GlobIce: mapping the movement of sea ice

GlobIce: mapping the movement of sea ice

University College London, 14 March 2012

A UCL-led project to map changes in sea ice in the Arctic has released its data after the conclusion of the 5-year project. 

Available for use in climate models by scientists and partner institutions such as the UK Met Office, the data could help improve current climate models. 

Launched in 2005 with a consortium of eight partners led by UCL, the aim of the €1 million GlobIce project was to measure sea ice motion for use in climate modelling and research.

Sea ice profoundly affects the exchanges of heat, water and momentum between the ocean and atmosphere, and plays an important role in oceanic convection and deep-water formation.  

“The data which the GlobIce system can provide is essential to understanding the dynamics of the rapidly changing sea ice cover in the Arctic,” said Dr Seymour Laxon (UCL Centre for Polar Observation and Modelling).

Using radar images of ice displacement determined at intervals of a few days, the team, which included engineers and project managers at the UCL Mullard Space Science Laboratory, used the images to generate a large number of high-resolution products useful for climate research, such as sea ice velocity maps.

Offering ten times better resolution than any other satellite images, GlobIce provides incredibly accurate information about sea ice dynamics in the Arctic. 

With missions like ESA’s CryoSat producing increasingly detailed measurements of the thickness and extent of polar ice, the high-resolution maps produced by GlobIce could also help interpret the data.

“GlobIce can also be used to interpret other critical data, such as the ice thickness measurements now being provided by CryoSat,” said Dr Laxon.

Although the GlobIce project primarily focused on developing operational products for the Arctic region, it has recently been prototyped to generate products over the Antarctic. Sample products of the Antarctic are now available for August and September 2010.

Owing to the different characteristics of south polar sea ice, which makes it difficult to monitor from many low-resolution sensors, there is very little sea ice dynamics data available. GlobIce could be used to fill this gap in the future.

 “The increasing complexity and resolution of climate models lead to a demand for comprehensive datasets against which to test them,” said Dr Jeff Ridley, climate scientist at the UK Met Office. 

“With GlobIce, we finally have a sea ice dataset which will endure and provide for model evaluation now and in years to come,” he added. 

Image: Average monthly sea ice velocity for 1st January 2009, overlaid on a cloud-free satellite image mosaic (Credit: UCL/ESA/Planetary Visions)

http://www.ucl.ac.uk/news/news-articles/March2012/14032012-GlobIce

Paul Nicklen: Narwhals contributing to mounting climate change data, collecting temperature data from Baffin Bay

Narwhals contributing to mounting climate change data

by Paul Nicklen, The Narwal's Left Tooth: Reflections on the Ice Whale of the Arctic, July 29, 2011

While the major heat wave last week may only hint at the long term climate changes taking place on Earth, the indisputable evidence from around the world – especially in the Arctic – continues to mount.  Even narwhals have been used to collect climate data.

Photo by Paul Nicklen

University of Washington biologist Kristin Laidre has found a new and unusual use for what may be the narwhal’s greatest behavioral claim to fame – their incredible ability to dive to great depths.  In 2006 and 2007, Laidre successfully attached satellite transmitters to14 narwhals in Melville Bay on the west coast of Greenland, and in addition to collecting data on the animals’ geographic positioning, the tags also recorded the temperature of the water as they dived to the bottom.  While Laidre knew that temperature data would be somewhat insightful to her narwhal research, she also guessed that oceanographers and climatologists might find the data useful as well.  It is difficult to use traditional oceanographic measuring devices to monitor water temperatures at great depths, especially in the winter when the water is frozen over for many months.  As a result, researchers have little data from the middle of Baffin Bay to feed into their climate models.  Instead, they have used temperature readings from coastal locations or estimates calculated from historic data, which clearly provide only a hint of the true picture.

“The gliders that oceanographers occasionally use to collect this data sort of look like a streamlined narwhal, with a long pointy antenna, but they’re not as smart as narwhals because sometimes they can’t find the surface and get caught under the ice,” Laidre said. When the narwhal-collected temperature data was published in a scientific journal in 2010, it generated considerable media attention, not only for what oceanographers learned about water temperatures but also for the unusual way the data were collected.  Thanks to the narwhals, water temperatures were determined to be about 1.8 F warmer than what the climate models predicted, and the surface isothermal layer – a layer of water that is at a constant temperature – was 160-260 feet thinner than previously believed.

“I’m not an oceanographer, but for me the excitement was the proof of concept -- that it worked and we collected useful data and the scientific community seemed to be interested in it,” Laidre added. “[The data] suggested that Baffin Bay has continued its warming trend, though I don’t know that it was terribly surprising to the oceanographers.”

Similar data is being collected by narwhals along the East Greenland coast this year.

http://narwhalslefttooth.blogspot.com/2011/07/narwhals-contributing-to-mounting.html

Drought spreads to Brazil, crop yields hit; Argentina and Paraguay already hit by reduced soy yields

Drought spreads to Brazil, crop yields hit

by Staff Writers, Sao Paulo (UPI), March 20, 2012

Drought has spread from Argentina and Paraguay to Brazil and is hitting soy yields at a time of concerns that regional economic growth may suffer as pressures mount on commodity prices.

Argentine yields of soy were affected by drought and labor disputes in that country are making farmers and grain traders jittery. Drought caused widespread economic dislocation in Paraguay, which was also hit by cattle disease.

Analysts said drought-related developments in Brazil had led to lower yield estimates, slicing about 2.8 million tons off an original estimate of 67.1 million tons for this year's harvest. The revised estimates are subject to further review, said the analysts.

Soy oil has gained importance in the energy market as a feedstock for the booming international biofuels sector.

Soy produced by Brazil, Argentina and Paraguay accounts for about half the world's soy exports. Although current worries have caused spikes in prices and buoyed futures trade in Chicago, Latin America and elsewhere, underlying worries over the eurozone crisis and an economic slowdown in China continue to cloud the outlook.

Some analysts predicted a 10-million-ton shortfall in Brazil's soy crop when compared with last year.

Brazilian traders watched with anxiety the growing labor disputes at Argentina ports that idled grain export terminals and threatened to put further pressure on global prices for corn, soy and what. The Latin America region is a major exporter to China, Europe, Africa and the Middle East.

Traders said lower crop yields would bring hardship to farmers and affect government tax revenue in Argentina and Paraguay.

The drought has caused political disruptions, more so in Argentina than in other Latin American countries. Relations between Argentina's government and importers soured after President Cristina Fernandez de Kirchner slapped new taxes on traders and refused to budge in the face of furious demands for change.

Fernandez also upset farmers' groups after ignoring demands for more emergency aid to drought-stricken areas of the country.

The latest potential political flash point was caused when the government refused to defer new legislation that importers denounced as punitive, restrictive and wrapped in red tape.

Further complications arose after trade partner Brazil, increasingly under pressure over drought damage to its own crops, objected to new Argentine rules coming into place. Argentina and Brazil have $30 billion-a-year trade.

Critics say the new rules that came into effect in February introduce more bureaucratic delays. Manufacturers said the rules would inhibit industrial production and growth as they would likely impede the flow of components, raw materials and other industrial inputs.

The influential Sao Paulo Federation of Industries in Brazil said the new Argentine import rules could affect 80% of Brazilian exports to the country. Drought damage to agriculture will further worsen that outlook, analysts said.

http://www.terradaily.com/reports/Drought_spreads_to_Brazil_crop_yields_hit_999.html

Gwynne Dyer: Scientists are very scared. The military are getting scared [about climate change]

Gwynne Dyer: Climate change the single most important problem the world faces

GWYNNE DYER has worked as a freelance journalist, columnist, broadcaster and lecturer on international affairs for more than 20 years, but he was originally trained as an historian. Born in Newfoundland, he received degrees from Canadian, American and British universities, finishing with a Ph.D. in Military and Middle Eastern History from the University of London. He served in three navies and held academic appointments at the Royal Military Academy Sandhurst and Oxford University before launching his twice-weekly column on international affairs, which is published by over 175 papers in some 45 countries.

        His first television series, the 7-part documentary 'War', was aired in 45 countries in the mid-80s. One episode, 'The Profession of Arms', was nominated for an Academy Award.  His more recent television work includes the 1994 series 'The Human Race', and 'Protection Force', a three-part series on peacekeepers in Bosnia, both of which won Gemini awards.  His award-winning radio documentaries include 'The Gorbachev Revolution', a seven-part series based on Dyer's experiences in Eastern Europe and the former Soviet Union in 1987-90, and 'Millenium', a six-hour series on the
emerging global culture.

       Dyer's major study "War", first published in the 1980s, was completely revised and re-published in 2004. During this decade he has also written a trio of more contemporary books dealing with the politics and strategy of the post-9/11 world: 'Ignorant Armies' (2003), 'Future: Tense' (2004), and 'The Mess They Made' (2006).  The latter was also published as 'After Iraq' in the US and the UK and as 'Nach Iraq und Afghanistan' in Germany.  

        His most recent projects are a book and a radio series called 'Climate Wars', dealing with the geopolitics of climate change. They have already been published and aired in some places, and will appear in most other major markets in the course of 2009.

http://www.gwynnedyer.net/

Republican meteorologist Paul Douglas says 'keep track of who the deniers are today': Poking a Hornet's Nest

Republican Meteorologist says 'keep track of who the deniers are today'

Poking a Hornet's Nest

By Guest Blogger Paul Douglas, Neorenaissance, March 31, 2012 | Comments (1)

My recent Op-Ed gave me a chance to summarize how I feel about the politicization of climate science in recent years - how it's become a bizarre litmus test for conservatism.

Meteorologist Paul Douglas

As I describe in the piece, my "belief" in climate science had nothing to do with Al Gore, and everything to do with what I was seeing with my own two eyes: on the weather maps, and out my window.

I'm not running a popularity contest. Q Ratings were important when I was in local broadcasting, but no more. This issue is too important, and I'm hoping I can encourage other moderate voices out there to step out from the shadows and speak up about your concerns. Contact your politicians. Assume nothing. D.C. is hopelessly deadlocked on climate science and (clean, carbon-free) energy policy.

I have no idea what it's going to take to move things along and start a rational national dialogue (without shouting at each other and the name-calling...I swear we're still in 7th grade, with slightly better wardrobes), but the status quo is not good for our country.

If this keeps up we'll be buying all our wind farms, solar panels and hybrids from China and other countries that (amazingly!) aren't still "debating the science."

Are we really going to drill and mine our way to prosperity -- indefinitely? I have nothing against drilling and tapping the resources we have, so long as it’s not the only way forward.

The trolls can rant and rave all they want -- I don't care. Do me a favor and keep track of who the (professional/persistent) deniers are today. Let's come back in a few years and see what they have to say - what excuses they have for ignoring the science and putting our kids at risk. That should be interesting.

Here is a link to Andy Revkin's Dot Earth Blog in the New York Times.  Shawn Otto posted the full Op-Ed at his Neorenaissance Blog, which can also be found at Huffington Post. (Ed: it was also reposted at ThinkProgress.)

Cherry blossoms near peak bloom in Washington DC's Tidal Basin, March 18, 2012, several weeks early.  Peak bloom was over by March 23, but the National Cherry Blossom Festival was scheduled to run through April 27. Photo: Michael Halpern

And to those of you who have e-mailed, tweeted, texted and called in your support and encouragement, thank you.

I'm no meteorological martyr or Paul Revere -- but I've seen enough evidence to make a call on this one. It's either the greatest scientific hoax ever perpetrated on the people of Earth or the climate scientists are correct. Call me crazy but I think it's possible to lean to the right, and still care about the environment and sound science. If that makes me a "RINO" (Republican In Name Only) then I wear the badge proudly. The forecast calls for more rinos.

---

Paul Douglas is a nationally-respected meteorologist with 32 years of broadcast television and 36 years of radio experience. He is the founder of several companies and author of two books: “Prairie Skies, the Minnesota Weather Book” and “Restless Skies, the Ultimate Weather Book.”

http://shawnotto.com/neorenaissance/blog20120331.html

NewScientist: How large is the greenhouse gas effect of Total's Elgin-Franklin blowout in the North Sea?

How large is warming effect of North Sea gas leak?

by David Strahan, NewScientist, March 30, 2012

Total's Elgin platform (Image: Total E&P UK/PA)

Coverage of the gas leak at Total's Elgin platform in the North Sea, off the UK coast, has so far focused on the potential for an explosion, and damage to sea life from sulphur contamination – the latter now discounted. But methane is a powerful greenhouse gas, so what about the global warming impact? Here's what emerged from the back of my envelope.

A company spokesman is reported as saying about 200,000 cubic metres is escaping per day, based on the plume visible above the platform. Of that, around 90% – or 180,000 m³ – is likely to be methane, according to gas expert John Baldwin, of CNG Services. Total says it may take six months to drill a relief well to plug the original, so if the leak continues at its estimated rate, 32,760,000 m³ of methane would be emitted altogether. At about 1,500 m³ per ton, that amounts to roughly 22,000 tons of methane. What would that mean in warming terms?

The standard global warming potential of methane is 25 over 100 years, meaning it has 25 times the warming effect of carbon dioxide over that period. So 22,000 tons of methane is the equivalent of 550,000 tons of CO₂. That's more than twice the annual emissions of the power station at the Sullom Voe oil terminal in Shetland, according to figures from the EU Emissions Trading Scheme.

However, scientists attribute methane with a much higher global warming potential over shorter periods, because it persists in the atmosphere for much less time than CO₂, so its impact is concentrated in the early years. The IPCC's 20-year global warming potential is 72, and on that basis the Total leak would be the equivalent of 1,584,000 tons of CO₂ over six months. That's almost four times the annual emissions of the Lafarge cement works at Dunbar, and more than a year's worth of CO₂ from RWE's power station at Staythorpe in Nottinghamshire, which serves almost 3 million homes.

Recent research has suggested methane should have an even higher short term global warming potential of 105, because it reduces the concentration of aerosols that cool the atmosphere. That would raise the emissions of a 6-month leak from Total to just over the equivalent of 2.3 million tons of CO₂ – roughly equal to the 2010 emissions of the massive Teesside Power Station. At 1,875 MW Teesside was – until its partial shutdown in 2011 – the largest combined cycle gas turbine power station in Europe, capable of supplying 3% of UK electricity needs.

Of course, the Total leak might turn out to be smaller than 200,000 m³ per day, or it could be fixed in less than 6 months. But if the BP Deepwater Horizon oil spill in the Gulf of Mexico in 2010 is anything to go by, early estimates of the size of the leak from the operator may turn out to be a massive underestimate.

No wonder Michael Liebreich, chief executive of Bloomberg New Energy Finance, has tweeted suggesting Total should be obliged to buy carbon offsets to compensate for the emissions.

http://www.newscientist.com/article/dn21649-how-large-is-warming-effect-of-north-sea-gas-leak.html

Total crisis team reveals source of ongoing gas leak - that has challenged Elgin for weeks - it's from the Hod formation, 4500 meters below the seabed

Total crisis team reveals source of ongoing gas leak - that has challenged Elgin for weeks

The Elgin rig. (Total)

Thierry Debertrand, of Total’s crisis team dealing with the leak at the Elgin/Franklin well system in the North Sea today told Bellona that the company has isolated the leakage as coming from the Hod formation, a natural gas-bearing limestone and chalk formation located 4,500 meters below the seabed.by Charles Digges, Bellona, March 30, 2012
Abnormalities were noticed at the well four weeks earlier, in February, and the crew that was evacuated from the Elgin on Monday had been aboard in an attempt to address these issues when the leak became critical, Debertrand told Bellona in a telephone interview. Debertrand took pains to note that the gas leak is coming from a reservoir and not a "gas pocket" as has been widely reported in mainstream media.

“On February 25th we observed irregular pressure in the annuli on the plugged G4 well. We very quickly moved to kill the annuli pressure by pumping it full with high density mud," Debertrand said. "During this process, on March 25th, we observed a sudden pressure increase followed by an escape of mud and then gas.”

The well was originally shut down in February of 2011.

Stratiography of Elgin/Franklin/Shearwater area, showing typical gamma ray response to the Hod formation. Click to enlarge.

Total (with additions by Keith Whiriskey)

Total is examining two possibilities to staunch the flow of gas, which is leaking from the Elgin platform itself 240 kilometers east of Aberdeen, Scotland, said Debertrand.

The first is re-boarding the rig and performing a dynamic kill, which involves reclosing the well drill mud.

The second and more likely scenario involves digging a relief well with the Rowan Gorilla V rig, which will take as much as six months to complete, but is a far safer option for workers, Debertrand said.

"The next 10 days will be critical – if a dynamic kill of the well from the Elgin platform is not feasible this leak will continue for months as a relief well is prepared," said Bellona President Frederic Hauge. "

“Bellona appreciates the openness of Total on this issue," he added. "Major concerns and uncertainties remain, assessing the quantity of gas in the Hod formation is of critical importance.”

The Gorilla V, according to Jake Molloy, of offshore union RMT-OILC, can work as many as 4.8 kilometers away from the Elgin in order to drill the relief well, he told Bellona in a telephone interview.

Debertrand told Bellona that crews were being mobilized for operations on the Gorilla V.

Debertrand confirmed the gas is reaching the surface via the well’s annulus as gas ingresses into the drilling column.

Problem plaguing development for years

The Hod geohazard has caused significant problems throughout the production life of the Elgin/Franklin fields, as described by Total experts in a report produced in 2005 obtained by Bellona.

“It was realized that conventionally cemented casings was unlikely to hold this gas back during the production lifecycle of the wells,” read the report.

The study resulted in improved drilling and completion procedures. However it is clear that these procedures did prevent gas ingress from the Hod geohazard.

The well, dating from 1997, and other older wells, may be susceptible to particular danger. It is known that other wells have shown increased annular pressure due to the Hod formation.

The Hod formation is regionally distributed, covering a wide area. It is of high pressure – 800 bars according to the Total spokesman. Information on the Hod formation is sketchy, as the reservoir has never been commercially produced.

However, it is known that the gas it contains is clean, meaning that it does not contain hydrogen sulfide. This will result in fewer detrimental environmental impacts.

It is estimated that the Hod formation still contains high quantities of gas, erasing the possibility that the gas leak will simply peter out on its own.

Debertrand estimated that some 2 kilograms a second, or 200,000 cubic meters of a day, of gas condensate were leaking, though he added that these figures are highly speculative. Satellites and airplanes have been used to establish the absence of hydrogen sulfide in the leaking gas.

He also said that condensate production is increasing with gas production.

Shell, meanwhile, which had evacuated its crew from the nearby Shearwater rig on Tuesday, may be returning its workers and rig to normal activity.

Keith Whiriskey contributed to the preparing of this report.

http://www.bellona.org/articles/articles_2012/elgin_total_iview

Over 20% of the organic carbon in sediments is directly bound to reactive iron phases and are locked up in surface marine sediments

Oceanography enters the Iron Age

by Liz Kalaugher, editor, environmentalresearchweb, March 26, 2012

For many years scientists have known that iron is often associated with organic carbon in sediment but did not know why. Now researchers from Canada have found that just over 20% of the organic carbon in sediments is directly bound to reactive iron phases.

They estimate that worldwide 19–45 Gigatonnes of organic carbon are locked up in surface marine sediments in this way. Because reactive iron phases are metastable over long time periods, the sediments could be an efficient "rusty sink" for organic carbon.

"Burial in sediments is the only long-term sink of organic carbon on the planet, on geological timescales," Yves Gélinas of Concordia University told environmentalresearchweb. "Yet only a tiny fraction of organic carbon – about 0.3% – produced in the surface waters through photosynthesis eventually reaches the seafloor and is preserved in sediments. The rest is degraded in the water column and at the surface of the sediment."

The most widely accepted explanation for the tiny proportion of organic carbon preserved, says Gélinas, is that it's protected by sorption on clay mineral surfaces in the water column and in sediments.

"Our work shows that iron oxides are also very important, which is totally new," he added. "Why does it matter? Simply because iron oxides are not stable in anoxic [no-oxygen] environments (they form only in oxic settings), while clay minerals are stable whatever the redox conditions of the system."

The expansion of oceanic "dead zones" – regions where oxygen levels are too low to sustain life – could eventually affect this iron complexation mechanism for preserving organic carbon. According to Gélinas, this will "create a positive feedback mechanism fuelling greater oxygen consumption" as more organic matter will be degraded in the water column or at the surface of the sediments, using additional oxygen and so contributing to the expansion of dead zones.

"Iron has become a very popular research topic in chemical oceanography since the discovery that it is a limiting nutrient for primary productivity in large areas of the ocean," said Gélinas. "We show for the first time that iron also plays an important role in organic carbon preservation. We are definitely in the Iron Age of oceanography."

Gélinas and colleagues from Concordia University and McGill University tested sediments from around the world sampled from freshwaters, estuaries, river deltas, continental margins and the deep sea, using an iron reduction method previously used in soils.

"We now better understand the controls on organic matter preservation in sediments through its stabilization by iron complexation," said Gélinas. "[This] means that we can do a better job building models representing carbon preservation and cycling in marine environments. It also means better prediction of the evolution of the organic carbon preservation function in these models as bottom-water dissolved oxygen concentrations keep decreasing."

Now Gélinas says the team plans to get a clearer idea of the types of chemical bonds that link iron and organic matter, and how changes in local redox conditions affect their relative proportions in sinking particulates and sediments.

"We have recently obtained Synchrotron X-Ray beam time at the Brookhaven National Light Source Laboratory (NLSL) in Long Island, US, and acquired a very promising first set of data showing that our working hypothesis – that iron complexation to organic carbon plays a much greater than anticipated role in preserving a large fraction of organic carbon in sediments – is correct," he said. "We have applied for more beam time at the NSLS and at the Canadian Light Source Synchrotron in Saskatchewan to pursue this work."

The team would also like to estimate the importance of the mechanism in the stabilization of soil organic carbon.

http://environmentalresearchweb.org/cws/article/news/49129

Ice fishing anyone? Not in the Great Lakes, you won't! Jeff Masters: Great Lakes ice cover down 71% since 1973

Great Lakes ice cover down 71% since 1973


by Jeff Masters, Ph.D., WunderBlog, March 30, 2012


Ice cover on North America's Great Lakes -- Superior, Michigan, Huron, Ontario, and Erie -- has declined 71% since 1973, says a new study published in the Journal of Climate by researchers at NOAA's Great Lakes Environmental Research Laboratory. The biggest loser of ice during the 1973-2010 time period was Lake Ontario, which saw an 88% decline in ice cover. During the same time period, Superior lost 79% of its ice, Michigan lost 77%, Huron lost 62%, and Erie lost 50%. The loss of ice is due to warming of the lake waters. Winter air temperatures over the lower Great Lake increased by about 2.7 °F (1.5 °C) from 1973- 2010, and by 4-5 °F (2.3-2.7 °C) over the northern Lakes, including Lake Superior. Lake Superior's summer surface water temperature warmed 4.5 °F (2.5 °C) over the period 1979-2006 (Austin & Colman 2007). During the same period, Lake Michigan warmed by about 3.3 °F (1.7 °C), Lake Huron by 4.3 °F (2.4 °C), and Lake Erie showed almost no warming. The amount of warming of the waters in Lakes Superior, Huron, and Michigan is higher than one might expect, because of a process called the ice-albedo feedback: when ice melts, it exposes darker water, which absorbs more sunlight, warming the water, forcing even more ice to melt. This sort of vicious cycle is also responsible for the recent extreme loss of Arctic sea ice. The increase in temperature of the lakes could be due to a combination of global warming and natural cycles, the researchers said. They noted a pronounced 4-year and 8-year oscillation in ice coverage, which could be caused by the El Niño/La Niña (ENSO) and Arctic Oscillation (AO), respectively.

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Figure 1. A tale of two winters: Lake Superior was choked with ice at the end of the winter of 2008-2009 (top) but was virtually ice-free at the end of the winter of 2011-2012 (bottom). Image credit: NASA.

The consequences of Great Lakes ice loss
Ice coverage on the Great Lakes was just 5% this past winter, the second lowest on record, behind 2002. The lack of Great Lakes ice this winter probably added a few degrees of warmth to the unprecedented "Summer in March" conditions observed in Michigan last week -- an event the National Weather Service in Detroit called "perhaps the most anomalous weather event in Michigan since climate records began 130 years ago." We can anticipate that areas surrounding the Great Lakes will see an increased incidence of warm spring weather due to decreased ice cover on the lakes.

The loss of Great Lakes ice has allowed much more water to evaporate in winter, resulting in heavier lake effect snow near the shore, and lower lake levels. Lower water levels have had a significant impact on the Great Lakes economy. Over 200 million tons of cargo are shipped every year through the Great Lakes. Since 1998, when water levels took a severe drop, commercial ships were forced to light-load their vessels. For every inch of clearance that these oceangoing vessels lost because of low water levels, $11,000-$22,000 in profits were lost per day. Hydropower plants have also been affected by low water levels; several New York and Michigan plants were run at reduced capacity, forcing them to buy higher priced energy from other sources and pass on the higher costs to consumers. The large loss of ice is also likely to accelerate shoreline erosion because of the increase in open water and promote more algal blooms. It is uncertain if the Great Lake water levels will continue to fall as the climate warms, since the region is expected to see an increase in precipitation over the coming decades. In Michigan, annual precipitation increased by about 14% between 1895 and 2011, according to the National Climatic Data Center.


Figure 2. Great Lakes ice coverage for the period December 4-March 5, from the winter of 1980-1981 through 2011-2012. The winter of 2011-2012 had the second lowest ice coverage on record, just 5%. Only 2001-2002 (4.5%) had lower ice cover. The median ice coverage between 1980-2011 was about 19%. Image credit: Environment Canada.


Figure 3. Water levels on Lake Superior between 1860 and February 2012. Since the late 1990s, water levels have seen a steep decline, due to the loss of ice cover allowing more evaporation. Image credit: NOAA/GLERL.

References

Austin, J. A., and S. Colman. 2007. Lake Superior summer water temperatures are increasing more rapidly than regional air temperatures: A positive ice-albedo feedback, Geophysical Research Letters, 34, L06604, doi:10.1029/2006GL029021

Wang, J., X. Bai, H. Hu, A.H. Clites, M.C. Colton, and B.M. Lofgren. 2012. Temporal and spatial variability of Great Lakes ice cover, 1973-2010, Journal of Climate, 25(4):1318-1329; DOI:10.1175/2011JCLI4066.1


http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2063