New paper and of course it’s worse than we thought.
New estimates of snow depth, from a combination of lidar and radar, improve sea-ice thickness estimates, according to a new study in AGU’s Geophysical Research Letters. Arctic sea ice has lost 16% of its thickness in the last three years, the study finds.
Credit: NASA/Kathryn Hansen
According to the press release:
– End-of-season Arctic multiyear sea ice is about 1.5 feet thinner in 2021 than in 2019
– Arctic Ocean sea ice lost one-third of its volume in the past 18 years
– New pan-Arctic snow depth suggests previous estimates of sea ice thickness may have been overestimated
https://news.agu.org/press-release/new-observations-from-icesat-2-show-remarkable-arctic-sea-ice-thinning-in-just-three-years
and
WASHINGTON—Over the past two decades, the Arctic has lost about one-third of its winter sea ice volume, largely due to a decline in sea ice that persists over several years, called multiyear ice, according to a new study. The study also found sea ice is likely thinner than previous estimates.
Seasonal sea ice, which melts completely each summer rather than accumulating over years, is replacing thicker, multiyear ice and driving sea ice thinning trends, according to the new research.
https://news.agu.org/press-release/new-observations-from-icesat-2-show-remarkable-arctic-sea-ice-thinning-in-just-three-years
And straight out of Rick’s Cabaret, I’m shocked I tell you.
“We weren’t really expecting to see this decline, for the ice to be this much thinner in just three short years,” said lead study author Sahra Kacimi, a polar scientist at the California Institute of Technology’s Jet Propulsion Laboratory.
https://news.agu.org/press-release/new-observations-from-icesat-2-show-remarkable-arctic-sea-ice-thinning-in-just-three-years
First published: 10 March 2022 | https://doi.org/10.1029/2021GL097448
Abstract
Using ICESat-2 and CryoSat-2 freeboards, we examine the variability of monthly Arctic sea ice snow depth, thickness and volume between October 2018 and April 2021. For the 3 years, satellite-derived estimates captured a decrease in mean April snow depth (∼2.50 cm) and ice thickness (∼0.28 m) equivalent to an ice volume loss of ∼12.5%. Results show greater thinning of multiyear ice with an end-of-season thickness in 2021 that is lower by ∼16.1% (0.50 m), with negligible changes over first-year ice. For the period, sea ice thickness estimates using snow depth from climatology result in thicker ice (by up to ∼0.22 m) with a smaller decrease in multiyear ice thickness (∼0.38 m). An 18-year satellite record, since the launch of ICESat, points to a loss of ∼6,000 km3 or one-third of the winter Arctic ice volume driven by decline in multiyear-ice coverage in the multi-decadal transition to a largely seasonal ice cover.
Plain Language Summary
Ice thickness and volume are critical variables for assessing the evolution and response of the polar sea ice cover to a warming climate. Retrieval of sea ice thickness from altimeter freeboards (i.e., the vertical height of the floating ice and snow above the local sea level) requires knowledge of loading due to snow. Until recently, snow depth has been prescribed with a climatology based on historical field records. Using freeboard differences from ICESat-2 and CryoSat-2, we are now able to derive snow depth estimates. In this paper we examine the differences between climatological and satellite-derived snow depth as well as the retrieved ice thicknesses from the two altimeter missions. Their changes for three winters between 2018 and 2021 are documented. Derived ice volume estimates are placed within the context of an 18-year satellite record.
1 Introduction
As of December 2021, ICESat-2 has completed its 3-year prime mission (Markus et al., 2017) and is currently in extended operation. For the ice-covered Arctic Ocean, the lidar on the ICESat-2 observatory is tasked to provide the heights of sea ice and local sea surfaces for the calculation of freeboard—the vertical height of the floating ice above the local sea level. The retrieved total freeboard (snow plus ice) facilitates the estimation of thickness of the Arctic and Southern Ocean ice covers. The non-stop operations (with only a few interruptions) have provided all season coverage of the polar oceans. Here, we examine estimates of Arctic snow depth and ice thickness between October 2018 and April 2021.
Time-varying snow depth over sea ice, for computing snow loading, has been a limiting factor in the accuracy of sea ice thickness estimates. Prior to the launch of ICESat-2, the potential of combining ICESat-2 (IS-2) and CryoSat-2 (CS-2) freeboards to provide estimates of snow depth was recognized by Kwok and Markus (2017). The measurement concept is based on differencing the freeboards from IS-2 (which measures the height of the air-snow interface above the local sea surface) and CS-2 (which measures the height of the snow-ice interface above the local sea surface). For one Arctic growth season (October 2018 to April 2019), Kwok et al. (2020) provided a first examination of the snow depth retrievals using IS-2 and CS-2 freeboards. Results showed that the snow depths compared well with airborne estimates and spatial patterns of reconstructed snowfields. As well, the variability of the freeboards, derived snow depth, and ice thickness estimates was assessed in the Antarctic (Kacimi & Kwok, 2020).
In this paper, we examine the interannual variability of the freeboard-derived snow depth, ice thickness and volume over the first three winters of IS-2 operations (between October 2018 and April 2021). The paper is organized as follows. The next section describes the data used in this analysis. Section 3 briefly describes the two different estimates of snow depths used here – one from the IS-2 and CS-2 freeboards and the other from a modified Warren climatology (Kwok & Cunningham, 2015; Warren et al., 1999) – followed by an analysis of their spatial variability and seasonal evolution. In Section 4, we describe the calculated sea ice thickness and volume from IS-2 and CS-2, and the observed interannual variability. Section 5 summarizes the record of ice volume estimates since the launch of ICESat in 2003. The last section concludes the paper.
https://doi.org/10.1029/2021GL097448
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Interesting techique. It is a pity it does not have a longer record.
Are griff and his “records” involved ?
😀
He may well be involved with saving Sequoia species….
“Giant sequoias are native to California, but due to climate change they are now classed as endangered, with just 80,000 left in North America, down by 98% from peak levels.
As California gets hotter and drier, it is predicted the sequoias will thrive more in the milder UK than the US by the end of the decade.”
https://www.mirror.co.uk/news/uk-news/grove-giant-sequoias-being-planted-26447432
I have questions about this project and few answers.
Might logging for timber have anything—anything at all—to do with the decline of sequoias in North America?
Giant Sequoias are NOT a timber species, do not make good lumber, and are not logged. They do, however, burn in catastrophic forest fires [LINK]
“… the 2020 Castle Fire killed between 31% to 42% of large sequoias within the Castle Fire footprint, or 10% to 14% of all large sequoias across the tree’s natural range in the Sierra Nevada.”
I realize your comment was pure sarcasm, even though you didn’t use the tag. Obviously you love your timber framed home, much prefer it to a mud hut, and couldn’t care less about Arctic sea ice. Me too.
Mike, not quite the accurate historical story :
“The wood from huge old-growth giant sequoia trees does not make good lumber, despite the its resistance to decay, because it is brittle and has little strength. Nevertheless, sequoias were logged in the 1870’s and their wood was used for fenceposts and shake shingles . . . Young growth sequoias, unlike old growth sequoias, have wood properties similar to young growth redwood and is suitable for lumber.”
— source: https://ucanr.edu/sites/forestry/California_forests/http___ucanrorg_sites_forestry_California_forests_Tree_Identification_/Giant_Sequoia_Sequoiadendron_giganteum/ (my underlining emphasis added)
But I do stand corrected: I should not have referred to Giant Sequoias as previously having been logged for structural timber.
BTW, I do care—and care deeply—about Arctic sea ice levels and trends. It’s just that I don’t believe the AGW/CAGW alarmists claims related to such.
Really? Your theory is that logging of Giant Sequoias in the 1870s caused Arctic sea ice to thin today? Unbelievable. Stunningly so.
And you care, deeply, about Arctic sea ice. Why? I don’t. Not one whit.
I care about 1,500 year old heritage trees burned up in predictable and preventable holocausts — caused not by gerbil worming but by absurdly ignorant and incompetent un-management perped by corrupt government agencies and their “expert” class of crony buffoons in scamademia.
Tell me how those trees survived for 1,500 years through all the climate perturbations until a year-and-a-half ago. Could it be that the current science paradigm of “virgin forests having a climax” in a steady state climate is Freudian psycho baloney?
Maybe the resident humans tending the landscape with frequent anthropogenic fire for millennia had something to do with Sequoia tree survival to incredible ages. Maybe modern humans are too self righteous to accept that ignorant savages (who didn’t even invent the wheel) were capable of far better forest management than know nothing Karens.
Mike, did I hit a nerve of yours?
Please re-read my above posts. I never mentioned any connection between the logging of Giant Sequoias and the thinning or Arctic sea ice . . . that is totally originated by you.
I just commented that the asserted reduction in Giant Sequoia (“down 98% from peak levels” in North America) as posted “fretslider” might be partially due to past logging activity by humans.
You independently brought up the subject that forest fires might also account for part of the asserted decline, which I agree with.
Also, you asked immediately above: “And you care, deeply, about Arctic sea ice. Why?” Short answer: Because a large amount of life on Earth is dependent on conditions in the Arctic and how temperatures in the Arctic drive both NH atmospheric circulation and NH ocean circulation (i.e., weather and climate). I live in Earth’s northern hemisphere.
There is no need for me to comment further on your philosophical musings and statements.
Excellent response, Gordon. Mike is obviously not a student of California logging history. Of course, it is also possible that Sequoia National Park and others no longer present that history.
I realize your comment was pure sarcasm, even though you didn’t use the tag. Obviously you love your timber framed home, much prefer it to a mud hut, and couldn’t care less about Arctic sea ice. Me too.
Sequoia trees NEED fire to survive. In the 1840s the frequency of fires in Sequoia habitat dropped dramatically due to human interference – perhaps that’s got something to do with their decline as well??
https://www.nps.gov/seki/learn/nature/giant-sequoias-and-fire.htm
They say a picture is worth a thousand words. The largest grove in Sequioa National Park is a grove of sawn stumps.
Old photo:
Thank you, Clyde.
As the saying goes, the Internet never forgets.
“… the 2020 Castle Fire killed between 31% to 42% of large sequoias within the Castle Fire footprint, or 10% to 14% of all large sequoias across the tree’s natural range in the Sierra Nevada.”
Will they grow back?
Yes. It is fire that releases their seeds AFAIK
That is because of the dumbasses not managing the fire hazard correctly. Sequoias are actually designed to survive a normal forest fire. In fact they must have fire to procreate because their cones don’t open without fire.
But mitigation efforts allow the deadfall to grow beyond what it naturally would before being consumed and the result is larger and hotter fires.
The Park Service has learned this and are now making controlled burns within the confines of their parks to prevent that kind of thing from happening.
I remember reading a National Park Service information at a sequoia grove in Yosemite. They emphasized how badly the sequoias needed forest fires to clear competing vegetation. They even speculated that maybe they grow so huge to attract lightning in order to start fires.
They also require the fires to cause their pine cones to open allowing the seeds to be planted in the soil.
If griff is the first thing you think of, then you really need to re-assess your priorities.
Actually, not having a longer record makes it more useful for the alarmits.
The study also found sea ice is likely thinner than previous estimates. Hmm, come back when you can say for certain one way or the other, instead of just hazarding guesses.
I’m guessing, David Guy-Johnson, if you were the teacher and the student wrote in a report “…sea ice is likely thinner than previous estimates.” when it said in the report that there was some thinning up to now, you would grade the paper somewhere south of “C”.
As far as area extent is concerned, it looks like the maximum is in for 2022 and it’s higher than that from 1974 by about 400,000 km2 or more.
Area and extent are different. Which one are you referring to? What is your source?
https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/JC094iC10p14499
Am I reading that correctly. The last year was 1987???
Yes, it covered the years 73-87 and was published in 1989.
Thanks. Unfortunately that is paywalled. So far the max for 2022 is about 14.88e6 km2. The 1981-2010 media is 15.52e6 km2 so 2022 is well below average. I looked at other extent reconstructions for the 1970’s and they all showed 1974 being well above 2022 for the winter max.
I wouldn’t stand there.
if this trend continues, humanity will be completely out of ice cubes by 2041
cocktails will have to use CO2 ice instead
sell your SUVs now sheeple
To paraphrase a previous alarmist prediction: “By 2041 your children won’t know what it means to have ice cubes in beverages.”
When I was working in the ice tunnel at Camp Tuto (Greenland), our work was interrupted several times by Danish airline pilots and stewardesses collecting clear ice from the walls of the tunnel for cocktail parties. They liked the ice because the entrained air bubbles would cause the ice to effervesce as it melted in their drinks.
Clyde, did you collect any of the stewardesses to assist in making your drinks with the ice they grabbed?
US snow and ice website. https://nsidc.org/
From the “Plain Language Summary” : “Ice thickness and volume are critical variables for assessing the evolution and response of the polar sea ice cover to a warming climate.”
From the PIOMAS update for February 2022: “The February time series (Fig 8) for both data sets have no apparent trend over the past 11 years.” (“Both” means CryoSat and PIOMAS.)
So if the Arctic ice volume trend has flattened out, we’re good, right?
http://psc.apl.uw.edu/research/projects/arctic-sea-ice-volume-anomaly/
http://psc.apl.uw.edu/wordpress/wp-content/uploads/schweiger/ice_volume/ts_cryosat_piomas_current.png
For this study to be legitimate, if she is serious, author Sahra Kacimi needs to distinguish the natural from the unnatural and cover sea ice thickness and extent during previous warm periods, especially 1910-1945.
IMHO this will never happen as these people are just doing their jobs, which is padding the academic consensus narrative. Climate science is funding dependent so first principles can be overlooked.
That’s funny, I don’t hear the arctic ice screaming. If it isn’t screaming there’s no catastrophe.
It’s sighing over Irritable Alarmist Syndrome.
IAS – Irritable Alarmist Syndrome. I’m going to steal that, thanks. 🙂
Is that a precursor to Irritable Bowel Syndrome ?
“May have been” and “Likely” is the new scientific standards
Have they replaced “could” and “possibly?”
I’ll stick with it likely could possibly be robust. Gotta work robust in there somewhere.
Anyone else see the shell-game that is being admitted to in the above article’s very first sentence:
So, here we have “estimates” being used to improve “estimates” . . . what could wrong with that?
IMHO, it would be much better to use scientific measurements to improve established scientific data.
Chalk up yet another brilliant statement to NASA’s science writer Kathryn Hansen.
I estimate that your estimation of these improved estimates is probably approximately correct.
Quite possibly.
If they are robust estimates.
maybe.. perhaps.. if …..
IMHO they are setting the scene to sell their new measurement technology
Technically, any time an electromagnetic signal is decoded it is an estimate. So boo on the writers for being imprecise in their language. A better way to write would be “new radar and lidar measurements were combined to reduce the variance of estimates of sea ice thickness estimates.” However, that showcases that their previous estimates were not very precise, and that they probably do not even have a good handle on how imprecise they are.
“Technically, any time an electromagnetic signal is decoded it is an estimate.”
Hmmm . . . that’s news to me. I thought one of the advantages of using binary coding for EM signaling (communication) was the certainty associated with the signal being either “on” or “off” . . . no ambiguity between the two. I realized that situation may breakdown in an EM-noisy environment, but that’s one reason that binary communications almost always have checksum encoding.
If instead you meant to refer to an electromagnetic signal output from a measurement device being an estimate due to a given number of bits being assigned to measurement resolution, then the word “estimate” is problematic. Yes, an “estimate” if one uses only, say, four bits resolution to measure what needs eight bits to be precise . . . but, no, if one uses, say, 32-bits resolution to measure what only needs eight bits to be consistent with the desired level of precision-of-measurement.
“We are guessing that…….”
Might be more precise.
Also, why is anyone taking a 3 year observation of phenomenon supposedly related to climate seriously? It should be mocked with derisive laughter. Not that anyone should be surprised. Leftists always think they’re at the pinnacle of history, “discovering” what has never happened before; despite overwhelming evidence to the contrary. The foundation of all their alarmism rests on their monumental hubris and selection bias.
Remember that funny moment when the alarmists explained away the 17-year warming pause by assuring us that it had in fact happened before (which we all knew from looking at the historical record instead of burying our heads up the climate models)? That you need at least 30 years to establish a trend? Suddenly they “discovered” natural variability (that had always been there) when it bit them hard in the tenderloin district of their backsides. Just as suddenly, they revert to their doomsaying ways with a paltry 3 years of observations and complete ignorance of historical reports of Arctic ice variability. Leftists are nothing if not unstable in their ways.
What is a ‘short year’? Three of them is how long??
If anyone doesn’t understand how thin the troposphere is in winter at mid-latitudes, they should be in the southeastern US right now. Then he will understand how a total freeze can occur in a few hours.
Living in central NC, this morning is a great example of that. With the front coming through this morning, we will go from 60F to 21F by early tomorrow morning. With all the plants coming into leaf and flower, it is going to be a catastrophe.
The IPCC tells us that Nights, Winters, and the Arctic will see the effects of warming due to the greenhouse effect. (AR4 Chapter ten page 750)
Reading between the lines, the warming in the Arctic will be in the Arctic Winter, and that’s when the ice forms. Summers won’t get any warmer. Longer maybe, but not warmer. So if there is any reduction in sea ice extent, it’s not because summers are melting more ice, if there’s any reduction in Arctic ice extent it would be because of winter warming and forming less ice.
I suppose this is a well known scenario.
Here’s a link to a 2009 WUWT article that shows that the summer temperatures don’t change much:
DMI arctic temperature data animation doesn’t
support claims of recent Arctic warming
There’s a very good animation 1958-2009 that illustrates the point.
So in winter at the pole it will be -40 instead of -45
Still forming ice
-40 Celsius or Fahrenheit?
Yes.
Only a few will get your comment.
So in winter at the pole it will be -40 instead of -45
Still forming ice
___________________________________________
Will more ice form at -45? Common sense says so. But it may be one of those things, that beyond a certain point it doesn’t make any difference.
Besides all that, exactly how does sea ice extent affect anything all that much? Doesn’t affect me, and the bears don’t seem to mind as were told that there’s less ice, but there’s lots of evidence that the bear population hasn’t decreased. If it had decreased the press would be screaming about it and they are not. So if sea ice extent really is decreasing all it seems to be is evidence of warmer Arctic winters and, “So What?”
Summer Arctic sea ice remains at several Wadhams, unlike it’s predicted disappearance by Wadham. So shift to an unverifiable estimate of volume rather than a verifiable estimate of surface extent. Another neat trick like Mike’s Nature trick.
“. . . unlike it’s predicted disappearance by Wadham.”
Ummm . . . didn’t Al Gore co-opt that prediction on his way to co-winning the 2007 Nobel Peace prize?
The Norwegian Nobel Committee, responsible for selecting the Nobel Peace Prize laureates, must today be so very proud of that particular selection back then . . . NOT!
“several Wadhams”
What is that, please?
Professor Peter Wadhams of Cambrige University made numerous predictions of Arctic ice extent falling below 1m square kilometres. Thus was born a ‘Wadhams’ or 1m sq kms of ice
I stumbled on this by chance:
http://www.cpom.ucl.ac.uk/csopr/seaice.php – Centre for Polar Observation and Modelling Portal (University College London)
It’s CryoSat…
What irks me is the constant moving of the goalposts by alarmism inc
Weather isn’t climate – unless it’s a disaster of some sort. Then climate change, well, changes everything; and on a daily basis, weather depending…
Global warming causes colder winters
One paper syndrome (h/t D Nuccitelli)
Etc
So, let’s take single paper syndrome. This is a single study, therefore….
How to recognise this tactic
This tactic shows up when a person who has a vested interest in a particular point of view pounces on some new finding which seems to either support or threaten that point of view.
“Why do people use this tactic?
People use this tactic to try to convince you that the evidence supports their position.”
https://scienceornot.net/2012/10/23/single-study-syndrome-clutching-at-convenient-confirmation/…
It works both ways.
The Gore Effect at play here. Their study period is 2019, 2020, 2021 (really?!) but 2022 is proving to be a big increase in multiyear ice. Compare north of 75 degrees in Canada where most of the multi year ice traditionally forms. Several meters increase in thickness this winter compared to last year.
“Our new wide area LIDAR method gives different answers than the old borehole-and-measuring-stick method. And over 3 years of flying around huge areas of the planet, we got 5% less ice thickness each year. “ And the odds of throwing “heads” 3 times in a row is…..
Someone obviously had concerns about the sampling protocol used for years, particularly when extrapolated to the entire Arctic. What they have done is confirm that the former sampling protocol was flawed. They can only then speak to the changes that occurred in the last 3 years. The time period is too short to draw any conclusions about the Arctic climate.
The way this becomes science is they then go out and do a bunch of boreholes over multiple years to check actual ice thickness vs the “estimate” of this new method.
At that point it becomes data
Today it’s just intellectual wanking.
I just love all the clowns- including Algore & Seth Borenstein- who
predicted the Arctic would be ice free:
https://www.climatedepot.com/2021/05/10/egg-on-their-faces-years-of-failed-arctic-sea-ice-predictions-by-scientists-al-gore-others/
https://realclimatescience.com/ice-free-arctic-forecasts-3/
BBBBBBBBwwwwwwwwaaaaaaaahhhhhhhhh!!!!!!!
The arctic is blowing a raspberry.
Ja. Ja. I told you what is happening or happened in the Arctic. Remember my name…
https://breadonthewater.co.za/2022/03/08/who-or-what-turned-up-the-heat/
“Arctic sea ice has lost 16% of its thickness in the last three years, the study finds.”
So the ice loses thickness while it gains ~3.6% more extent since 2018?
Question: if a 16% decline in three years is a product of climate change, should we not expect a corresponding 16% increase in sea water and air temperatures?
Warming in the past 100 years is not even remotely ose to 16%. Ergo, the study sucks, and or, other factors must be in play.
Oh No! We’re All Gonna Die!
Let me try to get my head around the math. There has been a 1/3 loss of sea ice. And a pretty negligible rise in sea level as far as I know.
So when the other 2/3rds are gone we can expect what, an inch of sea level rise?
Please try to remember Archimedes’ principle
CAGW is like Marxism: Every event proves it.
Our previous estimates of ice thickness turn out to have overestimated it, Our new estimates show it is thinner than our previous overestimates, which of course proves AGW is real.
Say what?