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Rich

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Re: The 2019 melting season
« Reply #4900 on: July 29, 2019, 11:57:46 AM »
Very interesting observation regarding the correlation between SST and ocean depth.

Looking at SST progression from various points on the Pacific side, there is one region where the >0C SST's are extending as far north as 76C. Elsewhere it is not extending beyond 74C.

Cross checking vs. a bathymetry map (at geology.com) reveals that the region in question sits above the Chuchki Plateau, a narrow strip of much shallower (min depth ~ 250m) ocean floor ridge that extends from N. Alaska out to ~ 79N before dropping off a cliff.

It will be interesting to see how the Pacific SST's correlate to the contours of the ocean floor going forward. This has implications for future projections of sea ice decline.

be cause

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Re: The 2019 melting season
« Reply #4901 on: July 29, 2019, 12:03:01 PM »
bathymetry and it's effects have been regularly discussed in this and previous seasons . It may be worth while looking through , for example , Uniquorn's posts .. b.c.
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 + 2 = 2021 + 1 =  ' if only we could have seen it coming ' ...

bbr2314

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Re: The 2019 melting season
« Reply #4902 on: July 29, 2019, 12:06:21 PM »
Right now it's uncertain if 2019's lead in extent will be enough to stay ahead of 2012 because of huge August melt caused by the 2012 GAC. Average melt won't suffice for the record, but then again there hasn't been much average melt this season.

To look this from another perspective, if an event comparable to GAC occurred also this year, 2019 would take the record easily. The consensus here seems to be that ice is badly enough preconditioned to make this possible.
I think this is incorrect. Some papers have indicated the GAC may have only contributed an extra 100K in melt in 2012. Of course at the time it was already record-setting so it made it seem much worse than what it actually was (debatably).

But you are definitely correct in that if 2019 sees a similar event, which IMO it will, we will easily clear 2012 for the record. However, I am also of the opinion that even without such an event, we will probably see the record anyways.

BenB

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Re: The 2019 melting season
« Reply #4903 on: July 29, 2019, 12:15:57 PM »
I'm attaching today's view of the area north of the Laptev bite (visible in the top left of the image), reaching as far north as 86N. The forecasts have this area being anomalously warm for the foreseeable future, even as the highs and lows move around the Arctic basin. As well as the many smallish polynyas, there is evidence of surface melting everywhere, and the ice looks in pretty bad shape. I think we'll lose quite a bit of it over the coming couple of weeks.

In fact, the next two weeks will be extremely interesting, because they will help to answer how much of an impact the GAC really had. Was the rapid melting mainly due to preconditioning, or would the ice have survived in the absence of the GAC? This time, with similarly preconditioned ice and warm SSTs, there will be more high pressure systems, clearer skies and warm anomalies.

heartofsun

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Re: The 2019 melting season
« Reply #4904 on: July 29, 2019, 01:51:01 PM »
All that ice being exported to the Beaufort will be facing some heavy wave action. Windy screen shot from 5 days out on Friday.

heartofsun

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Re: The 2019 melting season
« Reply #4905 on: July 29, 2019, 01:56:51 PM »
Does anybody know how common this wave action is coming out of the North end of the Nares?
Windy screenshot for Wednesday two days out.

uniquorn

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Re: The 2019 melting season
« Reply #4906 on: July 29, 2019, 01:59:41 PM »
..
« Last Edit: July 29, 2019, 09:52:25 PM by uniquorn »

Rich

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Re: The 2019 melting season
« Reply #4907 on: July 29, 2019, 02:52:02 PM »
Does anybody know how common this wave action is coming out of the North end of the Nares?
Windy screenshot for Wednesday two days out.

Windy has it's plusses and minuses.

You have stumbled upon one if it's flaws. The image you are sharing is generated using the "Waves* function. Windy has a flaw in that it sometimes produces areas that look like open water which are in fact covered in ice.

I noticed this a few weeks ago when the software produced an image of the NW Passage being open. If you zoom out to a CAA wide view, you can see the issue. Much more open water on Windy compared to other sources.

Glen Koehler

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Re: The 2019 melting season
« Reply #4908 on: July 29, 2019, 03:06:47 PM »
oren, subgeometer - Thanks for info on transport.  IMHO the one thing 2019 was missing to get real low was continued Atlantic transport.  Now that it appears to be coming back, the 2012 record may be in reach even without a 2019 cyclone (which with so much open water and high SSTs seems like that also becomes more likely).  Those warm SSTs just north of Greenland are striking at the heart of the ASI fortress.  And seeing Beaufort melting ice as soon as it arrives from CAB is another piece (esp. when Beaufort used to be the nursery for MYI).  Killiian's required loss per day stats seemed hard to reach until reading all these recent posts.  The combination of these assaults looks like a multifaceted equivalent of the 2012 GAC.  Continued decline of MYI seems like a sure thing, leaving 2020 with little ice over 3 years old, most of it 2 or less, and much of it as less resistant 1st year ice.   

    As for new record min in 2019, still a ways to go.  But all the talk in May-July about 2019 ice looking weak seems to be taking effect.  Predictions based on past patterns may not hold because it seems likely that the 2019 fractured thin ice will behave differently as end of melt season nears than it did in past years with thicker more contiguous ice.   
« Last Edit: July 29, 2019, 11:46:49 PM by Glen Koehler »

uniquorn

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Re: The 2019 melting season
« Reply #4909 on: July 29, 2019, 03:08:17 PM »
Does anybody know how common this wave action is coming out of the North end of the Nares?
Windy screenshot for Wednesday two days out.
Waves can travel for many kilometres beneath ice.
Please see https://forum.arctic-sea-ice.net/index.php/topic,1222.msg54730.html#msg54730
(and continue reading the whole thread, it's very informative about arctic and waves)

FishOutofWater

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Re: The 2019 melting season
« Reply #4910 on: July 29, 2019, 03:08:25 PM »
That overlaid bathymetry map shows the impacts of the subduction of heat in the Beaufort sea and the Nansen basin. The "Atlantification" of the Nansen basin is one of the major changes that has been taking place in the Arctic over the past 15 years. The new and very disturbing thing we're seeing this summer is the collapse of thick ice north of Ellesmere Island and in the Lincoln sea. I've looked on Worldview back as far as I could go and this summer is far worse around Ellesmere than any other year. It's hard to predict what this area will look like in September because this situation is like nothing we've seen before.

Rich

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Re: The 2019 melting season
« Reply #4911 on: July 29, 2019, 04:05:09 PM »
unihamburg amsr2-uhh, jul28 overlaid onto more detailed bathymetry

Outstanding. Nothing like a picture to demonstrate the correlation between ocean depth and ice retention.

The one significant exception over the Canada Basin is in a region proximal to a large heat advecting land mass (Alaska  / Canada).

Most of the rest of the CAB is in a different  league. Wind is a variable that can overcome depth and distance and I agree with be cause that wind is the key variable to end of season outcome this year.

We need to lose roughly 1/3 of the remaining CAB area to set a record this year.  That would be quite a spectacle.

uniquorn

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Re: The 2019 melting season
« Reply #4912 on: July 29, 2019, 04:26:39 PM »
unihamburg amsr2-uhh, jul28 overlaid onto more detailed bathymetry
Outstanding. Nothing like a picture to demonstrate the correlation between ocean depth and ice retention.
Thanks for the compliment (if it is one) but I don't agree with your interpretation. Both beaufort and laptev/cab (laptev bite) have had large areas of open water over deep ocean in recent years. It's highly likely the laptev bite will open up significantly over the next month.
Last year some of the ess arm never melted out over shallow water.
Please do more research, less posting.

Shared Humanity

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Re: The 2019 melting season
« Reply #4913 on: July 29, 2019, 04:31:05 PM »
Very interesting observation regarding the correlation between SST and ocean depth.

Looking at SST progression from various points on the Pacific side, there is one region where the >0C SST's are extending as far north as 76C. Elsewhere it is not extending beyond 74C.

Cross checking vs. a bathymetry map (at geology.com) reveals that the region in question sits above the Chuchki Plateau, a narrow strip of much shallower (min depth ~ 250m) ocean floor ridge that extends from N. Alaska out to ~ 79N before dropping off a cliff.

It will be interesting to see how the Pacific SST's correlate to the contours of the ocean floor going forward. This has implications for future projections of sea ice decline.

Absolutely agree. I think following the melt and freeze seasons in the context of the bathymetry would be very revealing and may help us understand how the future will look. I would love to see the melt season matched with a detailed bathymetry map like the one attached.

Shared Humanity

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Re: The 2019 melting season
« Reply #4914 on: July 29, 2019, 04:34:03 PM »
unihamburg amsr2-uhh, jul28 overlaid onto more detailed bathymetry. amsr2 0% concentration, usually dark blue, has been set to fully transparent to allow bathymetric features to show through. This does reduce the impact of some open water areas (eg CAA/CAB crack) but we are mostly familiar with these by now.
click to run. edit: changed animation order
no scale yet for bathy

Fantastic animation!

gerontocrat

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Re: The 2019 melting season
« Reply #4915 on: July 29, 2019, 04:43:04 PM »
This post started from the ice-drift map (latest attached) and a stray image in my mind. Wind will have very little traction blowing over a flat 100% concentration ice pack (until it hits a pressure ridge). But on a load of ice rubble?

So in an attempt to do something about my total ignorance I googled and found two papers produced in 2014 from a National Science Foundation project..

https://www.arcus.org/witness-the-arctic/2014/3/article/22794
Arctic Ocean Sea Ice Loss: Modeling the effect on Wind-to-Ocean Momentum Transfer
&
https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/2013JC009425%4010.1002/%28ISSN%292169-9291.FAMOS1
Seasonality and long-term trend of Arctic Ocean surface stress in a model

Most of the remarks below are from the first - written so even I could understand (most) of it.
Quote
The momentum flux from the atmosphere into the ocean (also known as ocean surface stress) depends on various factors such as wind speed, surface layer stability, surface roughness, and sea ice conditions. Roughness changes in response to changing ocean surface waves and variations in the geometry of ice floes and ridges. Three regimes characterize how sea ice moderates momentum transfer into the Arctic Ocean:

    1. At very high ice concentrations, near 100%, the pack ice is so compact that it barely responds to the wind forcing and hence also shields the ocean from the wind.

    2. Slightly lower ice concentrations, about 80-90%, allow the ice to drift freely with the wind as pressure within the ice pack is reduced to a minimum, while floe edges and ridges provide high drag (See Figure 1). We refer to this as an "optimal ice concentration", because ocean surface stress is maximal in this case -- as illustrated in the graph of ocean surface stress as a function of sea ice concentration derived from Pan-Arctic Ice Ocean Modeling and Assimilation System1 (PIOMAS) output (See Figure 2).

    3. For still lower ice concentrations, stresses decline because open water—even with surface waves—is generally smoother than pack ice.
graph attached
This suggests to me that when looking at the ice drift map the effect of winds will be highest in the high concentration (but less than 100%) areas


Quote
a shrinking summer sea ice extent means less momentum flux into the ocean in this season. How is that? In the 1980s and 1990s most of the Arctic Ocean featured high ice concentrations, even in summer, with an average close to the 80-90% optimum.

In recent years however, vast areas of open water have reduced the mean ice concentration below this optimum, which results in an overall ocean stress decrease at a small but significant rate in summer.

What does the future hold? The area of high momentum flux (See green in Figure 3a) is shrinking toward Greenland as sea ice continues to retreat. Further, an expanding summer season with increasingly less ice coverage might steepen the negative ocean stress trend and eventually even reverse the positive trends in spring and fall. But this assumes that wind forcing and ocean surface waves do not grow, an assumption that might prove incorrect in a changing climate. This illustrates the fascinating interplay between opposing forces that will determine the magnitude of Arctic Ocean currents in the future.
image attached


The second paper shows show how while in summer ocean stress trend is falling, in spring and especially autumn (period of highest winds is in October) ocean stress is increasing as concentrations in much of the remaining ice have fallen to below 100%.
See last image, and here is their conclusion (edited)
Quote
Our analysis indicates that sea ice in free-drift amplifies the momentum transfer from the atmosphere into the ocean, which contradicts the general perception that sea ice damps the atmosphere-ocean exchange.

On annual average, most momentum is transferred at an ice concentration of 85%.

On the seasonal scale, sea ice conditions are optimal for maximal momentum flux into the ocean twice a year, in spring and fall. However, wind speeds are much higher in fall

What do I take from this?
- when looking at a sea-ice drift / wind speed map, have the Bremen ice concentration map to hand to see where he biggest impact will be on ice mobility (green and purple not good, yellow and red good?,
- October is the month when winds can have the maximum effect on a weakened ice pack (also Spring?),
- the data goes to 2012. Were there follow-up projects?   I hope so.
___________________________________________________________
I think this is relevant to the end of season prognosis.
I await being shot down with interest.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

blumenkraft

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Re: The 2019 melting season
« Reply #4916 on: July 29, 2019, 05:05:11 PM »
This is an awesome find Gerontocrat. Thanks for sharing!

Rich

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Re: The 2019 melting season
« Reply #4917 on: July 29, 2019, 05:07:19 PM »
unihamburg amsr2-uhh, jul28 overlaid onto more detailed bathymetry
Outstanding. Nothing like a picture to demonstrate the correlation between ocean depth and ice retention.
Thanks for the compliment (if it is one) but I don't agree with your interpretation. Both beaufort and laptev/cab (laptev bite) have had large areas of open water over deep ocean in recent years. It's highly likely the laptev bite will open up significantly over the next month.
Last year some of the ess arm never melted out over shallow water.
Please do more research, less posting.

I don't do sarcasm. If I use the word "outstanding", that is a compliment. There's no reason to search for an ulterior meaning.

The word "correlation" describes a relationship. There is absolutely zero doubt that remaining end of season ice is correlated to ocean depth and proximity to heat advecting land masses.

When independent and dependent variables are correlated, it doesn't mean the relationship is ALWAYS present. Yes, of course there are exceptions and those exceptions will increase in the future as AGW progresses and gradually overcomes the CAB's defenses.

Personally, I think it is self-evident that there is not only correlation, but causation here  I don't see anyone making an argument that deep water and distance from heat advecting land masses are not part of the CAB's defense mechanisms.

You suggest I do more research. I suggest there is no research which disproves my point. I'll also suggest you consult a dictionary for the meaning of terms like "correlation". This is a scientific thread and correlation is a basic scientific term.

UCMiami

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Re: The 2019 melting season
« Reply #4918 on: July 29, 2019, 05:08:11 PM »
gerontocrat - very interesting research.

It makes me very curious to watch the results of the current high pressure systems as I think there is a significant area of the pack fits that 80-90% criteria. I am looking at the area from the laptev bite SE to Svalbard. There has been a system of cracks and gaps in a pretty consistent line north of Kara/Barents and depending on how the winds play out, it could end up spliting a sizeable section off the main pack. and send it south. Not sure anything like that has happened before - sort of like what 2012 did to the ESS ice in August.

The ice in that line is mostly much smaller flows surrounded by rubble and looks pretty weak, while the ice to the south contains some much bigger flows.

Sterks

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Re: The 2019 melting season
« Reply #4919 on: July 29, 2019, 05:25:38 PM »
unihamburg amsr2-uhh, jul28 overlaid onto more detailed bathymetry
Outstanding. Nothing like a picture to demonstrate the correlation between ocean depth and ice retention.
Thanks for the compliment (if it is one) but I don't agree with your interpretation. Both beaufort and laptev/cab (laptev bite) have had large areas of open water over deep ocean in recent years. It's highly likely the laptev bite will open up significantly over the next month.
Last year some of the ess arm never melted out over shallow water.
Please do more research, less posting.
There's an undeniable relationship between 2010's September ice pack shapes and the underlying bathymetry, what you are mentioning are especial regional cases and second-order effects.
That's what it will be so difficult global warming to force the edge of the pack over these deep waters very fast. It will be gradual over the years with weather-driven surprises.
Btw sensational graphics

petm

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Re: The 2019 melting season
« Reply #4920 on: July 29, 2019, 05:29:56 PM »
This post started from the ice-drift map (latest attached)

Thank you for the interesting new (to me) consideration (momentum transfer from atmosphere to sea as a function of sea ice concentration). Also, the drift maps over almost the last week have gotten progressively more disturbing each day.

Also, @uniquorn thanks for the extremely useful bathymetry overlay.

In other news, Wip's NSIDC 25 km area continues to bottom, unlike virtually every other metric. A sign of things to come, or just an outlier? Conversely, UH CAB area (Wip's definition) is in freefall and leads every other year including 2012. Will it slow in the next week or so like it did every other year? Very interesting times...
« Last Edit: July 29, 2019, 05:35:19 PM by petm »

philopek

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Re: The 2019 melting season
« Reply #4921 on: July 29, 2019, 06:14:36 PM »
All that ice being exported to the Beaufort will be facing some heavy wave action. Windy screen shot from 5 days out on Friday.

do you think you can turn your images upright ? thanks

turning the computer display to better see where the image is from is a bit of a hassle :D

philopek

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Re: The 2019 melting season
« Reply #4922 on: July 29, 2019, 06:20:05 PM »
IMHO the one thing 2019 was missing to get real low

I have some issues with that wording because:

Why WAS missing, the melting season and it's outcome are not yet over

Why "to get real low" after all we ARE in fact LOWEST on record for quite some time now
and in total this year.

I suggest to wait another 30-40 days for such kind of verdict. Once 2019 should be behind 2012 so much that only a miracle could do a turnaround, your reasoning could become valid IMHO :D
« Last Edit: July 29, 2019, 06:51:30 PM by philopek »

Retron

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Re: The 2019 melting season
« Reply #4923 on: July 29, 2019, 06:21:35 PM »
Time for another HYCOM thickness comparison - first today's chart, then the same date in 2016. The 2012 chart uses a different algorithm and isn't included here.

Of note is the way that the area adjacent to the north of Ellesmere has gone from having thick ice in 2016 to a thin area of no ice in 2019...

(The lack of ice north of Ellesmere shows up well on yesterday's EOSDIS, too - attached to this post).




cavitycreep

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Re: The 2019 melting season
« Reply #4924 on: July 29, 2019, 06:22:56 PM »
Sea Ice Concentration, July 14 – July 28

Milwen

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Re: The 2019 melting season
« Reply #4925 on: July 29, 2019, 06:27:06 PM »
HYCOM - Arctic ice thickness (CICE) model - July 30 - August 5


UCMiami

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Re: The 2019 melting season
« Reply #4926 on: July 29, 2019, 06:40:05 PM »
This post started from the ice-drift map (latest attached)

In other news, Wip's NSIDC 25 km area continues to bottom, unlike virtually every other metric. A sign of things to come, or just an outlier? Conversely, UH CAB area (Wip's definition) is in freefall and leads every other year including 2012. Will it slow in the next week or so like it did every other year? Very interesting times...
Petm - not meaning to be pedantic but ... I believe the chart you identify as 'Wipneus area' is actually extent - 15% area = extent calculation as far as I know. We had an early discussion as to why a 25km grid size could have a significantly smaller extent result in a largely dispersed ice environment.

Aluminium

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Re: The 2019 melting season
« Reply #4927 on: July 29, 2019, 07:58:56 PM »
July 24-28.

2018.

RoxTheGeologist

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Re: The 2019 melting season
« Reply #4928 on: July 29, 2019, 08:02:01 PM »
That overlaid bathymetry map shows the impacts of the subduction of heat in the Beaufort sea and the Nansen basin. The "Atlantification" of the Nansen basin is one of the major changes that has been taking place in the Arctic over the past 15 years. The new and very disturbing thing we're seeing this summer is the collapse of thick ice north of Ellesmere Island and in the Lincoln sea. I've looked on Worldview back as far as I could go and this summer is far worse around Ellesmere than any other year. It's hard to predict what this area will look like in September because this situation is like nothing we've seen before.

Perhaps seeing the effects of more heat in the Atlantic waters finally making it all the way around the Nansen Basin? It would be hard to prove as the salinity will be the same and the surface temperature pinned at that of melting ice.

petm

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Re: The 2019 melting season
« Reply #4929 on: July 29, 2019, 08:06:14 PM »
I believe the chart you identify as 'Wipneus area' is actually extent

No, these are his area graphs. (His extent graphs have blue backgrounds.) The extent graphs are showing similar trends, but I prefer area given that extent is most useful for boating not science. :)

Area:
https://sites.google.com/site/arctischepinguin/home/amsr2/grf/amsr2-area-all-cmpare.png
https://sites.google.com/site/arctischepinguin/home/amsr2/grf/amsr2-area-regional.png

Extent:
https://sites.google.com/site/arctischepinguin/home/amsr2/grf/amsr2-extent-all-cmpare.png
https://sites.google.com/site/arctischepinguin/home/amsr2/grf/amsr2-extent-regional.png

uniquorn

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Re: The 2019 melting season
« Reply #4930 on: July 29, 2019, 08:25:44 PM »
There's an undeniable relationship between 2010's September ice pack shapes and the underlying bathymetry, what you are mentioning are especial regional cases and second-order effects.
apologies
« Last Edit: July 29, 2019, 09:51:17 PM by uniquorn »

Sterks

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Re: The 2019 melting season
« Reply #4931 on: July 29, 2019, 08:38:41 PM »
Yes the ice in that original image is almost exclusively on deep waters. If that’s not a strong relationship... Ok thx.
« Last Edit: July 29, 2019, 08:58:36 PM by Sterks »

Shared Humanity

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Re: The 2019 melting season
« Reply #4932 on: July 29, 2019, 08:40:23 PM »
Looking at the animation, I think I also see some relationship between the bathymetry and the sea ice at minimum.

uniquorn

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Re: The 2019 melting season
« Reply #4933 on: July 29, 2019, 08:48:40 PM »
There's a relationship with bathymetry during the process to minimum, but it's not necessarily that closely related to deep water.
edit: my argument is very weak. I just didn't like Rich using my stuff to push himself forward. I'll have to work on that.
« Last Edit: July 29, 2019, 09:40:54 PM by uniquorn »

UCMiami

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Re: The 2019 melting season
« Reply #4934 on: July 29, 2019, 09:04:39 PM »
Or you could say the remnants of ice primarily end up in the area between the north pole and Greenland/CAA which just happens to include mostly deep arctic ocean, while the southern and asian ice melts whether on the continental shelf or over the rest of the deep arctic ocean.

Sure bathymetry has bearing on ocean currents and melt, but it does not define where the remaining ice in any year will be. I believe for example the Laptev bite's persistence year after year is attributed to warm deeper ocean atlantic current rising as it encounters the continental shelf at the northern end of the Laptev.

But the final melt map is probably more influenced by the extreme cold land mass of Greenland and generally colder CAA vs. the generally warm Asian land mass. Add in generally warm currents from the Atlantic entering through the Kara and Bering and ice exiting through the Greenland.

Rich

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Re: The 2019 melting season
« Reply #4935 on: July 29, 2019, 09:39:02 PM »
I think following the melt and freeze seasons in the context of the bathymetry would be very revealing and may help us understand how the future will look. I would love to see the melt season matched with a detailed bathymetry map like the one attached.

I wonder if anyone has gone through the process of adding the bathymetry data to the grid database?

If someone were to attempt this analysis, I would suggest adding a variable associated with distance from a large heat advecting land mass. That deep water near the coast of Alaska / Canada is much more likely to melt than ice over deep water in the CAB.

kassy

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Re: The 2019 melting season
« Reply #4936 on: July 29, 2019, 11:08:50 PM »
People look at peripheral seas and the ´high arctic seas´developments and that is as good as it gets.

How would you add the data? Divide area per depth?

Distance to landmass is probably a result of currents over time?

I wish we had thousands more of those argo floats there.
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

Rich

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Re: The 2019 melting season
« Reply #4937 on: July 29, 2019, 11:20:05 PM »
People look at peripheral seas and the ´high arctic seas´developments and that is as good as it gets.

How would you add the data? Divide area per depth?

Distance to landmass is probably a result of currents over time?


I have never perused the "grid" data, but the 2D database used for area and extent is obviously made up of data points corresponding to fixed areas of the Arctic surface.

The values associated with a) water depth and b) distance from land would also be fixed and never vary for the respective grid points.

If we pick a 625 km2 parcel of Arctic surface which is bounded by longitude and latitude coordinates, it's always sitting over the same piece of ocean floor and doesn't vary in relation to land.

Current is not a factor.

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Re: The 2019 melting season
« Reply #4938 on: July 29, 2019, 11:28:12 PM »
I don't think 2019 will beat 2012 in extent and area.  But it will be close.

The CAA is still going pretty solid and the Atlantic side is definitely not going to be crushed like 2012.

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a Desert Eagle that I call Big Pun
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my TEC 9 Imma call T-Pain
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it go e-e-e-e-ow e-e-e-e-e-e-blaow

Glen Koehler

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Re: The 2019 melting season
« Reply #4939 on: July 29, 2019, 11:36:29 PM »
IMHO the one thing 2019 was missing to get real low
I have some issues with that wording because:
Why WAS missing, the melting season and it's outcome are not yet over
Why "to get real low" after all we ARE in fact LOWEST on record for quite some time now
and in total this year.
I suggest to wait another 30-40 days for such kind of verdict. Once 2019 should be behind 2012 so much that only a miracle could do a turnaround, your reasoning could become valid IMHO :D

Fair critique of my imprecise wording.  By "get real low" I meant "go lower than the 2012 record-breaking September minimum Extent." 

Part of the 2012 blowout was the Great Arctic Cyclone in August 2012 which I have always assumed was a big part of why 2012 was so much lower than all previous years.  Recent comments in ASIF have me questioning that somewhat, but it still seems like a major contributing factor.  Since it seems unlikely that there will be repeat of the 2012 GAC in 2019, that was a missing factor that could keep 2019 Extent from going lower than 2012. 

The point I was making was that with this week's:
1) widespread Arctic air temperature heat wave,
2) very warm SST anomaly forecast north of Greenland in what used to be the heart of the thickest overwintering MYI,
3) that photo post by subgeometer showing Beaufort destroying ice moving in from the CAB,
and
4) the Oren post on return of wind patterns that could move Atlantic-side ice out of the Arctic to melt in the Barents or Greenland seas
  --- something seemed to snap in place that wasn't there before.

Looking at Killian's stats on daily average losses required for Sept. 2019 minimum to end up below 2012, prior to today it seemed unlikely to get those losses because they are quite high and we are already on the downhill side for daily melt rate.

What snapped was, with #1-4 above, it might not require a GAC in 2019 to keep up with what happened in August 2012.  Those four factors (#1-4 above) acting in concert could provide a similar negative impact on remaining sea ice even without another GAC uin 2019. 

Just a notion, not a verdict.  Obviously we won't know until September.   But that's what we do here right?  -- Track what's going on, look at weather forecasts, speculate about how it all works, and guess at where it's going to end up (primarily for Sept. minimum but other markers too) based on current observations and our evolving understanding of driving factors and patterns.  It is a fascinating puzzle and process to watch. 
« Last Edit: July 30, 2019, 01:01:07 PM by Glen Koehler »

petm

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Re: The 2019 melting season
« Reply #4940 on: July 30, 2019, 12:11:00 AM »
July 24-28.

Shocking. Huge areas on the Pacific and Asian sides look increasingly vulnerable.




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Re: The 2019 melting season
« Reply #4941 on: July 30, 2019, 12:13:41 AM »
There's an undeniable relationship between 2010's September ice pack shapes and the underlying bathymetry, what you are mentioning are especial regional cases and second-order effects.
apologies
No need.
What may be really interesting is why (and how) the Beaufort sea, while being in part over the Canada Basin, has become an ice graveyard when 20 years ago ice still survived, and all this regardless (or better say, against) its bathymetry. I can think on some causes, but this is out of scope here.

Glen Koehler

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Re: The 2019 melting season
« Reply #4942 on: July 30, 2019, 12:23:55 AM »

Shocking. Huge areas on the Pacific and Asian sides look increasingly vulnerable.

Not just the Pacific and Asian.  Am I the only one shocked by seeing less than 90% concentration in the heart of what used to be the MYI overwintering zone just north of Greenland and Ellesmere Island?   Is that as weird as I think it is?

Archimid

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Re: The 2019 melting season
« Reply #4943 on: July 30, 2019, 12:30:59 AM »
Quote
Am I the only one shocked by seeing less than 90% concentration in the heart of what used to be the MYI overwintering zone just north of Greenland and Ellesmere Island?   Is that as weird as I think it is?

I can't help but to blame this on the Nares straight flushing out all the thick ice early and exposing it to the area to the sun.
I am an energy reservoir seemingly intent on lowering entropy for self preservation.

Sterks

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Re: The 2019 melting season
« Reply #4944 on: July 30, 2019, 12:42:20 AM »
Ghostly image of part of the ESS ice

Csnavywx

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Re: The 2019 melting season
« Reply #4945 on: July 30, 2019, 01:00:44 AM »
I don't think 2019 will beat 2012 in extent and area.  But it will be close.

The CAA is still going pretty solid and the Atlantic side is definitely not going to be crushed like 2012.

Kind of depends on that -NAO. Even when the AO has relaxed, the NAO ridging has refused to relent. Much the same case now. Going to be really tough to get volume losses to slow down for more than a few days with that thing hanging around.

Kind of wondering if we don't end up with a 2016-esque minimum, where we end up with a lot of low concentration ice and record low volume.

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Re: The 2019 melting season
« Reply #4946 on: July 30, 2019, 01:04:01 AM »
Bob Henson at Weather Underground posted a good article today about the heatwave heading for Greenland.   

Heat Wave Heads North: Massive Week of Melting Likely in Arctic

https://www.wunderground.com/cat6/Heat-Wave-Heads-North-Massive-Week-Melting-Likely-Arctic

He even cited Subgeometer’s forecast in post #4877.  NOTE: I can’t get the link to work when I copy and paste the quote, but if you click the link to the full article above, you will find the link to Subgeometer’s post. 

Quote
Another region that bears watching over the next few days is the area north of Greenland, just east of to where the last remaining expanses of thick multiyear sea ice are clinging to the islands clustered at the north end of the Canadian Arctic. As noted in the Arctic Sea Ice Forum, very mild air, warming even more as it descends, will be flowing off the north coast of Greenland in the next several days. Satellite imagery over the last few days shows a crack developing where a large zone of Arctic sea ice is attached to the north coast of Greenland.

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Re: The 2019 melting season
« Reply #4947 on: July 30, 2019, 01:45:00 AM »
There's a relationship with bathymetry during the process to minimum, but it's not necessarily that closely related to deep water.
edit: my argument is very weak. I just didn't like Rich using my stuff to push himself forward. I'll have to work on that.

First, I want to express appreciation for your skill set Uniquorn. Your wonderful animations are beyond my pay grade and were very helpful in supporting a scientific point I was trying to make. You have a gift that we all benefit from.

Second, thanks for being honest about your lack of objectivity related to who the perceived beneficiary of your tool was. It doesn't matter whose observations your work supports.

I have a transparent agenda which IMO is grounded in science. The scientific process is OHERT. Observation, hypothesis, experiment, results, theory. Here on this thread we focus on physical science. Sometimes I have an incorrect hypothesis and the peanut gallery heaps scorn on me. I learn and move on with the process. Once in a while, I'll make a positive contribution.

Fortunately for me (and I think everyone here), this place has a leader who has the bandwidth to allow people like me in the lab to participate. I don't take that lightly and I try to be respectful of everyone here while pursuing critical thought.. If you think I'm an attention whore, for god sakes the best recipe for addressing that is to ignore me. I-G-N-O-R-E. The reactions to objectionable posts add 10x the disruption to the thread than the OP's. If you want to respond to this, I'll see you in the meaningless thread.


Freegrass

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Re: The 2019 melting season
« Reply #4948 on: July 30, 2019, 01:50:32 AM »
Can anyone explain to me the mechanism that can heat up an entire ocean by 4°C in just one day? Look at the Laptev sea, and how it warmed up in just one day. How is this possible? 4°C is a lot of heat. Where did that heat come from? Methane burp and mixing?

https://earth.nullschool.net/#current/ocean/surface/currents/overlay=sea_surface_temp_anomaly/orthographic=-28.51,97.19,1829/loc=133.558,75.075
« Last Edit: July 30, 2019, 01:56:32 AM by Freegrass »
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GoSouthYoungins

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Re: The 2019 melting season
« Reply #4949 on: July 30, 2019, 02:22:21 AM »
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