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Messages - oren

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September mínimums have been:

 Year               Extent
                  10^6 km2
1980's Avg.     7.19
1990's Avg.     6.49
2000's Avg.     5.41
2010's Avg.     4.33

I wonder if by going with trends the 2020's average is going to be about 3?

Another thing I have noticed is that usually all years of the following decade have beaten the previous decade's average. For example - the highest of the 2010's is 2014 (4.88), which is less than 2000's average. Only once there was a discrepancy in that 1990's Avg beat 2001.

So going by that every year of 2020's should beat 4.33. That's the very minimum we are looking at. Of course, the beginning of the decade is the most vulnerable in this context and this decade has just started out.

Arctic sea ice / Re: Latest PIOMAS update (June 2020)
« on: June 03, 2020, 11:10:57 AM »
Thickness map for day 152, compared with previous yeas and their diff's. Click for size.

Arctic sea ice / Re: The 2020 melting season
« on: June 03, 2020, 09:13:22 AM »
May 29 - June 2.


Arctic sea ice / Re: The 2020 melting season
« on: June 02, 2020, 02:12:51 PM »
Latest Five Day Forecast
Wind @ Surface + Total Precipitable Water

Arctic sea ice / Re: The 2020 melting season
« on: June 02, 2020, 03:02:58 AM »
THE JUDGEMENT DAY is coming. Terribly large low albedo region ever seen.

Antarctica / Re: Thwaites Glacier Discussion
« on: June 01, 2020, 09:28:10 PM »
On another note, I was looking at how the ice in the melange (between the and the Eastern ice shelf) was breaking up recently and I noticed how the red wedge near #8 in the image below has been developing over the past year.  To make a long story short, I began to see it as a part of a much larger multi-year pattern which I will try to sketch out.  There is a lot to unpack here so bear with me.

What I am calling the "Escalator" is a series of ice wedges that form in the "Fracture Zone" between the fast moving and slow moving areas of Thwaites ice shelf.  The wedges (or "steps" in the analogy) are formed from the faster moving shelf that breaks away from the slower moving shelf at the shear margin.

The rest of the faster ice does not display this behavior.  Most of the faster ice is in the calving zone where transverse (East-West) rifts form with separation of about a kilometer.  Those long trips of ice eventually break into more square shaped tabular icebergs that form the bulk of the Tongue.  Another portion of the faster ice calves at a front to the West.

The wedges are larger, 2-5 km in size, and they don't appear to fracture.  The mechanism of their formation is a bit of a mystery, but I assume that they undergo some amount of compression before they break away from the slower ice, giving them atypical strength and thickness that makes them more durable than the surrounding icebergs.

I have tentatively identified and numbered these wedges in the picture below.  The last two are still in formation so I am simply speculating on how they might emerge.  The choice of numbering is not arbitrary, since #1 is the first wedge that can be identified in the current Tongue.  Any previous wedges have since floated off (although the current tip of the Tongue may be the back end of an earlier wedge.)

This 5+ year GIF of the Tongue ( can help give a better picture of what may have led to the current structure and it deserves more analysis.  The calving of the current Cork from the Eastern Ice Shelf in 2014 and a massive calving East of the Fracture Zone in 2016 which makes up most of the current Melange have resulted in the Tongue being pushed to the West.  Before 2011 the Tongue was still connected to the Eastern Ice Shelf and it calved from an angular front which can still be seen in the pattern of the icebergs at the end of the Tongue.

The Western push from about 2015 to 1019 created the stair-step shape of the Escalator.  It also exposed more of the Northern faces of the wedges which caused them to push on more of the melange.  Most of the wedges can be associated with rifts in the melange (shown in red) where the points of the wedges have pushed apart the ice and even broken larger icebergs that they came in contact with.  Two of the wedges (#3 and #5) have pushed icebergs in front of them which are indirectly pushing on the cork.  The Western movement of the Tongue also resulted in it colliding with the underwater peak that has stripped off many of its icebergs.

Since the Cork now appears to be loose, it is assumed that the melange will eventually move off behind it.  If the Tongue is no longer pushed as far Westward (no new hangups in the Melange) then the new wedges could continue in more of a straight line and the width of the Tongue could be restored to at least part of its former glory.  However, the Western calving front will probably never be a part of the Tongue again.  Of course, the Shear Zone could be causing permanent damage and that part of the Tongue may also join the calving front.

Another reason to track these wedges is that they are becoming proportionally a larger and larger part of the Tongue.  In particular, #4 and #5 may comprise the entire width of the Tongue at some point, as the ice to their West gets stripped off.  It is hard to so how such a reduced Tongue could hold together if the sea ice were to retreat.

I expect to keep studying this and hope to glean more details as I go along and I am willing to answer questions or make clarifications.

A busy month is coming to an end:

Arctic sea ice / Re: The 2020 melting season
« on: June 01, 2020, 01:36:33 PM »
Latest Five Day Forecast
Wind + Temp @ Surface

Permafrost / Re: Permafrost general science thread
« on: June 01, 2020, 01:19:19 PM »
Apologies for the double post (this is also in the Arctic methane discussion)
Interesting research update on permafrost

Arctic sea ice / Re: The 2020 melting season
« on: June 01, 2020, 12:04:19 PM »
Alu - great videos thanks - but it would be handy to know dates as it rolls around - can't really even see start and finish as the first one (whole month) looks fairly similar throughout.  If its a compilation of frames maybe for example rather than 31 flashing numbers - maybe use week 1 / week 2 / week 3 ?
First and last frames stay 3-10 times longer. At least it works on my computer in Firefox. Text is added.

Antarctica / Re: Thwaites Glacier Discussion
« on: June 01, 2020, 06:59:28 AM »
Today's 6-day GIF of Iceberg B22-A shows that the Southwestern corner that broke off has moved away and possibly not coincidentally the larger iceberg has shifted to the West.  The theory being that the corner was grounding in the shallows and thus limiting the motion of B22-A.

Without the corner the iceberg may now have more freedom to move and rotate out of its trapped position and eventually float off, exposing Thwaites and neighboring glaciers to more currents and threaten their protecting sea ice.

Policy and solutions / Re: Lessons from COVID-19
« on: May 29, 2020, 01:07:30 PM »

Come on, bluice. The impact a virus can have is in large part determined by factors like general population health, demographics, etc. If your population has been systematically weakened for decades through profitable addictions, overprocessing of food and unsustainable soil-destroying agriculture, it becomes much easier for a virus - which is a natural occurrence - to wreak havoc and (help) induce panics that then cause further havoc.

Correct, but that is a massive if. When was the point in time people were healthier and more resistant to disease than nowadays? With the exception of the US with its disastrous health care industry people are living longer than ever. In fact we are panicking because we are so used to NOT dying to a contagious disease. Early/mid 20th century people still regularly died to small pox, diphteria, measles, TB etc. etc.

I do agree the comparison between present day and last century is a bit unfair. It's not either-or. We could have used all our medical knowledge and technology AND better sustainable general health to build a more resilient society.

Of course they are inept, as they have been made inept, and are now willfully inept. Because there is a system that wants something, namely the further growth and further concentration of concentrated wealth. Everything that has to do with this SARS-CoV-2 crisis (its coming about, its impact, the reaction to it, the consequences) has been directly caused or indirectly influenced by this system. The main reason it is hard to prevent these things - for instance, by making populations more healthy physically and mentally, so they become more independent - is because it would be bad for concentrated wealth.

Hence the castrating expression: How ya gonna pay fer it (if you need to pay me first)?
There obviously is a part of our society whether you call it 1% or The Concentrated Wealth or whatever that is out of touch with the realities of the rest of us. No question about it.

I don't like treating them as a one single entity however as it's too obvious people like Soros, Putin, Trump, Gates or Murdoch are all part of this establishment but have nevertheless completely different and conflicting interests. To group them all as one running a secretive system is too close to conspiracy theory or marxist class war IMO. It's more like a feudal society or 19th century great power game where the Powerful fight each other for glory and the small people get trampled by their war machines. A history repeating.

I live in north central South Dakota around 98.9 degrees west.  My personal experience on the ground indicates that, at least up here, the line is not moving east.  If anything, it is moving west.

Now, this may just be a temporary phenomenon.  The northern plains have an extremely variable climate.  There really is no normal.  We go in cycles, sometimes up to several decades long, where a given trend will stick around.  Ridiculously snowy winters come and go.  Wet and dry summers come and go.  Cold winters come and go.  I attribute this to being directly in the center of the North American continent, and thus subject to all the various weather patterns controlled and moderated by the oceans at the edges of the continent doing battle in the middle.

That said, it's stuck around for a while now.  Back in the late '90s, we had a bunch of fairly wet years together, along with the infamous winter of '96-'97 where it snowed SO MUCH.  Minnesota residents might remember the Halloween blizzard of '96.  It had already moved over us by the time it was time to go trick-or-treating, so my parents were able to safely drive me through temperatures approaching 0f to go trick-or-treating in the mall.  Anyway, spring '97, all that snow melted and made a bunch of new lakes that never went away.  They are still there today.  The state had to spend millions of dollars building up roads that now went through lakes.  That's why, if you're ever driving through NE SD and wonder why in the world they went through all the effort to make a road through a lake, they didn't.  The road was there first.  And once the lakes formed, there was no other way to get where that road went.

We have had an occasional dry year or three since then, even hitting D3 or D4 on the drought monitor, but that's normal for us.  The drought monitor measures soil moisture relative to average, but does not take into account standard deviation, which is huge here.  After those dry years those lakes never went away.  Now especially since ~2010, much like in neighboring MN, we have been getting much, much more humidity in the summer.  This reduced envirotranspiration as well as enhanced precipitation.  We historically averaged 17" of precipitation a year.  The latest 30 year average from 1980 to 2010 is 20".  It will undoubtedly go up when they refigure for 2020.

2019 was both the wettest and snowiest calendar year on record, with 30.35" total yearly precip including snow water equivalent, and 97.3" of snow, in Aberdeen.  We set a few dewpoint records last year too.  This is in a historically semi-arid climate.  Prickly pears grow here.  Or at least they did, until they probably all got drowned out last year.  Again, a whole bunch of new lakes formed that have not gone away.  This time, one even formed on our farm.  I'm thinking of stocking it with fish if it doesn't go away this summer.

Most climate models agree that we will get wetter, however the increases in temperature are expected to offset those increases and still lead to an overall increase in evapotranspiration.  So far, that does not appear to have occurred.  Increases in summertime humidity if anything have decreased it.  So, what are we looking at going forward?

There are a few factors.

One.  Possibly, we are just in a long multidecadal wet cycle, and it will get dry here soon enough.  Very possible.

Two.  The models failed to account for the expansion of King Corn's domain, and massive fields of corn are responsible for the significant dewpoint increases we've seen.  This is sort of a side effect of roundup ready corn.  When I was a kid here, no one grew corn or soybeans, they all grew wheat, sunflowers, barley, oats, rye, millet, sorghum, that kind of thing.  Cultivation and tilling and plowing release a great deal of moisture from the soil into the atmosphere with each pass.  Having to go over each field many times a year for weed control lost lots of moisture.  Now, they only have to till going from corn to beans, and even then, not all the time.  No till from beans to corn, and of course, no cultivation during the growing season either since all weeds are controlled by sprays.  You see spring wheat or sunflowers every now and again these days, like 1%-5% of fields in this area, but the rest is all a corn/soybean rotation.  So that corn transpires a lot of water, and as corn's range extends west upwind of us in southern SD and Nebraska, we are getting their evaporated corn water triggering thunderstorms up here.  Corn has been shown to increase local dewpoints from 5 to 15 degrees fahrenheit.  I think actually that overall, agriculture is a poorly understood influence on global climate that is probably underestimated.

Three.  The models failed to account for the increase in plant water use efficiency due to elevated CO2 levels, and while the climactic evapotranspiration line may indeed move, it may do so independently of the plant life.  We have found already through satellite imagery that, independent of yearly precipitation variation, the world's deserts are greening due to CO2.  The more of a water deficit a biome operates at, the more sensitive the plants are to CO2.  This is because the plants must open their somata to absorb CO2 for carbon to build their structures, but in so doing, they lose water at the same time.  Higher CO2 concentrations mean plants lose less moisture in acquiring the same amount of carbon.

I think point number 3 is already having noticeable effects in semi-arid agriculture.  While 2019 was wet, both 2017 and 2018 were major droughts.  D2, D3, areas of D4 popping in and out through the summer.  And they still harvested a halfway decent corn and soybean crop here even so.  I don't live in town, I am surrounded by crops as soon as I leave my house, and I spend a lot of time outside gardening.  I watched those crops all summer long, thoroughly convinced from April through July that they were dead men walking, going to die any day now.  No way they could keep alive through all of this.  All this stuff is dryland, we don't have irrigation here.  2017 hit 100 a couple times and 2018 we went over 100 5 times and hit 105 once.  An inch or two of precip a month both years, usually in one big storm a month that came with the fury of Thor and did a lot of damage with high winds and hail.  But live they did, and the farmers made money.  Nothing short of amazing.  I do know they are breeding drought tolerant corn and beans, but all the same, I mean, you just had to see it for yourself or you wouldn't believe it.  It wasn't just hot.  The plains are windy, almost all the time, and often very very windy.  You've probably seen the Wyoming Wind Sock.  We evaporate a LOT of water.  It can't just get 105 here without a stiff, stiff SSW wind pumping in air straight from the desert before it has a chance to cool down.  The best you can do in calm air is typically mid 90s.  What I mean to say is the wind was stiff out of the southwest all summer long.  We had several dust storms in 2018 like what you saw pictures of from the great depression.  It got dark enough the photosensitive nighttime light in the driveway turned on.  None of the farmers are afraid of drought anymore, because they all say only half jokingly, "well we learned in 17 and 18 that you don't need moisture to grow a crop."  Just absolutely incredible and I don't have any other explanation for it.

Four.  Things I'm not thinking of.  Do you have any idea what they might be?

I don't really know what to expect in the next 100 years.  Especially considering the region naturally oscillates between dry and wet on long and short timescales. is a great paper on the recent history of plains droughts.  But that was in a relatively stable climate.  Now everything is changing.

Anyone else living near the meridian at other points that can comment on their experience on the ground?

Antarctica / Re: Pine Island Glacier (PIG) Calving and Discussion
« on: May 26, 2020, 10:43:20 PM »
Oren asks, Paolo executes  ;)

Click twice to zoom in

EDIT: I don't remember that there were so many calvings

Consequences / Re: World of 2030
« on: May 26, 2020, 04:31:19 PM »

The world currently consumes around 20 TW of energy. Much of the population of that world belong to developing economies and they earn less than $10 daily. They lack one or more basic needs.

To make sure that the current population receives at least basic needs, around 50 TW of energy will be needed.

To meet a population of around 10 billion, it will need around 75 TW.

To ensure continuous economic growth (because most of the wealth of the same population consists of money whose value can only be maintained with increasing economic activity), much more than that.

To adjust to diminishing returns, even more.

What about diminishing returns?

The ave. ecological footprint per capita is in excess of biocapacity, leading to diminishing returns, pollution, and the effects of pollution, including global warming. Even more energy will be needed to minimize the effects of those problems.

Part of that biocapacity are fossil fuels needed for mining, manufacturing, and shipping of even components needed for renewable energy, not to mention mechanized agriculture.

Arctic sea ice / Re: DHACSOO - A Durable Arctic Hypothesis
« on: May 26, 2020, 01:50:49 PM »

Rather than argue, I'll ask a few question.

Let's construct an example. There is a land based heat wave in Siberia near the Laptev Sea with 25C temps over land. The GFS weather map indicates a plume of heat into the Laptev with color coded gradations representing heat in degrees C. Immediately adjacent to the coast is a semicircle which extends 100 km into the Arctic at a temperature of 3C. A bigger area extends beyond to 300 km from the coast at a temp of 2C and a 1C plume extends out to 800 km from the coast.

How do you interpret that?

I see that the sun has warmed the earth and that the warm air from the earth is traveling out over the coast and dissipating as it gets farther away from the coast. Do you see the same thing?

So you give me an imaginary anectdote and want me to say something other than the obvious? Of course there is warm air advection from Siberia to the Arctic at times, and sometimes quite significant, although of course, this is only air moving about, with very low heat capacity, and the reason it gets so hot is that it's not really moving very much in the first place. Because, you see, the sun doesn't shine any harder on continents than other ents.

Heat transfer from the continents is real but is very unlikely to rank higher than at best third place after direct insolation on the ice in first place, and ocean heat absorbtion and transfer (and increasingly, wave action) in strong second place when accounting for ice melt during summer. My own guess would be that third place is taken by low-pressure areas bringing kinetic energy from the southern oceans, stirring up heat from below and bashing the floes together.

The oceans have much higher heat capacity, are much more easy to move around than the continents, and have much lower albedo. So the oceans are the clear winners by far when it comes to collect, store and transfer the heat energy from the sun from anywhere to anywhere when compared to warm air over contintents.

And of course, the flip side of the continental hot summers are the very long and very cold continental winters. Were the Arctic not sheltered in the cold embrace of those massive continents, it would grow much more slowly in winter and disappear easily every summer.

Arctic sea ice / Re: The 2020 melting season
« on: May 25, 2020, 06:46:30 AM »
I think this forum is quite balanced and that collectively we do an excellent job at holding each other accountable to the science, independent of our inevitable biases. Back to the data and observations.

The winds around Beaufort are opening coastal areas, etc to wave action and insolation – especially given the clear skies so far in this animation. In the last frame, it looks like some conditioning may be happening to the sea ice off coastal western Canada & Alaska, as inferred up thread. Caveat, I contrast enhanced this image to emphasize changes in the corrected reflectance bands 7-2-1.

Arctic sea ice / Re: The 2020 melting season
« on: May 24, 2020, 11:01:29 PM »
I get the Blue in Hudson. But what is turning the ice grayish around Akimiski Island ?

Arctic sea ice / Re: The 2020 melting season
« on: May 24, 2020, 03:46:43 PM »
What concerns me most at this point is not the lead of 2020 over 2019 by extent or area numbers, but rather the conditions that seem consistent with persistent preconditioning all around the CAB. I agree that its too early to call this year a "monster," implying that its completely unprecedented in every way. Rather I'm concerned that current conditions are setting up to leave the CAB vulnerable by July and the peripheral seas (and even high arctic) able to soak up enough sun to screw us over come winter and years ahead.
We have just seen massive WAA anomalies set the stage in the Kara and Laptev, while the next 7-10 days seems to shift intensity to the pacific side. Several have noted how we're behind in Beaufort and Chukchi, but those are the very areas to be blow-torched this upcoming week (see both GFS and Euro temp anomalies at 48hrs from 00Z below).

Arctic sea ice / Re: The 2020 melting season
« on: May 24, 2020, 01:08:43 PM »
... Huge leads in places where we know 2019 gets to zero or close to it are almost meaningless, especially in peripheral locations like Baffin and Hudson.
Incorrect. Unusually faster melt in peripheral locations can often indicate faster melt in high Arctic, which would happen later in a melt season. Whenever cause(s) which resulted in much faster peripheral melt early in a season would largely persist through the whole melting season, and we have a number of such indeed, for 2020.

... Baffin, Hudson, Laptev and  Kara combined are ~ 500k km2 ahead of 2019 and is offset by Bering being ~ 60K behind 2019. Knowing where 2019 ends, we know that 2019 is going to catch up at least 400K in these seas. The current 100k lead is vapor.
My bold. I believe that the two statements i enhanced with bold text - can not be true simultaneously. Those seas are either 500k km2 ahead - or 100k ahead. I am surprised to see such "wordplay" in this topic. I think it has no place here.

On the whole, 2020 has work to do to put itself in position to be a favorite to surpass 2019.
My italic. On the following graph, we can see how 2012 did ~1800k of such "work" between 23rd May (at which date 2020's line ends on this graph) and September minimum. See, by 23/05, 2012 was ~1000k higher than 2019, but at the minimum 2012 was ~800k lower than 2019. Which number - 1800k - dwarves numbers you gave, and in my opinion, proves your whole point wrong:

So, 2012 is one good "hindsight" about how much melt work a season can do. One can easily see how much lower-than-2019 this melting season can end up, if it'll just do "same amount of melt work" 2012 did, while "starting" from today's much lower than 2012's extent (and thus, roughly, also much lower-than-2012's area).

Given those facts, can you please elaborate what was, exactly, the meaning of your statement i quoted (the one in italic right above)? How, exactly, this statement helps us understand this melting season? What's its "meaning", exactly?

Arctic sea ice / Re: The 2020 melting season
« on: May 23, 2020, 10:13:12 PM »

We don't know what is going to happen in June but so far we are likely going into June in best modern set up to ravage the inner Arctic basin.
2020 having slightly more ice thickness means nothing if we have melt weather going into June.

IMO, thickness is an important reflection of a preconditioning process which begins long before the melt season begins.

The CAB is the reservoir of most of the season ending ice. At 4/30/2020, PIOMAS was indicating ~ 500 km3 more ice in the CAB vs. 2019 and ~1,300 km3 more vs. 2017.  The Beaufort also was running a few hundred km3 above those years. You might characterize these as "slight" differences. I don't.

When faced with the prospect of cutting down a tree and a limited time frame to do, the thickness of the tree and the amount of time remaining to cut it down matter.

7 years ago I might have agreed with you, but my read of the last 7 melt seasons suggests to me otherwise.

By your logic, 2013 should have been a blow-out, as thickness and over-all volume were massacred at the end of 2012.  However, they were not, and the reasons why are the flip-side of the points Friv is making.  Preconditioning and weather are more critical to the melt season's progress than the modest increase in volume which may have been gained.  The additional ice won't be enough to off-set the increase in heat budget we are seeing, presuming weather continues on in the dismal trend it is currently following.

Continental snow pack has been smashed, especially in Eurasia, and the Siberian Arctic coast increase in temperatures are astonishing.  While we typically have not considered air temperature that significant a factor in direct melt, quantity has it's own quality, and we're talking about coastal temperatures running as much as 10-20C above normal and higher.  With sunlight at those temperatures, the ice may not even have a chance to form deep melt ponds as significant fractions of it sublimate directly to the atmosphere.  Flow off the continent will work like Foehn winds in the Alps which can strip snow pack in hours.

Like Friv, I think we are seeing late June ice conditions moving up to late May.  I think it's hard to understate the importance of this as it pertains to the Arctic heat budget. 

Instead of setting up to  do it's most efficient heat capture in July, its looking like it will be set up in early June *before* the solstice, which will effectively double the amount of peak insolation (Solstice +/- 3 weeks instead of the 3 weeks or so after) the Arctic will capture.  That will also have the effect of amplifying the impact of insolation later in July and into August, as proportionately more heat will be able to get captured by increased melt ponding and plain open water.

That's an awful lot of Joules, which in previous years would be mostly tossed back out of the atmosphere by albedo - by both the ice and continental snow pack.  None of that this year, and the result may be disturbingly spectacular.

Arctic sea ice / Re: The 2020 melting season
« on: May 22, 2020, 05:06:13 AM »
For some real time images of the snow in the CAA there are a few good cameras at Canadian airports on the Nav Canada WxCam site.

Arctic sea ice / Re: The 2020 melting season
« on: May 18, 2020, 01:40:56 PM »
Latest Five Day Forecast
Wind + Temp @ Surface

The Kara sea will be getting a roasting in a few days from now, with the Laptev also getting its share of heat.

Positive temperatures for the Beaufort are also in the forecast.

The forecast for Fram exports looks good, with southerlies holding the ice back. But I've seen a possibility of that changing on the long term forecast.

Wind in the Bering strait will continue to come from the north until the end of the week, when a change in wind and temperature is expected.

I was under the impression from last weeks forecast that temperatures on the CAB would go down a little, but it seems they won't be dropping anytime soon.

Arctic sea ice / Re: The 2020 melting season
« on: May 18, 2020, 09:39:42 AM »
May 13-17.


April 27 - May 17 (fast).

Arctic sea ice / Re: The 2020 melting season
« on: May 16, 2020, 01:47:20 AM »
    Ditto ArcticMelt2, thanks for the WAPost article and also those ice thickness images.  They could have spiced it up with some ASIF quotes from the Fabulous Friv.  It is a credit to the ASIF that the experts quoted in the article didn't add to what has already been noted in greater detail in the forum.  Good to see a major US press outlet paying attention to news that matters vs the latest ramblings of the mad King.  Actually, the WAPost climate team led by Chris Mooney is among the best of all the major newspapers/magazines.  Mooney even did a story about Neven and the ASIF back in 2016:

     Comparing the 2012, 2019 & 2020 sea ice thickness images, the one strength 2020 had was the thick ice near the Fram Strait.  That is the very ice that was presumably pummeled by the warmth, sun, and WIND this week.   2012 and 2019 each had a long arm that may have impeded Arctic-wide rotation.  2020 lacks that structural brace.  I don't know if Arctic-wide ice translocation is affected by the distribution of thick ice at that scale.  The significance of that pattern could just be a visual figment of my imagination.  (Or as Pete Walker said: a "Fig Newton of my immaculation") 

     The last 7 days of the current GFS shows Kara Sea temps consistently above 0C.  Not much clear sky & direct sun in that forecast, but the clouds bring some rain (too warm for snow) to deliver additional thermal energy to the surface.  All of which leads to forecast zero snow cover in the Kara by May 24

    The Kara is already running below previous years (,2975.600.html#lastPost thanks to Gerontocrat).  Putting that together with the forecast suggests that by June 1 the Kara could be in unprecedented condition.

    The Barents Sea hardly seems to matter since any ice in it is doomed anyway.  But FWIW, Earth Nullschool shows continued low-pressure system winds scouring it out for another day or two.  Does it make much difference to clear the lanes for more export out of the CAB?  Erosion of the ice on the CAB - Barents border can't help.  At least the great Fram Flush of early 2020 has ended. 

     Following up on Freegrass's tiptoe through the tulips of DMI images, looking at the DMI temperature graph for every year since 1958 shows that this early-mid May warmup has no real match in previous years. 

     It seems like every year the ASIF gets all heated about impending ice doom.  2020 so far is providing some hard numbers in that direction.  Yes, it is still early, but as wiser watchers have noted, it is the early momentum that sets the stage for the rest of the melt season.  True enough that a basin-scale clear-sky event would be worse if it happened 2-3 weeks from now and closer to the solar max.  Then again, decreasing albedo well BEFORE the solar max increases the impact of reduced reflection of solar radiation. And having a clear-sky event early does not preclude having another one later.

Arctic sea ice / Re: The 2020 melting season
« on: May 15, 2020, 08:04:54 PM »
Something's moving north of Ellesmere in the last three days...

Consequences / Re: COVID-19
« on: May 15, 2020, 02:12:44 PM »
It's sad to verify the disfunction of my country's political structure.
Central government bureaucrats require regions (autonomías) to comply with certain thresholds in order to de-escalate from the confinement. Certain autonomies (Madrid among them) have been kept behind. This has created a lot of political tension, and a slight social unrest.

One of the things argued to keep Madrid confined is the poor capability to test all cases and trace, and to enable primary care centers to provide testing.

Our psychopath president of Madrid community claims we are already well prepared. I could verify first hand we are not.

My father was in antibiotic treatment since a week ago or so. He is 90. He later showed minor fever and cough, and my sister called the doctor. Doc says he's pretty sure father's not Covid given his history, but insists he should be taken to the hospital, 'it's the protocol' . My sister says no way unless he's taken a test first, we know going to the hospital is big risk of catching it.

Doctor says we wait then. Primary care center does not bring COVID-19 tests. My father improves at home as expected, especially after finishing antibiotics treatment.

To this day: primary care has not called, the doc probably has forgotten, no testing, no tracing.

It's all a freaking lie. And they go on with their petty political clashes.

Arctic sea ice / Temperature Point Comparison : GFS v Polarstern
« on: May 14, 2020, 06:19:49 PM »
There have been discussions in the main melting thread about comparing output from forecasting models and actual point data over the Arctic.

Personally, I look at two main models, the ECMWF and the GFS to give me an idea of conditions over the whole Arctic Basin, Data from GFS is more widely available and they make more runs available per 24 hours.

We currently have data from the Polarstern ship drifting in the Arctic at circa 83 N 13 E. Using the GFS data displayed on Nulschool, it is possible to do a point comparison with the data from Polarstern. (I am not aware if the GFS model assimilates these hourly synops from the Polarstern ship).

This is not intended to single out the GFS model -I have only used that model for comparison as it was most readily available on Nullschool. I am not making a statement on which model is the best.

I have noticed there can be a huge difference with some models when it comes to plotting surface temperatures over the Arctic Basin. Example the French Arpege model quite recently was showing temperatures circa -14 C over a wide area near the pole whereas both GFS and ECMWF were showing temperatures much closer to zero.

The first comparison attached is for the 48 hours on 14th May to 12th May. I hope to do some other days also - to give a longer idea over time.

Arctic sea ice / Re: Arctic Image of the Day
« on: May 14, 2020, 12:37:11 AM »
Kassy/Freegrass. I don't profess to have an in-depth knowledge on drift ice. Like you I have often seen long sea ice strips form especially during windy spells in the Greenland Sea and the Bering sea, like a flock of gigantic sea gulls heading away from the pack.

I have found this information from this book Arctic Sea Ice, which I hope is not too small to read and I think helps explain the process. 

Arctic sea ice / Re: The 2020 melting season
« on: May 13, 2020, 01:45:52 PM »
I also want to say there is decent correlation between nuetral Enso conditions towards weak Nina that correlates with the negative AO, negative NAO summers of 05, 07-12...

It's not perfect 1996 had the most anomalous vortex in the modern record with nuetral/weak Nina.

We have had a weak Oni nino through March.

However real time conditions are going straight towards a big Nina event.

Does that matter?

I don't know .

Why did we have 05, 07-12 with historic dipole ridging during the summer months and anchored over GIS.

We have had major ridging events like 2015 July the warmest July on record in the Arctic that semi-extended to GIS.

However after 2015 we have been far more reliant on huge WAA incursions from land to decimate ice versus good ole sun bathing of the golden era 05-12 minus 06 and 09.

2009 had dipolish but 2009 had above normal snow cover that retarded the major surface heating.

2011 on the other hand had almost no snow cover all over so the Southern CAB almost bit the dust

My two favorite thickness images ever


April 2011 not much thickness in the CAB but 2.5-3.5M

And May typically sees ice thickening above 80N.

But holy smokes...if 2011 didn't have August go cloudy and cold.

Like when did all that CAB ice melt?

Anytime it was warm enough because by early June snow cover was gone over most of the cab.

Was there a major fire at some point darkening the cab?

This is why we desperately need a reliable snow thickness in the Arctic.

I want to see a total ice collapse so maybe funding will go back into satellite and buoy expenses.

Arctic sea ice / Re: The 2020 melting season
« on: May 13, 2020, 07:13:15 AM »
I agree with friv, and think one additional ingredient here is the amount of ice that will be sent down the death zone past Svalbard and out the Fram strait. We're looking at 4+ days of strong surface winds exporting ice. Just look at how packed the isobars are on this output and how well they are positioned to export ice.

That ain't no joke that is crazy you're going to see open water come in the kara or the laptev because of all this

Chiming in.

Add Ekman pumping.  The ice is far more mobile than previous years, so it will not prevent transfer of force from the wind to the water below.  We should see significant mixing of the column under those regions where the wind in this dipole are *already* at work.  The CAB immediately north of Svalbard will be shattered more thoroughly than we would normally see before July.

The High combined with the storm over Svalbard create a near perfect hammer and anvil to shatter the Arctic.  The only question remaining is just how severe the damage will be.

To underscore what Friv said earlier about albedo,  we are talking about conditions being created (dropping albedo from 85 down to 60) which will more than double the amount of insolation being captured by the ice.   It will be doing that about a month earlier than typical, during increasing insolation.

Certainly we've seen ice get beaten up with lowered albedo, but mostly that is happening after the solar peak in late June, so the ice is basically riding the end of a wave (diminishing insolation) after it's broken.

We may be about to see that equation shifted a full month, so that those late July conditions are reached in late June instead - at peak insolation. In short, the ice will be getting pulled into the "wave" of insolation just as it's breaking, with pretty serious consequences.

If that happens, it will be hard *not* to overtake the 2012 extent and area losses. 

Arctic sea ice / Re: The 2020 melting season
« on: May 13, 2020, 06:50:09 AM »
Considering blocking pattern, the melting pond will be more and more. The melting pond is a signal of massive melt. The weather of MAY is important to decide the ice compared with June and July. June and July is common high speed melting months. However, the sensitivity of ice is high in May.

This is everything.

Historically actual surface ice melt anywhere from 70N+ doesn't take place until July.

With limited bottom ice melt in August between 70-80N.

In the 90s the surface ice melt onset steadily started earlier and earlier.

But the big change first happened in 2007.

Really starting in the fall of 2006 because there was unprecedented loss of MYI into the NATL that winter.

Well almost all of the very limited snowfall in the Arctic basin takes place between September through November..

Between January and April essentially little to no snow falls and what does tends to sublimate.

A lot of the dry Sandy like snow also gets blown into ridges between thicker myi flows that press together essentially forming small 3-20M high mtn ranges of ice.
Or gets blown into the water when floes get roughed up in wind events.

Anyways in 2007 adding to the insult was a ruthless massive top down ridge that blew up right at the start of June that was anomalous from 300MB to the surface meaning dry sinking air that quickly warmed up as soon as surface albedo sank.

This brought us 1.5-2.5CM a day melt from the Beaufort to the ESS on the surface. 

The sun was 24/7 so the subsurface quickly warmed to -1C to 1.5C by the first week of July.

For every 0.5C of warmth about 1CM of ice is lost per day.

So by July first we had 2CM top melt and 2-4CM bottom melt wrecking 3-3.5M ice.

However unlike be every other year on record the ridge didn't break down and vanish.

It weakened but strengthen over and over all summer.

A new normal was born.

My point is even between 2007-2019 the solar energy was mostly moot for melt because albedo, clouds, snow cover, what have you.

Can you imagine if we see widespread surface ice melt by the 20th-25th of May instead of getting established after June 15th.

That's 3 weeks of extra melt that's 3 weeks of early July level solar energy not being floated back to space by 0.85 albedo versus 0.55-0.60 albedo where 2-3X more energy is not only melting ice but warming the ice to the melt point and warning the sub surface.

Many of us have preached for years it will take a May solar beating like June 07 to blow by 2012 like 07 blew by 2005.

Arctic sea ice / Re: The 2020 melting season
« on: May 13, 2020, 05:40:06 AM »
I said something about it yesterday and I'm not trying to be rude but who cares what the Euro or the GFS say about surface temps.

It's totally moot when we have an almost cloudless basin which is almost impossible to find anytime of year.

The only thing that matters right now is preconditioning of the basin surface how fast the land snow melts.

The GFS is probably too warm.

But the ESS and laptev gave been above 0C because the surface is wet.

This is so unprecedented.  This surface darkening didn't happen in 2012 until the 6th-12th of JUNE!







Antarctica / Re: Thwaites Glacier Discussion
« on: May 12, 2020, 03:06:59 PM »
Today the Iceberg B22-A fully separated from its Southwest corner and rotated clockwise to the North.  Below is a 6-day GIF.  Yesterday's 6-day comparison showed no change.

As you can see, the pivot of the rotation is in the Northeast (top left) corner and the concern is that the Western end of the iceberg may eventually escape from the shallows which can be roughly defined as the group of grounded icebergs in the bottom left of the image.  The loss of the SW corner may make it easier to float off.

B22-A broke off from Thwaites Tongue in 2002 and has been grounded in its current location since then.  If seems to stabilize the sea ice off of Thwaites and the surrounding glaciers to the West and if it were to float off it could weaken the melange of ice currently trapped off of these glaciers.

Arctic sea ice / Re: Nullschool Forecasts
« on: May 12, 2020, 01:20:32 PM »
Latest Five Day Forecast
Wind @ Surface

I'm curious to see how much ice will pile up in the ESS with those anticyclonic winds.

Arctic sea ice / Re: The 2020 melting season
« on: May 12, 2020, 05:11:54 AM »
I don't mean to be rude but who cares about modeled 2M y

Let's take a look at only thing that really matters.

Surface albedo. So for May 11th everything looks as you would expect.

The surface albedo is steadily dropping quickly over the ESS and Chuckchi and that line is marching North.

The thing that stands out to me is how sunny things are.

Man it won't take long under sunny conditions with the current solar insolation levels equal to July 30th for surface albedo to plummet.

Arctic sea ice / Re: The 2020 melting season
« on: May 11, 2020, 12:06:05 PM »
... and after gfs's improvements last year they are no longer an outlier ( or out'n'out liar :) ) with regard to forecast heat in the Arctic basin .

.. and last year Neven was saying anticyclonic weather in May was no bad thing when it came to ice survival . Good to have another chance to observe .. b.c.

Arctic sea ice / Re: The 2020 melting season
« on: May 11, 2020, 11:53:30 AM »
The 850 hPa temperature is somewhere away from the ice. I'm not sure of the altitude, maybe someone with more knowledge than me can provide that.

But it is the temperature adjacent to the ice that is going to impact the ice, not the temperature 1,000 feet above sea level. For the benefit of the lurkers who are reading the thread, I think it's useful to kick the tires and questions some assumptions about the magnitude of the current events.

The heat coming into the Chukchi and ESS and the high winds pushing ice through Fram is quite significant and easily understandable and acceptable. No problem.

Maintaining heat over ice for a very long distance over ice and delivering it to the surface of much of the CAB where it can impact the ice in May is a completely differently animal. Skepticism of this is healthy from a scientific perspective.

Surface air temperatures over the ice are held close to a 0C maximum due to the latent heat of fusion of ice. This is quite apparent each year on the DMI 80N temperatures. For that reason, using something like the 850hPa temperature (or the less common, 925hPa value) is useful for assessing the relative heat mass over the ice. It's far from perfect, and temperature inversions, fog and such will add more complications, but much of the time in summer, 850hPa temperatures are more useful than surface temperatures.

Antarctica / Re: PIG has calved
« on: May 09, 2020, 09:16:46 PM »
In general, when looking at satellite images we see structures revealed by lighting: surface rises, depressions and fractures, or structures highlighted by colour or surface granularity.
What we are interested in here is a long depression and we detect it by more illuminated areas and less illuminated areas because of the slopes facing or turning our backs to the sun. It is clear that, depending on the direction of the sun, these areas can be highlighted or hidden.
Moreover, these slopes are gentle and very extensive, the "heights" correspond to a few meters and, at most, to a few tens of meters, the "lengths" (in the direction of the slopes) can range from a few hundred meters to a few kilometers. It is therefore obvious that we will have better visibility if the sun is low.
In general, in the PIIS, the surface depressions correspond to deep channels in the ice shelf (i.e. deep incisions and thus the depressions correspond to minimum thicknesses of the PIIS) and this is the case for the arc structure.
In our case we have an overflight in 2009 of the downstream part (northern direction) of the arch structure (see first image): eastern slope: height 31m, length 1 km, western slope height 24m, length 1.7km; bottom width 400m; channel depth > 150m (the image containing the data is cut).
Note: this channel is in the SIS and its thickness is greater than that of the MIS in front.
These canals are excavated by the outgoing currents that rise to the surface and are occasionally driven by the force of Coriolis, i.e. if there is a choice between two paths, the one further south will be chosen. Clearly nothing can be said about the situation in which the southward diversion was created, but once the process is set in motion, with the outgoing current digging the channel, there is no turning back until the downstream movements of the ice shelf make it disappear.

Attached images:
"overflight of 2009 of the arc structure", this is the 2009 overflight data of the arc structure used to calculate the metric data of the arc structure at the overflight point.

"SSM 1973-2001": history of the arc structure (as well as SSM (PIG) and ESM (SWT) between 1973 and 2001.

"PIG 2001-2019" is an animation based on MODIS images from 2001 to 2019, one image per year. These images are generally from the beginning of February (min 17th day of the year, max 50th day of the year) and between 13h50 and 16h40 (in both cases extreme values are rare).
The first image, as well as that of 2015 (a milestone year) and the last one, are displayed longer.
Given the time of the image capture: sun in the east, the part of the arc downstream with a northern direction is highlighted and the part downstream with a south-eastern direction is clearly less visible. Note: but this does not mean that it is less present, as can be seen in the following image (MODIS 02-2004)
> the structure is always visible
> the structure is clearly moving northwest, which makes sense, it's moving with the SIS.
> In 2015 the fracturing of the zone between the arc structure and the SSM begins, giving origin to the "SW Destruction Zone" (the SW-ZD).

"MODIS 02-2004", this is a MODIS image of 04/2004. In this case the sun is south and consequently :
> the part of the arc downstream with a north direction is clearly less visible
> the downstream part, with a south-eastern direction is highlighted
(to be compared with the image of the animation)

Arctic sea ice / Re: The 2020 melting season
« on: May 09, 2020, 04:28:54 PM »
Fram export May 04 - May 09. There is this relatively big block interesting to follow. Images: Worldview.

Arctic sea ice / Re: The 2020 melting season
« on: May 08, 2020, 08:24:06 PM »
Will you tolerate this thread saying "there are no melt ponds in April" and also saying "no data from CryoSat-2 for 2nd half of April because meltponds confuse sensors"?

There are two separate issues here as the CryoSat-2/SMOS thickness/volume is based on two different sensor types.

CryoSat-2 (radar altimetry): It is common practice to not compute thickness in the Arctic beyond April, since the snow will get wet in May which causes extinction of the radar waves. Open melt ponds that form later are a different issue.

SMOS (L-Band radiometry): Here, the method of thin-ice thickness estimation is based (in essence) on the temperatur difference between the sea water and the ice surface. And this difference can get too small at already in the end of April for reliable ice thickness estimates.

Thus, CryoSat-2 thicknesses stop at April 30 and SMOS (respectively CryoSat-2/SMOS) thicknesses stop at April 15.

Cheers, Stefan

Arctic sea ice / Re: The 2020 melting season
« on: May 08, 2020, 01:48:33 PM »
Five Day Forecast
Wind + Temp @ Surface

My apologies to the people with low bandwidth, but this weather event is too big to ignore. There's a lot of ice that's gonna go down the drain in the coming week...

Consequences / Re: COVID-19
« on: May 08, 2020, 07:59:43 AM »
co morbidity might not be such an underlying cause in critical cases of Covid 19:

"ICU supports failing organs while a patient’s underlying illness is treated, and is usually only helpful when the patient has a potentially reversible condition.
The Intensive Care National Audit and Research Centre’s (ICNARC) report of 17 April 2020 ( on COVID-19 critical care patients and their outcomes presents a useful profile of the 5,578 patients recorded. Figure 3 summarises the age and sex profile of these patients.
Most patients (72%) are male and, on average, 60 years old; 38% are obese (BMI > 30), compared to 30% in the
general population. Just 7% have very severe comorbidities and 7% needed some assistance with daily activities prior to contracting COVID-19. (ICNARC also provides corresponding numbers for normal viral pneumonia cases during the past two years, where we see 24% of patients with very severe comorbidities, and 26% needing assistance with daily activities). It seems clear from this high ratio that the majority of deaths can be regarded as being due to COVID-19, not to other conditions.
For reference, of the actual deaths detailed in the report, only 9% were recorded as occurring in the presence of severe comorbidities. In the next section, we consider whether that statistic is representative."
"ICU patients are obviously not representative of the general population – it would be worrying if they were – but, other than the severity of the disease, are they broadly representative of all those known to have COVID-19? In other words, is the triage process applied to COVID-19 sufferers likely to have removed, for instance, those deemed incurable or too frail, given that the numbers of potential ICU patients may exceed the number of spaces?
We can consider the impact of triage by examining the COVID-19 Decision Support Tool, believed to be in use by the NHS at the time of writing. This sets out a points-based system to help clinicians prioritise patients who are most likely to benefit from intensive care. Core to the assessment is a Clinical Frailty Score, ranging from ‘1 – Very Fit’, through ‘4 – Vulnerable’ up to ‘9 – Terminally Ill’. Most people without life limiting conditions would score 1-3. Points are added to this score based on age/sex and certain comorbidities as indicated in the tables below (the full co-morbidity list is not shown for simplicity).
Individuals whose score exceeds 8 would not typically be recommended for ICU-based care, though of course clinical discretion overrides. While it is clear that there will be some selection effect, the majority of patients below age 75 and a significant proportion of older people will be recommended for ICU-based care where necessary. We can cautiously conclude that the current ICU population is not highly selective and therefore the disease is making significant numbers of individuals who were otherwise fairly healthy (and certainly not ‘at death’s door’) seriously unwell.
This conclusion is consistent with our discussions with two critical care consultants, who have confirmed that COVID-19 ICU patients are broadly representative of general hospital patients (albeit with the most and least healthy tails of the distribution removed) and that “COVID-19 patients admitted to our ICU are generally healthier than our normal patient population, but despite this, have a high mortality. People are dying in middle age, with many years ahead of them.”
While it is very likely that other conditions or unhealthy lifestyles weaken the immune system and increase the chance of death from COVID-19, that is quite different from attributing the deaths to those other conditions."

Antarctica / Re: PIG has calved
« on: May 08, 2020, 06:31:50 AM »
Nice find paolo.  I took a shot at lining it up and it seemed to work out OK.  I measured the distance and angle between Evans Knoll and Wold Nunatak.  I used the 20200429 hi-res image and scaled the horizontal image size from 15,104 pixels to 2,532 and then rotated it by 61 degrees.  Then it was pretty easy to line up the other landmarks in the North.

The South looks OK, but there are not a lot of landmarks to go by, so the projection may still be a little off.  The Western corner of the SWT looks to be about right, but the margin between the SWT and the SIS is nowhere near where it was and other features of the SIS bear no resemblance.

On the whole, I would say I'm surprised it's as similar as it is and would have dated it to about the year 2000 if you had held a gun to my head.  Of course, the changes between 1973 and 2000 might seem insignificant to us today.

Antarctica / Re: PIG has calved
« on: May 07, 2020, 07:12:18 PM »
No problem. ;)

Passing on to something else: I just found a prehistoric image of the PIG: 24/01/1973  :)
At first glance it is almost unrecognizable  ::)

double-click to zoom

Arctic sea ice / Re: Nullschool Animations
« on: May 07, 2020, 01:15:49 AM »
Five Day Forecast
Wind @ Surface

Arctic sea ice / Re: The 2020 melting season
« on: May 05, 2020, 03:19:14 PM »
does anyone think the increasing open water lead in the bering strait is the incursion of a warm current? It looks that way, especially given the shape and speed, but it could just have been a weak area given it's almost dead centre.
That open water was created by wind and movement of the ice.
If the forecast holds, the Chukchi and Bering Seas will start to see positive temperatures at the end of the week.

Arctic sea ice / Re: The 2020 melting season
« on: May 04, 2020, 08:07:13 AM »
2-3 weeks is what i expect, Friv. Not 1 month. Cleaner air, you know. Instruments confirm, overall Arctic.

I'm just going by the historic modis 3-6-7 images.

Not one year sees surface darkening over the Arctic basin until the first week of June at the earliest.

And most of the major melt season's don't see that until the 10th-20th.

The models are showing some favorable patterns going into mid May but we have seen that many times and the issue is while the mid levels 500-900MB scream warm sunshine the bad angled sun even with it shining all day takes so much time to start denting and lowering that silly high .75-.85 albedo.

We really need to see snow cover start to vanish earlier than it ever has on the modern records.

And we have seen the last decade see a wall being hit in spring snow melt which delays the advance of warm surface air and warm melted river water flooding parts of the basin.

The forecast is looking like 3-4 days or more soon of major sunshine with 3-6C 850mb temps taking over all of Northwest NA and a Southerly to SSW wind blowing over the Yukon and over Alaska downsloping into the Arctic.

And this is with major incoming insolation.

Insolation by the 10th will be blowing well over 400w/m2 really about 425w/m2 between 60-70N and yet it sure takes a while to melt that snow and warm up the ground and local lakes and rivers.

Arctic sea ice / Re: The 2020 melting season
« on: May 03, 2020, 03:14:55 PM »
... Not sure what kind of weather pattern can cause this and what the probability is for it to remain sustained for a long period. ...
Why, we can see it alright. Quite a pattern indeed.

Day 68 is early March, and we had "positively persistent, persistently positive" AO at the time, as conviniently reported exactly in early March on this page.

So i took a quick look and it seems we had up to some 25 km/h winds exactly "between Pole and Greenland" at day ~68, surface level:

Importantly, this was very wide wind field, as you can see. Looks like ~25% of CAB ice was pushed sough and then south-east by those winds, which push mounts to huge pressure, i'd imagine, given how large area this wind was working against. Which usually doesn't do much in winter because ice holds structurally. But i think this time, it snapped under the pressure near that day 68. It'd probably still remain mostly stuck, but ~4 days later, this started (and lasted for a few days):

Given your numbers, which mean some ~0,5 km/h drift speed average for those 37 days, and given this wind speed - that drift does not surprise me the least.

I also checked same (or very close if no data for exactly March 8th is available) all the way back to 2014, and not a single year had anything similar even to 1st picture, normally it's smaller much more wavy winds much within CAB itself; and especially nothing even remotely close to the 2nd picture.

P.S. It was also then and there we had that massive ozone hole present. I read most stratospheric ozone was gone. The gas absorbs / traps IR really well, so when there is little of it and no sunlight to speak of, big temperature gradients form up. Ergo, stronger winds. Which we exactly see per above.

Consequences / Re: COVID-19
« on: May 02, 2020, 02:01:25 PM »
This is an amazingly low mortality: 0,16-0,33%. I don't know how they did it.

I think the best place to look for an answer is the age structure of the people infected.

Iceland provides this: [First chart below]

Graphing Iceland's CFR by age range [Second chart below] shows a similar pattern to other jurisdictions [Third chart below].

The third chart is from Richterman and Meyerowitz second literature review presentation, p. 22.

Iceland's population by age group is found here:

If we rearrange Iceland's cases to this age distribution and multiply it through the whole population we get a CFR of about 0.9% [Fourth table below].

Obviously reality won't turn out exactly this way, and I think Iceland is to be commended for their testing, tracing and isolation strategy, but I think the main reason for their low CFR is they kept it from spreading widely within their elderly population, which has had a higher than expected CFR in the small sample of people who have been infected so far.

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