Support the Arctic Sea Ice Forum and Blog

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - RoxTheGeologist

Pages: [1] 2 3
1
Arctic sea ice / Re: The 2020/2021 freezing season
« on: Today at 04:24:24 PM »
Here's a quick summation of the 2020 melt season, at 2 week intervals. Max extent was around the March 4th, while min seems like Sept 13th (so the final period is not quite 2 weeks!).

I should probably mention the top one is an animation. Click to play!

2
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: September 15, 2020, 07:50:55 PM »
As a long time lurker and persistent reader of this forum, I think it appropriate at this time to especially thank Oren, Juan C. Garcia, Frivolousz21, Jim Hunt, Born From The Void, Aluminum, A-Team, ArcticMelt2, Gerontocrat, and other participants on the ASIF for their continued outstanding analyses of the Arctic environment.  I also want to thank Neven for making this all possible as well. For people like me publishing these analyses in the concise and straightforward manner is a godsend for us.  The lack of garbage and political interference is indeed refreshing. So, "Thank You" to everyone.....

VaughnAn

3
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.

4
Arctic sea ice / Re: The 2020 melting season
« on: September 07, 2020, 11:16:48 PM »
Actually the many Ascat animations posted earlier best capture the ice motion from Oct 15 to May 15, that's why we enhance them rather than use secondary low resolution products that don't allow ice feature tracking or delaunay shape change quantitation.

More recently, there's been some question of extraordinary melt atlantification of the Atlantic side (largely decoupled from shelf bathymetry) vs the wind simply blowing the ice pack north and west. The time series below suggests some of both but going by the arrows, feature conservation, lack of compactification and 5dp GPS of the newly moored Polarstern buoys, it was mainly just the wind.

Thus this is different from the massive opening north of Greenland which the Polarstern's captain correctly described as ice melt from the extraordinary heat wave (documented at Alert and Morris Jessup wx stations), rather than bulk pack advection towards the NSI creating open water gaps.

Regardless of how it got there, the largely unprecedented position of the ice pack today has many implications for the coming freeze season in terms of surface mixing of areas usually ice covered, possible lateral extension of long term atlantification, winter Fram export, and reduced Barents stratificational maintenance.

The Atlantic side has had a much more orderly progression than the Beaufort-Chukchi (which got just hammered in late July by an anti-cyclone). For clarity, the shrinkage is shown in a matched-pair palette created for this type of adjacency map at Colorbrewer2 (and used to good effect on NOAA-PSL maps). The AMSR2_UHH are set 4 days apart which surprisingly provides enough spacing. They are flipped horizontally so the two views face each other to bring matching areas visually closer.

5
Arctic sea ice / Re: The 2020 melting season
« on: September 02, 2020, 12:40:41 AM »

I’d hypothesize the major difference is that 2012 took some pretty extreme weather in a perfect setup to get where it was which also consequently released a lot of the absorbed energy possibly resulting in the 2013-2014 rebound. 2019 was not followed by a rebound and 2020 does not look quite likely to be either, so I think the difference lies in position regarding the overall trend, and the fact that this “extraordinary looking” melt season isn’t really all that out of the ordinary, especially compared to 2012 in its time. Next year could quite easily compound on this year further and maybe even pass 2012 while being plausibly expected instead of being a moonshot. The Arctic is much thinner and more fragmented while holding more thermal energy than before.

A very nice and concise summary of this year's melting season and what it may portend for the future. Thanks.

And it's not entirely over yet, when looking at the ECMWF forecast. That pressure gradient is going to do a real number on the ice north of Severnaya Zemlya. It's amazing what consistent weather can do in this final stage of a melting season that has seen a huge amount of melting momentum being built up. The only question left is how close 2020 can still get to 2012.

Keep those animations coming, everyone. Especially of the ice edge retreat/annihilation between 135° and 60° East. What a stunning sight that is. I think animations will be jaw-dropping by next week.

6
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: August 30, 2020, 10:55:32 AM »
JAXA Extent - a bit more

Minima Table
- If extent loss stopped on this day, extent would be the 4th lowest minimum in the satellite record.
- A further 100k extent losses will make 2020 indisputably 2nd lowest.
- But it would require 0.88 million km2 of further extent losses to make 2020 #1, i.e. lowest in the satellite record.

Average extent loss from this date to minimum is 250k, with on average just 16 days to minimum.

Arc-PLUME The range of outcomes from remaining melt in the last 10 years is now just 260k.

7
Arctic sea ice / Re: The 2020 melting season
« on: August 26, 2020, 07:06:10 AM »
August 21-25.

2019.

8
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: August 15, 2020, 01:37:22 PM »
As I was saying before I was so rudely interrupted by my daughter's dog.....

JAXA ARCTIC SEA ICE EXTENT:  5,039,562 KM2 as at 14-Aug-2020

- Extent loss on this day 82k, 24 k more than the average loss on this day (of the last 10 years) of 58k,
- Extent loss from maximum on this date is 9,408 k, 555 k, 6.3% more than the 10 year average of 8,853 k.
- Extent is at position #3 in the satellite record
- Extent is  271 k MORE than 2019,
- Extent is  295 k LESS than 2016,
- Extent is  389 k MORE than 2012
- Extent is  145 k LESS than 2007
_____________________________________________
On average 89.0% of melting from maximum to minimum done, and 31 days to minimum

Projections. (Table JAXA-Arc1)

Average remaining melt (of the last 10 years) would produce a minimum in Sept 2020 of 3.94 million km2, 0.76 million km2 above the 2012 minimum of 3.18 million km2.

For a record low, remaining melt needs to be  69.6% or more above average.
For the 2020 minimum to be above the 2019 minimum of 3.96 million km2,  remaining melt needs to be  1.6% or more below the previous 10 years average remaining melt.

Like most of us, I have been bemused by the rotten state of the sea ice so clearly shown on the melting season thread while measured sea ice losses have been so low. Just maybe today's above average extent loss is the beginning of sea ice disintegration being reflected in extent loss.
______________________________
N.B. Click once on an image to make it full-size

9
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 http://dx.doi.org/10.5194/tc-14-2173-2020)

-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.

10
Arctic sea ice / Re: The 2020 melting season
« on: August 01, 2020, 07:02:21 AM »
July 1-31 (fast).

11
Arctic sea ice / Re: The 2020 melting season
« on: July 29, 2020, 06:14:18 AM »
with respect, reversion to the mean isnt remarkable. And the selection of time slices is one of the most seductive analytical fallacies.

12
Arctic sea ice / Re: The 2020 melting season
« on: July 25, 2020, 06:04:20 PM »
I believe this more of a coincidence than meets the eye. In normal years the deep Beaufort is much emptier of ice, the shallower ESS often has lots of ice at this stage. And this year the deep Laptev/CAB sector is ice-free.
amsr2-uhh overlaid onto gmrt bathymetry, minimum jaxa dates, 2012-2018
must add 2019 sometime.
edit:Perhaps someone will put together all the nsidc minimums one day. I think they go back a lot further. If they do, I will attempt to overlay them onto bathy.

13
Arctic sea ice / Re: Freeform season chatter and light commentary
« on: July 18, 2020, 07:46:01 PM »
Autocorrect strikes again.

Whatever, if Frivolous is not a black guy living in St. Louis (and he posts like he's on European time) this whole incident would not have occurred. Really nasty garbage shows up on line here in the U.S. by people who are not black using the images of people who are. We don't want that stuff to happen here.

Please let's get back to the observations and the science.

14
Arctic sea ice / Re: The 2020 melting season
« on: July 17, 2020, 07:56:21 AM »
July 12-16.

2019.

15
Arctic sea ice / Re: The 2020 melting season
« on: July 08, 2020, 09:58:31 PM »
And I still think that the lack of airplane aerosols is worsening the impact of the GAAC.


I (normally) quietly agree with that. For me it was obvious the first week of widespread lockdowns.


Only that the topic usually leads to back and forth arguments which is why I usually keep it for me.

16
Arctic sea ice / Re: The 2020 melting season
« on: July 02, 2020, 06:34:20 PM »
In case anyone is interested in an on-the-ground perspective on this year's melting season, I put together a time-lapse video using still images from the observatory's webcam here in Alert.  The video covers 12 days from June 18-30, which includes the record-breaking June high temperature of 18.6°C recorded on the 28th.


17
Arctic sea ice / Re: The 2020 melting season
« on: June 17, 2020, 10:02:56 AM »
June 12-16.

2019.

18
Arctic sea ice / Re: The 2020 melting season
« on: April 20, 2020, 10:35:19 AM »
April 14-19.

2019.

19
Antarctica / Re: PIG has calved
« on: January 25, 2020, 07:46:45 PM »
I can't believe i didn't think of that one...  ;D

Well played, Rox.

20
Science / Re: Where are we now in CO2e , which pathway are we on?
« on: January 25, 2020, 06:09:44 AM »
<snip, no need for this at all, don't do it again, please; N.>

You know Jan concentrations are not reflective of what the year average will be.

21
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: December 03, 2019, 08:37:26 PM »
Yeah, winter doesn't really show so far.  :-\
We're definitely noticing it here on station.  We're still getting fog rolling in off the ocean occasionally, which doesn't normally happen by December...

22
Arctic sea ice / Re: The 2019/2020 freezing season
« on: November 19, 2019, 07:32:32 AM »
November 14-18.

2018.

23
Arctic sea ice / Re: The 2019/2020 freezing season
« on: November 03, 2019, 07:07:42 AM »
October 29 - November 2.

2018.

24
Arctic sea ice / Re: The 2019/2020 freezing season
« on: November 01, 2019, 07:05:23 AM »
October 27-31.

2018.

25
Arctic sea ice / Re: MOSAiC news
« on: October 24, 2019, 10:34:54 PM »
Deformation test suggesting there is still significant movement up to 7am this morning. A few buoys reported till 10am but not really enough to run a separate subset. There are 32 in this animation.
The iabp page updates a few times a day(not sure of the exact times yet), the mosaic buoy data less often.

26
..
ASLR, I find your post troubling.
Interesting how you juxtapose 'skill of analysis' to 'peer reviewing'. Is there some systematic bias here, so that peer reviewing implicates a lack of skill of analysis? Or maybe this regards only MICI issues?
Also, would be very interesting if you could say some more on those 'vested interests', as you explicate that AR6 is 'subject to manipulation' here.
While this can be made into a very complex topic as hinted at by RoxTheGeologist's reply, the primary points that I was thinking of include:

1. The dynamics of MISI models are currently poorly understood, and MICI models are only at the beginning of their refinement/calibration process; thus all of this uncertainty means that ice sheet models currently have a wide range of outputs and papers on these different ice sheet models can easily pass peer review by merely stating their input and assumptions that determine their various outputs, whether or not the outputs windup matching what actually occurs in the future.  Thus by 'skill of the analysis' I mean the future correction between the various model projections and what actually occurs (say this century).

2. By 'vested interests' I primarily mean the fossil fuel industry that heavy influence government policies and research funding; where such policies can encourage the conduct of numerous simplified models that do not include the complexity to correctly match MICI-types of required conditions (such as those currently occurring in the Thwaites gateway); and which err on the side of least drama but which easily pass peer review.  If a sufficient number of such overly simplified models are included in the AR6 review, this could/will bias their projections on such topics as sea level rise and ice-climate feedbacks.

27
Arctic sea ice / Re: The 2019/2020 freezing season
« on: October 20, 2019, 08:23:11 AM »
October 12-19.

2018.

28
Greenland and Arctic Circle / Re: The Nares Strait thread
« on: October 07, 2019, 10:54:37 PM »
The winds in the last 24 hours have opened up plenty of water off shore of the station.  I took this this morning on the drive to the lab.  The winds are supposed to continue the rest of the week, which could push things quite a ways out.

29

Thus, I reject calling any of these models "the best".
https://isccp.giss.nasa.gov/role.html
I prefer to think of the scientific method as a process that is continually improving climate change models, and as an example of the next generation (of new & improved) climate change models, I provide the following link to special issues of the JGR Atmospheres publication, update September 13, 2019, focused on the Energy Exascale Earth System Model (E3SM), which is one of the CMIP6 preliminarily indicating that the mean value of ECS is currently over 5C (as discussed earlier in this thread):
Title: "The Energy Exascale Earth System Model"
https://agupubs.onlinelibrary.wiley.com/doi/toc/10.1002/(ISSN)2169-8996.ENERGY1

ASLR, thanks for providing those references to the open source project E3SMv1. I read some of the articles that disclose various details about the modelling work, and want to provide some further insights here.

Unsurprisingly, the model makers continue to have insurmountable difficulties to handle the hydrological cycle/convection issues, as evidenced in the previous generation of CMIP5 models.

It's not astonishing that this particular GCM displays a high ECS, over 5.
"E3SMv1's high climate sensitivity is solely due to its large positive cloud feedback, which causes its net feedback parameter (which quantifies how strongly the 4xCO2 forcing is radiatively damped) to be less negative than all but two CMIP5 models"

My impression is that the model makers delibaretely set this model on a trajectory that is sure to yield a high ECS, starting in around 1990, but that is rather inconsistent with GSTs from around 1960, see the attached figure.
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018MS001603

Digging deeper, we go into the art of tweaking/tuning of the models:
"...two adjustments were made to the deep convection scheme in EAMv1. One is to reduce the number of negative buoyancy levels (capeten) that deep convection is allowed to penetrate from 5 to 1. The other is to lift the air parcel launch level (liftlevel) from the model bottom level to 2 levels above. Results showed that these two adjustments, and particularly the rise of parcel launch level, could have significant impact on high clouds and precipitation as well as their vertical structure. They typically act to suppresses deep convection over tropical oceans and enhance convection over lands.
...
Similar to what we saw over the TWP, these EAMv1 configurations have substantially underestimated clouds below 6 km and only show one peak in the upper troposphere. The lack of middle and low clouds over deep convection regions is an issue that needs to be addressed in the future development of EAM"
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018MS001350

The model manipulators would like to be able to include 'more convection', but instead have to suppress convection. Convection is not allowed to be as deep in the model as it is in nature - model makers delibaretely chose to suppress convection.

 "The physical processes associated with deep convection, shallow convection along with cloud macrophysics and cloud microphysics are treated via separate parameterizations in EAMv1. In each parameterization scheme there are multiple, often dozens of, uncertain parameters that cannot be constrained by using direct measurements and so they can be tuned within a reasonable range to improve model fidelity."

What they say here is that they have a lack of data on convection, so they have to guess and tune the models with a range of free parameters.

ASLR, you prefer to think of this as a "scientific method"? Is the art of tweaking and tuning a GCM really science? The modelling magicians themselves describe their method in terms of educated guesses that necessitates physical intuition:

"...combining experience, physical understanding, and educated guesses has difficulty anticipating nonlinear relationships between parameters and model output as soon as the number of parameters exceeds a few (Hourdin et al., 2017). The procedure relies heavily on experienced climate scientists and their physical intuition, and the outcome is not always as expected.
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018JD028927

I don't deny that GCM models can be useful to get a hunch about where climate is going, but at the end of the day they are nothing more than the educated guesses built on intuition that go into the tweaking and tuning efforts.

30
Arctic sea ice / Re: The 2019/2020 freezing season
« on: September 29, 2019, 07:26:50 AM »
September 24-28.

2018.

31
Arctic sea ice / Re: The 2019 melting season
« on: September 21, 2019, 08:45:06 AM »
In Kane Basin, refreeze becomes obvious.

32
Arctic sea ice / Re: The 2019 melting season
« on: September 21, 2019, 07:33:18 AM »
September 15-20.

2018.

33
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: September 20, 2019, 09:44:18 PM »
A timely point for me to say thank you Geronto and to Juan and ... +1

34
Arctic sea ice / Re: The 2019 melting season
« on: September 12, 2019, 09:15:20 PM »
According to Jim's graphs, ice volume has decreased from 14.9 to 4.7 * 1000 cu. km from mid 80's to now
This represents approx 0.35 * 1000  cu km change / year  at time of minimum volume. Assuming a BOE occurs  when there is 15% of the 16,000,000 max in 1980 and an average thickness of remaining ice of 1 metre, the volume at a BOE would be 2.4 cu km
Therefore , at 0.35 * 1000 loss in vol / year , we could expect a BOE in (4.7-2.4)/0.35 = 6.6 years
This makes a big assumption - that system behavior will be consistent as we reach that limit.

Based on the surprising end of season slowdown this year, I'm not sure that's safe. I'm still mulling hypotheses for what we are seeing and why the dynamics are not falling more in line with your assumptions. 

"Blue Ocean" is a boundary condition, and the retreat of the ice to where it stands now - post 2007 - suggests to me that the dynamics for the ice north of 80 are significantly different from those of the peripheral seas, which is were most significant visible changes in the Arctic have unfolded.

The ice in the CAB and along the CAA by dint of higher latitude appears less influenced by the effects of insolation and atmospheric heat.  It is also *somewhat* protected by the deeper waters of the central basin.

I  think it will require more import of oceanic heat - from the Atlantic side in particular - to push the system out of the state I think it may have settled into.

I think we may see quite a number of years like this - following the pattern of post 2012 - with the ice retreating to the high-latitude bastion we see.

We *could* see a weather driven event driving a season below 2012, but am leaning more and more to a conclusion that this would be anomalous rather than a signal of impending BoE.

I think we need a lot more data on changes in Arctic ocean enthalpy changes, as I'm thinking that and attendant changes in water column structure are what will drive us to a BoE.

35
Arctic sea ice / Re: Home brew AMSR2 extent & area calculation
« on: September 04, 2019, 09:07:31 AM »
A late century drop in extent shows there are still possibilities for second lowest place ( in my limited data set).

Here is an animation of the Arctic Basin compared with 2012. Click to start.

36
Arctic sea ice / Re: Latest PIOMAS update (September 2019)
« on: September 04, 2019, 08:52:08 AM »
The thickness map on 2019-08-31, compared with previous years and the differences. All need a click for full size.

37
Arctic sea ice / Re: Latest PIOMAS update (September 2019)
« on: September 04, 2019, 08:46:25 AM »
Fram volume export was about normal for August: low.

38
Arctic sea ice / Re: Latest PIOMAS update (September 2019)
« on: September 04, 2019, 08:28:36 AM »
PIOMAS gridded thickness data has updated (official volume data not yet). Volume on 31st August was 4.17 [1000km3], second lowest behind 2012 (3.93[1000km3]).

Here is the animation for August.

39
Arctic sea ice / Re: The 2019 melting season
« on: August 27, 2019, 03:28:11 AM »
Heat is radiating out from the cloudtops and above so the polar atmosphere is becoming increasingly unstable as we move into September. The models are struggling to capture what's happening more than 3 or 4 days out.

There's still the potential to melt out dispersed ice on the Siberian side of the pole but the horse race is now for the second or third position. It's a good thing that 2012 is looking unbeatable. The fires in Siberia and the Amazon have been depressing enough. We don't need to see any new sea ice records this year to get the message across that the climate is in trouble.

40
Arctic sea ice / Re: The 2019 melting season
« on: August 13, 2019, 02:53:53 PM »

It would be interesting to know how much ice the Barnes Ice Cap lost this yet. It seems to have been under blue sky for most of July and August.

I love to see some more data on this do you have any.

Wikipedia says it averages about a meter year lost.

This year probably way abbve that

Here is a timelapse from 1984 - 2018 (Will be interesting to see when they add 2019/2020)

https://earthengine.google.com/timelapse#v=70.08059,-74.06429,6.626,latLng&t=0.03&ps=100&bt=19840101&et=20181231&startDwell=0&endDwell=0

Here you are:

41
Arctic sea ice / Re: 2019 vs 2012
« on: August 12, 2019, 08:11:51 AM »
Looking at the most recent extent graphs in the data thread, using a cycling analogy: It kinda looks like the 2012 GAC amounts to a breakaway while 2019 is the peloton, going steady. Will 2019 chase it down? Did 2012 break too early & lose steam? Very interesting!

Here's my graphical scientific representation of 1 potential outcome (exaggerated for clarity):


42
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: August 11, 2019, 08:06:06 PM »
You picked not the relevant chart. Past days at ESS and the Pacific side in general were really cold with massive surface refreezing, but winds have already shifted.

Any evidence of this massive surface refreezing in the ESS or the Pacific side in general would be appreciated.
Yes, your pattern recognition ability to observe the increase in concentration in the pacific edge between the 4th and the 10th of August.
I think you are being rude and you are also incorrect, there was no increase in concentration, but there has been an increase in CLOUDS which creates the artifact you incorrectly attribute to refreeze.

43
Killian, it is not OK because he is doing it too. I think you know that is not an excuse. Be above it.

Covert agression.
Quote
You both have a weird sense of what is aggressive and rude
I'm not going to engage further, sorry to have disturbed the discussion, but these phrases are abrasive and covert agressive in my view:
"First, cherry picking is the domain of the intellectually dishonest"
"This should be obvious."
"Your problem is, rather than be curious, research, investigate,"
"If you are claiming any skill whatsoever in math, analysis, ASI, "
"you should seriously consider not spending any further time on the issue of ASI"

44
Killian, your insults outweigh your insights by a great margin.

45
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: August 07, 2019, 06:51:49 AM »
When your going down the highway at 100mph and another vehicle goes past you at 150mph. :o

46
Arctic sea ice / Re: The 2019 melting season
« on: July 31, 2019, 10:42:18 PM »
I think ESS resistance may also be partly the result of the Beaufort gyre and the southern winds in from the Bering pushing Chukchi ice toward the ESS.

The gyre sends the strongest ice that doesn't melt in the Beaufort toward the northern reaches of the ESS where some at least gets shifted south most years into the ESS.

The winds coming from the pacific into the Chukchi and at least some of the current part of the time are shifting Chukchi ice west on both sides of Wrangel Island.

And if the winds are from the east, some ice arrives from the shift of ice from the Laptev.

The ice in the Chukchi is attacked from the Bering, the Ice in the Laptev is hit with whatever causes the Laptev bite, and the Kara is attacked from the Atlantic - the ESS (in a similar fashion as how everyone talks about the CAB being 'protected' late into the season) is the arctic coastal sea most protected by the other seas around it and can more easily import ice regardless of whichever direction the bias of the melt season is tilted toward.

47
Arctic sea ice / Re: The 2019 melting season
« on: July 26, 2019, 12:29:54 AM »
Repeating myself, the continuation of the current wave, days 6 to 10 can be evaluated using 5-day average over ensemble of forecast, to fail in the conservative side.
What the EC ensembles say is that the Greenland ridge will be strengthened, and the corresponding high will be strongly reinforced. Not as bad circulation as present, but not party time for the pack either. And a very bad news for Greenland

48
Arctic sea ice / Re: The 2019 melting season
« on: July 25, 2019, 09:50:17 AM »
Thanks again Aluminium. Any chance you can increase the height of the cropping so that we can watch the potential collapse of CAA ice in your updates?
I like this size and long sequences of similar data or images. Maybe I'll try to make something another when i have finished trip.

I shifted window by 30 px.

49
Arctic sea ice / Re: The 2019 melting season
« on: July 25, 2019, 05:00:36 AM »
I suspect that melt ponds lasted later in July before the year 2000. The thick multiyear ice would have kept its below -1.5C temperatures longer into the melt season supporting melt ponds later into the year.

I think that explains the paradox of 80N temperatures being lower after Y2k than prior to it. Melt ponds support warmer surface temperatures. An saltwater ice mixture supports negative 1.5 C temperatures at the surface.  The effects of solar heating and atmospheric heat may lead to a higher 2m temperature. The paradox is that melt ponds over thick ice support higher 2m temperatures than drained melt ponds over ice that's almost melted out.

Observe that there has been a significant dip in temperatures the past few days, but 80N to the pole is still above freezing on average.



Yes, I'm sitting in a dining room chair in North Carolina. It has been sweltering here but today we got relief from a cold front that passed through. I am very frustrated by the paucity of data out of the Arctic. I know that my hypotheses could be wrong and would like more data.

50
Arctic sea ice / Re: The 2019 melting season
« on: July 23, 2019, 09:11:25 PM »
Insolation at 90 degrees is greater than at the Equator until the first week in August.

Ought to settle this question.
Except that the albedo of the underlying surface is in large part a function of the angle of incidence of the solar radiation. This is true not just for water but also for sea ice.


Source: Hudson, 2011 https://doi.org/10.1029/2011JD015804

At 90°N latitude at this time of year the solar zenith angle is about 70° so that all the time is spent in the high-albedo part of the curve. South of 30°N, once the sun rises, almost all daylight hours have a solar zenith angle less than 70° and for much of the day less it's than 40°; at tropical latitudes it can obviously reach 0° at high noon. The end result is a great deal of time is spent in the low-albedo part of the curve.

I have no idea how to quantify this difference. My point is that it's not as simple as calculating the theoretical 24-hour solar insolation based on latitude alone and calling it a day.

Pages: [1] 2 3