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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This all seems to be based on computer modelling rather than observation. Computer modelling in the hands of a CAGW afficionado has the scientific veracity of a circus monkey. There is so great a dearth of confirmation of the CAGW scare that they are looking under all the stones and at the bottom of the sea (lake).
Steven Mosher says: February 4, 2014 at 9:37 am
“The warming we’ve seen there over the past few decades has consequences:
ground ice at the bottoms of lakes declining”
What is ground ice at the bottoms of lakes?
Do you mean permafrost under the lake?
Usually there is no permafrost under a lake or ocean. The exception being the ocean near Resolute where there is permafrost.
An area where the lake drains, for instance a river delta, often have unfrozen areas called Taliks.
http://www.physicalgeography.net/fundamentals/10ag.html
Permafrost is not new. When they built the Alcan (Alaska) they had many problems with it.
BC says: @ur momisugly February 4, 2014 at 1:17 pm
Anyone else paying attention to great lakes ice?
>>>>>>>>>>>>>>>>>
Yes
Great Lakes ice cover: Setting records during the Winter of 2013-2014 ~ Michigan State University Extension.
My view of CAGW / AGW is very simple. MOST of the recent warming has been natural.
Even if MOST of the recent warming was caused by man it is generally a good thing. Paleo says so and observations of the biosphere says so. The rest is made up of climate stimulations, circle jerks, temperature pasteurizations, UHI, outright lies, banning editors, re-defining what the peer review process is, hidden heat, hot spot is actually therenotthere, lavish funding, tropical jaunts, hypocrisy, contradictory crap, unfalsifiable hypothesis, cold is warm, warm is global warming, up is down, et. al. I raise my hat off to the Warmist chaps.
Someone once commented that propaganda is very expensive and the truth is cheap. After HUNDREDS OF BILLIONS OF US DOLLARS the climate propagandists are slowly but surely losing the battle for the truth. What a waste of money in the face of massive global hunger, cold weather deaths etc. I hope Warmists are proud of themselves. This is one of the reasons why I keep coming to WUWT.
Where is Mosher the Arctic expert? I am not an Arctic expert, like most people here, therefore I am surprised that Mosher, the Arctic expert, is not here.
Are sea creatures continuing their way north to seek cooler climes? If yes then they will soon head south. The oceans are like that (1920 – 1940).
I assume these are large freshwater puddles ? There has been an increase in rainfall over the period that may have had an effect.
There is no scale bar so I’m assuming the radar image is about 160 km by 160 km. The lakes that are warming are totally enclosed within this area with frozen lakes to the north, south, east and west. This is a local effect.
Also note that the article starts with “Northern Alaska’s lakes” and in the very next paragraph switches to “ice cover on lakes in the Arctic”.
This is the same “measure local – claim global” science that the moss-guy was doing in Baffin Island.
Dr Burns says:
February 4, 2014 at 4:01 pm
If the scientists didn’t measure the water level of each lake they could very well be measuring an increase in lake levels (lower lake levels more likely to lead to bottom freezing).
Interesting link to Barrow Alaska permafrost observatory. Permafrost less than 45 cm deep on average. Was much deeper in 1970s than 1950s, significant warming in 1998-1999.
http://permafrost.gi.alaska.edu/project/permafrost-observatory-barrow
97% of the people, animals and plants surveyed in the Arctic would prefer it to be warmer.
And up to 100% of the plants surveyed wanted it to be warmer. 1 plant’s response may not have been clear, so the survey might not be 100% but close enough.
100% of these global warming studies have 97% fake data in them.
Its an industry that is based on production. Production of fake data that is.
Gail Combs says:
February 4, 2014 at 3:01 pm
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Gail, the link predicts no significant ice by 2040.
http://phys.org/news/2014-01-great-lakes-ice-decades-bitter.html
Great link from GB Dorset
http://www.dot.gov.nt.ca/_live/pages/wpPages/Open_Close_Dates_Ice_Bridges.aspx
This chart represents the first and last day for a given year the various ice bridges can safely be crossed without crashing through the ice and drowning. The dates show little change over the years. Incidentally Fort Providence is the first community on the Mackenzie River downstream from Great Slave Lake and Tsiigehtchic is the last crossing of the Mackenzie before the last leg of your journey into Inuvik.
Do these people really expect things to be static and exactly the same all the time??
I have watched the daily changes in Arctic temps since early last year. As the seaons changed and fall set in, there was a rapid chill that descended on the northwest US and western Canada, Alaska to California. Yet the Barrow area and for a little ways east and south into northern Canada remained noticeably warmer. There was a warm wave that sat in that region for months. It was the last section of northern Canada to chill, as winter set in. I use this site for a quick glance at Arctic and northern temps…http://www.weather-forecast.com/maps/Arctic?symbols=none&type=lapse
It is amazing to see how quickly temps can shift over large areas. Today for example shows that the Scandanavian countries and south into Europe temps warmed up considerably from just 2 days ago. Alaska and eastern Siberia have also warmed in the last 2 days, as has the northern Canadian coastline right where this article is basing it,s research on.
Jimbo says:
February 4, 2014 at 11:49 am
Oh boy, imagine if this happened today? We must accept the reality of climate change in Antarctica.
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Wow!. We might not have to wait too many years to see the start of that process. I had no idea that the potential consequences could be so dire, though. This is what bothers me the most with the CAGW argument taking up so much resources and time, when in all probability there is a real climate change coming that mankind needs to pay attention to, and the time to start planning for the potential consequences is now.
And in news just in.
Extent was also up by 50%. Is this how Arctic amplification works?
Steven Koptis says…
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My point Steven is that if you look at ACTUAL breakup dates, the study’s conclusion that there are 24 fewer days in the freeze season is pure nonsense with no grounding in the real world of observation. Last year’s breakup of a week later than average at the very least shows a natural variation that dwarfs any trend.