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Arctic sea ice / Re: The 2020/2021 freezing season
« on: October 31, 2020, 02:50:55 PM »
One thing you learn quite quickly as a programmer is that what you yourself think is easy is pretty much black magic to all non-programmers. In spite of having worked in software development for 30 years, I have absolutely no knowledge or experience in graphics programming and the images that  A-Team and BFTV and Uniqorn and others keep posting here seems like black magic to me. I enjoy it but don't try to convince me that it is easy.

Arctic sea ice / Re: MOSAiC news
« on: September 13, 2020, 04:57:57 AM »
Oren points out that people may read but not post, and may look at the thumbnails of the graphics but not open them up and thus not get counted as having viewed the graphic. I can confirm anecdotally that Oren is correct. I am exactly such a person.

Glaciers / Re: Glaciers worldwide decline faster than ever
« on: September 01, 2020, 01:45:32 PM »
Russian Glacier In Urals Region Has Completely Melted, Scientists Say

One of the largest glaciers in Russia’s Urals region has completely melted, according to members of a research group that carried out an expedition.

The glacier known as MGU, which was 2.2 kilometers long when it was discovered in 1953, has vanished, the researchers from the Scientific Center for Arctic Studies said in an August 31 statement.

The researchers carried out their expedition from August 19 to August 28 and visited the sites of two other glaciers.

MGU was the second largest glacier by mass in the Urals polar region and its longest when it was initially discovered.

Mikhail Ivanov, one of the scientists, said a “large amount” of ice still existed when they last visited MGU in 2010.

Parts of the iceberg were still visible in photographs taken by tourists to the area in recent years, he said.

“This year, it turned out, it completely melted,” Ivanov said.

Russia’s Urals and Siberian regions have experienced unusually high temperatures in recent years that have been blamed on global warming.

Arctic sea ice / Re: The 2020 melting season
« on: August 22, 2020, 11:31:48 PM »
Thanks for the feedback all.

Thoughts on this version?

Arctic sea ice / Re: The 2020 melting season
« on: August 20, 2020, 05:15:36 AM »
The strength of that storm is highly likely below 975hpa. The path is still uncertain. if it is quite near the north pole, it will be a disaster.
If it goes to the North Pole, the people from MOSAiC are there!  ???
I hope they will be fine, but it is time to move out.

Arctic sea ice / Re: The 2020 melting season
« on: August 19, 2020, 09:54:20 PM »
Some pretty incredible news from the North Pole today!

Below, is a photograph taken from the Polarstern at 12:45 pm on August 19, 2020 as the ship reached the North Pole. There are lots of melt ponds, and the ice that is left looks very thin.

”Based on the satellite imagery, at first we weren’t sure whether the loose ice cover was due to wind and currents, and were concerned that, if it was, a change in weather conditions could compact it again. Then we would have been caught in a mousetrap, and could have become trapped in the ice,” reports the MOSAiC Expedition Leader, who had previously reached the North Pole on board a research aircraft, in 2000. Once in the region, however, they found that much of the sea ice truly had melted away, and hadn’t simply been broken up by the wind.
Not much sign of compaction at the pole - and I don't think there ever was. Concentration does not mean compaction.

And the winter field evidence also suggests otherwise. the Mosaic expedition had a really bad time finding a floe to be their base - and it was never stable the whole winter. The Russians had to abandon their usual yearly camp near the North Pole. Those lunatic skiers were in permanent trouble. Concentration reached near as dammit 100% - but the ice was rotten.

And so far the Area and Extent losses in the Central Arctic Sea have been impressive, and concentration is very low.

Arctic sea ice / Re: The 2020 melting season
« on: August 09, 2020, 09:33:10 PM »
This remarkable freeze/melt cycle has been unfortunate but perhaps inevitable, putting us literally in uncharted waters with regards to massive climate change impacts.

It’s easy to forget, as the post-BOE forum properly notes, that once upon a time the Barents, Baltic, Bering, Baffin. Chukchi, and Kara hosted millions of sq km of year-round ice. (And that not so long ago, 1000 m thick ice gouged the Lomonosov ridgetop.) On 08 Aug 2020, 38% of the remaining ice (the Arctic Ocean basin, was open water. Vast areas of tundra are free of reflecting snow as well. We’re already well into BOE in most respects.

What’s going on at the moment is baffling, notably between Greenland and the north pole. It’s clear we don’t really understand the current physical state of the ice. Thus even if surface weather were predictable three days out, where things will end up by mid-October still remains up in the air.

However we do have a good grip on some of the pre-conditioning events that have brought the ice to its current state:

-1- The melt season really began in the previous freeze season, even earlier. Vast areas of surprisingly thin 0.3m ice remained in the Laptev when the Polarstern moored on Oct 4th. That and a slow start to freeze-up are documented by thousands of km of ship thickness transects with no graduating SYI floes thick enough to stand on for Mosaic. (T Krumpen

-2- The TransPolar Drift over winter, as accurately imaged in Ascat time series, bore little resemblance to recent years in two key respects: months of very rapid Fram-ward displacement and extensional engagement of ice to the pole and beyond. Often the ice drift is just circumpolar.

-3- The whole icepack does not rotate CW with the TPD but rather participation is demarcated by immense  curvilinear leads, newly visualized in a dockside posting by L Kaleschke and enhanced on the Mosaic forum by directional convolution. These fracture lines, coincidentally or causally, approximately delimit the puzzling openings to the pole above Morris Jesup. A lot of MYI ice between Greenland and the pole was fractured by lead formation.

-4- Missing this year was any significant CW rotational movement of thick ice out of the western CAB. While this ice has never moved further than a half gyre in the last ten years of tracking, commonly a strip of CAB ice moves to inevitable melt in the warmer open seas of the Chukchi (which might be called internal export).

-5- Export out the Fram was robust during the TPD, pushing everything ahead of a 500 km east-west line through the initial position of the PS to oblivion in the Greenland Sea. Behind this line, newly formed Laptev ice filled the growing open water gap to shore. However, since mid-May, export out the Fram, SV-FJL gap, Bering Strait, CAA garlic press and Nares have all been inconsequential (and will remain so, too little time is left).

-6- A record heat wave off Ellesmere in mid July coupled with persistent easterly winds melted vulnerable matrix ice joining floes, enabling churning of offshore ice into residual rubble. The observed movement to the west is not unusual but it was far more narrowly restricted to the CAA coast in past events. The main CAB ice pack, being no longer attached to coastal land or ocean bottom, might be set adrift to elsewhere by persistent winds from the south. We’ve not yet seen that game-changer.

-7- The Pacific-side cyclone centered on July 27th hit like a tornado at 75º/-160º decimating the ice, on Sentinel-1 and WorldView, making clear that error-prone thickness and area/extent whole-ocean numbers don’t capture key issues such as ice mechanical strength, internal pressure or response to stress.

Both the Chukchi and slow-melting Beaufort were pre-conditioned by dispersion for flash lateral and bottom melt after the storm; note insolation today at 75º surprisingly is still 64% the strength the week centered on solstice (4th image below) but has to get through clouds and escape low angle surface reflection.

Are these independent events or somehow consequent to a single master change (such as breakdown trend of equatorial heat gradient as manifested in the jet stream)? Yes to a certain extent but this view has to be distinguished from the slot machine model put forward by Csnavywx in #4662.

That is, the multi-decadal downward trend of ice has created a set-up for which a coincidental confluence of bad weather events over a single freeze/melt cycle sequentially sum to an ice disaster. Even bland weather from here to October may suffice for a seriously below-trend outcome. Regardless of how the season turns out, as @Zlabe notes, fractional BOE has gone on all summer.

The files below expand or animate with a click. File names explain the topic addressed. I thank uniquorn for valuable discussions. Clouds are removed by setting a sequential five day AMR2 stack to 'darken only' in gimp.

Glaciers / Re: North Cascade glaciers Disastrous conditions
« on: August 09, 2019, 07:19:29 PM »
Massive Boulders, Floodwater Rush Down Mount Rainier After Glacial Outburst

A glacial outburst at about 6:50 p.m. Monday at the Mount Rainier’s South Tahoma Glacier sent debris and boulders as big as pickup trucks flowing down the mountain, said Mount Rainier National Park geologist Scott Beason.

The debris flow registered on seismic monitors and ran for more than 8 miles, Beason said.

Beason suspects warm, sunny weather filled the glacier with melt, rearranged the “internal plumbing” at the glacier’s base, caused water to blast a new channel through the glacier, and then flooded glacial melt into Tahoma Creek.

A glacial blowout on Mount Rainier sent debris as big as a pickup truck flowing for miles.

“The event lasted an hour and had four separate surges,” Beason said of the outburst flooding. “The outlet channel definitely shifted. It picked up a lot of loose material just below the glacier and carried it downstream and mobilized it into a debris flow.”

As the world warms and Mount Rainier’s glaciers thin and retreat over time, these massive debris flows have become a common occurrence on the mountain’s south side. The park is building systems to forecast massive debris flows and send alerts to park staff when they’re triggered, Beason said.

A view of a cavern in the terminus of the South Tahoma Glacier, from where floodwaters burst, carrying debris miles down.

The park has recorded some 32 debris flows along Tahoma Creek. The South Tahoma Glacier that feeds the creek began to retreat in the 1960s, Beason said.

Arctic sea ice / Re: 2019 sea ice area and extent data
« on: July 26, 2019, 04:28:47 PM »
2nd attachment - .csv file with the data.

Sadly, won't display properly in OpenOffice.

Suggest you try LibreOffice. I would go for one of the older versions - newer ones were really difficult for me to use - kept on hanging.

You will need an afternoon free unless you've got a decent internet connection (I don't).

It is what I switched to when Microsoft demanded money from me.

Arctic sea ice / Re: 2019 sea ice area and extent data
« on: June 20, 2019, 11:46:19 PM »

Quite a lot of hyperbole on the melting season thread on expected sea ice collapse not yet showing in the data NSIDC and AMSR2 data.

Perhaps a graph showing the number of hyperbolic predictions written per day on the melting season thread would be useful?  That would allow comparison with the NSIDC and AMSR2 data and we could see whether there was any correlation or not.   :)

Arctic sea ice / Re: The 2019 melting season
« on: June 19, 2019, 01:53:52 AM »
On extent flattening, part of the issue is that ice loss in Kara has flattened due to low pressure keeping this area cool.  This area is often freefalling at this time of year.  Note also that area is not dropping fast because of a genuine reduction in area, but because of melt ponding.  I think it is more the fast drop in area rather than the slow drop in extent that is false.  Although the drop in area does reflect rapid surface melting, so while false in some sense, it is still significant and real loss of ice is likely to follow.

 This error happens every year so you are still comparing apples to apples and can even interpolate extra data from this. Stick around for this forum for a few years please :)
Say that to yourself, that guy has been around forever.

Arctic sea ice / Re: The 2019 melting season
« on: June 15, 2019, 10:30:35 AM »
Hycom for the record.

 When the ice retreats to 800N there'll be no resistance to rotation, on the CAA side the channel by 110W looks primed to open.

Antarctica / Re: Halley base shut down and new crack in Brunt shelf
« on: June 14, 2019, 08:01:47 PM »
From Adrian Luckman:  animation of the McDonald Ice Rumples on Brunt Ice Shelf

Arctic sea ice / Re: The 2019 melting season
« on: June 14, 2019, 04:48:35 AM »
I guess it's all a matter of perspective.

I agree that too much emphasis is placed on individual melting season's. But not because they create the appearance of catastrophe, more because they distract from the larger catastrophic decadal trend.

Other than the early season burst of heat, 2019 has been pretty average in terms of SST's until this recent Russian coastal increase. That 2019 is in contention with the all-time leaders after so much unremarkable temperature speaks to the progression of the chronic influence of AGW.

2019 is in position to go low and enter the freezing season where the signature impact of AGW (heat retention) dominates.

The chances of March 2020 setting a record low maximum are very good at this point.

Arctic sea ice / Re: The 2019 melting season
« on: June 14, 2019, 12:26:45 AM »
Long time lurker here and the little bit that I would have to offer in way of analysis is to humbly suggest to apply the brakes to the talk of the "catastrophe" (and other superlatives) for what is happening to the Laptev.

Yes, it visually looks bad with all the melt ponding on Worldview and SMOS. Yes, the forecast has been and continues to be rather bad in regards to temperatures, wind and insolation.  However I would encourage everyone to take a good look at Worldview and run it from June 13 to July 13th for 2012.  While some here would argue that for the Laptev the ice is in worse shape than 2012 due to the condition of the fast ice, there is counter argument that perhaps 2012 is worse because of the size of the Laptev bite.

Regardless of where you come down on this argument take a good look at the condition of the fast ice at this time of the year in 2012 and note how much ice was still around near the shore 1 month later.  The point being that it takes a lot of energy and a fair amount of time to melt ice here and a visual scan of the last 10 years indicates that while this year looks bad and the forecasts look bad, there is historical evidence that suggests this ice doesn't just go poof over night.

I'll go back to lurking but just wanted to also say that I appreciate all the insights that you all provide and I really love coming here each day.  I have a bit of geeky joy in my heart when I see that there are a lot of posts to digest over the last 12 to 24 hours (particularly on the melting season thread and the extent thread) especially when it stays on topic.

Cheers and thanks to all.

Arctic sea ice / Re: 2019 sea ice area and extent data
« on: May 17, 2019, 11:45:55 AM »

It would be interest to get some kind of sense of how people rank the various variables.

As a newbie, I would guess water temperature is at least up there with atmospheric temperature . Sunlight has been pointed out. The spin which brings ice to Fram seems important. Nares being open with a steady throughput. Wind. The thickness of the ice. The level of surface fracturing.

Thanks for your patience. I'm just trying to get oriented. Asking questions helps.
For discussions on the various parameters that influence sea ice area and extent the 2019 melting season thread (and other threads such as salinity) is where you need to go. There you will find the posts on the weather, the climate, the sea temperatures, the ocean currents etc etc etc. There you will also find the more you know the less you know.

This thread is mostly just about the data itself. I only make a comment on my posts in this thread about where the very short-term direction of travel may be.

Most of us also use the "Stupid Questions" thread from time to time. You will get good answers and links to places within this forum and elsewhere.  It is a big and wide-ranging forum. Good hunting.

Arctic sea ice / Re: Glossary ... for newbies and others
« on: March 21, 2018, 07:58:04 PM »
SWE - Snow Water Equivalent

Side note: It appears that all you lovely people are now on the brink of developing a totally new & unique language, which is based entirely on acronyms. Extremely interesting from an ethnolinguistics perspective, I must say! (but one helluva bugger to learn! The dev team at Rosetta Stone have their work cut out for them!)

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