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Messages - Juan C. García

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1
Arctic sea ice / Re: Latest PIOMAS update (September 2020)
« on: September 20, 2020, 12:16:15 PM »
Changes from August 31.

Chukchi ... -100%
Beaufort ... -32%
CAB ... -6%
CAA ... +14%
Greenland ... +12%
Baffin ... +43%

2
Permafrost / Re: Siberian permafrost hole/blowout
« on: September 19, 2020, 09:56:39 PM »
A large new ‘hole’ appears in Gydan tundra, following record-warm Arctic summer
17 September 2020

200 metres wide thermocirque seen weeks after scientists find funnel in the Yamal peninsula, caused by build up of methane.

Sciences said gas emissions were not the origin of this phenomenon.

‘This is a thermocirque; gas funnels have nothing to do with it.

‘We have been studying thermocirques for many years, they became active in warm year 2012.

'They look like huge landslides of semi-circular shape with outcrops of ice.

'Earlier such thermocirques were observed near the sea, now they are seen deeper on land. They are associated with ice layers and warming, alike to funnels’, she said.

http://www.siberiantimes.com/other/others/news/giant-new-hole-appears-in-russian-arctic-200-metres-in-diameter-and-20-metres-deep/

More than 400 sealed ‘craters’ are ticking time bombs from a total 7000+ Arctic permafrost mounds

http://www.siberiantimes.com/other/others/news/more-than-300-sealed-craters-are-ticking-time-bombs-from-a-total-7000-plus-arctic-permafrost-mounds/

At least three of the recorded eruptions had witnesses, who reported seeing the ignition.

These were the Antipayuta crater (C3), the Seyakha crater (C11) and the Yerkuta crater (C12) eruptions.

‘We believe the ignition was caused by electrostatic discharges, which adds to the danger of the mounds’, Vasily Bogoyavlensky said.


3
Arctic sea ice / Re: The 2020 melting season
« on: September 18, 2020, 07:33:35 PM »
This is the best thread on the Internet. Thanks, everyone.

4
Arctic sea ice / Re: The 2020 melting season
« on: September 18, 2020, 11:03:36 AM »
Today's images and animation. There can be little doubt now that the passed the minimum, as gains in the Beaufort Sea easily outweigh any changes elsewhere.

5
Arctic sea ice / Re: What's new in the Arctic ?
« on: September 18, 2020, 07:32:10 AM »
Wildfires in Arctic Circle release record amounts of greenhouse gases - BBC News

5 minute video, gives a ground level view of Siberia and some of the folks who live there.

6
Arctic sea ice / Re: The 2020 melting season
« on: September 17, 2020, 01:01:16 PM »
AMSR2: Some recent days of 2020 compared to 2012
Rough overlay of 2012 vs 2020 using awi amsr2 v103, aug20-sep15 (am/pm)

gimp grain extract, the years were slightly different sizes so there is a small scaling error

7
Arctic sea ice / Re: The 2020 melting season
« on: September 15, 2020, 11:39:58 AM »
Today's images an animation.
Clear gains in the Beaufort and CAA outweighing losses along the Kara and Laptev facing ice edges.

8
Arctic sea ice / Re: The 2020 melting season
« on: September 15, 2020, 06:04:08 AM »
September 10-14.

2019.

9
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: September 14, 2020, 03:29:22 PM »
Last four years. Note 2017 conditions after 2016 summer and winter, in a position to melt all FYI and dump most two-three year ice... but was a relatively cold static year.
2020 sees a buildup of 4+ year MYI. No comparison to 1980, obviously, but it’s some rebound and it will take time to have a ice distribution as ready for meltout as was 2017

10
Antarctica / Re: Pine Island Glacier (PIG) Calving and Discussion
« on: September 12, 2020, 04:29:49 PM »
Some elements to complete and finalize this discussion:

Dimension at stake :
Sea ice: ~1m (the last place in the bay where the sea ice stabilizes and is no longer carried away, neither by the bay's current (turning clockwise) nor by the winds, being precisely the front of the PIG and it has only recently stabilized. The outgoing current, see below, can probably explain this.

Icebergs/Glacier: ~400m

Translated: an elephant and a small beetle

Clearly there is no possible comparison: when an iceberg is " ejected " by calving (expression of the existing tensions before calving which are released almost instantaneously), for it the sea ice does not exist.
Similarly, given its dimensions, if, following calving, it is no longer in static equilibrium and turns over.

On the other hand :
> the presence of sea ice can stop the movement of an iceberg more quickly than sea water alone
> a free iceberg surrounded by sea ice can be retained, even in the presence of currents or winds, if these are not too strong.


Warm current CDW :this enters the bay at depth (< -700m), reaches the grounding line, melts the PIG and comes out, passing under the glacier (and continuing to melt it), with water, whose temperature has dropped, but which is still warmer than sea water, which explains the formation of polynyas especially where it is stronger as in correspondence of the NSM, of the SSM and of the centre of the front (after the last big calving in February a new site appeared in correspondence of the Shear Margin between the SWT and the SIS).
This current is at its peak in autumn, but this is of no importance in relation to calvings. In fact its action, melting of the PIG, clearly has an influence on the dynamics of the glacier, but over the long term and not on a seasonal level.

To conclude, I would like to remind you, as Baking has already done, that the dynamics of the PIG is not currently linked to the seasons!

11
Arctic sea ice / Re: The 2020 melting season
« on: September 12, 2020, 03:05:51 PM »
Probably not. We haven't had the teasing ups and downs yet.
mercator 0m temperature(SST) with amsr2-uhh sic overlay, jun1-sep11

12
Arctic sea ice / Re: The 2020 melting season
« on: September 11, 2020, 06:06:22 PM »
The Polarstern from above on "Sunday morning", via the MOSAiC Twitter feed:

https://twitter.com/MOSAiCArctic/status/1304440835119906817

13
Arctic sea ice / Re: The 2020 melting season
« on: September 11, 2020, 06:07:55 AM »
The latest low pressure system is having an effect on the ice. Here's an animation comparing yesterday to today—you can see two broad swaths of lower concentration appeared in the latest update.

click to animate

14
Arctic sea ice / Re: The 2020 melting season
« on: September 10, 2020, 01:53:49 PM »
Weekly sea ice losses from July 1st

15
Arctic sea ice / Re: The 2020 melting season
« on: September 09, 2020, 01:18:52 PM »
Hello everyone!
I have been lurking this forum since December 2018 (I discovered this website through a Paul Beckwith video) and I want to thank you all for the high quality content posted here everyday by the ASIF community.

I wanted to share my findings regarding some questions that were asked about the Bremen sea ice extent numbers:
-In their website https://seaice.uni-bremen.de/sea-ice-concentration/amsre-amsr2/time-series/, it is stated that
Quote
Since July 3, 2012, AMSR2 data is displayed which is adapted with the same parameters as its predecessor AMSR-E. The fit parameters are not deduced by comparing it during an overlap period to another time series. Hence, the data ought to be treated with caution until confirmation by independent sources.
therefore if I've understood this well there's no reason we couldn't compare the (future) September 2020 sea ice extent minimum with 2012's.
-Moreover, I've found Bremen's 2012 September daily minimum here : https://seaice.uni-bremen.de/data/amsr2/today/extent_n_19720101-20191231_amsr2.txt, It was reached September 15th with a value of 3,274,138.00 km², today's daily value is 3,318,268.00 km², https://seaice.uni-bremen.de/data/amsr2/today/extent_n_2020_amsr2_smooth.txt, so for 2020 to beat 2012, by that measure, it would need an extent loss of at least 44,131 km². If it happens, it will surely be by the end of the week.

I hope you found my post informative and useful. I have nothing else to add for all I know about sea ice I have learnt from here. I shall now return lurking in the shadows.  8)
Welcome mv89! And thanks for the information. I hope you post more when you find inspiration.

16
Arctic sea ice / Re: The 2020 melting season
« on: September 09, 2020, 11:54:20 AM »
Today's images and animation.
No sign of the storm yet...

17
Arctic sea ice / Re: The 2020 melting season
« on: September 09, 2020, 02:33:20 AM »
Another excellent reply Allen. Thank you!

A few weeks ago I watched a 2015 Discovery Channel documentary - you probably all know - called Melting: Last Race to the Pole (link), and it really helped me a lot to understand what the Arctic sea ice actually looks like after winter.

The reason I mention this is because when they took off on their journey, they had to cross a lot of broken up ice that was stacked on top of eachother (ridges). And this dynamic probably pushes the older ice even more upwards and sideways? It was a lot of blue ice that was sticking out, and I'm sure that some of that ice will get pushed down under other floes as well. So I guess the thinner and weaker the ice pack gets, the more mobile it will become, creating even bigger areas of these large broken up "rubble piles" of ice on the North American Arctic Coast where FYI, MYI, and frozen melt ponds are all being mixed up.

So maybe the end result is smaller floes in the future as the weaker FYI melts and/or breaks up earlier and release those broken up pieces of stronger MYI?

Anyway... Thanks for teaching me a few new things! Hopefully someone will make that thesis soon.   :)

PS: Did someone take pictures of the sea ice in the mega crack this year? I wonder what it looked like a few weeks ago...

18
Arctic sea ice / Re: The 2020 melting season
« on: September 08, 2020, 02:15:11 AM »
While I understand the classification of ice by age in a historic sense, I wonder how useful it is in the modern arctic. Current summer minimum is 25% of maximum and what ice remains has been seriously degraded. Most of it will likely have lost 50-75% of its thickness over a melt season like 2020 if it hasn't completely melted out. And in the last number of years larger portions of the oldest/thickest ice has been transported out of the CAB to its destruction.

I also understand that ice character does change over time as it loses brine and becomes more solid freshwater - I'm unsure how significant this change is but it seems to be secondary to the larger forces involved in melt/freeze seasons.

What I am suggesting is age maps to me really do not tell the story they used to when age was an indication of thickness. At this point I suspect there are some 4 year flows that are less than a meter thick, and some first year ice that somehow retained a meter of thickness.

(The distance the various ice buoys have traveled through winter and summer also makes me wonder how well these maps really are able to track ice age.)

19
Arctic sea ice / Re: Arctic Image of the Day
« on: September 02, 2020, 06:49:32 AM »
The Barents Observer has some pictures of the ice around the north pole.
What surprised me most is that they didn't go on the sea ice for the picture at the north pole. That picture was a "must be" when I registered in this forum.
https://thebarentsobserver.com/en/2020/08/mosaic-climate-expedition-shares-scary-photos-north-pole

20
Arctic sea ice / Re: The 2020 melting season
« on: September 01, 2020, 11:27:10 AM »
Bathymetry will give us a BOE. It doesn't save any ice anymore. It melts it. (I know that's way to simplistic, but I think you know what I mean)

Quote
The eastern Arctic Ocean's winter ice grew less than half as much as normal during the past decade, due to the growing influence of heat from the ocean's interior, researchers have found.

Typically, across much of the Arctic a thick layer of cold fresher water, known as a halocline, isolates the heat associated with the intruding Atlantic water from the sea surface and from sea ice.

This new study shows that an abnormal influx of salty warm water from the Atlantic Ocean is weakening and thinning the halocline, allowing more mixing. According to the new study, warm water of Atlantic origin is now moving much closer to the surface.

"The normal position of the upper boundary of this water in this region was about 150 meters. Now this water is at 80 meters," explained Polyakov.

Quote
The moorings measured the heat released from the ocean interior to the upper ocean and sea ice during winter. In 2016-2018, the estimated heat flux was about 10 watts per square meter, which is enough to prevent 80-90 centimeters (almost 3 feet) of sea ice from forming each year. Previous heat flux measurements were about half of that much.

https://phys.org/news/2020-08-arctic-ocean-winter-sea-ice.html

21
Arctic sea ice / Re: The 2020 melting season
« on: September 01, 2020, 05:04:14 AM »
August 27-31.

August 1-31 (fast).

2019.

22
Arctic sea ice / Re: The 2020 melting season
« on: August 31, 2020, 12:32:05 PM »
A look back at the development of low concentration ice north of greenland, jun17-aug30 (amsr2-uhh sic)

23
Arctic sea ice / Re: The 2020 melting season
« on: August 31, 2020, 11:14:49 AM »
Today's images the slow animation covering 25th to the 30th. The a slightly larger version of the animation on my twitter page too.

24
Arctic sea ice / Re: The 2020 melting season
« on: August 31, 2020, 08:33:39 AM »
August 25-29.

2019.

That retreat north of Severnaya Zemlya is really spectacular, wow. And it's not over yet. Today and tomorrow there's a peak pressure gradient of 42 hPa, but according to ECMWF it will be 44 hPa at 120 hrs. The direction of the winds will shift a bit, but overall the ice pack should continue to get pushed towards the Pole.

This could easily become the highlight of this melting season! In many ways it's worse than 2012. And no GAC.

It will be very interesting if you explain in more detail what you are thinking. I will learn for sure. I don't see anything special with Freegrass' wind video.

I was referring to Aluminium's Uni Bremen SIC animation, more specifically to the retreat of the edge of the ice pack north of Severnaya Zemlya. It's really fast, even if the pressure gradient (due to dipole) isn't all that huge. But not small either, of course.

This will continue for several more days. If the ice edge makes it beyond 85N, it should make headlines. I agree the concentration loss between Greenland and the NP was spectacular too, but only for icewatchers like us, not to the general public. For that, it needs to be open water.

2020 made it to second place, without extreme weather. Melting momentum.

25
Arctic sea ice / Re: The 2020 melting season
« on: August 30, 2020, 12:49:16 PM »
August 25-29.

2019.

That retreat north of Severnaya Zemlya is really spectacular, wow. And it's not over yet. Today and tomorrow there's a peak pressure gradient of 42 hPa, but according to ECMWF it will be 44 hPa at 120 hrs. The direction of the winds will shift a bit, but overall the ice pack should continue to get pushed towards the Pole.

This could easily become the highlight of this melting season! In many ways it's worse than 2012. And no GAC.

26
Arctic sea ice / Re: What's new in the Arctic ?
« on: August 29, 2020, 07:32:46 PM »
"Changes are occurring so rapidly during the summer months that sea ice is likely to disappear faster than most climate models have ever predicted. We must continue to closely monitor temperature changes and incorporate the right climate processes into these models," says Jens Hesselbjerg Christensen.

https://www.science.ku.dk/english/press/news/2020/new-study-warns-we-have-underestimated-the-pace-at-which-the-arctic-is-melting/?fbclid=IwAR1G4p-Rq3hiZWPOWOQORLr_qOpwOq5wPo9BXhlNAZNo-sAgHXv0h_DV9mU

27
Arctic sea ice / Re: MOSAiC news
« on: August 26, 2020, 11:20:16 PM »

29
Arctic sea ice / Re: The 2020 melting season
« on: August 25, 2020, 03:03:58 PM »
Well we can all agree that ice is going to Zero for most of the Arctic in summer one day.
[/quote]

That's for sure Glennbuck.

Arctic Death Spiral


30
Arctic sea ice / Re: The 2020 melting season
« on: August 22, 2020, 06:57:46 AM »
August 17-21.

2019.

31
Arctic sea ice / Re: The 2020 melting season
« on: August 21, 2020, 10:10:24 PM »
-snip-

I am beginning to become worried that as ice is transported back into Lincoln Sea, it is going to be flushed into the Nares. The Nares is going to export a huge amount of ice into Baffin and the open water in Lincoln may keep growing through mid-September. The EURO portends something along these lines, IMO.

I've been literally mulling the EXACT same things. I'm sure you're aware, but even over the last 5 days export out of the Nares has been fairly impressive. There are just so many fronts which are under attack. I'm still in compete awe at the destruction above North Greenland.

Either way, to supplement your point and since I'm on my fancy work computer here's a gif to emphasize all of this:

32
"Red ice" has melted. "Blue ice" is alive.

33
Changes from July 31.

Laptev ... -100%
Barents ... -100%
Hudson ... -100%
Kara ... -91%
Chukchi ... -72%
ESS ... -63%
Greenland ... -61%
Beaufort ... -37%
CAA ... -28%
Baffin ... -22%
CAB ... -16%

Great representation of the Arctic, Aluminium!
A question: What is the meaning of the red circle?

If I'm reading it right, the red circles are the amount of ice on July 31, and the blue circles on top of the red ones are the amount left now. Kudos to Aluminium! It's a clever way of conveying that data.

34
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: August 20, 2020, 06:13:24 PM »
NSIDC Daily Area: August 19

Arctic Sea ice area: 2,950,099 million km^2.

Change from yesterday: 16,278 km^2

August 19, 2020 daily Area and Extent below.

Daily Sea ice Area moves into the 4th place record today at 2.950 with 30 or less days to daily minimum, ahead of 2019 Area daily minimum, 18th September at 2.960

(2020) NSIDC: Area daily: 2.950               NSIDC: Extent daily: 4.816       

NSIDC: September daily area minimum     NSIDC: September daily extent minimum

(2012) 2.241                                             : 3.340  <<  Sep  16
(2016) 2.477                                             : 4.145         Sep   7               
(2011) 2.940                                             : 4.333         Sep   8
(2019) 2.960                                             : 4.166         Sep 18
(2017) 3.020                                             : 4.635         Sep 13
(2007) 3.050                                             : 4.155         Sep 18
(2008) 3.120                                             : 4.586         Sep 19
(2015) 3.160                                             : 4.387         Sep   8
(2018) 3.270                                             : 4.630         Sep 21

35
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: August 20, 2020, 06:03:45 PM »
And now for something completely different....

NSIDC has published their mask file as a txt file. So I dragged it into my spreadsheet file and played with it. It is simply an array 304 x 448, each box for a pixel with the code for the sea in it.

From that one can get a map simply by copying the whole lot into Paint and reducing the size.-
See attachments 0 & 1.

Then I told the spreadsheet to pull out the number of pixels for each sea and calculate the area using 25 x 25 = 625 km2 as the multiplier. That, of course does not produce an accurate result as the pixel size varies as the array is applied to a curved surface.

But it does show that back in 2007, when Meier et al made the mask, they were assuming the possibility of a much greater area of ice at maximum -especially in the Okhotsk, Bering, St Lawrence, Baffin, Greenland & Barents Seas.

see attachment 2.

Fascinating stuff.

36
Arctic sea ice / Re: The 2020 melting season
« on: August 19, 2020, 08:24:39 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.

Quote
”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.

https://www.awi.de/en/about-us/service/press/press-release/mosaic-expedition-reaches-the-north-pole.html




37
Arctic sea ice / Re: The 2020 melting season
« on: August 19, 2020, 05:59:26 PM »
Polarstern seems intent on taking a close look at the North Pole in the near future:

Didn't take them long ...

Scientists on Arctic Mission Make Unplanned Detour to Pole
https://www.apnews.com/2b290e199aef10bd18683bb021133052

BERLIN (AP) — A German icebreaker carrying scientists on a year-long international expedition in the high Arctic has reached the North Pole, after making an unplanned detour because of lighter-than-usual sea ice conditions.

Expedition leader Markus Rex said Wednesday the RV Polarstern was able to reach the geographic North Pole because of large openings in sea ice that would normally make shipping in the region above Greenland too difficult.

“We made fast progress in a few days,” Rex told The Associated Press. “It’s breathtaking — at time we had open water as far as the eye could see.” ...

38
Permafrost / Re: Arctic Methane Release
« on: August 19, 2020, 05:31:56 PM »
Is there any information available yet on the release of methane in the ESS this year? All those storms in the ESS these last few weeks must be mixing up all that hot water there and causing a massive amount of methane to be released, no?

You can see it daily from the Copernicus Atmosphere Monitoring Service.  Here's today's forecast (North Pole view):




https://atmosphere.copernicus.eu/charts/cams/methane-forecasts?facets=undefined&time=2020081800,3,2020081803&projection=classical_north_pole&layer_name=composition_ch4_totalcolumn

And then compare that view to the NOAA globally averaged measurement.



https://www.esrl.noaa.gov/gmd/ccgg/trends_ch4/

ESAS methane emissions are less than the global average.  Areas with large concentrations of people and lots of agricultural and industrial activity are more than global average.

39
Arctic sea ice / Re: The 2020 melting season
« on: August 19, 2020, 12:31:28 PM »
Beaufort and Chukchi change over the last 12 days.
Bigger version on twitter: https://twitter.com/Icy_Samuel/status/1296031203162808320

(Edit: Sorry, gif was too small and autoplayed. Just put up a new one.)

40
Arctic sea ice / Re: The 2020 melting season
« on: August 19, 2020, 10:26:10 AM »
Latest daily change here.


41
Arctic sea ice / Re: The 2020 melting season
« on: August 18, 2020, 09:58:08 AM »
Change from 16th to 17th


42
Arctic sea ice / Re: The 2020 melting season
« on: August 17, 2020, 01:16:22 AM »
Polarstern seems intent on taking a close look at the North Pole in the near future:

43
Arctic sea ice / Re: The 2020 melting season
« on: August 16, 2020, 02:39:36 PM »
Here's a comparison in the ice loss between 2012 and 2020 for the first half of August.

Larger version of the animation is here: https://twitter.com/Icy_Samuel/status/1294975421201645570

44
Arctic sea ice / Re: The 2020 melting season
« on: August 16, 2020, 07:51:37 AM »
August 11-15.

2019.

45
Arctic sea ice / Re: Updating the ASIG
« on: August 15, 2020, 04:26:38 PM »
I apologize for being so late with updating the SIC maps. I always tend to procrastinate when it comes to tedious jobs. But it's all updated now, all the way to end of November.

46
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: August 14, 2020, 10:17:02 PM »
Below is a better color-resolved substitution (click to compare at original scale). It uses matched-pair palettes from Colorbrewer2 to replace blocks of 8 original colors in the AWI original. In other words, 1% increments may be 'too much' resolution for the eye (eg 100 colors) whereas as 17 colors simplifies the ice pattern, bringing out the clustering in the Chukchi-Beauford as well as a stream of wind-borne clouds from Ellesmere to the NSI.

Herald Island by Wrangel has been successfully added but two of the DeLong Islands are still missing from the map though the scale is such that a pixel or two is warranted for Jeanette in view of the epic disaster and its effect on drifting ice and perhaps Vilkitsky too for completeness.

47
Arctic sea ice / Re: The 2020 melting season
« on: August 12, 2020, 03:05:11 PM »
drift update, may29-aug12

48
Arctic sea ice / Re: The 2020 melting season
« on: August 11, 2020, 07:39:24 PM »
Latest Five Day Forecast
Wind @ Surface + Total Precipitable Water
Large GiF!

49
Arctic sea ice / Re: The 2020 melting season
« on: August 11, 2020, 06:56:33 PM »
Following a heads up from a certain Mr. Watts I bring you news of an interesting new article in Nature Climate Change:

https://GreatWhiteCon.info/2020/08/past-evidence-supports-complete-loss-of-arctic-sea-ice-by-2035/

Allegedly:

Quote
Using the [UK Met Office’s Hadley Centre climate] model to look at Arctic sea ice during the last interglacial, the team concludes that the impact of intense springtime sunshine created many melt ponds, which played a crucial role in sea-ice melt.  A simulation of the future using the same model indicates that the Arctic may become sea ice-free by 2035.

50
Arctic sea ice / Re: The 2020 melting season
« on: August 11, 2020, 04:13:47 PM »
Here's the animation from Freegrass, in combo with sea ice concentration

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