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oren

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Re: The 2021 melting season
« Reply #150 on: April 06, 2021, 10:51:49 PM »
what really worries me with the PIOMAS setup is the risk that the ESS and Laptev will repeat last year's early melt despite the increased modelled volume. If that happens somehow then all bets are off, with the CAB as vulnerable as it is and Fram export taking big bites out of the thick ice.

Paul

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Re: The 2021 melting season
« Reply #151 on: April 07, 2021, 01:15:30 AM »
I just cannot see a repeat of last year's record retreat happening this year in the ESS especially. Laptev is always a bit more uncertain due to how the Laptev bite may form but both areas got significantly thicker ice and there is alot more fast ice this year and fast ice that should be more resilient to break up than last year.

What we may see however is open water between the fast ice and the normal ice happening quite a fair way in the basin like it did in 2014 which of course had the ice edge retreating to 85 degrees north if albeit a small portion rather than a full on ice retreat.

As for the CAB numbers, I think the main reason why it's so low is due to a lack of compaction against the CAA whereas last year saw lots of compaction. I don't think the ice volume around the pole is much different to previous years either but there does seem to be thinner ice from 85 degrees latitudes down towards the Barants sea and that is my main concern for this year. Atlantification could well be severe again.

Shared Humanity

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Re: The 2021 melting season
« Reply #152 on: April 07, 2021, 02:47:06 PM »
I just cannot see a repeat of last year's record retreat happening this year in the ESS especially. Laptev is always a bit more uncertain due to how the Laptev bite may form but both areas got significantly thicker ice and there is alot more fast ice this year and fast ice that should be more resilient to break up than last year.

What we may see however is open water between the fast ice and the normal ice happening quite a fair way in the basin like it did in 2014 which of course had the ice edge retreating to 85 degrees north if albeit a small portion rather than a full on ice retreat.

As for the CAB numbers, I think the main reason why it's so low is due to a lack of compaction against the CAA whereas last year saw lots of compaction. I don't think the ice volume around the pole is much different to previous years either but there does seem to be thinner ice from 85 degrees latitudes down towards the Barants sea and that is my main concern for this year. Atlantification could well be severe again.

All of the thick ice and fast ice will melt in the ESS before the end of the melt season IMHO. I don't know what this means regarding a record retreat.

Aluminium

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Re: The 2021 melting season
« Reply #153 on: April 07, 2021, 03:56:13 PM »
PIOMAS volume in the ESS is the highest since 2010. The closest years are 2018, 2016, 2013, 2012, 2006... Excluding 2006, all these year had a minimum below 110 km3 in the ESS.

VeliAlbertKallio

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Re: The 2021 melting season
« Reply #154 on: April 08, 2021, 05:02:58 AM »
I would add onto this comment that the lack of compaction towards Nunavut coastal margins means lower production of leads and open seas where thin, replacement ice forms due to spatial contraction. This means more heat retention on the underlying water layer sheltered by stable ice. The substrate water layer therefore may start warming from a notch warmer starting point, this being case the overall melting once leads open may happen somewhat speedier despite overlying volume. This is because there had been less outbound long wave radiation to space from the leads. If the ice is single year, and sunlight and vertical mixing conditions favour, aggressive melt may result despite initial apparent good-looking starting point. This is just one possibility, not prediction that will happen as it is premature to the season to say. The snowfall variability on ice also masks the heat retaining property of non- or little broken sea ice that didn't compact much.

I just cannot see a repeat of last year's record retreat happening this year in the ESS especially. Laptev is always a bit more uncertain due to how the Laptev bite may form but both areas got significantly thicker ice and there is alot more fast ice this year and fast ice that should be more resilient to break up than last year.

What we may see however is open water between the fast ice and the normal ice happening quite a fair way in the basin like it did in 2014 which of course had the ice edge retreating to 85 degrees north if albeit a small portion rather than a full on ice retreat.

As for the CAB numbers, I think the main reason why it's so low is due to a lack of compaction against the CAA whereas last year saw lots of compaction. I don't think the ice volume around the pole is much different to previous years either but there does seem to be thinner ice from 85 degrees latitudes down towards the Barants sea and that is my main concern for this year. Atlantification could well be severe again.

All of the thick ice and fast ice will melt in the ESS before the end of the melt season IMHO. I don't know what this means regarding a record retreat.
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jdallen

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Re: The 2021 melting season
« Reply #155 on: April 08, 2021, 08:33:40 AM »
I just cannot see a repeat of last year's record retreat happening this year in the ESS especially. <snip>
All of the thick ice and fast ice will melt in the ESS before the end of the melt season IMHO. I don't know what this means regarding a record retreat.

Unless it is *egregiously* higher than pretty much anything we have in the record, what amount to modest increases in volume in places like the ESS are quite irrelevant.

I haven't been saying much yet, as we have not seen the opening act - what starts to happen in May with the melt  and conditioning of the ice.

The weather we have seen has not left me particularly optimistic. Whatever ice has been built, under the right conditions can be destroyed as or more quickly than it was created, especially with the increase reservoirs of heat that have built up under the peripheral seas over the last several years. 

Any increase in volume this winter pales in comparison to the losses which happened in 2007, 2010, 2011, 2012 and more recently.  With the right weather, it will vanish like smoke in a gale, and has in the past, with *much* better starting ice conditions.

What has been emphatically demonstrated to me since I started following the forum in 2013, weather is key.

While increased volume is laudable, and what we hope for, the net energy sink it represents is insufficient to resist the massive increases in captured heat typical over the last 5 years, especially when considered in tandem with the massive influxes of heat into peripheral seas and in particular on the Atlantic side of the basin. 

The question I ponder at this point is not whether melt this year will equal or exceed 2020, but rather whether we will be fortunate enough to avoid it.
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Re: The 2021 melting season
« Reply #156 on: April 08, 2021, 12:57:08 PM »
Zack Labe
@ZLabe
·
5 Apr
#Arctic air temperature rank by month over the satellite era - now updated through March 2021, which again was an unusually cold month (especially around the Kara Sea)

+ Ranks: 1=warmest (red), 42/43=coldest (blue)
+ Download visual:

https://cpb-us-e2.wpmucdn.com/sites.uci.edu/dist/2/2231/files/2021/04/925T_70N_rank.png
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 + 2 = 2021 + 1 =  ' if only we could have seen it coming ' ...

gerontocrat

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Re: The 2021 melting season
« Reply #157 on: April 08, 2021, 01:38:09 PM »
Zack Labe

#Arctic air temperature rank by month over the satellite era - now updated through March 2021, which again was an unusually cold month (especially around the Kara Sea)
9th coldest air temps in the satellite record, coldest since 2004.
And yet there was a little bit of open water at and above 80 North for the whole month.

What lies beneath?
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Paul

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Re: The 2021 melting season
« Reply #158 on: April 08, 2021, 02:52:19 PM »
Zack Labe

#Arctic air temperature rank by month over the satellite era - now updated through March 2021, which again was an unusually cold month (especially around the Kara Sea)
9th coldest air temps in the satellite record, coldest since 2004.
And yet there was a little bit of open water at and above 80 North for the whole month.

What lies beneath?

Lack of northerlies through the Atlantic is one reason for sure. Most of the cold temperatures has been on the Pacific side of the basin also.

I disagree somewhat with Jdallens thoughts about the weather, it has been a favourable winter for ice thicknesses and March has been cold and so has the start of April. All that is set to change now though with increasing storminess and significantly above average temperatures for the most part.

Jim Hunt

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Re: The 2021 melting season
« Reply #159 on: April 08, 2021, 03:03:58 PM »
It has been a favourable winter for ice thicknesses

Are you quite sure about that?

https://GreatWhiteCon.info/2021/03/the-2021-maximum-arctic-sea-ice-volume/#Apr-08

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The [March 2021 PIOMAS] update also includes this comparison with CryoSat-2/SMOS volume, which highlights the current divergence between the two metrics:
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Paul

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Re: The 2021 melting season
« Reply #160 on: April 08, 2021, 04:34:29 PM »
Depends on what you believe in Jim. A negative AO winter tends to favour ice thickness due to compaction in the Siberian regions especially. A positive AO tends to favour more ice thickness along the CAA but thinner ice elsewhere and that was certainly the case last year. This winter has been more of a negative AO hence the better build up of ice in the Siberian regions and more fast ice than there was this time last year.

Crysosat seems to have a flaw of mistaking thicker snow cover for ice thickness as shown in 2017 because despite a cool summer, the ice pack over the CAB was quite diffused to say the least. PIOMAS is not perfect because of the resolution so I suspect its over playing the deep red over the the fast ice for example but from my experience, it's has given a good indication of where the ice is thicker and thinner. This year, its the Atlantic front that looks most vulnable.

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Re: The 2021 melting season
« Reply #161 on: April 08, 2021, 04:47:23 PM »
Dammit Jim! I'm a doctor, not a climatologist, but that is quite extreme divergence! 5000km^3, nearly 25% volume disparity. (Sorry, couldn't pass up the Star Trek reference).

The cryosat-2 data is particularly alarming for me, not just regarding the numbers but the position of the thickest ice poised to be flushed through dire straits, as others have noted. I've been watching the drift-maps on Hycom and Woods Hole (WHOI) and they've been poised for high levels of Fram export from 4/3 with predicts of high levels until 4/13. I am very curious to see if Cryosat will show signs of this afterward.

However, even regarding the PIOMAS grid, the thickest ice (and nearly the entire positive anomaly) seems to now be in areas that have melted out almost completely in recent years (mostly ESS and Kara), lower latitude at best and at worst exposed to the extreme Siberian heatwaves we have been seeing (with Kara about to get a 4-5 day scorcher).

Even going beyond what Jdallen expressed, I'd say that without even trying to predict the weather both the PIOMAS modeled volume and observed Cryosat-2 thickness have placed us in a poor starting position for this year's melt season. The ice is either displaced where it can easily be flushed out of the arctic, or exposed to greater insolation and warmer airmasses. My apologies if some of this has been redundant to what others have posted, but I feel that recent data has further corroborated this.
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Paul

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Re: The 2021 melting season
« Reply #162 on: April 08, 2021, 05:19:47 PM »
However, even regarding the PIOMAS grid, the thickest ice (and nearly the entire positive anomaly) seems to now be in areas that have melted out almost completely in recent years (mostly ESS and Kara), lower latitude at best and at worst exposed to the extreme Siberian heatwaves we have been seeing (with Kara about to get a 4-5 day scorcher).

Remember though, the red is an anaomoly so it does not mean the thickest ice out of the whole basin is in the ESS, it could be for example the ice is 3 metres in the ESS but it might be 3.5 metres along the CAA but that will show as an negative(blue) anaomoly because its usually thicker than that. So the conclusion I'm getting is that ice thickness is more evenly spread out across the basin and the ice should be more resilient than it was last year where we saw the Siberian regions had alot of negative anaomolies and the result of that(thanks to the weather conditions also) was a record of sea ice retreat in these regions. That does not mean a record low can't happen or even get lower than last year but as it stands, I'll favour an ice extent higher than last year and above 4 million square miles.

Also I think the NSIDC mentioned a long time ago of a possible link of very low summer extents come after positive AO winters and negative AO favours higher extents. Its not full proof by any means as we saw in 2017 and weather will still have a big say where we will end up.

Jim Hunt

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Re: The 2021 melting season
« Reply #163 on: April 08, 2021, 05:25:17 PM »
Depends on what you believe in Jim.

I don't "believe in" any of the metrics Paul, especially when the divergence between them is that great!

However this one isn't exactly redolent of "a favourable winter for ice thicknesses" in the centre either?
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Jim Hunt

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Re: The 2021 melting season
« Reply #164 on: April 08, 2021, 05:37:29 PM »
Weather will still have a big say where we will end up.

We can certainly agree on that!
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

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Re: The 2021 melting season
« Reply #165 on: April 08, 2021, 05:53:20 PM »

Remember though, the red is an anaomoly so it does not mean the thickest ice out of the whole basin is in the ESS, it could be for example the ice is 3 metres in the ESS but it might be 3.5 metres along the CAA but that will show as an negative(blue) anaomoly because its usually thicker than that. So the conclusion I'm getting is that ice thickness is more evenly spread out across the basin

I understand your point Paul, but I'm not really sure one can say the ice is more evenly spread across the basin, but rather that PIOMAS is showing it shifted more "bicoastally." There is less ice along the CAA/North Greenland coast, which is closer to the pole and more protected, relative to much greater thickness in the ESS (not just relatively as you can see in the most recent PIOMAS grid below) which is at lower latitude and more prone to melting. In the Laptev and Kara you are correct in that there is positive anomaly, but not greater absolute thickness relative to the CAA/NG coast. But in ESS PIOMAS is showing thicker ice, saturating more pixels at 4m+ of ice thickness. I think this is giving PIOMAS absolute numbers a "false sense of security" as to where we stand with current ice volume.
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Re: The 2021 melting season
« Reply #166 on: April 08, 2021, 06:14:30 PM »
2-5 days of perfect melting conditions can beat any possible advantage. Just one armageddon-like heatwave from Siberia in early June. But in case of mild weather I see a chance.

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Re: The 2021 melting season
« Reply #167 on: April 08, 2021, 06:22:07 PM »
By the way, the Kara Sea already has positive 5-day average in forecast in some places.

Paul

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Re: The 2021 melting season
« Reply #168 on: April 08, 2021, 06:25:29 PM »
Depends on what you believe in Jim.

I don't "believe in" any of the metrics Paul, especially when the divergence between them is that great!

However this one isn't exactly redolent of "a favourable winter for ice thicknesses" in the centre either?

That is for a small part of the basin though and ironically where ice thickness is below average.

Also negative AOs can attract higher temperatures because of the PV being more split but there tends be less fram export and better thicknesses along the Siberian coasts in particular. Positive AOs can bring colder temperatures but increased fram export and less thick ice in Siberia as it gets pulled away from the coasts.

I think the upcoming weather pattern is a good example of what we don't want too see during winter(or most of the time) because yes, it looks like the Atlantic side will see cold temperatures but that comes with increased fram export and ice pulling away in the Siberian regions.

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Re: The 2021 melting season
« Reply #169 on: April 08, 2021, 11:45:43 PM »
I think the upcoming weather pattern is a good example of what we don't want too see during winter(or most of the time)

We can agree on that too:

https://GreatWhiteCon.info/2021/04/facts-about-the-arctic-in-april-2021/

Quote
At least all the assorted models agree that the isobars are closely packed over the Fram Strait, and hence some of the thickest sea ice remaining in the Arctic is currently heading towards oblivion in the far north Atlantic Ocean.

Quote
Also negative AOs can attract higher temperatures because of the PV being more split but there tends be less fram export and better thicknesses along the Siberian coasts in particular. Positive AOs can bring colder temperatures but increased fram export and less thick ice in Siberia as it gets pulled away from the coasts.

The 2020/21 freezing season has been a game of two halves. Which do you suppose is better for ice retention? AO positive first, or negative first?
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Re: The 2021 melting season
« Reply #170 on: April 09, 2021, 06:47:46 AM »
A negative AO winter tends to favour ice thickness due to compaction in the Siberian regions especially. A positive AO tends to favour more ice thickness along the CAA but thinner ice elsewhere and that was certainly the case last year.

Are these claims based on research or intuition? And if the former, do you have any links to relevant papers?
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Paul

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Re: The 2021 melting season
« Reply #171 on: April 10, 2021, 02:08:05 AM »
I think the upcoming weather pattern is a good example of what we don't want too see during winter(or most of the time)

We can agree on that too:

https://GreatWhiteCon.info/2021/04/facts-about-the-arctic-in-april-2021/

Quote
At least all the assorted models agree that the isobars are closely packed over the Fram Strait, and hence some of the thickest sea ice remaining in the Arctic is currently heading towards oblivion in the far north Atlantic Ocean.

Quote
Also negative AOs can attract higher temperatures because of the PV being more split but there tends be less fram export and better thicknesses along the Siberian coasts in particular. Positive AOs can bring colder temperatures but increased fram export and less thick ice in Siberia as it gets pulled away from the coasts.


The 2020/21 freezing season has been a game of two halves. Which do you suppose is better for ice retention? AO positive first, or negative first?

Hard to say in many respects but I do believe the best winter growth weather is a lot of high pressure but only true Arctic highs. Any highs that ridge in from the Atlantic or the Pacific tends to bring well above average temperatures.

A negative AO winter tends to favour ice thickness due to compaction in the Siberian regions especially. A positive AO tends to favour more ice thickness along the CAA but thinner ice elsewhere and that was certainly the case last year.

Are these claims based on research or intuition? And if the former, do you have any links to relevant papers?

Just going on basic meteorology gy really, negative AOs bring more high pressure into play and this helps winds head towards the siberian regions hence a build up of compaction here whilst positives AO does the opposite. 2020 had a good build up ofbvolume along the CAA coasts but the ice elsewhere apart from the Beaufort sea and to an extent the Atlantic front was thin with the Siberian regions seeing notable negative anaomolies.

Back to the melt season and the well above average temperatures have well and truly set in across the Barants and Kara seas, the results of the strong winds is also making it mark on the ice in the Kara sea, not really through melting I would not of thought, more down to ice drifting away from the coastline. I suspect we may see something similar in the Laptev sea in the next few days also.

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Re: The 2021 melting season
« Reply #172 on: April 10, 2021, 09:53:49 AM »
However, even regarding the PIOMAS grid, <snip>

Remember though, the red is an anaomoly <snip>

The PIOMAS image is not an anomaly grid.  It's a thickness grid.
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Jim Hunt

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Re: The 2021 melting season
« Reply #173 on: April 10, 2021, 10:35:53 AM »
The PIOMAS image is not an anomaly grid.  It's a thickness grid.

It depends where you look. On the "official" PSC PIOMAS page they currently only show a anomaly map:

http://psc.apl.uw.edu/research/projects/arctic-sea-ice-volume-anomaly/
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Re: The 2021 melting season
« Reply #174 on: April 10, 2021, 11:27:38 AM »
April 3-9.

2020.

Pavel

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Re: The 2021 melting season
« Reply #175 on: April 10, 2021, 02:16:23 PM »
April 3-9.

2020.
It's impressive how easily the ice have melted  north of FJL. It's just the early April. The Atlantic side is very vulnurable this year

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Re: The 2021 melting season
« Reply #176 on: April 10, 2021, 04:44:07 PM »
Trying to figure out what I'm seeing here off the N. coast of Greenland on WV between 4/9 and 4/10.  Looks a bit like a large area "dropped" in some way?  That area would be something like 70k km^2.  Will be interested to see what the next week brings in this area.  [Click to see 2-day animation]
"When the melt ponds drain apparent compaction goes up because the satellite sees ice, not water in ponds." - FOoW

oren

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Re: The 2021 melting season
« Reply #177 on: April 10, 2021, 05:07:32 PM »
Isn't this the effect of clouds?

gerontocrat

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Re: The 2021 melting season
« Reply #178 on: April 10, 2021, 05:16:41 PM »
Here is a little gif of The Altlantic Front and Greenland for the 2 dates of 2/4 and 9/4.

You can see clearly ice drift sending ice down the East coast of Greenland. You can also see that off the SE coast of Greenland the sea ice is melting. Hence total sea ice in the Greenland sea is starting to fall.

You can also see clearly that a lot (perhaps not all) of the ice loss in the Barents is melting. not ice mobility.

click image to start gif and enlarge. Plays 6 times
« Last Edit: April 10, 2021, 06:43:03 PM by gerontocrat »
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Re: The 2021 melting season
« Reply #179 on: April 10, 2021, 06:36:55 PM »
Here ye go
I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

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Re: The 2021 melting season
« Reply #180 on: April 10, 2021, 07:15:22 PM »
Trying to figure out what I'm seeing here off the N. coast of Greenland on WV

As oren points out, experimenting with the "false color" layers on WV should make it apparent that you're seeing clouds over fractured sea ice?

https://go.nasa.gov/3s6K1Bl
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Re: The 2021 melting season
« Reply #181 on: April 10, 2021, 07:16:15 PM »
There was +4.0°C and rain in Ust-Kara (69.25N 64.93E). Doesn't look like the best weather for the ice.

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Re: The 2021 melting season
« Reply #182 on: April 10, 2021, 09:04:07 PM »
Here ye go
FWIW - That imagery seems to support the HYCOM and PIOMAS estimates of ice thickness NE of Greenland more than the Cryostat estimate that there is a large area of thick ice in that area.
« Last Edit: April 10, 2021, 09:13:12 PM by Glen Koehler »

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Re: The 2021 melting season
« Reply #183 on: April 11, 2021, 06:22:02 AM »
The question that bugs me continues to be "Is smoke from Siberian fires bad or good for ice retention?"
My experience of smoke from a bonfire in the UK in cold weather is that it absorbs "all" of the direct heat from the sun, making me much colder.
The accepted view appears to be that Arctic fires are bad for sea ice retention because soot darkens the snow and adds CO2 for the greenhouse effect.
But if the smoke and CO2 is at high altitude, where temperature is naturally colder, is there a significant net reduction in solar radiation reaching the ice during the summer set against the "blanket" effect? If so, the smoke from the massive fires in the last few years would have tended to protect the residual sea ice - particularly in the later summer when lower sun angles would increase the path length for solar radiation to reach the ice.
The more Siberia and North America warm up the worse the fires are likely to be - and consequently we will see more effects in the future     .    .    ?

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Re: The 2021 melting season
« Reply #184 on: April 11, 2021, 07:11:06 AM »
A negative AO winter tends to favour ice thickness due to compaction in the Siberian regions especially. A positive AO tends to favour more ice thickness along the CAA but thinner ice elsewhere and that was certainly the case last year.

Are these claims based on research or intuition? And if the former, do you have any links to relevant papers?

Just going on basic meteorology gy really, negative AOs bring more high pressure into play and this helps winds head towards the siberian regions hence a build up of compaction here whilst positives AO does the opposite.

So you are just guessing based on intuition. You have no evidence that negative AO causes high pressure to form in such a way that it causes compaction against the Siberian coast.

Unfounded guesswork should be indicated as such by the author.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

oren

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Re: The 2021 melting season
« Reply #185 on: April 11, 2021, 07:55:43 AM »
Binntho, please do not start flame wars. We are all speculating and guessing, whether unfounded or not is up to the reader to decide. Sea ice science has a hard time catching up with reality, and the data is roo short and too much of a trend to be able to prove much about the effect of various factors. Simply state your opinion if it's different.

binntho

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Re: The 2021 melting season
« Reply #186 on: April 11, 2021, 08:28:21 AM »
Binntho, please do not start flame wars. We are all speculating and guessing, whether unfounded or not is up to the reader to decide.

No, oren. Paul makes extensive and authoritative claims that sound as if he knows what he is talking about, when in fact he is just guessing like most of the rest of us. And it is not up to the reader to decide whether those posting here are making claims based on knowledge or claims based on sticking their finger up in the air.

My guess was that Paul was not making claims based on knowledge, but just guessing. I asked him and he confirmed. So I suggest that in future he, like others, marks as appropriate whether claims are just guesses or have a more solid base. This is simply holding himself to a standard that I try to hold myself to and that most other people posting here respect as well.

Phrasing claims with caveats like "i guess ..." or "I suspect that ..." or similar is simply good etiquette, and you yourself should have pointed this out to Paul.

This is not me trying to start a flame war. This is simply politely requiring a mininum standard of behaviour that enables the reader to evaluate the claims of the different posters.

<I disagree, but will leave it at that. Corrected spellinng of his name though. O>
« Last Edit: April 11, 2021, 12:19:36 PM by oren »
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

BornFromTheVoid

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Re: The 2021 melting season
« Reply #187 on: April 11, 2021, 10:24:52 AM »
Slow animation for the last week (click to play)
I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

KenB

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Re: The 2021 melting season
« Reply #188 on: April 11, 2021, 04:31:45 PM »
Trying to figure out what I'm seeing here off the N. coast of Greenland on WV

As oren points out, experimenting with the "false color" layers on WV should make it apparent that you're seeing clouds over fractured sea ice?

https://go.nasa.gov/3s6K1Bl

Thanks - I need to try that out.  The "3-d" effect is still pretty strong for me there.
"When the melt ponds drain apparent compaction goes up because the satellite sees ice, not water in ponds." - FOoW

The Walrus

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Re: The 2021 melting season
« Reply #189 on: April 11, 2021, 07:21:37 PM »
A negative AO winter tends to favour ice thickness due to compaction in the Siberian regions especially. A positive AO tends to favour more ice thickness along the CAA but thinner ice elsewhere and that was certainly the case last year.

Are these claims based on research or intuition? And if the former, do you have any links to relevant papers?

Just going on basic meteorology gy really, negative AOs bring more high pressure into play and this helps winds head towards the siberian regions hence a build up of compaction here whilst positives AO does the opposite.

So you are just guessing based on intuition. You have no evidence that negative AO causes high pressure to form in such a way that it causes compaction against the Siberian coast.

Unfounded guesswork should be indicated as such by the author.

Does not appear to be guesswork.

https://www.climate.gov/news-features/understanding-climate/climate-variability-arctic-oscillation

uniquorn

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Re: The 2021 melting season
« Reply #190 on: April 11, 2021, 09:18:00 PM »
Here ye go
FWIW - That imagery seems to support the HYCOM and PIOMAS estimates of ice thickness NE of Greenland more than the Cryostat estimate that there is a large area of thick ice in that area.

Some more food for thought. Here is a more detailed look at Cryosat2 SMOS merged thickness for apr2-8 and a Polarview S1 from yesterday morning showing some darker areas which may indicate thicker ice, iirc Mosaic intimated that darker was possibly thicker when they were looking for their first floe.
Otherwise, perhaps a regular check of rammb or worldview will show if any large floes make it through the Fram. Today there is one candidate just about to cross the 80N line.

nadir

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Re: The 2021 melting season
« Reply #191 on: April 11, 2021, 11:25:14 PM »
Warm weather gradually turns to the Pacific and American side of the Arctic this week.
A ring of low NH snow cover might form around the Arctic by the end of the week.

Jim Hunt

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Re: The 2021 melting season
« Reply #192 on: Today at 12:04:48 AM »
Does not appear to be guesswork.

That rather brief overview of the AO doesn't mention sea ice. The NSIDC's introduction does, although it also starts off talking about "middle latitudes":

https://nsidc.org/cryosphere/icelights/2012/02/arctic-oscillation-winter-storms-and-sea-ice

When it does get around to sea ice it states that:

Quote
Over the long term, sea ice extent has been declining. However, during any particular winter, extent can vary because of weather conditions. Meier said, “The Arctic Oscillation primarily affects sea ice through winds that cause changes in where the sea ice drifts.” When the Arctic Oscillation is in its negative mode, the winds and ice tend to flow in a clockwise direction, generally keeping more of the older, thicker ice in the middle of the Arctic. In the positive phase, that old ice tends to get pushed out of the Arctic along the Greenland coast. Meier said, “This means that the sea ice tends to be younger and thinner and more prone to melt after a winter with a strong positive Arctic Oscillation.
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Paul

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Re: The 2021 melting season
« Reply #193 on: Today at 01:57:33 AM »
A negative AO winter tends to favour ice thickness due to compaction in the Siberian regions especially. A positive AO tends to favour more ice thickness along the CAA but thinner ice elsewhere and that was certainly the case last year.

Are these claims based on research or intuition? And if the former, do you have any links to relevant papers?

Just going on basic meteorology gy really, negative AOs bring more high pressure into play and this helps winds head towards the siberian regions hence a build up of compaction here whilst positives AO does the opposite.

So you are just guessing based on intuition. You have no evidence that negative AO causes high pressure to form in such a way that it causes compaction against the Siberian coast.

Unfounded guesswork should be indicated as such by the author.

Like I say its basic meteorology of high pressure forms more in a negative AO situation where as a positive AO brings more low pressure. I seen more than enough weather charts during winter over the years which favours Siberian ice thickening. Of course a negative AO tends to favour less export  hence why the Atlantic sector ended up so thin and its rapidly retreating at record pace at the moment, helped by the weather of course.




binntho

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Re: The 2021 melting season
« Reply #194 on: Today at 06:34:04 AM »
A negative AO winter tends to favour ice thickness due to compaction in the Siberian regions especially. A positive AO tends to favour more ice thickness along the CAA but thinner ice elsewhere and that was certainly the case last year.

Are these claims based on research or intuition? And if the former, do you have any links to relevant papers?

Just going on basic meteorology gy really, negative AOs bring more high pressure into play and this helps winds head towards the siberian regions hence a build up of compaction here whilst positives AO does the opposite.

So you are just guessing based on intuition. You have no evidence that negative AO causes high pressure to form in such a way that it causes compaction against the Siberian coast.

Unfounded guesswork should be indicated as such by the author.

Like I say its basic meteorology of high pressure forms more in a negative AO situation where as a positive AO brings more low pressure. I seen more than enough weather charts during winter over the years which favours Siberian ice thickening. Of course a negative AO tends to favour less export  hence why the Atlantic sector ended up so thin and its rapidly retreating at record pace at the moment, helped by the weather of course.
I think the quote from Jim just above negates what you are saying.

<Edited. Stop hounding other users for their intuition, while making confident posts yourself. O>
« Last Edit: Today at 09:51:07 AM by oren »
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6