could delay the eventual BOE. Also, look at where the temperature increase caused by removing aerosols is coming from: it's increasing the effective power of the sun by unblocking light instead of decreasing the amount of heat escaping from Earth like the usual greenhouse effect. This probably means all the additional heat is going to end up at the equator (which sea ice doesn't care about), not the poles.

The studies after 9/11found that contrails decreased daytime temps and increased night time temps. When contrails are reduced (like right now) the daytime temps rise more then night time temps decrease. This is because it matters when the contrails form. Because most flying is during the day the daytime temps are suppressed more by the cloud formation. So the current flying situation will provide more data to the weather scientists.

Somewhat related I believe “smog” from China and India (among the biggest producers of SO2)  also reduces incoming solar radiation. So if we are in a six month world wide recession is it not possible we will see one of the hottest years on record without an El Niño?

On the other hand oil is really cheap now...

I’d really like some of the professional weather experts to comment on this if they have time.

[Freegrass]

The studies after 9/11found that contrails decreased daytime temps and increased night time temps. When contrails are reduced (like right now) the daytime temps rise more then night time temps decrease. This is because it matters when the contrails form. Because most flying is during the day the daytime temps are suppressed more by the cloud formation. So the current flying situation will provide more data to the weather scientists.

Somewhat related I believe “smog” from China and India (among the biggest producers of SO2)  also reduces incoming solar radiation. So if we are in a six month world wide recession is it not possible we will see one of the hottest years on record without an El Niño?

On the other hand oil is really cheap now...

I’d really like some of the professional weather experts to comment on this if they have time.

I wanted to point you to the Black Carbon thread, but that doesn't exist yet?

It's important to note that black carbon actually warms the planet. Here's a little info, but I think this is not the place to discuss this?

In climatology, black carbon is a climate forcing agent. Black carbon warms the Earth by absorbing sunlight and heating the atmosphere and by reducing albedo when deposited on snow and ice (direct effects) and indirectly by interaction with clouds, with the total forcing of 1.1 W/m2.[2] Black carbon stays in the atmosphere for only several days to weeks, whereas carbon dioxide (CO

https://en.wikipedia.org/wiki/Black_carbon

Direct effect Black carbon particles directly absorb sunlight and reduce the planetary albedo when suspended in the atmosphere.

Semi-direct effect Black carbon absorb incoming solar radiation, perturb the temperature structure of the atmosphere, and influence cloud cover. They may either increase or decrease cloud cover under different conditions.[66]

Snow/ice albedo effect When deposited on high albedo surfaces like ice and snow, black carbon particles reduce the total surface albedo available to reflect solar energy back into space. Small initial snow albedo reduction may have a large forcing because of a positive feedback: Reduced snow albedo would increase surface temperature. The increased surface temperature would decrease the snow cover and further decrease surface albedo.[67]

Indirect effect Black carbon may also indirectly cause changes in the absorption or reflection of solar radiation through changes in the properties and behavior of clouds. Research scheduled for publication in 2013 shows black carbon plays a role second only to carbon dioxide in climate change. Effects are complex, resulting from a variety of factors, but due to the short life of black carbon in the atmosphere, about a week as compared to carbon dioxide which last centuries, control of black carbon offers possible opportunities for slowing, or even reversing, climate change.[67][68][69]

Radiative forcing
Estimates of black carbon's globally averaged direct radiative forcing vary from the IPCC’s estimate of + 0.34 watts per square meter (W/m2) ± 0.25,[70] to a more recent estimate by V. Ramanathan and G. Carmichael of 0.9 W/m2.[71]

The IPCC also estimated the globally averaged snow albedo effect of black carbon at +0.1 ± 0.1 W/m2.

Based on the IPCC estimate, it would be reasonable to conclude that the combined direct and indirect snow albedo effects for black carbon rank it as the third largest contributor to globally averaged positive radiative forcing since the pre-industrial period. In comparison, the more recent direct radiative forcing estimate by Ramanathan and Carmichael [71] would lead one to conclude that black carbon has contributed the second largest globally averaged radiative forcing after carbon dioxide (CO2), and that the radiative forcing of black carbon is “as much as 55% of the CO2 forcing and is larger than the forcing due to the other greenhouse gasses (GHGs) such as CH4, CFCs, N2O, or tropospheric ozone.”

[kassy]

So if we are in a six month world wide recession is it not possible we will see one of the hottest years on record without an El Niño?

We had one last year without a recession...

[gandul]

Will possible aerosol reduction from covid-19 economic decline affect this year’s minimum?

I wouldn't be surprised if it causes an increase. The lack of soot in the air will give the ice higher albedo, especially in the upcoming freezing season. [sarcasm]Time to start the 2020/2021 freezing thread?[/sarcasm] This may cause the ice to be much more resilient, especially next year, and could delay the eventual BOE.

Also, look at where the temperature increase caused by removing aerosols is coming from: it's increasing the effective power of the sun by unblocking light instead of decreasing the amount of heat escaping from Earth like the usual greenhouse effect. This probably means all the additional heat is going to end up at the equator (which sea ice doesn't care about), not the poles.

This theory of yours is peculiar. So lack of aerosols caused by depressed economic activity will lead to a small cooling?
I would expect a small short-duration increase of global temperatures beyond what is the current trend, and indirect (small) negative impact on sea ice.
Unless the current crisis leads to a real depression...

[grixm]

Some fast ice in Laptev and Kara is starting to crack. Maybe just because of drift, not melting. Click to play.

[blumenkraft]

If i interpret the weather correctly, the Fram export could be rampant in the upcoming days.

This week's ice drift map. 

[blumenkraft]

Sunday to Sunday movie of the 7-day mean temperature anomalies.

[blumenkraft]

And the Fram export via SAR.

[gerontocrat]

It's windy in the Arctic Ocean and surrounding land today.
Looks like staying that way for a few days.

from Nullschool 15 March.

[PragmaticAntithesis]

Wow, that is a lot of Fram export. Is there any precedent for this much ice going down the drain early in melt season, and if so, how bad was the extent that year?

[P-maker]

PA, no precedent.

But, previous estimates were that prior to the first BOE in the Arctic, the Greenland Sea ice extent would hit one million square kms.

Let's see if we get there this year...

[jdallen]

Will possible aerosol reduction from covid-19 economic decline affect this year’s minimum?

I wouldn't be surprised if it causes an increase.
<snip>

Counter intuitive and I think possibly counter factual as well.

Aerosols tend to reduce insolation, and the last few years, we've had far more particulates at high latitude introduced by wildfires than any sort of human activity.  Compared to that, a drop in human black carbon won't make a lot of difference, I expect.

Also big... assuming it does reduce consumption, will be a reduction in SO2, which we know produces an increase at energy arriving at sea level.

Now, as to albedo - particulates at this point really haven't produced major effects on the ice.  Open water, melt ponds and bare ground really remain the primary drivers in determining how much direct insolation gets picked up north of 67 degrees latitude.

We already have an anomaly there with European snow cover.  I'll have to check numbers, but my suspicion is we'll see a fairly fast drop in snow pack coverage.

[binntho]

Also big... assuming it does reduce consumption, will be a reduction in SO2, which we know produces an increase at energy arriving at sea level.

So I assume you are saying that a decrease in SO2 causes an increase in energy reaching the surface? My first reading of this sentence implied the opposite ...

[binntho]

PA, no precedent.

But, previous estimates were that prior to the first BOE in the Arctic, the Greenland Sea ice extent would hit one million square kms.

Let's see if we get there this year...

What previous estimates?

[Freegrass]

Snow is disappearing rapidly...

https://go.nasa.gov/38RadpN

[binntho]

Snow is disappearing rapidly...

https://go.nasa.gov/38RadpN

I'm not seeing any real difference between now and previous years. Easy to scroll between the years for comparison.

[blumenkraft]

Perhaps not the area at the link, but there is indeed less snow at the European side. This is taken from Nico Sun's website. Red areas on the map means less snow.

[P-maker]

Binntho:

 

What previous estimates?

That would be my own estimates in a debate some years ago with a fellow discussant on this site.

My main argument at that time was that in order to reach one mio. sq. kms in the Arctic, spring had to come up with an extraordinary export of at least one mio. sq. kms through Fram Strait to the Greenland Sea (since Nares Strait is not delivering nearly enough at this time of year).

You have yourself delivered a splendid example of a record year (1947) when the Greenland sea in April was nearly full of Arctic sea ice: https://www.pmel.noaa.gov/rediscover/datalist/phpFileTree/dmi_sea_ice_maps/1947/1947.pdf

In those days however, the Arctic was full to the brim of multi-year ice, thus filling up the Greenland Sea was much easier.

Natural variability in the Arctic melting of sea ice due to freak weather may deliver a couple of mio. sq. kms at best (or worst), which will eventually get us under 1 mio. sq. kms in August/September/October. Thus, we will not get below the threshold proposed by some in the IPCC, unless we see extraordinary spring export figures through the Fram.

[binntho]

Perhaps not the area at the link, but there is indeed less snow at the European side. This is taken from Nico Sun's website. Red areas on the map means less snow.

All the red areas are far to the south of the Arctic, and unlikely to influence temperatures there. But it would not surprise me if parts of Siberia had less snow than usual, the temps there have been extremely high this winter.

But if less snow is to make any difference, then there has to be significant difference in insolation in the Arctic itself. This is not happening yet, but remains one of the things to look out for.

[binntho]

Binntho:
 

What previous estimates?

That would be my own estimates in a debate some years ago with a fellow discussant on this site.

Good to know.

You have yourself delivered a splendid example of a record year (1947) when the Greenland sea in April was nearly full of Arctic sea ice: https://www.pmel.noaa.gov/rediscover/datalist/phpFileTree/dmi_sea_ice_maps/1947/1947.pdf

I wasn't aware that 1947 was a record year ... what records did it break?

[blumenkraft]

(since Nares Strait is not delivering nearly enough at this time of year

This would be zero so far to be pricise. The NS is frozen over and there is a stable southern arch at the moment.

I'm guessing here, but NS export could be extremely low this year. The temperatures in the area have been lower than average during the winter and the arch might break late in the year or not break at all.

[blumenkraft]

and unlikely to influence temperatures there

You might be right, but don't forget the albedo effect. I wouldn't dismiss that so easily.

[Freegrass]

Easy to scroll between the years for comparison.

True. I keep forgetting that.

[P-maker]

Binntho,

Please try to goggle "1947 record-breaking" and see what comes up. Europe was record-warm mainly during the summer and North America had record-Breaking snowfall in December. Many more 1947 records were beaten during the last few years, so maybe the Arctic was weird too, although few measurements were taken just after WW II.

[binntho]

Binntho,

Please try to goggle "1947 record-breaking" and see what comes up. Europe was record-warm mainly during the summer and North America had record-Breaking snowfall in December. Many more 1947 records were beaten during the last few years, so maybe the Arctic was weird too, although few measurements were taken just after WW II.

Really. How interesting. I thought perhaps 1947 broke the record of not having broken any records. But the reliability of the "previous estimates" is rapidly clarifying.

[jdallen]

Also big... assuming it does reduce consumption, will be a reduction in SO2, which we know produces an increase at energy arriving at sea level.

So I assume you are saying that a decrease in SO2 causes an increase in energy reaching the surface? My first reading of this sentence implied the opposite ...

Correct.  SO2 in the atmosphere reduces incoming insolation.  Reduce it, and you get a small uptick in insolation reaching the surface.

[The Walrus]

Also big... assuming it does reduce consumption, will be a reduction in SO2, which we know produces an increase at energy arriving at sea level.

So I assume you are saying that a decrease in SO2 causes an increase in energy reaching the surface? My first reading of this sentence implied the opposite ...

Correct.  SO2 in the atmosphere reduces incoming insolation.  Reduce it, and you get a small uptick in insolation reaching the surface.

Yes, SO2 reduces incoming insolation, resulting in a cooling effect.  Oftentimes, SO2 emissions are accompanied by carbon black (i.e. soot).  This has a warming effect.  Coal burning releases CO2, SO2, and carbon black, with a net warming effect.  So-called cleaner fuels have reduced sulfur content, such that the aerosol effect is likely less than the greenhouse effect.

[Glen Koehler]

     As I understand it -- SO2 primarily has an effect when large volcanic eruptions, esp. those near the equator, inject large amounts of SO2 into the stratosphere where they can persist for an extended period.  Lower height eruptions are less likely to have a significant effect on incoming solar radiation and global average surface temperature because the SO2 falls out rather quickly.

   The most recent years when volcanic SO2 aerosols had a major effect on temperature were 1982-1983 and 1992-1993.  There is about a 7 month lag between the measured global average aerosol level and an effect on global average surface temperature.  The temperature suppression in those years was on the order of 0.1 to 0.2 C below what the temperature would have likely been without the aerosol influence. 

    The “Year without a summer” in the Northeastern US in 1816 was caused in part by the Mt. Tambora eruption in 1815.  There was snow in Dennysville Maine on June 6, 1816.  Massachusetts had a severe frost in every month.  Less than a quarter of the corn crop was harvestable.  This was all caused by a decrease of average global temperatures of 0.4–0.7 °C (0.7–1.3 °F), and a decrease of average land temperature by about 1C.

    Monthly aerosol level is updated by 11th day of the following month at https://www.esrl.noaa.gov/gmd/webdata/grad/mloapt/mauna_loa_transmission.dat 
Values are transmission through atmosphere, thus lower values = more aerosol blockage.  Values above 0.9160 are unlikely to cause a noticeable temperature effect.

[Glen Koehler]

    Given the importance of snow cover ...
 (see for ice dynamics https://forum.arctic-sea-ice.net/index.php/topic,2906.msg254713.html#msg254713 )
   

   ... is there a status report of how snow cover on top of the ASI at this time compared to same date in previous years, and what that suggests about the 2020 melt season?  I know Siberia has reduced snow cover and that has consequences for spring warm up.  But what about the snow cover directly on the ASI?  What is the current situation for that?

[interstitial]

snow cover topic
https://forum.arctic-sea-ice.net/index.php/topic,2876.0.html

[El Cid]

 
 This was all caused by a decrease of average global temperatures of 0.4–0.7 °C (0.7–1.3 °F), and a decrease of average land temperature by about 1C.

   

Let's not forget that if global land temps go down 1 C that is oftentimes 2-3 C for NH mid and high-latitudes plus cold outbreaks with late frosts that can kill any plants   

[Glen Koehler]

   Thanks, but instead of NH snow cover, I'm wondering about the snow cover directly on the ASI.  The MOSAIC scientist in the video blumenkraft posted says that snow quality (albedo, roughness, stratigraphy, crystal structure) has a huge effect on the atmosphere-ice interaction and melt season progression.  I suspect that these relationships are only beginning to be understood and that the scientists need more time to collect and crunch data before reaching any conclusions about the current situation.  Thus, there may not be an answer to my question at this time. 

    Snow cover characteristics on top of the ASI could be a missing factor in melt season variability that (in addition to weather, melt ponds, drift currents etc.) makes multi-month ASI prediction difficult.  Stephan shared regressions a month or so ago that showed Extent and Volume in prior months have poor correlation with September minimums.  Basically nil in May, weak in June.  It isn't until July that knowing those values gets you much predictive skill about September.

    Then again, Slater model and some other methods seem to do a halfway decent job of predicting Sept. minimums.  The more I think about this the less I pretend to know!

[PragmaticAntithesis]

Let's not forget that if global land temps go down 1 C that is oftentimes 2-3 C for NH mid and high-latitudes plus cold outbreaks with late frosts that can kill any plants

Well, it's a good job the temperatures are going the other way then, right?

[uniquorn]

uni-hamburg amsr2-uhh, bering, mar10-17
added wipneus regional extent, bering, mar17

[tybeedave]

Greetings from Midway Georgia,
 I've been lurking here for years, but after some 26 tears online, this the very 1st forum that I have ever joined.  This is my 5th attempt to make a post, so bear with me as i learn the ropes
 I've been alarmed by the huge export through Farm and subsequent melting signified by the foam left over from the melting ice in the GS as illustrated by the attached image.
 Also included in the image of some beautiful cloud vortices.  It's too bad that they overlay a field of death for ice

https://worldview.earthdata.nasa.gov/?v=348385.3212968977,-1205274.273347458,1466593.3212968977,-680986.2733474581&p=arctic&t=2020-03-18-T19%3A13%3A07Z

td

think good thoughts, do good deeds, enjoy good results

[interstitial]

Welcome Tybeedave

[Niall Dollard]

Welcome TybeeDave and don't be shy !

Re the Fram foam, I wouldnt call it foam. These are strips of sea ice that are pulled off the main pack.

We see it a lot in the Bering Sea where the ice is often thin and can break away easily. Here is an image from the Bering on March 3rd. Strips of ice are very close to St. Paul Island (arrowed). This was about as far as it got this year.

This was more or less predicted by NWS Anchorage in their outlook post on Feb 25th. Quote :

...FREEZE-UP OUTLOOK FOR THE BERING SEA...

"There is a 30 percent chance that the sea ice will make it to Saint Paul Island this season. The most likely scenario that would allow sea ice to reach the island is if northerly winds and cold air
persist for several days. If sea ice does reach Saint Paul Island, we expect it to generally be in the form of strips of sea ice that are pulled off the main pack. The northerly winds and cold air would likely have to persist for a couple weeks or more for the main ice pack to reach the island."

[tybeedave]

ty interstitial, and ty Niall for the insight, I'm not shy

I based my idea on the vision of an ice cube melting in a glass of water.  Except, in the purest of ice and water, a few scummy bubbles are left behind. Add that to my amateur perception of the ice waves (foam) in my image appearing to be moving (in a convex shape) towards the flowing ice.
But I will defer to your experience while I'm self-quarantining and homeschooling
td
think good, do good, enjoy good...er, well