The 2019 melting season

[Clenchie]

arctic.io Arctic Explorer has been off for a week now.
No Wonder, more & more People must be checking out the Reality- as has the number of new members started to grow.

I was wondering what had happened to arctic explorer.

All I get is the following message:

This site can’t be reached www.arctic.io’s server IP address could not be found.
Try running Windows Network Diagnostics.
DNS_PROBE_FINISHED_NXDOMAIN

Have switched instead to Worldview on https://worldview.earthdata.nasa.gov/?p=arctic&l=VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels(hidden),Reference_Features(hidden),Coastlines

Apologies if off topic.

[be cause]

I noticed I was looking at post 1042 on page 42 at 10 42 am .. and I always say if surrounded by 42's I am in the right place .. b.c.

 p.s.  more important perhaps is it is another good Worldview day over the Arctic . The amount of open water in the cracks toward the pole is ever more unusual . I assume extent ignores them .. is area taking them into account ?
also of interest .. the 850 anomalies show very warm air above 80'N but yesterday the surface temps were just edging into negative anomaly ..

 pps ... just noticed I've 420 posts and 42 likes ..
 

[Sterks]

I don't expect a collapse at this point. There is positive snow anomalies in Siberia and melting goes slower than 2012

Agree, there seems to be more snow volume as well.
However, the tendency says another story. Snow cover anomaly during May reversed a stall and is going full throttle toward a bad negative value. Also compare 2019 and 2012, day 144. I think it is catching up, is even worse in North America, and forecast says it may be bad near Siberian coasts in a week.

[b_lumenkraft]

I noticed I was looking at post 1042 on page 42 at 10 42 am .. and I always say if surrounded by 42's I am in the right place .. b.c.

Happy towel day!

 

[b_lumenkraft]

East Siberia (upper left in the picture) coast drifting off now.

Gif showing 23. vs 25.05.

[GoSouthYoungins]

So my understanding is the fear for the season is:

-Pacific side heat from open water and snow anomalies.
-Central basin high pressure leading to clear skies and melt from insolation.
-Consistent export into the Atlantic ocean (and Baffin Bay)

[Neven]

So my understanding is the fear for the season is:

-Pacific side heat from open water and snow anomalies.
-Central basin high pressure leading to clear skies and melt from insolation.
-Consistent export into the Atlantic ocean (and Baffin Bay)

-Couple of cyclones between sunny periods to stir the pot.

[Jim Hunt]

I'm willing to debate the Siberian slush. I'll go and see if Landsat/Sentinel have snapped the area recently.

As luck would have it Landsat 8 did snap the sea ice just off Ostrov Kotelny on the 23rd. It still looks to me as though the image below reveals melt ponds on the more substantial chunks of sea ice, but I'm open to persuasion.

The VISHOP algo reckoned there was surface melt in the area also.

[jdallen]

Ok, so as Frivolousz21 is not around, I have to replace him:

I'll give you a 5/10 for the effort, but friv cannot be replaced so easily. 

edit: I've just seen the ECMWF forecast and it looks pretty terrible indeed. Anything above 1030 hPa around this time of year, is a disaster for the ice. I'll post the latest forecast this evening.

I'd take it a step above terrible, Neven.  They are positively terrifying.

[jdallen]

Dove-tailing with the melt pond and snow cover discussion, here's a couple of screen grabs of the snow cover model from Climate Reanalyzer; the first is today, the second is for June 1st.

The takeaway is, GFS predicts snow cover over the next 6 days will be hammered, seriously.

A lot of that melt - 6-10CM worth - will be on the snowpack in the CAB.

That translates into melt ponding, some exposed, some still sub-snowcover, but absolutely suggests serious drop in albedo and preconditioning in favor of melt, under an almost arctic-wide high pressure dome.

(Edit:  A number of other things strike me.  During the entire run, there are 4 persistent circum-polar areas of low pressure - the outer Bering, SE Hudson's bay/Quebec, Northern Scandinavia/Barentz and Central/Eastern Siberia.  These low pressure regions are shoving polar air out through the Mackenzie basin south to the North American Great Plains, out through the FRAM/Svalbard region, far eastern Europe/Urals and to a lesser degree, the west side of the Bering/extreme eastern Siberia.  Heat and moisture of course flowing north between.  It looks surprisingly stable, and, with the tendency towards more stable/slower moving jet stream/rosby waves is very concerning for the rest of June.)

[HelloMeteor]

Ok, so as Frivolousz21 is not around, I have to replace him:

I'll give you a 5/10 for the effort, but friv cannot be replaced so easily. 

edit: I've just seen the ECMWF forecast and it looks pretty terrible indeed. Anything above 1030 hPa around this time of year, is a disaster for the ice. I'll post the latest forecast this evening.

Can you explain why you say it's bad in reference a pressure? I understand Pa refers to a Pascal. I'm an engineer, and the importance of air pressure rather than temperature is not obvious to me.

[be cause]

Hi JD .. that looks unbelievable .. but somehow this year it seems like such horrorcasts are coming true ..

I notice that open water is appearing in a massive new fracture zone north of Greenland and multiple new zones of fracture are appearing everywhere as winds change .. almost all with open water visible on Worldview .
 In past years it has been argued that side melting of floes is negligible but this year I wonder .. the ice is not so thick and is already in trillions of fragments , and the sides are partially exposed to low angle sun 24/7 . Could this not be important as it bypasses the snow on the surface ? This sunlight would be absorbed by the ice and water , while the snow above prevents it radiating back to space ..
  It may not be a huge fraction of incoming solar radiation but it is a growing fraction , especially important in a sunny summer . Any thoughts ?   b.c.

[ArcticMelt2]

The situation in the Pacific sector is terrible.

[aperson]

edit: I've just seen the ECMWF forecast and it looks pretty terrible indeed. Anything above 1030 hPa around this time of year, is a disaster for the ice. I'll post the latest forecast this evening.

Can you explain why you say it's bad in reference a pressure? I understand Pa refers to a Pascal. I'm an engineer, and the importance of air pressure rather than temperature is not obvious to me.

High pressure indicates subsidence. This inhibits cloud formation which means that the Arctic regions underneath the high will receive more incoming shortwave radiation.

[Jim Hunt]

Sarat - it's hard to gauge thickness from ASCAT. Someone like Jim probably has a more trained eye that can better interpret the shades of grey.

I'm not sure about that! The ASCAT "shades of grey" are dependent on the porosity and salinity of the ice, and perhaps the surface "roughness" as well:

https://www.researchgate.net/publication/299525691_Multiyear_arctic_ice_classification_using_ASCAT_and_SSMIS

That's a reasonable proxy for age, but perhaps less so for thickness? However as A-Team revealed, the boundary between the two reveals the sea ice movement towards the Atlantic over the last few months.

So does the movement of snow buoy 300234066342810, which is now almost at the North Pole:

BTW, comparing the US Navy's 2012 (ACNFS) and 2019 (GOFS 3.1) model outputs is apples versus oranges:

https://forum.arctic-sea-ice.net/index.php/topic,1602.msg201189.html#msg201189

[Neven]

High pressure indicates subsidence. This inhibits cloud formation which means that the Arctic regions underneath the high will receive more incoming shortwave radiation.

Or in other words: High pressure -> clear skies -> lots of sunshine -> melt ponds, melting in general, open water absorbing radiation, etc.

[JamesW]

Hi HelloMeteor,

If your interested in understanding shortwave radiation and longwave radiation downwelling effects on sea ice this rather comprehensive text will enlighten you on the subject at length.

https://journals.ametsoc.org/doi/full/10.1175/JCLI-D-15-0238.1

[Rich]

So my understanding is the fear for the season is:

-Pacific side heat from open water and snow anomalies.
-Central basin high pressure leading to clear skies and melt from insolation.
-Consistent export into the Atlantic ocean (and Baffin Bay)

-Couple of cyclones between sunny periods to stir the pot.

There's more. The peripheral resistance of  ice connected to the coast is fraying. We''ve had a test run of lift off from CAA earlier in the season. When those connections are lost, the main pack is going to be freer to rotate in the direction of the export.

Nares being open doesn't help. The amount of ice loss there isn't tremendous, but it's like a lubricant in a potentially sticky corner as the ice pack might try to rotate later in the season.

[bbr2314]

The upcoming / imminent pattern looks like the worst we have ever seen for the high Arctic at this time of year. The satellite pictures are already shocking. This is truly unprecedented IMO.



As others have noted / hinted, checking EOSDIS, most all of the PAC sector is now light blue in imagery. Unlike previous years where the advance halted before Wrangel Island, I think 2019 will see the advance continue fairly rapidly into the Chukchi and Beaufort, with most of both seas gone by 7/1.

Perhaps the biggest impact of this will not be a BOE, which is unlikely (though a record minimum? increasingly possible). But, I think it would be the accumulation of insolation in open water that has never been this open in recorded history. This is likely to result in worst-ever cyclonic activity in the High Arctic in late summer and autumn (IMO). And that is likely to translate into record-breaking disruptions for the hemispheric pattern as well, i.e., chaos in the mid-latitudes, where we all actually live.

Finally: I am shocked by the fires in Canada this year. I had been gung-ho on a worst-ever Siberian fire season, and still am. But Canada.... wow! I think this is a culmination of the worsening oscillations between hot and cold killing vegetation, as well as the warming / dissipation of permafrost. That is leading to increasing amounts of vegetation that is dead, and peat bogs that are now accessible to flames. Combined with what we are already seeing, this year is shaping up to be the worst-ever for extent and area.



PPS: it is worth noting that Slater's model shows a record-low for 7/14, of 7.75 million KM^2. But the picture is worse than that. As of 7/14, Slater's model shows most of Hudson Bay still covered to substantial %. Same with Baffin. That ice is going to be gone by 9/1. We have an abundance of "easy" ice remaining, and even if a smidgen does survive the melt season, this will result in sustained momentum through August, and steep cliffs whenever ^^^ does melt out.

[FishOutofWater]

The open Nares is important because thick old ice passes out of the Arctic instead of piling up on the NW shores of Greenland and the NE shores of the CAA. This year, when the Fram outflow slowed the outflow through the Nares often increased. That's what happens when the pressure is relatively high over the pole and relatively low over the far north Atlantic and the subarctic seas on the Atlantic side and the Nares strait is open.

[HelloMeteor]

edit: I've just seen the ECMWF forecast and it looks pretty terrible indeed. Anything above 1030 hPa around this time of year, is a disaster for the ice. I'll post the latest forecast this evening.

Can you explain why you say it's bad in reference a pressure? I understand Pa refers to a Pascal. I'm an engineer, and the importance of air pressure rather than temperature is not obvious to me.

High pressure indicates subsidence. This inhibits cloud formation which means that the Arctic regions underneath the high will receive more incoming shortwave radiation.

Seriously? You have to throw the word subsidence in there instead of an actual explanatory few words?

[FishOutofWater]

An engineer should understand compressional heating and drying. The ECMWF model and it's ensembles are forecasting a dome of warm air at 500mb - half of surface pressure - centered over the Arctic ocean, combined with a strong surface high. This situation produces maximum solar heating in early June and produces maximum surface heating and high temperatures.

It's a worst case forecast for sea ice.

[Shared Humanity]

edit: I've just seen the ECMWF forecast and it looks pretty terrible indeed. Anything above 1030 hPa around this time of year, is a disaster for the ice. I'll post the latest forecast this evening.

Can you explain why you say it's bad in reference a pressure? I understand Pa refers to a Pascal. I'm an engineer, and the importance of air pressure rather than temperature is not obvious to me.

High pressure indicates subsidence. This inhibits cloud formation which means that the Arctic regions underneath the high will receive more incoming shortwave radiation.

Seriously? You have to throw the word subsidence in there instead of an actual explanatory few words?

Hi HelloMeteor. Welcome to the site.

Actually answered the question pretty succinctly. I've been here for about 7 years and still find myself having to google terms to understand what some type here. Might be better to try this rather than ridiculing someone trying to answer your question.

Actually googled subsidence before I typed this.

[HelloMeteor]

I did too. The predominant definitions are about geology.

It's just stupid to insist on using jargon when there are plenty of words 90% of people with a technical background wouldn't need to look up.

[Tor Bejnar]

I'm not a weather map person, particularly, but I can put my left thumb up over the "H" on a map (helps that I'm left handed in the northern hemisphere (NH) ) and see how the air flows (follow my other curled fingers).  With the strong high over the central Arctic and a weaker high over Greenland on the 2nd just post map (thanks FOoW), I read this to mean strong Fram export next Tuesday is forecast.

[Jim Hunt]

I did too.

Does this help at all? http://lmgtfy.com/?q=high+pressure+subsidence

[HelloMeteor]

I did too.

Does this help at all? http://lmgtfy.com/?q=high+pressure+subsidence

Lol, what a bunch of pretentious assholes you all are. How was I to know I had to google "high pressure" with "subsidence" to get an applicable definition of subsidence? If I should be expected to know the word, I should expect to be able to look up the definition of the word, by itself, and find it among one of the several definitions.

Jesus, you want the general public to be informed, but you make a point of trying to look WAY more intelligent than you are and attacking people who call you out on it.

If the public never "gets it", it's precisely because people acting like you.

You care more about looking smart than educating people.

[Pragma]

I'm not a weather map person, particularly, ...

Neither am I but I did some googling, so to add a bit to this:

As you indicated, the high pressure systems rotate clockwise and the low pressure systems rotate anti or counter-clockwise, but I just also learned that there is a spiral aspect. The air mass in a high pressure system is "flung out" so to speak, whereas a low pressure system draws air into the centre. Makes sense, like explosion and implosion.

So, the two systems on either side of Svalbard are like two gears meshing. The HP system throws the ice from the central arctic to the LP system, which then draws it in, closer to it's demise in the North Atlantic.

Thanks FOoW, I'm with both of you that the ice is going to get very mobile soon.

Even worse is that a smaller but very similar system exists on either side of the Bering Strait. A vacuum cleaner at each side of the Arctic, how convenient!

[Rodius]

I did too.

Does this help at all? http://lmgtfy.com/?q=high+pressure+subsidence

Lol, what a bunch of pretentious assholes you all are. How was I to know I had to google "high pressure" with "subsidence" to get an applicable definition of subsidence? If I should be expected to know the word, I should expect to be able to look up the definition of the word, by itself, and find it among one of the several definitions.

Jesus, you want the general public to be informed, but you make a point of trying to look WAY more intelligent than you are and attacking people who call you out on it.

If the public never "gets it", it's precisely because people acting like you.

You care more about looking smart than educating people.

This seems over the top. People here have answered your question by giving links and explaining the question.
If it is confusing, it is because it is complex.
And people tend to forget that the words they use are not always in common usage or have specific meaning within the niche.

You have only been a member for a little over a week, the people here have been studying the climate for many years, are specialised in the topic and know what they are talking about. That is not being pretentious, they just forget sometimes that what they know is not common knowledge.

Google is your friend. Sometimes it takes effort to learn on your own part. Rather than lash out, thank the people for answering your question, keep asking more questions and be prepared for a learning curve.
The general public does not have time for this type of thing, which is understandable in some ways because it is complex, and many people dislike complexities because it requires effort to unfold them. It is also why the climate crisis will continue to be underestimated and will only be acted on when the brut force personally affects them.

[Jim Hunt]

You care more about looking smart than educating people.

Like this you mean?

High pressure indicates subsidence. This inhibits cloud formation which means that the Arctic regions underneath the high will receive more incoming shortwave radiation.

Or in other words: High pressure -> clear skies -> lots of sunshine -> melt ponds, melting in general, open water absorbing radiation, etc.

If your interested in understanding shortwave radiation and longwave radiation downwelling effects on sea ice this rather comprehensive text will enlighten you on the subject at length.

https://journals.ametsoc.org/doi/full/10.1175/JCLI-D-15-0238.1

An engineer should understand compressional heating and drying. The ECMWF model and it's ensembles are forecasting a dome of warm air at 500mb - half of surface pressure - centered over the Arctic ocean, combined with a strong surface high. This situation produces maximum solar heating in early June and produces maximum surface heating and high temperatures.

It's a worst case forecast for sea ice.

[aperson]

You care more about looking smart than educating people.

You indicated you were an engineer, I gave you a short response that I figured was geared toward an engineer. I will try to provide a better Simple English answer in the future to spare you from throwing a tempter tantrum.

[jdallen]

I notice that open water is appearing in a massive new fracture zone north of Greenland and multiple new zones of fracture are appearing everywhere as winds change .. almost all with open water visible on Worldview .
 In past years it has been argued that side melting of floes is negligible but this year I wonder .. the ice is not so thick and is already in trillions of fragments , and the sides are partially exposed to low angle sun 24/7 . Could this not be important as it bypasses the snow on the surface ? This sunlight would be absorbed by the ice and water , while the snow above prevents it radiating back to space ..
  It may not be a huge fraction of incoming solar radiation but it is a growing fraction , especially important in a sunny summer . Any thoughts ?   b.c.

Side melt doesn't really become a factor in melt until the flow size drops considerably - 150 meter diameter and smaller.  Until then, top and bottom melt rule the day.

Insolation on side surfaces will similarly be negligible as it won't really increase the uptake of solar energy significantly.

It's all about albedo right now, which is why with snow melt (which lowers albedo), open water (which also better captures insolation) and little cloud cover (due to high pressure) is such a disturbing combination.

The interesting bit, is it might not cause immediate and steep drops in area or extent.  Volume however may start to dive, because with melt ponds and full sunlight, 4cm of ice or more could be getting stripped off each day. 

Combine that with bottom melt, and by the end of June we could end up with vast swaths of ice that has the appearance of being "OK", but is only a meter thick or less.  In this case, the real drops in area and extent will happen in July and August, as accumulated heat attacks lingering ice and just crushes it... unless we are saved again by the weather.

What also worries me is enough heat getting picked up that bottom melt continues well into late September, or potentially even early October, if SST's end up high enough.

This is going be a very interesting and possibly disturbing melt season.

[Greenbelt]

Subsidence is a pretty useful precise term in meteorology. Would you also complain about a pilot using precise jargon like "elevator" or "horizontal stabilizer" or "trim" to explain an aviation concept? If you want explanation using layman's terms, feel free to ask, preferably in a different thread. This thread watches the ice and the weather etc. Mackenzie delta.

[Rich]

I'm not a weather map person, particularly, ...

Neither am I but I did some googling, so to add a bit to this:

As you indicated, the high pressure systems rotate clockwise and the low pressure systems rotate anti or counter-clockwise, but I just also learned that there is a spiral aspect. The air mass in a high pressure system is "flung out" so to speak, whereas a low pressure system draws air into the centre. Makes sense, like explosion and implosion.

So, the two systems on either side of Svalbard are like two gears meshing. The HP system throws the ice from the central arctic to the LP system, which then draws it in, closer to it's demise in the North Atlantic.

Thanks FOoW, I'm with both of you that the ice is going to get very mobile soon.

Even worse is that a smaller but very similar system exists on either side of the Bering Strait. A vacuum cleaner at each side of the Arctic, how convenient!

Also not an expert, but I don't think comparing the Bering Strait to Fram Strait is very useful. The forces driving the ice to Fram are largely based on the Earth's spin which isn't changing. The circumpolar winds rotate clockwise and the powerful East Greenland Current is pulling Arctic surface water into the Atlantic.

The weather may accentuate the movement of ice toward Fram as winds pick up and ice melts and offers less resistance to the prevailing forces, but we shouldn't expect to see a lot of ice leaving via the Bering.

If any of the more expert contributors can weigh in on how a weather system like this can change the pace of ice export, that would be appreciated.

[HelloMeteor]

I did too.

Does this help at all? http://lmgtfy.com/?q=high+pressure+subsidence

Lol, what a bunch of pretentious assholes you all are. How was I to know I had to google "high pressure" with "subsidence" to get an applicable definition of subsidence? If I should be expected to know the word, I should expect to be able to look up the definition of the word, by itself, and find it among one of the several definitions.

Jesus, you want the general public to be informed, but you make a point of trying to look WAY more intelligent than you are and attacking people who call you out on it.

If the public never "gets it", it's precisely because people acting like you.

You care more about looking smart than educating people.

This seems over the top. People here have answered your question by giving links and explaining the question.
If it is confusing, it is because it is complex.
And people tend to forget that the words they use are not always in common usage or have specific meaning within the niche.

You have only been a member for a little over a week, the people here have been studying the climate for many years, are specialised in the topic and know what they are talking about. That is not being pretentious, they just forget sometimes that what they know is not common knowledge.

Google is your friend. Sometimes it takes effort to learn on your own part. Rather than lash out, thank the people for answering your question, keep asking more questions and be prepared for a learning curve.
The general public does not have time for this type of thing, which is understandable in some ways because it is complex, and many people dislike complexities because it requires effort to unfold them. It is also why the climate crisis will continue to be underestimated and will only be acted on when the brut force personally affects them.

It's not confusing because it's complex. It's not even confusing. Physics, except on the quantum level, isn't confusing even when it is complex, because it's purely logical and everything fits together neatly, even when it gets complicated because physics on the macro scale fundamentally makes sense if you have a technical background. Unlike quantum physics nothing about it contradicts our experience.

Google is your friend is an obviously intentionally insulting statement.

Here's something else that is your friend:

When someone wants to learn, and asks, in so doing proving they don't know a lot about the subject, don't use jargon specific to that subject if you don't need to.

A person uses ONE WORD as if it explains something. I google it, and it's all about geology, and oh, my mistake, I should have known I had to include high pressure or meteorology as an additional keyword. Except no. There is nothing obvious about that.

Except the thing is, if I ask what's so bad about high pressure, if you apparently know so much about meteorology, you should infer quite easily that subsidence will mean even less to me than high pressure as high pressure is a term obviously more commonly used in basically every context than subsidence. That makes it quite absurd to claim the use of that word is in any way helpful to anyone that doesn't know what makes high pressure bad.

I work with mechanical engineers every day, I got a degree in aerospace engineering. We don't deal with heat transfer or HVAC often, but heat transfer has come up. The word subsidence has never come up between engineers, and we're pretty nerdy.

[HelloMeteor]

High pressure indicates subsidence. This inhibits cloud formation which means that the Arctic regions underneath the high will receive more incoming shortwave radiation.

Or in other words: High pressure -> clear skies -> lots of sunshine -> melt ponds, melting in general, open water absorbing radiation, etc.

This on the other hand makes tons of sense. I am acquainted with meteorology and know low pressure correlates to bad (not sunny) weather, like hurricanes, the worst case example of low pressure bad weather, and high pressure correlates to bluebird or at least fair weather cumulus clouds. 

I was more interested if there was something about the pressure itself that is bad for ice. Like does high pressure mean the air is at greater density, which would mean more heat transfer from the ice to the air.

[Rod]

Welcome HelloMeteor.

People were trying to help, and you got very rude.  if you have a question post it in the "stupid questions" thread. 

This thread is for a discussion of the melt season.  It turns some people off when it gets cluttered with personal attacks. 

Again, welcome to the forum.  Please try to treat people with respect.  There are some really good posters who go quiet when things get too far off topic, and things are really getting interesting now and I want to hear what they have to say.

[HelloMeteor]

I only got very rude after people insulted me by saying let me google that for you or saying google is your friend.

"Seriously? You have to throw the word subsidence in there instead of an actual explanatory few words?"

That does not qualify as very rude does it? Maybe a little rude, but not very.

[jdallen]

High pressure indicates subsidence. This inhibits cloud formation which means that the Arctic regions underneath the high will receive more incoming shortwave radiation.

Or in other words: High pressure -> clear skies -> lots of sunshine -> melt ponds, melting in general, open water absorbing radiation, etc.

This on the other hand makes tons of sense. I am acquainted with meteorology and know low pressure correlates to bad (not sunny) weather, like hurricanes, the worst case example of low pressure bad weather, and high pressure correlates to bluebird or at least fair weather cumulus clouds. 

I was more interested if there was something about the pressure itself that is bad for ice. Like does high pressure mean the air is at greater density, which would mean more heat transfer from the ice to the air.

Barometric pressure in and of itself really doesn't have any effect on the ice.

Further, heat transfer from air to ice is pretty negligible when compared to that from insolation or directly from the water - that's why melt ponds are so dangerous - they reduce albedo and put a layer of warm(relatively) water on the top surface of the ice which concentrates and transfers the heat quite efficiently.

The mechanics of the ice itself changes dramatically with temperature - ice at -20c is 4-5 times more structurally resistant to crushing and shear forces than ice at freezing ~ minus 1.8c for water in the Arctic.

But again, air pressure in and of itself really doesn't alter the melt equation.

[HelloMeteor]

High pressure indicates subsidence. This inhibits cloud formation which means that the Arctic regions underneath the high will receive more incoming shortwave radiation.

Or in other words: High pressure -> clear skies -> lots of sunshine -> melt ponds, melting in general, open water absorbing radiation, etc.

This on the other hand makes tons of sense. I am acquainted with meteorology and know low pressure correlates to bad (not sunny) weather, like hurricanes, the worst case example of low pressure bad weather, and high pressure correlates to bluebird or at least fair weather cumulus clouds. 

I was more interested if there was something about the pressure itself that is bad for ice. Like does high pressure mean the air is at greater density, which would mean more heat transfer from the ice to the air.

Barometric pressure in and of itself really doesn't have any effect on the ice.

Further, heat transfer from air to ice is pretty negligible when compared to that from insolation or directly from the water - that's why melt ponds are so dangerous - they reduce albedo and put a layer of warm(relatively) water on the top surface of the ice which concentrates and transfers the heat quite efficiently.

The mechanics of the ice itself changes dramatically with temperature - ice at -20c is 4-5 times more structurally resistant to crushing and shear forces than ice at freezing ~ minus 1.8c for water in the Arctic.

But otherwise, air pressure in and of itself really doesn't alter the melt equation.

Thank you.

[be cause]

and back to the weather up north .. and in reply to JDAllen's reply to me .. can you , or anyone , provide any references re ice floe size and side melt ?
   My observations are that the fracture form being taken is pretty fractal this year .. and I would suggest that already in areas like 83N 130W a large proportion of the floes are under 150m ...
   I assume that these zones appear darker on Worldview because less light is escaping .. am I right ?
   If so it is busy working out of sight ..
 
Please please put my concerns to rest .. I am convinced that in increasingly large parts of the Arctic basin the angle of sun and floe size will play a measurable and perhaps unexpectedly important part in the outcome this season .. b.c.

ps . same devastating scene across the pole at @ 83N 130E  Worth looking at both spots on Worldview on the 20th  .

[Pragma]

Also not an expert, but I don't think comparing the Bering Strait to Fram Strait is very useful.The forces driving the ice to Fram are largely based on the Earth's spin which isn't changing. The circumpolar winds rotate clockwise and the powerful East Greenland Current is pulling Arctic surface water into the Atlantic.

The weather may accentuate the movement of ice toward Fram as winds pick up and ice melts and offers less resistance to the prevailing forces, but we shouldn't expect to see a lot of ice leaving via the Bering.

If any of the more expert contributors can weigh in on how a weather system like this can change the pace of ice export, that would be appreciated.

OK, good. This is useful but I am a little confused. If the dominant influence on ice movement is earth rotation, and Atlantic currents, it makes perfect sense that the majority of ice movement would be to the east.

At the same time, we all seem to agree that ice distribution can be affected greatly by prevailing winds, which seems contradictory.

Also, I was under the impression that the cyclone(s) of 2012 at the end of the melting season what what took the 2012 ASIE to a new low. I assumed that that was due to ice movement, but I now want to clear up any misconceptions I have. It may have just been the mechanical movement that boosted melting or delayed freeze-up?

So I guess a good way to put the question is:

What are the relative effects of weather patterns, currents and earth rotation  when it comes to ice movement out of the arctic and is it only observed in the east via Fram,  Nares, and between Svalbard and Novaya Zemlya?

Further, is the concern about the large stationary high in the Arctic more an issue of clear skies and higher temperatures? 

[b_lumenkraft]

It's not confusing because it's complex. It's not even confusing.

So it's too complex for you to add a search term to your google search to get a non geology result, but the obviously extreme complexity of weather systems isn't? That makes no sense. You underestimate the complexity of the Arctic and overestimate your ability to use Google.

When someone wants to learn...

...they would ask a followup question if something is not understood. You opted for insulting many intelligent people instead.

Don't you dare using logic as an argument here ever again. Obviously, you don't understand the concept.

[Rich]

Also not an expert, but I don't think comparing the Bering Strait to Fram Strait is very useful.The forces driving the ice to Fram are largely based on the Earth's spin which isn't changing. The circumpolar winds rotate clockwise and the powerful East Greenland Current is pulling Arctic surface water into the Atlantic.

The weather may accentuate the movement of ice toward Fram as winds pick up and ice melts and offers less resistance to the prevailing forces, but we shouldn't expect to see a lot of ice leaving via the Bering.

If any of the more expert contributors can weigh in on how a weather system like this can change the pace of ice export, that would be appreciated.

OK, good. This is useful but I am a little confused. If the dominant influence on ice movement is earth rotation, and Atlantic currents, it makes perfect sense that the majority of ice movement would be to the east.

At the same time, we all seem to agree that ice distribution can be affected greatly by prevailing winds, which seems contradictory.

Also, I was under the impression that the cyclone(s) of 2012 at the end of the melting season what what took the 2012 ASIE to a new low. I assumed that that was due to ice movement, but I now want to clear up any misconceptions I have. It may have just been the mechanical movement that boosted melting or delayed freeze-up?

So I guess a good way to put the question is:

What are the relative effects of weather patterns, currents and earth rotation  when it comes to ice movement out of the arctic and is it only observed in the east via Fram,  Nares, and between Svalbard and Novaya Zemlya?

Further, is the concern about the large stationary high in the Arctic more an issue of clear skies and higher temperatures?

While we wait for more expert input....

The prevailing winds are a function of the Earth's rotation. The Beaufort Gyre spins clockwise and puts the ice in a position to catch the current heading east.

The impact of a storm like the GAC can also include upwelling of warmer saltier water to the surface.

There is some non zero amount of ice exiting via the Bering, but it is small relative to the Atlantic side.

The strength of the export current is also due to salinity. The Atlantic is much saltier (and warmer) than the Arctic or Pacific. Where they meet, the lighter surface layer of the Arctic (where the ice is located) is pushed east over the top while warm Atlantic water moves into th Arctic at depth along the coast of Spitsbergen.

You've got earth spin based wind.  salinity and temperature gradients all pushing the surface layer east. You're earlier reference to a vacuum cleaner was a good fit.

The vacuum cleaner is going to work better on small pieces that aren't stuck in place.

[Pragma]

As you said, while we wait for more expert info, a final comment for the evening from me.

I was likely inaccurate using the term "prevailing winds", whereas I meant the conditions that exist in a localized area regardless of what is expected due to location or season.

I understand the mechanisms you described and it all makes sense. The Beaufort Gyre is a new twist (lol) that I had not considered.

It still leaves the question of how big an influence the highs and lows are to ice export. All other things being equal, it would seem to me to be at least a moderate factor.

[HelloMeteor]

It's not confusing because it's complex. It's not even confusing.

So it's too complex for you to add a search term to your google search to get a non geology result, but the obviously extreme complexity of weather systems isn't? That makes no sense. You underestimate the complexity of the Arctic and overestimate your ability to use Google.

When someone wants to learn...

...they would ask a followup question if something is not understood. You opted for insulting many intelligent people instead.

Don't you dare using logic as an argument here ever again. Obviously, you don't understand the concept.

You overestimate your rhetorical prowess. And your reasonableness. And your intellect. This forum is condensed weapons grade intellectual masturbation and your comment proves it. If you cared about the issue at hand, you wouldn't resort to insults immediately.


How precisely have I underestimated the complexity of the Arctic? Please be specific and explicit.

How have I overestimated my ability to use Google? Please be specific and explicit.

How have I insulted many intelligent people? Please be specific and explicit.

Don't I dare use logic? Jesus, grow TF up you freaking lightweight. Looks like you're afraid of logic itself. Not surprising for someone that is most likely a progressive ideologue. I'll match my logical prowess against yours any day. Any subject, any context, any stage.

How should I have known to add some indeterminate term to a search to arrive at a definition of a word any technical person should understand if were common parlance? Except it's not common parlance. Which was precisely my point.

[nanning]

Don't you dare using logic as an argument here ever again. Obviously, you don't understand the concept.

Jesus, grow TF up you freaking lightweight.

I am disappointed that this is an acceptable way to communicate for intelligent people here. it reads as putting someone down, a new curious member in this case. Is it an effect of adult (academic) hierarchical groupbehaviour?
No offence intended (if you can find any). Sorry to be off-topic.

[HelloMeteor]

Don't you dare using logic as an argument here ever again. Obviously, you don't understand the concept.

Jesus, grow TF up you freaking lightweight.

I am disappointed that this is an acceptable way to communicate for intelligent people here. it reads as putting someone down, a new curious member in this case. Is it an effect of adult (academic) hierarchical groupbehaviour?
No offence intended (if you can find any). Sorry to be off-topic.

Logic offends the ideologue.

Someone that requests another doesn't use logic isn't exactly in the right. Kind of by definition, ya know?

Notice how it has so far not been me that has escalated this?

[HelloMeteor]

edit: I've just seen the ECMWF forecast and it looks pretty terrible indeed. Anything above 1030 hPa around this time of year, is a disaster for the ice. I'll post the latest forecast this evening.

Can you explain why you say it's bad in reference a pressure? I understand Pa refers to a Pascal. I'm an engineer, and the importance of air pressure rather than temperature is not obvious to me.

From lurking to trolling in two posts. A record?

High pressure indicates subsidence. This inhibits cloud formation which means that the Arctic regions underneath the high will receive more incoming shortwave radiation.

Seriously? You have to throw the word subsidence in there instead of an actual explanatory few words?

I and everyone else notice how you made no argument there.

Can you make an actual argument or criticism of my behavior or are you only going to non-slyly suggest things? Leftists are always duplicitous.

Regardless, I am amused.

[Aluminium]

May 21-25.