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.
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
(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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Be interesting to see the results for this winter.
Regional, one winter comparison… So what?
“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
Why did they only report on the small area shown.
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.
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.
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?
” 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…
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.
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.
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.
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?
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.
Let’s wait for a new paper analyzing 2012 and 2013. I only ask because…..
http://climate.gi.alaska.edu/ClimTrends/Change/TempChange.html
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.
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.
Forgot the link for the article.
http://www.livescience.com/25907-alaska-climate-pdo.html
I wonder what the Arctic lakes were like during the 1920s to 1940s Arctic Warm Period?
Was this natural or man made? You decide.
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.
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
I dunno. The abstract says
But what’s this I see?
Why near Barrow?
So without global warming, ice out in the Twin Cities, Minnesota would have been in mid May last year?