Claim: Dramatic thinning of Arctic lake ice cuts winter ice season by 24 days

Arctic lakes have been freezing up later in the year and thawing earlier, creating a winter ice season about 24 days shorter than it was in 1950, a University of Waterloo study has found. But, I don’t think they are paying attention to cycles like the PDO. And, in 1992, Mt. Pinatubo’s eruption had global effects on lowering temperature, making their start point a cherry pick.

Dramatic thinning of Arctic lake ice cuts winter ice season by 24 days

Arctic lakes have been freezing up later in the year and thawing earlier, creating a winter ice season about 24 days shorter than it was in 1950, a University of Waterloo study has found.

Cracked ice

Researcher Claude Duguay stands on the cracked ice of an Arctic lake

(Credit: Claude Duguay/University of Waterloo) Download image

The research, sponsored by the European Space Agency (ESA) and published in The Cryosphere, also reveals that climate change has dramatically affected the thickness of lake ice at the coldest point in the season: In 2011, Arctic lake ice was up to 38 centimetres thinner than it was in 1950.

“We’ve found that the thickness of the ice has decreased tremendously in response to climate warming in the region,” said lead author Cristina Surdu, a PhD student of Professor Claude Duguay in Waterloo’s Department of Geography and Environmental Management. “When we saw the actual numbers we were shocked at how dramatic the change has been. It’s basically more than a foot of ice by the end of winter.”

The study of more than 400 lakes of the North Slope of Alaska, is the first time researchers have been able to document the magnitude of lake-ice changes in the region over such a long period of time.

“Prior to starting our analysis, we were expecting to find a decline in ice thickness and grounded ice based on our examination of temperature and precipitation records of the past five decades from the Barrow meteorological station,” said Surdu “At the end of the analysis, when looking at trend analysis results, we were stunned to observe such a dramatic ice decline during a period of only 20 years.”

The research team used satellite radar imagery from ESA to determine that 62 per cent of the lakes in the region froze to the bottom in 1992. By 2011, only 26 per cent of lakes froze down to the bed, or bottom of the lake. Overall, there was a 22 per cent reduction in what the researchers call “grounded ice” from 1992 to 2011.

Researchers were able to tell the difference between a fully frozen lake and one that had not completely frozen to the bottom, because satellite radar signals behave very differently, depending on presence or absence of water underneath the ice.

Graph showing the reduction in grounded ice between 1992 and 2011

Graph showing the reduction in grounded ice between 1992 and 2011

(Credit: Planetary Visions / University of Waterloo, Canada / ESA) Download image.

Radar signals are absorbed into the sediment under the lake when it is frozen to the bottom. However, when there is water under the ice with bubbles, the beam bounces back strongly towards the radar system. Therefore, lakes that are completely frozen show up on satellite images as very dark while those that are not frozen to the lake bed are bright.

Researchers used the Canadian Lake Ice Model (CLIMo) to determine ice cover and lake ice thickness for those years before 1991, when satellite images are not available.

The model simulations show that lakes in the region froze almost six days later and broke up about 18 days earlier in the winter of 2011 compared to the winter of 1950. Shorter ice-cover seasons may lead to shifts in lake algal productivity as well as thawing of permafrost under lake beds.

“The changes in ice and the shortened winter affect Northern communities that depend on ice roads to transport goods,” said Surdu. “The dramatic changes in lake ice may also contribute to further warming of the entire region because open water on lakes contribute to warmer air temperatures, albeit to a lesser extent than open sea water.”

The ice regimes of shallow lakes were documented using radar images from ESA’s ERS-1 and -2 satellites. More information on the ESA is available online.

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Oldseadog

Be interesting to see the results for this winter.

TomRude

Regional, one winter comparison… So what?

Admad

“Researchers used the Canadian Lake Ice Model (CLIMo) to determine ice cover and lake ice thickness for those years before 1991, when satellite images are not available.”
Oh, a model to create the earlier data. So that’s all right then.

I’m curious why the observed breakup dates for the Yukon River disagree with their modeled data
http://www.yukonriverbreakup.com/statistics.html

Tim Clark

Why did they only report on the small area shown.

Rick

In the area we live, we’ve found that ice thickness can be affected by unrelated variables such as the date snow arrives. Early cold with no snow can produce an astonishing layer of ice, especially when combined with strong chilling winds. Alternatively when snow arrives early it acts as an insulator and less ice is formed.

Myron Mesecke

Changes in PDO and soot increase from Chinese power plants.If like most countries as they develop China will implement pollution controls in the next 20-30 years so there will be less soot when we reach peak cooling from PDO and possibly the Sun. I’ll bet ice will be much like in 1950 at that time.

Steven Kopits

Dave –
The historical average for the Yukon River breakup is May 8th, with a standard deviation of 3.5 days.
The breakup date for 2013 was May 5th, that is, one standard deviation below the 117 year mean. Only once since 1990 has the breakup occurred at the historical mean, and that was in 2003. All others were earlier than the historical mean.
May 1 is two standard deviations from the mean, representing a 97.7% probability that that date is not just a chance aberration from the mean. The Yukon has broken up only four times on May 1, the earliest breakup date on record. These occurred in 1992-1995.
Until about 1975, the historical breakup mean was around May 9th. Since then it has fallen to around May 4th. Again, it was May 5th last year.
We can debate the causes of the change, but there is little doubt that the breakup date has occurred earlier since 1975, albeit with no net deterioration since around 1990.

And, in the meantime …. “IT IS EVEN WORSE THAN YOU THINK!”
See, Hudson Bay is a large, near-circular body of water that freezes over every year whose center lies right at 60.0 north latitude. (Churchill is on its west coast.) Right at 1.3 Mkm^2 in area.
Husdon’s Bay melt-off is coming now about a week early, and its freeze out has been delayed about 2 weeks from what the earliest reports (back in the little ice age years of 1650 …he added quietly.) At 60 degrees north latitude, Hudson Bay is “somewhat larger” than all these Arctic rivers combined, squared in area, and them squared again. (He added sarcastically.)
So, you’d think that anything as large as Hudson Bay melting out completely the entire year would be noticed by the CAGW crowd and would be a matter of great concern and loud gnashing of teeth, right? (He asked again, very sarcastically.)
But, regardless, we would be hearing about it, right? if Hudson Bay melted out completely not just one year, but if it never even re-froze across three winters we would certainly hear about it, right?
Now. Flip the counter.
What if an area the size of Hudson Bay completely froze over and did not melt at all for an entire year at latitude 60? Would that matter to the earth’s climate? What if that trend of increasing sea ice at latitude 60 was steady, and the area of “excessive sea ice” continued to increase since May 2011? Not just “one week” as is so strongly reported in this paper, but a multi-year-long trend of excess ice not at the Arctic’s 82 and 83 north latitude (where there is little sun) but excessive sea ice at Hudson Bay’s latitude 60, latitude 59, latitude 58?
Well. The Antarctic sea ice anomaly in October and November WAS +1.5 million square kilometers — Larger than the entire Hudson Bay . The Antarctic sea anomaly is now right at 0.9 Mkm^2 and the trend continues positive. UP.
So, when Antarctic Sea Ice threatens shipping around Cape Horn, will the CAGW religion allow its priests to write a paper?

Froggy

” Researchers used the Canadian Lake Ice Model (CLIMo) to determine ice cover and lake ice thickness for those years before 1991, when satellite images are not available.”
The model simulations show that lakes in the region froze almost six days later and broke up about 18 days earlier in the winter of 2011 compared to the winter of 1950.”
Reasonable folks might infer that the CLIMo inferred timing is off by 6 and 18 days!
“Shorter ice-cover seasons may lead to shifts in lake algal productivity as well as thawing of permafrost under lake beds.”
Any attempt to uncover concrete evidence of “shifts in lake algal productivity” and/or “thawing of permafrost”?
This study is another gross example of flawed methodology and speculation masquerading as Science! The European Space Agency is joining NASA on the AGW bandwagon; how sad…

juan slayton

The model simulations show that lakes in the region froze almost six days later and broke up about 18 days earlier in the winter of 2011 compared to the winter of 1950.
Do the simulations agree with the observations? There were observations, were there not?

Steven, the earliest recorded breakup day was Apr 28, 1940, at 1:54 PM. There’ve also been eight other breakup days in late April.

Billy Liar

Doesn’t comparing real data for 2011 with imagined data from 1950 strike anyone as being just a tad unscientific.
Why didn’t they compare 2011 with, say, 1867 (when Alaska was purchased from Russia); after all a model is a model.

Rud Istvan

This is just Barrow Alaska, ground zero for ARctic Warmists. Lots of recent changes probably caused by ocean currents/PDO, etc. The only real data is the sat stuff. And the only discernable decline in grounded ice is the years 2008-2011. Which is why no meaningful statistical analysis was done.Start year with higher grounded ice is Pinatubo. Rest are “flat” until 2008. Subsequent years correspond to the general shrinkage of Arctic sea ice that has now reversed. I bet that when 2014 is added, you will see reversion to the normal mean of grounded ice, thus disproving the papers thesis, which is swamped by natural variability unless models are used to project backwards to 1950. There are effectively no observational data before 1991.

hunter

Hmmmm…. Dr Pielke, Sr did a study a while back that showed freeze start dates and thaw dates had not shifted. Who to trust in this day of climate hype?

mpainter

This paper is based on invented data- the data is not real world but furnished by “models”. Claude Dugay of the University of Waterloo is another would-be scientist.

Jimbo

Analysis of available SAR data from 1991 to 2011, from a sub-region of the NSA near Barrow, shows a reduction in the fraction of lakes that freeze to the bed in late winter.

Let’s wait for a new paper analyzing 2012 and 2013. I only ask because…..

Frozen Alaska Bucking Global Warming Trend – January 02, 2013
As the rest of the world contends with unusually warm temperatures and scorching drought, Alaska has been bucking the trend since 2000 by reporting some of the coldest winters on record……
But since 2000, nearly all the National Weather Service monitoring stations sprinkled across the vast state have reported colder-than-average temperatures. The station at King Salmon on the Alaska Peninsula, for example, experienced an average 4.5 degree Fahrenheit (2.9 degrees Celsius) drop in temperature over the course of the first decade of this century.
The state hasn’t become immune to global warming. Instead, researchers blame a climatic phenomenon known as the Pacific Decadal Oscillation. When the PDO is in a positive (warm) phase, a low-pressure center called the Aleutian Low hovers over the state and relatively warm winter winds blow into Alaska from the southwest, according to the National Oceanic and Atmospheric Administration (NOAA)………..

http://climate.gi.alaska.edu/ClimTrends/Change/TempChange.html

Carbomontanus

To all and everyone
Yes, we are aware of it and have been so for long.
Who can cut out fighting a hockeystick and quit slamming around with a silly cycle that is broken / kaputt / has got flat tire …….to his / her denial defence……
will be able to discuss it.

Historical average for Yukon river breakup is May 8th eh? With a std dev. of 3..5 days. Wonder just how long the period was to obtain the average? What 30 years worth of data during the coldest part of the 20th century? I sincerely doubt that if you had data going back to the MWP that the std dev would be anywhere close to 3.5days. May 8th is likely just a cherry picked number to generate a finding they were predetermined to show. Before you can say something is unprecedented or shocking, you need to know what the natural variation is, and when it comes to climate, periods of 100yrs or less just is NOT sufficient. What was the average breakup date for the Yukon during the medieval warming period?Temperatures back then were ALL natural.

Jimbo
Jimbo

I wonder what the Arctic lakes were like during the 1920s to 1940s Arctic Warm Period?

“The Warming Arctic” – 1938
http://climate-ocean.com/arctic-book/pdf/3_2.pdf
—————
ICE, OPEN WATER, AND WINTER CLlMATE IN THE EASTERN ARCTIC OF NORTH AMERICA: PART I* – 1949
http://arctic.synergiesprairies.ca/arctic/index.php/arctic/article/view/3976/3950

Was this natural or man made? You decide.

FerdinandAkin

Claude Dugay of the University of Waterloo has collected a few data points that demonstrate the Earth is warming out of the Little Ice Age. When Dugay has a model that will show the Earth entering the Little Ice Age and then recovering from it, he may have something of interest to report.

Alec aka Daffy Duck

There start year was at a time when OA had been wicked positive, which keeps the cold in the arctic; unlike this year with AO being negative making it offer colder in northern virginia than in Fairbanks.
Their graph seems to match the ‘black line’ five year mean graph for AO jan/feb/mar
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/JFM_season_ao_index.shtml

Jimbo

Tim Clark says:
February 4, 2014 at 8:08 am
Why did they only report on the small area shown.

I dunno. The abstract says

“Analysis of available SAR data from 1991 to 2011, from a sub-region of the NSA near Barrow, shows a reduction in the fraction of lakes that freeze to the bed in late winter.”
http://www.the-cryosphere.net/8/167/2014/tc-8-167-2014.html

But what’s this I see?

Temperature Changes in Alaska
The period 1949 to 1975 was substantially colder than the period from 1977 to 2009, however since 1977 little additional warming has occurred in Alaska with the exception of Barrow and a few other locations. The stepwise shift appearing in the temperature data in 1976 corresponds to a phase shift of the Pacific Decadal Oscillation from a negative phase to a positive phase. Synoptic conditions with the positive phase tend to consist of increased southerly flow and warm air advection into Alaska during the winter, resulting in positive temperature anomalies.
http://climate.gi.alaska.edu/ClimTrends/Change/TempChange.html

Why near Barrow?

Todd

So without global warming, ice out in the Twin Cities, Minnesota would have been in mid May last year?

sagi

So if there is water under the ice that simply does not contain bubbles, or if there are bubbles within the ice itself, how does this play out?
I see no particular reason that bubbles should necessarily be present in such water in the first place or, even if they are present, why they should disappear to radar imaging when the water freezes to the bottom of the lake, presumably with these echogenic bubbles now still present within the ice.
What am I missing?

Les Johnson

Lake ice season is obviously different than sea ice extent.
Using Cryosphere data, I get a pretty flat line for max and min ice dates, with an average of 254.21 and 66.67 days respectively (about 12 Sep and 8 Mar).
I STD Dev is 9.96 for max, and 6.83 for min.
The melt season is getting slightly longer, with the max date arriving earlier by 0.0401 days per year. Ice max is also shortening, at 0.0453 days per year. This works out to the melt season arriving about 1/2 day earlier, every 1000 years.
This is confirmed by counting the total melt days per year. On average, ice decreases 187.89 days per year, and increases 177.36 days per year. The trend for the melt days is 0.0052 days per year increase. 3 years have been less 1 std Dev of 10.5 for melt season length, and 3 years have been above this. Only 1 year has been outside 2 std Dev, and that was 1997, which had nearly 220 melt days.

somehow the corrupt station data is melting ice at the bottom of lakes.
of course forget the fact that we see confirming evidence in the loss of permafrost.
Arctic amplification is real.. regardless of the cause. When the planet warmed in the 20-40s
we saw the same thing with retreat of ice at the NP. When the globe warms it does not warm uniformly. The arctic warms more. The warming we’ve seen there over the past few decades has consequences:
1. generally less ice
2. ground ice at the bottoms of lakes declining
3. permafrost declines
4. species migration northward at 3 times the normal rates.
11 meters in elevation per decade and 16km in latitude per decade.
Simple fact. plants and animals dont migrate because of “biased” surface stations. Their migration is driven by changes in the climate.
In other words, the LIA was real. It used to be colder. Now its warmer. and the arctic warms more generally speaking. during the MWP the Vikings were glad of this

R2Dtoo

In this short press release we find “dramatically affected”, “decreased tremendously”, “shocked”, “dramatic”, “stunned” and again “dramatic”. I hope the paper addresses variation in the depth of water before freeze up, the timing and depth of snow over early ice and the actual dates of the opening and closing of winter roads each year. I also want to see a graph of the annual met records and their modelled ice thickness for the entire time period. A further question relates to the use of Barrow data- is it representative? real or upjusted?

Les Johnson

corrigendum:
max date arriving earlier by 0.0401 days per year
Should be
min date arriving earlier by 0.0401 days per year
The dates of the ice max and ice min are both arriving slightly earlier. The ice max date is coming just slightly earler than ice min, enlarging the melt season by 1/2 day per 1000 years.

Les Johnson

In other words, there has been no significant change in sea ice extent melt season, over the record.
In fact, the length of the melt season has been remarkably constant.

Tim Clark

Why did they only report on the small area shown.
Jimbo says:
February 4, 2014 at 9:32 am
Why near Barrow?
Yes, Jimbo, you recognize both are rhetorical questions.
Don’t tell mosh, but the answer probably is…….
The correlation doesn’t hold for other the vast other areas along the Canadian Arctic coastline.

albertalad

Another computer model – about as accurate as the global warming models.

Jimbo

Steven Mosher says:
February 4, 2014 at 9:37 am
….of course forget the fact that we see confirming evidence in the loss of permafrost…..

You are correct.

Abstract – 1949
Oriented lakes of northern Alaska
…Many of the lakes are believed to be the result of thawing of permafrost; others may be produced by the segmentation of uplifted lagoons….
http://www.jstor.org/discover/10.2307/30063634?uid=2&uid=4&sid=21103345440241

Steven Mosher says:
February 4, 2014 at 9:37 am
…..Simple fact. plants and animals dont migrate because of “biased” surface stations. Their migration is driven by changes in the climate…….

You are correct.

Abstract
The regime shift of the 1920s and 1930s in the North Atlantic
During the 1920s and 1930s, there was a dramatic warming of the northern North Atlantic Ocean. Warmer-than-normal sea temperatures, reduced sea ice conditions and enhanced Atlantic inflow in northern regions…………
Ecosystem changes associated with the warm period included a general northward movement of fish. Boreal species of fish such as cod, haddock and herring expanded farther north while colder-water species such as capelin and polar cod retreated northward. The maximum recorded movement involved cod, which spread approximately 1200 km northward along West Greenland. Migration patterns of “warmer water” species also changed with earlier arrivals and later departures. New spawning sites were observed farther north for several species or stocks while for others the relative contribution from northern spawning sites increased. Some southern species of fish that were unknown in northern areas prior to the warming event became occasional, and in some cases, frequent visitors. Higher recruitment and growth led to increased biomass of important commercial species such as cod and herring in many regions of the northern North Atlantic……..
http://www.sciencedirect.com/science/article/pii/S0079661106000036

Mike Tremblay

There is actually a very simple way to test the validity of one of their claims. Are there any fish in those lakes? If there are no fish then the lake could have frozen to the bottom. If there are fish, the lake cannot have frozen to the bottom, at least not in the lifetime of that population of fish (when they were either introduced or initially migrated into the region – potentially thousands of years).
According to the Alaska Department of Fish and Game: North Slope Management Area – “The state’s third largest lake, Teshekpuk Lake, is found here on the coastal plan, as are hundreds of smaller lakes. Most of these lakes are inaccessible by road and too shallow to support fish populations, but there are dozens of lakes that contain lake trout, Arctic char, Arctic grayling, and burbot.” The key phrase in this statement is “too shallow to support fish” – if it is too shallow to support fish it is most likely to have frozen to the bottom.
As far as their claim that the winter ice season is 24 days shorter than it was in 1950, this is simply a case of laziness. To paraphrase a comment an older limnologist friend of mine expressed – ‘Students today don’t want to do the footwork of going out and collecting samples and data and are far too willing to stay warm and comfortable at home working with computers and models.’

Ed Caryl

1998 and 2010 were El Niño years. Warm. Move along, nothing to see here…

Looks like they left out last winter (2012-2013) which one of the coldest in many years.

Jimbo

It’s worse than we thought! Early climate alarmism at work, they too made assumptions in a straight line.

The North American Review – 1932
The man in the street knows that weather is not what it used to be, that the seasons have changed since his boyhood, that winters used to be colder, that spring now barely bridges the gap to summer, that autumn lingers long and mild…….
……It will warm up until the temperate zones become tropical. Bostonians will stroll about the Common under the thick shade of mango trees,…..
…….according to Professor J. Edmund Woodman of New York University, one of the most eminent American geologists. Eighty-five to ninety per cent of the Arctic ice already has vanished, he estimates.
http://www.jstor.org/discover/10.2307/25114066?uid=2&uid=4&sid=21103345664011

Sound familiar? LOL.

george e. smith

So dark lakes are frozen to the bottom, and bright lakes have water under the ice.
Now where is the data on how the water depth in those lakes has changed. Did the frozen stiff lakes have the same water level they had before, or have the bright lakes got more water in them, than they had before.
Enquiring minds, want to know.

Jimbo

Oh boy, imagine if this happened today? We must accept the reality of climate change in Antarctica.

IN the last decade of the nineteenth century, between 1892 and 1897, there occurred an enormous outburst of ice from the Antarctic which filled the Southern Ocean with ice floes and icebergs to such an extent that traffic between South America, Africa, and Australia had to seek a more northerly track. This outburst had far-reaching climatic repercussions. The monsoon regimen of the Indian Ocean was profoundly disturbed……In 1899 – 1900 upwards of 6,500,000 people were on famine relief for several months. The loss of cattle was great, running into many millions…….
http://www.jstor.org/discover/10.2307/208079?uid=2&uid=4&sid=21103345664011

[Apologies if I have made any typing errors as it is from an image.]

Tom in Florida

It is 83 F this afternoon at my house in SW Florida. Just wanted y’all to know the only ice I am thinking about is how much more I need in my beverage. Why anyone would want a colder world is beyond me.

Box of Rocks

Cool – the ice is melting earlier and refreezing later.
Means that there is more time to go fishing!

GB_Dorset

Seems to be at odds with Mackenzie River area ice bridge opening and closing date data
http://www.dot.gov.nt.ca/_live/pages/wpPages/Open_Close_Dates_Ice_Bridges.aspx

Les Johnson

The graphs of the arctic melt season.
[IMG]http://i62.tinypic.com/20uae79.jpg[/IMG]

Les Johnson
Steven Kopits

Dave –
Apologies, I applied the stats to the wrong column. My entry above should read as follows:
The historical average for the Yukon River breakup is May 8th, with a standard deviation of 5.1 days.
The breakup date for 2013 was May 15th, that is, about 1 and 1/2 standard deviations above the 118 year mean. In the 24 years since 1990, only three times has the breakup occurred later than the historical mean, three times at the mean (on May 8th), and 18 times earlier than the historical mean. On the whole, the last quarter century speaks to relative warmth.
On the other hand, only ten times in the 118 year record has the ice broken after May 15th.
*******
Kids, don’t let what happened to me, happen to you. Don’t play with moving averages at home.

BC

Anyone else paying attention to great lakes ice? Haven’t seen anything like it in my lifetime.
http://iceweb1.cis.ec.gc.ca/Prod20/page2.xhtml?CanID=11080&lang=en

murrayv

Looking at the Yukon breakup at Dawson City, the earliest occur between 28 April (1940) and 3rd May (1926). In the 1930s warm perid there were 6 years in this range, averaging May 2. In the 2000s warm period there were 7 years, averaging April 30, 2 days earlier. Upstream, the population of Whitehorse went from about 1000 people in the 1940s to 25,000 in the oughts. For the period from 1971 to 2000 the average Dec temperature in whitehorse was -14.9 degrees C, with the average high -10.6 and the average low – 19.1. In 1944 these temps were – 11, -7 and -14. In 2009 they were -13, -9 and -16. Could it be that there has been no real warming in the Yukon and the growth of Whitehorse has warmed the Yukon enough to move the breakup 2 days earlier? Since global warming is manifested most strongly at high latitudes and in the winter, this would not suggest much warming since the late 1930s.

Jeff

Was this study necessary to “prove” the ice has shrunk since 1992? We have satellites for that. Common sense tells you the ice on arctic lakes would follow a similar pattern. The problem for the warmistas, as usual, is their failure to understand/recognize that this all happens in a pattern. The arctic ice will follow earth temperatures when it cools as well.

Gary Pearse

File this under the history of global warming. Check the lakes out now!!