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Messages - FishOutofWater

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1
Arctic sea ice / Re: The 2019 melting season
« on: May 17, 2019, 12:41:21 PM »
The whole Arctic pack is rotating clockwise now. The ice has transform faults all around the CAA and Greenland. Faults are continuous in ice on the north of Ellesmere island on today's Aqua image.
A bit of a 'hill start' but ice north of caa definitely joining the rotation now.
Worldview terra modis may10-16. https://go.nasa.gov/2EinfAu

2
Arctic sea ice / Re: The 2019 melting season
« on: May 13, 2019, 03:16:26 AM »
I haven't followed any of this so bear with me if this is a wrong conclusion.

But it looks like the Euro and the global forecasting system.  I'm using talk to text that's why I didn't just say GFS because sometimes it doesn't come out right.


Anyways both of them at least on their runs today in about 48 to 60 hours start essentially a hemispheric wide pattern change and the upper latitudes.

You can see not just high pressure blowing up in around the Beaufort sea.

But the huge banana high pressure structure becomes evident.  With the cut-off vortex just south of Greenland and over Eastern Canada.

The way the euro depicts this straight nasty.

But both models are now onto this.


Infact the GEM and UKMET is going down the same path.


For those who are not aware:


Meteorology speaking this setup is essentially the Holy Grail of having a record-setting Arctic sea ice loss during the summer.

Solar energy right now is booming over the arctic.  The best way to set up things for huge loses of sea ice is sprawling upper level atmospheric ridges of high pressure that exist from top down.

This is the path to dry sinking air and wall to wall sunny skies. 

We have never had a May 20-30th GARGANTUAN RIDGE that preconditioned the ice for huge June and July loses.


Stay tuned

3
Arctic sea ice / Re: The 2019 melting season
« on: May 11, 2019, 10:07:09 PM »
Mercator (model) salinity 0m and 34m indicating a surge of atlantic water around north greenland combined with returning atlantic water from the north. The surge may be temporary, the other isn't.

The CAA coast isn't looking too good either. https://go.nasa.gov/2DYOu2z
@b_l nice, but there are many repeat frames in that ani

4
Arctic sea ice / Re: The 2019 melting season
« on: May 11, 2019, 09:23:18 PM »
At least it means a temporary reversal of Fram export.

Sorry Oren, but i have my doubts about this. For how i see it Fram export has rather increased recently. I will keep this in sight and will report.

Edit: add GIF 07.04 to 11.05 for reference.

5
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: May 06, 2019, 02:32:09 PM »
A zoom on the Nares Strait using AMSR2 data 2013-2019.

https://twitter.com/seaice_de/status/1125354599282610177



Click to start animation.

6
Arctic sea ice / Re: The 2019 melting season
« on: April 29, 2019, 09:38:40 AM »
Thanks a lot for doing that Sark. I was just musing, and didn't expect you to do it!

Still does not provide clarity for me either... but some recent years look like they have more pronounced differences using this time frame.

Here's something a little more useful, perhaps.  A fun way to use this tool.  This is the 500mb anomaly running mean.  I took about a 25 day chunk of time across recent months, this is the resulting 500mb anomaly vs ESRL's climo

7
Arctic sea ice / Re: The 2019 melting season
« on: April 26, 2019, 03:36:17 AM »
Combining 2 images - April 25th on the left, and April 21st on the right to take out cloud -  you can see the broken ice is joined together now. I looked back in the years, and don't see this any other year doing that at this time of year. 2010 comes close on May 4th. A cracked and fractured icesheet from Nares to Fram now.
 

8
Arctic sea ice / Re: The 2019 melting season
« on: April 24, 2019, 08:23:22 PM »
Took a glance at Worldview today. Not my favourite medium. I used to work a lot on the Rapid response-tiles. Not available anymore. But I’m still capable to look at some spots out of 15 years of experience. Yes, still with you…
Inspired by 2 meter temps through DMI and volume projected by PIOMAS, it seemed not that bad a winter for sea ice. Worldview reveals that is mostly illusive. There are a multitude of influences at work. Just some make it to our attention. As Bering is mostly Pacific by now, sea ice in front of fast ice is crunched and mobile in East Siberian, Chukchi and Beaufort Seas, Baffin Bay ice looks vulnerable and 4 MK Central Basin is torn by long leads, things don’t look a little better at all. The big crunch didn’t happen in ’17 nor in ’18. But it can happen any year now.

9
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: April 22, 2019, 09:47:54 PM »
mercator-salinity-0m-34m-92m-318m--arctic-jan1-apr21.
Had this set up for nares, posting full arctic for ref..

10
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: April 21, 2019, 12:12:44 AM »

In 2016 the open water due to wind drift in Beaufort reached a unprecedented extent during May. And iirc Barents melted  soon that year.

+ Look at the NH snow cover extent anomalies from February to June 2016. Low albedo.

11
Arctic sea ice / Re: Latest PIOMAS update (April 2019)
« on: April 04, 2019, 01:21:33 AM »
question to the specialists, theoretically i can calculate but there may be hidden traps for a layman, hence i thought to ask:

how much thicker must the ice be to keep the same volume while loosing > 1'000'000km2 in the 2 other dimensions. i assume extent and area won't produce the same result and since i'm not privy with the calculations, i ask that question.

trigger for the question is that each time after a month of steep losses i wonder how it can be that volume could keep level or even increase, is it realistic that the reminder at the same time would grow that much in thickness ?

after all the real area of thickness increase is relatively small, since i think that if the ice is melting at the periphery, there must be some significant range in the midle between the pole and the periphery where ice is melting, just not to zero, keeping thickness and another part where thickness is growing only a little, hence there is not much area left where ice would grow so much to compensate for all the losses.

so much my logics which may be wrong (apparently) and i want to know why i'm apparently erring.

In simple terms the ice that melts at the edge must be replaced by new ice in the centre. The major problem here is that everyone is only publishing average thickness values for the entire Arctic. The ice that was in Bering Sea and Guld of St Lawrence was probably just 10-20cm thick. So 20cm*1million km2 divided by 10 million km2 for the central Arctic gives you a thickness increase of only 2cm.

PIOMAS is really bad at getting the ice edge right, most of all soutwest Greenland which is pretty much never frozen. It's one of the reason why I developed the high resolution "AMSR2 Snow & Ice Volume". It's not as good for the very thick central Arctic, but much better for thin ice and defining an ice edge.

https://cryospherecomputing.tk/SIT

12
Arctic sea ice / Re: The 2019 melting season
« on: April 01, 2019, 01:18:56 PM »
From the data thread:
The weather is going to shift to deep lows in the Labrador sea over the next week. That's going to increase ice export and fresh water out of the Labrador sea and increase deep water formation where the cold air blasts off of eastern Canada onto the shelf edge. The coming weather will speed up ice loss in the Labrador and Greenland seas.
amsr2-uhh, baffin/labrador mar1-31

13
Arctic sea ice / Re: The 2018/2019 freezing season
« on: October 19, 2018, 07:38:32 PM »
Couldn't resist comparing SMOS and 0m salinity.

14
Arctic sea ice / Re: The 2018/2019 freezing season
« on: October 19, 2018, 04:38:28 PM »
That new ice is very thin. The NSIDC resolution may be exaggerating the change a little. ;)

Indeed, have a look at SMOS data. Ice thickness calculation resumed after the melting pause.

15
Arctic sea ice / Re: The 2018/2019 freezing season
« on: October 12, 2018, 10:01:01 PM »
The problem on the Bering side is the unprecedented heat flux into the Arctic. Warm, moderatly salty Pacific water has flowed into the Arctic then descended to the 30m to 100m level, below the fresh water layer caused by Siberian river ...
This has the sense about it as being a change in system-state - that increased base enthalpy present  the Bering and Chukchi may have tipped them over into a new climate regime. 

The next few months may be definitive. If the Bering in particular continues at the low levels of area over winter, the heat budget it has will be altered radically by way of increased capture of spring insolation.  This may be a precursor to tip over.

The attached graphs show the extent to which the Bering and Chukchi are changing from icy seas to open water seas. The Bering story is about winter, the Chukchi story is about summer.

16
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: October 12, 2018, 03:48:45 AM »
Here is the animation I mentioned. It focuses on the behavior of the Chukchi on its way to being seasonally ice-free. Before 1990 the Chukchi was rather stable, with about half of it melting each year. But then changes came along - earlier melt onset, a higher percentage of melt culminated by the first BOE in 2007, a later refreeze onset, and a later refreeze completion. The process wasn't immediate, but over two decades the changes are enormous. The length of time in which the Chukchi is less than fully ice-covered has increased from ~5 months to ~8 months.
I believe the CAB will undergo a quite similar process, though hopefully longer. The process has already started, and 2012 and 2016 proved a lot of the CAB is vulnerable, while 2018 is proving that the refreeze can be delayed significantly.

Notable years pushing the Chukchi envelope:
1991 (late refreeze)
1993 (new minimum)
1998 (new minimum)
2004 (new minimum)
2006 (late refreeze)
2007 (new minimum near zero, late refreeze)
2012 (earlier near zero)
2016 (late final refreeze, first into January)
2017 (early melt, late refreeze)

Notes: January of the following year is appended to each year. The date range shown is April 15th to January 20th. Data is NSIDC extent.

17
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: October 08, 2018, 07:24:32 PM »
If it was a malfunction, wouldn't the temperature profile be similarly affected? Not if it's a sensor problem.
Remember that there is a fresh water pool more or less centered under the atmospheric Beaufort high pressure area. <snippage>
It looks like a deep pool but we should see if the sensor is ok in a few days.

Mercator Temperature 30m, jun2017-oct2018, every 7days. According to the model, heat was lost everywhere except North of Svalbard at 30m in 2017/18 freezing season. It looks like there is more heat in the Chukchi this year.

18
Arctic sea ice / Re: Arctic Ocean salinity, temperature and waves
« on: October 05, 2018, 06:16:02 PM »
Thanks johnm33, shame to see that thick ice going into the Mclure Strait.
Oren, yes, thanks to Bruce Steele, but it will take me a while and a steep learning curve to verify if they match up.
There are two new ITP buoys in the Beaufort, ITP 109 and 110. They both seem to be working and sending out temperature / salinity numbers.

http://www.whoi.edu/page.do?pid=163196

ITP110 data is here ftp://ftp.whoi.edu/whoinet/itpdata/itp110grddata.zip
edit: It starts at day263, sep20 2018, so will be useful going forward.
edit2: 300m looks like a layer boundary. Hopefully ITP110 will drift into the modelled higher salinity over the next few days. (based on johnm33 hycom gif above)
edit:The Ice-Tethered Profiler data were collected and made available by the Ice-Tethered Profiler Program (Toole et al., 2011; Krishfield et al., 2008) based at the Woods Hole Oceanographic Institution (http://www.whoi.edu/itp).

19
Arctic sea ice / Re: The 2018/2019 freezing season
« on: October 02, 2018, 07:39:50 PM »
Ascat, day264-274(2.6MB).
Worldview, end of the Beaufort arm, oct1
Refreeze and export into the CAA and Fram Strait but no clear signs of refreeze on the ice edge in the Arctic Ocean. Compaction from Pacific and Atlantic sides gives little chance of refreeze between opening leads. Perhaps the recent flashing in/out on amsr2 has been snow on thin ice.
Hopefully the Mclure Strait will freeze completely before all the thicker ice escapes.
edit: That gap north of SZ is going to be trouble.
Reminder that viirs brightness temperature, band15 is handy when Worldview goes dark.
Worldview, Ellesmere, oct2. https://tinyurl.com/yau9af5c
Looks like a lemon squeezer

20
Arctic sea ice / Re: The 2018 melting season
« on: September 23, 2018, 01:53:14 AM »
edit: mercator 300m salinity 20170601-20180922, every 5th day (2.5MB)
scale is not static

21
Arctic sea ice / Re: The 2018 melting season
« on: August 27, 2018, 06:12:12 PM »
Are you quite sure about that? I agree that the claims on the "Image of the day" thread were overblown, but have you examined all the evidence carefully?
I am 100% sure, that the Ward Hunt Ice Shelf was not "obliterated" and has not "disintegrated" in the last view days. That was the claim. And calling it "overblown" doesn't make it better. I, and others, have shown you satellite image comparisons with previous years or current SAR images indicating nothing of that sort.
Look, I already apologized for and retracted my 'obliterated'  comment  in 'Images', but as discussion is spilling over here, I must put on a hair shirt and apologize for my error here again as well.  In that *particular* thread ('Images'), I treat less seriously and do not check as closely as posts elsewhere.

It is obvious you do not find that satisfactory, for which again, I apologise for offending you.

I am smart enough to be terrified by what is happening, and overwhelmed with my decreasing ability to have any influence on outcomes, and damn near clinically depressed over the staggaring toll of life coming changes will cost.  It leads me to occasional hyperbole.

I will try to do better in the future.

Please don't belabor the forum or this tired, depressed, frightened, old man over a minor error in judgement.

Please just point out the mistake without rancor and let us move on.

22
Arctic sea ice / Re: The 2018 melting season
« on: August 24, 2018, 11:55:33 AM »
The forecast is for higher waves next week.

Looking for reasons for the Lincoln Sea melt, here is mercator 34m salinity, jun2017-aug2018, every 8th day and a bathymetry map

23
Arctic sea ice / Re: Latest PIOMAS update (August mid-monthly update)
« on: August 21, 2018, 07:00:30 PM »
They should start to use data from UH but U.S. scientist refuse to use non-U.S. data most of the times. sorry if that's not a qualified statement but as an observer in various fields of science and technology one can get the impression. ready to stand corrected if that's an entirely incorrect assumption
Of course that's a wrong assumption, their model was built in 2003 long before AMSR2 was launched. NSIDC is integrated into the model. Overhauling models never comes easy. In addition, there is no historical data for AMSR2 before 2012, while PIOMAS has monthly volume calculations since 1979 and daily calculations since 2000.
I assume recalibrating PIOMAS for AMSR2 data so that it would fit the historical data calculated using NSIDC is doable, but surely very difficult. I am certain this has nothing to do with such U.S/non-U.S politics as you suggested.
BTW, Dr. Zhang is extremely nice. They used to publish PIOMAS data once a month. At some point I wrote to him, told him how much the data was valued at the ASIF, and asked whether they could publish it twice a month. He simply said yes... and they have been doing it ever since.

24
Arctic sea ice / Re: The 2018 melting season
« on: August 12, 2018, 11:15:50 PM »
The images below look into a suggestion of FishOut that the north Greenland anomaly has to do with warm Atlantic Water somehow making its way west rather than (or in addition) to its usual circling to the east around Yermak and Svalbard.

This could result from a weakening of the East Greenland Current, or an eddy from countercurrent flow or layers at different depths passing under/over each other, perhaps as a 'new normal' for late summer or just a pulse due to one-off wind or salinity patterns.

The first gif shows the relevant 17 days of WorldView ending Aug 12th, enough to cover the transition to Lincoln Sea ice disintegration. The same days of surface water temperature according to Mercator Ocean are embedded in its lower left corner. The first and last days of salinity are also shown.

The mp4 shows 84 days of four radar views: Jaxa RGB, Ascat, AMSR2 and PR89 from 20 May to 11. Aug 18. There does appear to be some support for anomalous forking of the West Spitsbergen Current. In this view, the Lincoln Sea ice matrix is melting out from below from warmer waters, though air temperatures, wind displacement, wave mixing, insolation and weaker-than-we-thought ice will have contributions to make too.

The two stills show the fragmented nature of the ice (from zlabe, Sentinel) and an analysis of the 12 Feb 18 SSW event (polar cap geopotential, m) relative to a later NAO turning negative (from ypeings@UC Irvine).

25
Arctic sea ice / Re: The 2018 melting season
« on: August 03, 2018, 09:51:49 PM »
Quote
Even after a summer BOE, ice will still form in the Arctic during the dark, polar winter for many decades
So, this being merely 2018, it surely follows that Svalbard-FJL-SZ corridor froze over this winter?

Except it never came close. And this year was only a continuation of a long-term regional trend, not a variational swing attributable to unusual weather, cycle, oscillation, phase or teleconnection event.

The interface to the Pacific Ocean and the once-icy Bering Sea is similar: the Chukchi had open water right up to January 20th (in the sense of persistent non lift-off UH AMSR2 0-10% sea ice concentration). It was fully frozen over only on 13 days over the entire winter (measured as 95% of Chukchi pixels at 80-100% concentration).

So the Chukchi is now partly open 242/365 or 93% of the year and again this is just 2018, not many decades out in a warmer future. The same can be said for basin margins affected by earlier melting major rivers.

Once again, a more nuanced assessment (area, time series) works better than binary binning (will/won't freeze over in winter). That is, the mean sea ice concentration over the winter has already departed significantly from freeze-over in many peripheral areas.

Despite continuing -- and possibly accelerating -- Arctic Amplification that predominantly affects fall and winter, no doubt large central areas will indeed continue to freeze over for some time, but both extent and duration of coverage can be expected to diminish over time from the periphery inward, unless new Hail Mary feedbacks emerge. The Arctic Ocean with a thin but extensive ice cover over fall and winter in conjunction with a severely diminished summer coverage is actually the worst case scenario for global warming.

Often termed the planet's refrigerator because the Antarctic can't do the job, the Arctic's loss of summer ice reduces reflection of sunlight energy back into space, which coupled with retention of the extra ocean heat by a thin ice cover during winter, will notably worsen the overall yearly heat budget. New feedbacks will surely emerge but both their qualitative and quantitative specifics are for now very much up in the air.

The first animation shows the retreating ice front on the Svalbard-FJL-SZ corridor. The second animation runs from 15 Nov 17 to 01 May 18. Zero concentration regions have been picked and replaced with blue-green rimmed with yellow; solid ice is shown as gray. Both are 'grown' by one pixel to reduce clutter.

The third 4-day animation to 02 Aug 18 shows the shocking deterioration of the ice pack in the Beaufort-Chukchi region. This time of year especially, sea ice concentration in products like AMSR2 have to show a consistent blue for three or more consecutive days, allowing for ice motion, for artifacts to be distinguished.

Jaxa is working fine with no data gaps: take the 36:36:18 to its rgb components and delete all but the blue channel (18V ghz) to get rid of seasonal weather artifacts. The lesser-resolution, different wavelength result is fully supportive of AMSR2, 4th animation.

RoxGeo had a thoughtful post a ways back on melt season topology, roughly being the time reversal of freeze season (LIFO in CS) but with a topological twist: the ice pack freezes and melts along its boundary, no holes or free blocks (connected with vanishing first homotopy). It appears that August 2nd saw some catch-up, with the seemingly solid loose block off the ESS and Wrangel perhaps flashing (and maybe the Alaskan shoreline block as well). But let's see what tomorrow brings.


26
Developers Corner / Re: Creating Animated GIFs
« on: August 03, 2018, 12:46:38 AM »
Given that we have 1442 members, it would be better if the 2-3 people on phone pay-per-MB plans would re-set their profiles so fewer posts are shown per page, say 5 instead of 50 (forum software says 'messages' when it means 'posts').  That way older posts don't have to re-load. This would be better than going to the lowest common denominator of the 1442 internet accesses which is probably someone in a remote location still on a rotary phone dial-up connection.

It is a bad idea to force everyone else's animations not to run by going to 701 pixels etc. Very few people will click on through, as shown by the counter. Often there is not indication in the first static thumbnail frame that the animation would be all that interesting.

The real problem is that very few people understand the concept of cropping their images down to the relevant areas. Like that person posted that 13 MB file the other day of which 1.3 MB was needed to show the Arctic. Also, many people are not resizing images down to forum max of 700. Again, they need to look at the menus -- all graphics software including cell phone offers crop and resize ... or you can do it free and fast online.

27
Arctic sea ice / Re: The 2018 melting season
« on: July 27, 2018, 06:07:34 PM »
I am as surprised as everyone else by the quick deterioration of the ice. ...
We've had hints.  Thinking back to the refreeze, the regions now disintegrating were late to freeze, and suffered heavily from persistent imports of heat through the Bering.  This was reflected in some of the thickness maps, but others consistently reported that the ice was probably a meter or more thicker than it actually was.

Roll forward to today.  Speaking in approximations, in recent years (2015 to present) volume at peak is running around 21,000 KM3 at max.  If you take the most recent maximum extent - about 14,000,000 KM2, we end up with an average ice thickness of about 1.5 meters.

Looking earlier - here I'm thinking of the old regime - 1980-89, the extent isn't particularly greater - only about 16,000,000 KM2, but typical average volume is much higher - on the order of 31,000 KM3, which gives us at that time a typical average thickness of around 1.93 - call it almost 2 meters.

The difference between the two - 50 centimeters - is very key, because the drop in thickness and volume means that we've passed a key threshold:  the typical energy taken up during the melt season in the Arctic is almost enough to melt out all volume.  The number here, approximating from Jim Pettit's graphs examining typical volume lost during the melt season, divided by max area works out to be about 1.3 meters of melt.

Obviously that melt isn't distributed evenly, nor is ice thickness.  However, it does mean that regions which do not pass that 1.3 meter thickness during the refreeze are now at serious risk.  It will take extraordinarily favorable conditions for ice retention to prevent an *average* melt from melting out the areas where this is true.

I think that's what we are seeing here, and elsewhere, such as the interior of the CAB where we've been having surprising losses in area.  Interstitial ice formed in leads during the season which did not have time to thicken sufficiently past that 1.3 meter threshold is disappearing.

We are definitely in a new regime.

28
Arctic sea ice / Re: The 2018 melting season
« on: July 25, 2018, 01:31:53 PM »
Ice is moving south from the Arctic ocean towards Baffin bay through the main channel of the CAA. The white stripe that was the demarcation line between Arctic ocean ice and CAA ice has moved south significantly in the last 3 days. Much of the channel has been obscured by clouds but the white line can be very clearly seen on today's image and in images from 3 days ago and earlier. Specifically, look at the Davis strait region on 21July and 24July on Worldview MODIS Terra.

This is important because it not only will transport ice out of the Arctic, it will also drain some relatively fresh water from the Beaufort sea's fresh water dome.

Images 21July18 on top
24July18 on bottom
AMSR2-UHH and ascat, Mclure strait, jul19-24

29
Arctic sea ice / Re: SMOS
« on: July 22, 2018, 10:34:46 PM »
No, it was simply taking up too much time and energy, reading the posts from beginning to end, deciding whether to approve, editing out the bad parts, replying to angry mails.

If there's a BOE, I will reinstate Hyperion and apologise. In fact, I will do so if I ever think there could be a BOE (and I hope I will be able to see it coming).

30
Arctic sea ice / Re: Latest PIOMAS update (July mid-monthly update)
« on: July 19, 2018, 11:47:05 AM »
Here are several regional charts based on the data from Wipneus. This time I am focusing on this year's laggards - Kara, Beaufort and the ESS, in addition to my usual chart summing up all the regions typically participating in the September volume minimum.
As can be seen, Kara has done some catching up, Beaufort and ESS are still lagging, and the "Inner+" is still keeping up with the leaders.

31
Arctic sea ice / Re: Latest PIOMAS update (July mid-monthly update)
« on: July 19, 2018, 10:37:34 AM »
Updated Fram export graph: no export in July.

32
Arctic sea ice / Re: Latest PIOMAS update (July mid-monthly update)
« on: July 19, 2018, 10:15:25 AM »
The PIOMAS gridded thickness data has updated upto 15th of July. Calculated volume for that day is 10.18 [1000km3] which is fourth lowest for the day (hope I got that right).

Here is the animation.

33
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: July 15, 2018, 01:41:45 PM »
Thanks Geron!

They also have a great 10 day ice concentration map that I like to keep tabs on.

https://www.canada.ca/en/environment-climate-change/services/ice-forecasts-observations/latest-conditions/concentration-map-last-10-days.html

Here is the Canada ice concentration chart for 14 July.  Red areas are over 90% concentration (and elsewhere are described as "thick first-year ice").  The chart is based on SAR imagery from Radarsat-2 and Sentinel-1A/B:



And here's the same thing, but with the AMSR2 ice concentration data from Uni Bremen overlaid.  Purple patches are any grid cells where AMSR2 shows at least 10% ice concentration:



In other words, there is a huge area of the Bay that is currently 90-100% concentration, but is showing up as < 10% concentration in the AMSR2 sea ice maps. 

This very extensive ice can be clearly seen in the Sentinel-1A SAR imagery that I posted yesterday.  Here's an enlargement showing the ice edge in west-central Hudson Bay:



Again, the purple patches are the only locations Uni Bremen's AMSR2 map is reporting any ice concentration above 10%.  Here's the same area, with the Canada ice charts overlaid:



Unsurprisingly, the ice chart shows the ice edge exactly where it can be seen on the Sentinel-1A cross-polarized imagery.  The orange area ("F") is over 70% concentration, and the red areas (i.e., most of this enlargement) are over 90% concentration. 

So, again, AMSR2 is failing to see most of the ice in Hudson Bay right now.

34
Arctic sea ice / Re: The 2018 melting season
« on: July 08, 2018, 10:48:24 PM »
Currently the lows tend to flow in over Iceland because they are pushed to the west by the unusual high pressure area over the United Kingdom. Greenland has nothing to do with it.

Indeed they do. We were told this as kids at school in England in the early 1960s, and told that that meant hot sunny days in summer and cold sunny days in winter.

This pattern has been in operation for what feels like up to a month, and the UK Metoffice tells us is likely to continue for at least another two weeks.

So what has been, could be, might be, the effect so far on the Arctic of this continuous movement of wettish air (and surface water currents?) up North twixt Scandinavia and Greenland?

I attach some 5-day images from cci-renalyzer that seem pretty typical of the weather story for the last month and maybe the rest of July. If nothing else these images are pretty.



35
Arctic sea ice / Re: The 2018 melting season
« on: July 08, 2018, 02:56:51 PM »
The most recent on nullschool, we can see that already the cold fresh blob out of the Labrador sea has been swept north to the Faroes Iceland shallow area. Not good news for latter, as it will be preventing underlying Gulfstream water from radiating and evaporating heat, while up taking energy from insolation and the atmosphere better. Also mixing into the saltier hot waters underneath will lighten them, making them more able to stay near surface as they reach the ice.
Nope. There is nothing on Nullschool showing a "fresh blob" out of Labrador sea going towards the "Faroes Iceland shallow area" (which is what exactly?).

The currents go in the opposite direction, flushing the Labrador sea southwards, and SSTA's around Iceland and the Faroes Islands show normal fluctuation.
Repeating your previous image is not proving anything. If you go back in Nullschool you can see that the SSTA in the area between Iceland and the Faroes fluctuates, nothing new happining now. If you set Nullschool to show currents, you can see that the currents from Labrador sea go southwards and there is simply no way that any cold or fresh water could be swept from Labrador sea to the east of Iceland.

It does feel like you are just spouting nonsense, stringing together a series of dubious claims and this particular claim is easily disproved.

36
Arctic sea ice / Re: The 2018 melting season
« on: July 08, 2018, 04:31:46 AM »
I'm no saint, no prude and no stranger to vulgarities, but I can say definitively that I believe this sort of language and 'humor' has zero place in any scientific discussion.  Furthermore, I can see this sort of thing as being particularly distasteful to women, or to persons who have been victims of sexual assault or those who have loved ones who have suffered such assault. 

It doesn't matter if some people say "Oh, it's alright with me" -- all members of the forum need to be considered.  Nor is the intent relevant, nor I am interested in castigating who wrote it -- it is the presence of such language, used in this manner.  Neven, I respectfully request that you draw the line here. 


I think he meant ANALysis.

As in, ANALrapist.


37
Arctic sea ice / Re: The 2018 melting season
« on: July 06, 2018, 12:46:48 AM »
<snippage>
I strongly recommend watching the full length animations at Mercator Ocean to get an idea of what's been happening for the last 16 months at various levels. Set it to the highest speed possible and focus on the salinity and sea surface height model runs. Here's the link to the animation of salinity over time at the 30 meter level.
http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20170228/20180714/2/2
<snippage>
that 30m animation, every third frame to reduce size

38
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: July 05, 2018, 06:00:37 PM »
Area with melt has increased considerable (>70%) as the Jaxa AMSR2 thickness/melt data shows. Only 2012 and 2015 had a bigger ratio.


39
Arctic sea ice / Re: Latest PIOMAS update (July)
« on: July 04, 2018, 10:04:51 PM »
Tor, I like your analysis but there are some caveats. The first is the CAA, which I did not include in the Inner Basin following Wipneus' convention, but that has never reached zero volume at minimum. I'd say add about 0.2 for a total of 4.5.
The second is the Greenland Sea, which historically has never been "empty" at minimum, but came very close to that in 2017. I'd say add 0.05, with the total remaining at 4.5.
The third is that day 260 is not necessarily the minimum, so potentially the minimum could come in a bit lower.
In any case, the big wildcard is the CAB.

40
Arctic sea ice / Re: The 2018 melting season
« on: July 03, 2018, 05:08:36 PM »
NCEP Reanalysis temperature data for June (since 1948):

Arctic: 6th
Atlantic: 46th or thereabouts
Siberian: 1st (more than 1° C higher than previour record)
Pacific: 12th
Canadian: 37th or thereabouts

41
Arctic sea ice / Re: Latest PIOMAS update (July)
« on: July 03, 2018, 04:44:58 PM »
thickness for 30th June compared with previous year and the differences with 2018.

42
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: June 30, 2018, 03:56:30 AM »
Yes, there are other uses for the DMSP satellites, but Congress has always had trouble seeing it as more than a USAF program and has generally focused on that. 

DMSP-20 had been on and off the chopping block for years before that hearing.  Of course Rep Rogers wouldn't respond positively to pleas that it was needed to study Arctic sea ice, but that is not the reason that it was canceled.

I'm also not arguing for "smaller and cheaper satellites" exactly.  It's a lot more complicated than that and hard to sum up easily -- as I pointed out above, the wiring failures on the ICESat-1 lasers were a consequence of trying to build it "smaller and cheaper".  But it's extremely hard to justify keeping a heavy (i.e., expensive-to-launch) satellite on mothballs for 20+ years. 

In general, Congresses and White House staff of both parties have really had trouble understanding how the US earth observation satellite program works and how well-intentioned but bad decisions on their part keep screwing it up.  This is only the latest instance in a long sordid history going back to Reagan's attempt to privatize the entire constellation of meteorological satellites back in the 1980s. 

I wish that DMSP-20 were launched, though I understand both sides of the debate that raged over that question and that long predated Rep Rogers's involvement.  Even better would have been to not screw up plans for the follow-on mission by changing horses in midstream again and again. 

43
Arctic sea ice / Re: The 2018 melting season
« on: June 30, 2018, 01:47:36 AM »
I played around a bit with those SMOS images. 

Just for fun, Here's the correlation between Steven's hard earned numbers and NSIDC Min Extent.  The dot at x=4.5 on the line is the projection for 2018.

44
Arctic sea ice / Re: The 2018 melting season
« on: June 29, 2018, 10:51:40 PM »
Here's how the CMOS microwave maps look for the past 40 days.

Downloaded from: https://seaice.uni-bremen.de/data/smos/png/
...
There is a definite trend from beige to other colours: dry -> wet

I played around a bit with those SMOS images.  I wrote a script to download the daily SMOS images for June 2010-2018 and to count the number of beige pixels in each image:




Average for the first 28 days of June:

(For what it's worth...)

45
This is the asthenosphere, the top part of the mantle where the solidus and the geothermal gradient converge. There isn't necessarily any partial melt (magma), but the viscosity is lower than the upper mantle and the lithosphere (the brittle part of the top of the mantle and the crust). The asthenosphere does flow, and that is where the compensation mechanism for PGR is thought to originate. The ductile flow that is thought to happen as the mechanism for isostatic compensation will not affect mantle convection or necessarily increase or decrease the temperature at the base of the lithosphere. Even if it did the timescales for this change are much greater than the time for ice melt.

Thinning or thickening of the lithosphere can effect the geothermal gradient (e.g. you get volcanic activity at rifts). Melting ice effectively thins the lithosphere, and you get pressure release, but also you change the temperature at the crust/ice boundary. I'm not sure how that would effect the solidus/geothermal gradient, but if you do increase partial melt, again, that will take a long time to effect the surface unless you already have existing magma chambers at high levels in the crust.

Rox,

Please review the linked pdf, and see if you are interested in revising any of your statements.

Best,
ASLR

Begeman, C. B., Tulaczyk, S. M., & Fisher, A. T. (2017). Spatially variable geothermal heat flux in West Antarctica: Evidence and implications. Geophysical Research Letters, 44. https://doi.org/10.1002/2017GL075579

https://websites.pmc.ucsc.edu/~afisher/CVpubs/pubs/Begeman2017_GRL_AntWGZ-HF.pdf

Abstract Geothermal heat flux (GHF) is an important part of the basal heat budget of continental ice sheets. The difficulty of measuring GHF below ice sheets has directly hindered progress in the understanding of ice sheet dynamics. We present a new GHF measurement from below the West Antarctic Ice Sheet, made in subglacial sediment near the grounding zone of the Whillans Ice Stream. The measured GHF is 88 ± 7 mW m_2, a relatively high value compared to other continental settings and to other GHF measurements along the eastern Ross Sea of 55 mW m_2 and 69 ± 21 mW m_2 but within the range of regional values indicated by geophysical estimates. The new GHF measurement was made ~100 km from the only other direct GHF measurement below the ice sheet, which was considerably higher at 285 ± 80mWm_2, suggesting spatial variability that could be explained by shallow magmatic intrusions or the advection of heat by crustal fluids. Analytical calculations suggest that spatial variability in GHF exceeds spatial variability in the conductive heat flux through ice along the Siple Coast. Accurate GHF measurements and high-resolution GHF models may be necessary to reliably predict ice sheet evolution, including responses to ongoing and future climate change.

Extract: "Current geophysical GHF models underestimate the observed magnitude and spatial variability of GHF, which may be enhanced by magmatism or advection of crustal fluids."

Caption for the first image: "Figure 2. (a) GHF measurements and estimates for West Antarctica (Engelhardt, 2004a; Fisher et al., 2015; Foster, 1978; Fudge et al., 2013) and the western Ross Sea region (Morin et al., 2010, and references therein; Schröder et al., 2011) overlain on ice velocity (Rignot et al., 2011). Grounding line outlined black (Bindschadler et al., 2015). Profile line (A-A0) shown in black. Extent of GHF estimates below Thwaites glacier (THW, dashed line) (Schroeder et al., 2014). (b) Estimates of spatial variability in heat conduction and production along the profile line shown in Figure 2a, as difference from mean conductive heat flux along that profile (79mWm_2). (c) Shear heat flux estimates calculated from ice velocity and associated errors. GHF measurements and estimates close to the profile line are plotted (mean ±1 SE, SLW value lies off axis)."

Caption for the second image: "Figure 3. (a) Analytical model for GHF based on Fox Maule et al. (2005) (black and gray lines) compared with GHF measurements and estimates (blue) as a function of magnetic crustal thickness. The SLW value lies well above the plot. Dotted lines show the envelope of ±15% variation in crustal thermal conductivity from 2.8 W m_1 °C_1. (b) GHF anomaly due to modeled magmatic intrusions with cubic geometry. Intrusion depths are the distance from the surface of the crust to the top of the intrusion. GHF values are the maximum achieved at the surface over the center of the intrusion. Black contours represent mean ±1 SE bounds on GHF at SLW. Gray contours mark the time since emplacement at which the maximum GHF values plotted are achieved. (c) Probability density functions of GHF models for West Antarctica (An=An et al., 2015; FM=Fox Maule et al., 2005; SR=Shapiro & Ritzwoller, 2004) and GHF measurements in the Basin and Range Province, USA, 16% of which exceed 300 mW m_2 (National Geothermal Data System). In Figures 3a and 3c, GHF measurements and estimates for West Antarctica are plotted as mean ±1 SE, where available (references in Figure 2). GHF estimates below Thwaites glacier (THW), shown in Figure 3a, plotted as mean, ±1 SD (solid line), and the full range of THW values (dotted line) which extend off axis to 375 mW m_2 (Schroeder et al., 2014)."

46
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: June 22, 2018, 05:49:39 AM »
[ADS-NIPR-JAXA] ASI Extent.

June 21st, 2018: 9,988,672 km2, a drop of -61,552 km2.
2018 is the sixth lowest on record.

47
Arctic sea ice / Re: The 2018 melting season
« on: June 18, 2018, 09:43:15 AM »
ESS

49
Arctic sea ice / Re: The 2018 melting season
« on: June 16, 2018, 12:17:10 AM »
Quote
What  a "blue-ocean" event would look like?  some possibility this 2018 melting season. Does it look like  any of these?
No. The key items to consider are the 2007 and 2012 ice age youtubes. They have been posted here dozens of times. Many people here are overly focused strictly on thermodynamics and single-point summaries of the entire Arctic Ocean, such as a number for area without regards to how that area is distributed. However that distribution is critical to end-of-season.

In those record years (and most others), while thermodynamics plays a decisive role in setting the stage, when extent gets low, winds become the decisive agent via both dispersion of ice to scattered more vulnerable floes, rapid advection to places where the ocean surface water is too warm, and out-of-basin export.

This results in a September picture resembling a comma ","rotated 180º CWwith its tail in the Chukchi and ESS. As with 2018, the lower CAA is the source of this residual ice which was initially about the oldest and thickest left.

Given enough weeks of a quasi-stationary high centered off the Beaufort with an associated westward wind along the Alaskan coast but not a return gyre (a frequent pattern this spring), another 2007 will develop, in conjunction with strong FJL-SV and Fram export.

However pack strength and ice thickness are drastically reduced today relative to 2007 whereas surface water is warmer and freeze-up much later. There's no requirement for another GAC black gray swan event though one would certainly contribute.

/*/*/*/*

The whole question of 'first blue ocean' is ill-posed to begin with. It just kicks the climate change can  down the road. We should be talking about the knock-on effects of the partially blue ocean  already the current reality. No significant effects at 25% ... 50% ... 75% blue ocean?

For example, the Chukchi Sea has open water 11.5 months of the year now. Surely that is way past 'seasonally ice-free'. Who here can remember a meaningful winter ice cover of the Barents Sea? It is actually part of the officially defined Arctic Ocean but now gets thrown in with the Greenland Sea or even North Atlantic. 

The discussion on some forums reminds me of one soccer team moving their goal post into the grandstands and even out to the street but the other team somehow not noticing and still playing up to the newly contrived set-up. They'll never score a blue ocean goal because the goal post will then be moved to "twelve months for five consecutive years". After that, thirty years of stats needed to rule out "natural variation". Then more decades to rule out cycles.

Meanwhile we're already in big trouble now from Arctic amplification, with more of it baked in. Whatever the full effects of an altogether missing 'planetary refrigerator' might be, the partial effects of a diminished planetary refrigerator are already upon us. And that's just the albedo part ... there are many other adverse considerations in the literature.

50
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: June 14, 2018, 07:53:20 PM »
ADS/NIPR Sea Ice Monitor does not show images beyond 29th May, bummer because the meting images are of interest.

Luckily forum member Tealight found a source for the binary data, so the images can be created independently (and that data source is up to date).

So here is an animation for the last couple of days, light blues are the regions with over 30% melt (what ever that means). Thickness colors don't mean much during the melt season.

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