New Clues to Greenland's Hidden Plumbing

What occurs below Greenland's ice sheet, where water, ice and rock meet, is fundamental to predicting how its glaciers will react to international warming.

Turns out, beneath the island's mysterious middle, wherein the ice is thick and the bottom bedrock tough to attain, meltwater flows thru channels and voids that open when flowing ice travels over rough ground, a new look at unearths. The passageways are areas between the rock and the overlying ice. The consequences, primarily based on laptop modeling and fieldwork observations in Greenland, had been published these days (Aug. 15) within the journal Science.

The observe shows that meltwater flows through a unique network in the interior of the ice sheet than at its edges, stated lead take a look at writer Toby Meierbachtol, a graduate scholar at the University of Montana.

Ice vs. Water

In the steep canyons at the edge of the ice sheet, near the coast, gushing rivers and streams under the ice lubricate glaciers, dashing their flows to the ocean. The frictional heat of water flowing down the precipices melts the ice from underneath, creating channels and cavities. The meltwater ought to fight to maintain its space towards the significant weight of the ice, which attempts to close the voids.

"There is a regular conflict between establishing and final," Meierbachtol said.

But far from the coast, Greenland is by and large flat. Without the frictional heating won from flowing down canyons, water can't soften large channels, the researchers consider. Instead, the meltwater collects in pits and passageways that open up as the ice shifts.

"The geometry of Greenland is such that there may be now not as an awful lot power to pressure that heating, so the heating is quite a bit less far from the [edge]," Meierbachtol told LiveScience. "As a end result, that melting effect is muted, and we discover other procedures are pretty critical. One such process that would be as vital is the sliding of the ice itself, [which] opens up area on the bottom of bedrock bumps."

Meierbachtol and his colleagues drilled 23 boreholes to the bed of the Greenland ice sheet, in ice up to two,700 feet (825 meters) thick and as much as 21 miles (34 kilometers) from the ice sheet side. They measured water stress to gauge the energy of go with the flow inside the subglacial drainage network.

Predicting Greenland's destiny

The meltwater beneath the ice sheet is a key driving force of the way speedy glaciers flow, each in the center and at the threshold of Greenland's ice sheet, the researchers stated.

And in current decades, the amount of summer meltwater has expanded.

Seasonal summer time heating thaws the ice sheet, forming a network of aquamarine ponds. The location of melting ice and the period of the melt season each are growing, with a report 97 percentage of the surface transformed to water in 2012. However, no longer all surface melt reaches the bottom of the ice sheet, Meierbachtol stated. For instance, a few soaks into the firn, that's layers of compacted snow.

Understanding how meltwater behaves beneath the ice sheet is a key factor in modeling Greenland's future reaction to weather exchange, the researchers stated.

"We need to recognise the mechanisms of basal motion, due to the fact this is a significant element of ice motion, and this determines how swiftly ice is discharged toward lower elevations, wherein it's far exposed to melt," said Martin Truffer, a glaciologist on the University of Alaska, Fairbanks, who turned into not worried inside the look at.

"This look at indicates that some of the seasonal version that is well-known on alpine glaciers can indeed be discovered near the margin of the ice sheet," Truffer stated in an electronic mail interview with LiveScience. "But the subglacial plumbing operates differently away from the margins, wherein the ice sheet is flat and hydraulic gradients are low. This is an thrilling vicinity, because it seems to be concern to more water in recent years. Also, if warming persists, we are able to expect that the vicinity of the glacier bed that can be reached by using meltwater will amplify inland," he stated.

Source : LiveScience

Greenland's Ice Loss Now Comes from Surface

Greenland's disappearing ice shifted gears within the past decade, switching from shrinking glaciers to floor melting, researchers suggested here last week on the American Geophysical Union's annual assembly.

Instead of dropping ice where huge glaciers meet the ocean, Greenland now sends meltwater rushing into the sea via a significant community of lakes and rivers, consistent with numerous research. The effects do no longer imply that glaciers have stopped their speedy float, most effective that surface melting now exerts a greater powerful have an effect on on ice loss, researchers stated.

 "We no longer see giant icebergs calving" from glaciers, liberating ice into the ocean, stated Lora Koenig, a glaciologist on the National Snow and Ice Data Center, who led one of the new studies. "The majority of water is coming from surface melt." [Photos: Under the Greenland Ice Sheet]

Koenig found that lakes in west Greenland now stay liquid thru the frigid wintry weather, as long as an insulating snow blanket continues the water warm. These lakes get a head start on melting the next summer season. "Water is not a great component to have persisting yr-spherical," Koenig stated Dec. 15 at a information convention. "What this water is clearly doing is priming the pump [for melting] for the next season."

The meltwater boosts sea degrees, which might be projected to rise through 1 to four toes (zero.Three to one.2 meters) by using 2100, in line with the National Climate Assessment. Water that percolates under the ice sheet can also lubricate the bottom of Greenland's glaciers, rushing up ice go with the flow. But researchers are still figuring out wherein all of this new floor meltwater will grow to be.

"The water is what we have to observe," stated Vena Chu, a hydrologist and graduate scholar at the University of California, Los Angeles.

Follow the water

For instance, each summer, a considerable community of rivers seems in Greenland, channeling meltwater off the ice surface. Researchers said they want to know how a lot water refreezes in location, how lots ends up beneath the ice sheet and how much flows out to sea. By tracking west Greenland's rivers on satellite pictures, Chu discovered that the river water all disappears into moulins — deep cracks that steeply plunge into the ice, she stated at the assembly.

"Now we need to recognise if the water gets caught in there or if it comes immediately out [to the ocean]," Chu said.
The growing flood of floor runoff has additionally converted snow layers that blanket the ice sheet, researchers suggested Dec. 16. Typically, the top of the ice sheet is blanketed by means of in part frozen, old snow referred to as firn, that may suck up summer meltwater like a sponge. But 12 years of heavy summer melts have crushed the firn's capability in southwest Greenland, said Mike MacFerrin, a glaciologist and graduate scholar on the University of Colorado, Boulder.

The waterlogged snow is now frozen solid in many locations, with ice more than 15 toes (4.6 m) thick just under the floor, he said. Now, summer time meltwater streams over the ice instead of sinking into the snow. In 2012, this caused document flooding throughout a big soften occasion in Greenland, stated MacFerrin, who led the have a look at.

However, in different areas, Greenland's old snow still stockpiles large amounts of water. Rick Forster, a glaciologist on the University of Utah, has exposed additional evidence of a shallow aquifer of liquid water in southern and western Greenland. In 2013, Forster said that components of Greenland's snow firn keep an expected one hundred billion gallons of water thru the winter months within the southeast. 

From sea to surface

Koenig said global warming has induced the shift to surface melting, which came about among 2006 and 2009. Temperatures within the Arctic are rising two times as fast than at decrease latitudes, consistent with the National Oceanic and Atmospheric Administration's annual "Arctic Report Card."

Greenland's glaciers have answered quick to converting temperatures inside the beyond, said Anders Bjork, a researcher at the Natural History Museum of Denmark.

Using historic images from Danish aerial surveys of Greenland, Bjork mapped out the development and retreat of glaciers that passed off whilst temperatures climbed between the years 1900 and 1930. The retreat changed into greater fast than has been visible in the last 15 years, he said.

Though the beyond century of exchange seems remarkably fast, usual, the Greenland Ice Sheet is more resilient than the majority anticipate, said glaciologist Dorthe Dahl-Jensen, head of the University of Copenhagen's Center for Ice and Climate. The ice has survived 900,000 years of climate alternate, and it might take a temperature upward push of 18 ranges Fahrenheit (10 levels Celsius) before a forest begins to grow again in Greenland, she suggested right here Dec. 17.

"We are simply seeing the start of a response to the warming," Dahl-Jensen said.

Source : Live Science

Arctic Glacier Has Its Own Aquifer

Isolated glaciers can keep liquid water of their higher layers yr-spherical, a brand new observe finds.

The discovery means that the Greenland ice sheet isn't the most effective icy spot on Earth wherein snow and ice can hoard meltwater for years.

"I do think they may be determined in extra glaciers which have similar procedures at work," stated lead take a look at creator Knut Christianson, a University of Washington glaciologist.

In recent years, researchers have discovered that positive elements of the Greenland Ice Sheet maintain widespread liquid water. These water reservoirs are called "firn" aquifers due to the fact the water is stored in the firn, which can be the older layers of snow that didn't soften in preceding years, and in which old snow ultimately compacts into ice.

The water is trapped in small areas among snow debris, like the juice in a snow cone.

Now, researchers from the University of Washington and the Norwegian Polar Institute have discovered a similar firn aquifer in Norway's Holtedahlfonna glacier, within the Svalbard islands. Holtedahlfonna is ready 31 miles (50 kilometers) lengthy and covers approximately one hundred fifty square miles (390 rectangular km). [Ice World: Gallery of Awe-Inspiring Glaciers]

The aquifer became observed more than twenty years ago by means of Japanese scientists, who reportedly recovered an ice middle from within the glacier that became dripping moist with water, Christianson informed Live Science. However, summer aquifers are commonplace on remoted glaciers, and so the water wasn't considered uncommon, he said. "Aquifers on mountain glaciers were acknowledged since the Nineteen Seventies, however they may be notion to drain each summer time," Christianson stated.

But surveys on the glacier in the course of freezing wintry weather temperatures, a decade later, also discovered liquid water, which became well worth a better look.

Christianson and his colleagues mapped the aquifer with a combination of floor radar and GPS among 2003 and 2007. Water returns a "brighter" sign in the radar facts than ice does.

The researchers determined water that lasted through numerous winters, and the crew watched the pinnacle of the aquifer rise for the duration of warm summers (meaning there was extra water) and fall in the course of wintry weather, when the water tired, the researchers pronounced Feb. 17 inside the magazine Geophysical Research Letters. The water stage additionally dropped by way of up to eleven.5 toes (three.Five meters) between 2005 and 2007.

Firn aquifers form in areas wherein there may be both a whole lot of snow accumulation and summer time melting. The layer of liquid water that percolates into the firn survives freezing iciness temperatures because it's far insulated by using the thick snow. But if wintry weather temperatures are too cold, snowstorm is simply too sparse or there may be too much meltwater, the firn will freeze solid.

The Holtedahlfonna aquifer is handiest 33 to 66 feet (10 to 20 m) thick and doesn't have the capability to raise international sea degree, the researchers said. However, studying this aquifer, and undiscovered aquifers at comparable glaciers, ought to offer new insights into how glaciers keep meltwater, Christianson stated. And in comparison to the Greenland ice sheet, some of the ones different glaciers can also be easier to get to, he said.

"It would be genuinely great to build our knowledge at a smaller machine, and take that to Greenland," he stated.

In Greenland, scientists are now investigating whether the ice sheet aquifers are likely to develop large with international warming. The huge volume of the aquifers in Greenland method the water saved inside the glaciers there may want to probably offset sea level upward push, Christianson stated.

The aquifers took up a number of the massive quantities of meltwater produced by using the island's intense 2012 surface melt, in keeping with initial results with the aid of different scientists. Researchers who have a look at how glaciers move also are watching to peer if water escaping the aquifers could lubricate glaciers and boom ice loss — a faster-transferring glacier drops extra ice into the sea.

source : live science

Every Year, the Swiss Cover Their Melting Glaciers in White Blankets

Summer's coming, which means that soon sufficient, it is going to be time to tuck the glaciers in.

This 12 months, like each yr, a group of Swiss will traipse up via the mountains to the Rhône Glacier, hauling massive white blankets. As E&E News stated in a latest article on geoengineering, the once a year hike is part of a doomed attempt to guard the large blocks of ice from the rising summer time warmness.

The Earth is getting warmer, and glaciers around the arena are taking flight and shrinking. As Live Science has formerly reported, humans seem to have caused sixty nine percentage of glacial melting among 1991 and 2010 — and warming has best improved inside the almost eight years seeing that.

In the Rhône vicinity, that shrinking represents an monetary emergency in addition to an environmental one. The ice mass, which 11,500 years ago covered a large chunk of Switzerland, is a considerable traveller attraction; Agence France-Presse said in 2015 that an "ice grotto" has been carved into the ice every 12 months considering 1870 for site visitors to stroll via, and is threatened by the shrinking ice. The glacier has retreated 4,six hundred toes (1,400 meters) in view that 1856.

The blankets, their white color selected to reflect mild earlier than it strikes the ice, may sluggish the glacier's decline. But they won't forestall it. Glaciologist David Volken instructed Agence France-Presse that the glacier nonetheless loses three to 5 inches (10 to 12 centimeters) on a hot day.

Nonetheless, this idea and others like it are becoming increasingly more popular, because it grows clearer that the arena will blow through the 2-diploma-Celsius temperature upward thrust target policymakers have set for proscribing the worst results of weather change. If the world's glaciers do disintegrate totally, the capacity for raising global sea stages is widespread, in accordance to research posted in 2013 in the magazine Science.

As Oceans Deeply stated, scientists on the December 2017 assembly of the American Geophysical Union significantly considered proposals like spreading large sheets of reflective fabric on top of landlocked polar ice, building big mounds on the seafloor to keep heat water away from melting glaciers, or pumping massive quantities of ocean water on pinnacle of sea ice in the summer time so as to add to its mass.

All these ideas and extra seem in an ongoing E&E collection on geoengineering, which Live Science recommends reading in full.

source : Live Science.

How Six Americans Changed Their Minds About Global Warming

What precisely is worldwide warming? Global warming is the term to describe the overall climate trade to the Earth. It is the massive growth in the Earth’s temperature over a extraordinarily brief time period due to human pastime. It doesn’t just have an effect on the northern hemisphere, or the southern. In order for worldwide warming to be fully understood, one should consider the Earth’s structures like clockwork. Each little dial impacts the alternative.

Even an increase of 1 degree in temperature is classified as international warming. Over the path of 100 years, an increase of 0.Four percent might be taken into consideration purpose for concern. The IPCC (Intergovernmental Panel on Climate Change) comprised of 2500 scientists have charted the Earth’s climbing temperature, and finish it has warmed 0.6 levels in nine years by myself. Just inside the closing decade, the Earth’s weather has doubled that of a hundred years in the past.

Is it over exaggerated reactions to the Earth’s changing temperature, or is it surely taking place on its very own? Global warming is a rather heated subject matter (no pun meant) among the maximum well-known scientists internationally. Ever because Al Gore spent big amounts of time and resources on his “An Inconvenient Truth” documentary, humans have been discussing the causes and troubles associated with worldwide warming. Whether you accept as true with the Environment Protection Agency (EPA) or now not, some thing is certainly going on to the Earth’s atmosphere. Observable weather modifications in the past many years is proof the arena is heating up. Is this herbal happenstance, and there’s nothing we can absolutely do to prevent it? Or, is it actual, and we’re the guilty birthday party? What is worldwide warming, precisely, and how does it without a doubt work, in keeping with scientists?

There’s no distinction between global warming and climate disruption. Yes, there can be climate anomalies or phenomena in patters that cause temperatures to trade unpredictably or unexpectedly, and sure, worldwide warming is the measurable remark of climate disruption. It’s simplest to think about the smog hanging over a bustling town. The gases emitted from oil, coal, carbon dioxide, methane, and nitrous oxide all constructed up to supply a “smog” over the Earth. Just like in a large metropolis thick with congestion, the greater gases you've got, the thicker the cloud. Harmful gases get stuck inside the cloud and environment in which they can’t get away. As the sun’s ray warmness the Earth, the gases trapped internal reason temperatures to upward thrust. Basically consider it as we’re roasting ourselves with the entirety we produce, very slowly.

The Global warming is an environmental assignment that whole global going through these days. The stage of greenhouse gases is increasing at an exorbitant fee in the ecosystem. Unless we maintain a tab on our moves and reduce our dependance on fossil fuels, the trouble of world warming isn't always going to quit every time faster.

Warning Signs

The Arctic is warming up more than twice as fast as the rest of the world, due to numerous feedbacks. At times, large areas over the Arctic Ocean can become 30°C or 54°F warmer than 1979-2000, as illustrated by the image below.

On February 27, 2018, large parts of the Arctic Ocean north of Greenland had turned into open water, as illustrated by the image below.

Yet, while the situation in the Arctic is desperate, with sea ice north of Greenland collapsing and more, mainstream media do not seem to care. If there ever were warning signs of what could eventuate, this is one. The sea ice north of Greenland is typically the thickest, as it is the least affected by melting and can build over many years. Early February 2018, sea ice north of Greenland was up to 5 m thick. To see sea ice this thick getting pushed away and open water emerging north of Greenland in the middle of winter is simply stunning.

For years, I've been warning about the situation in the Arctic, in particular the 'Open Doors Feedback', which is accelerating Arctic warming. Such feedbacks were taken into consideration in an earlier analysis that warned about a potential 1.6°C warming globally due to albedo changes in the Arctic, in combination with associated changes such as loss of the ice buffer (latent heat), more heat transfer from the Atlantic Ocean to the Arctic Ocean due to stronger winds along the path of the Gulf Stream, and more heat entering the atmosphere or remaining in the atmosphere, due to more open water in the Arctic Ocean and as oceans get more stratified and take up less heat from the atmosphere.

So, the current situation doesn't come as a big surprise, but it's stunning to see sea ice collapse north of Greenland.

Back in March 7, 2007, I posted the article 'Ten Dangers of Global Warming', describing events getting progressively worse, with one danger feeding and reinforcing the next one, culminating in panic. Then, I thought that reading that post could at least help people better understand what's going on, and thus help people avoid panicking, but right now, I wonder whether most people do want to understand at all. Anyway, here are some images and words describing what happened over the past few days.

Jet Stream over Arctic Ocean on February 25, 2018

As Arctic warming keeps accelerating, there's ever less temperature difference between the North Pole and the Equator, and this slows down the speed at which the jet stream circumnavigates Earth.

Jet Stream over Arctic Ocean on February 26, 2018
The jet stream is getting more wavy and a more wavy jet stream makes it easier for cold air to move out of the Arctic and for warm air to move into the Arctic, so this 'Open Doors Feedback' is a self-reinforcing feedback that further accelerates warming in the Arctic.

During the northern winter, the Arctic is increasingly getting warmer than North America, Europe and Siberia. This increases the temperature difference between these continents and the oceans, which at times is causing winds to strongly speed up over the North Atlantic and the North Pacific, making an already wavy jet stream extend even further over the Arctic Ocean, reaching areas well beyond the North Pole.

Atmospheric river of heat reaches the North Pole; temperatures were as high as 1.1°C or 34.1°F on February 25, 2018

As the jet stream makes this detour, a huge amount of heat enters the Arctic from the south.

Temperatures above 6°C at Kap Morris Jesup, Greenland's northernmost weather station, on February 25, 2018

These events were preceded by the Polar Vortex splitting up. On February 9, 2018, the Polar Vortex was split up into 4 vortices and reached speeds as fast as 425 km/h or 264 mph.

Polar Vortex split up into 4 vortices

A Sudden Stratospheric Warming event occurred on February 16, 2018, with temperatures reaching as high as 8.9°C or 47.9°F over Hudson Bay.

Polar Vortex splitting up into 4 vortices with a Sudden Stratospheric Warming event occurring on February 16, 2018

The image below is an animation of sea ice thickness, from the Naval Research Laboratory.

Arctic sea ice extent was at record low for the time of the year on February 26, 2018, at 14.159 million km². Arctic sea ice extent typically reaches its maximum in March, but maximum extent in 1991-2000 was reached on February 24. So, there is a chance that Arctic sea ice extent will go all downhill from now on this year.

Zero sea ice volume is within the margins of the trend depicted on the image above on the right. Disappearance of the sea ice also means loss of the buffer that until now has consumed huge amounts of heat. 

The Buffer has gone, feedback #14 on the Feedbacks page
Here's another warning sign. High methane releases followed this chain of events on February 27, 2018, pm, likely originating from the seafloor of the East Siberian Arctic Shelf (ESAS).
Methane levels as high as 2892 ppb on February 27, 2018
Add up the impact of all warming elements and, as an earlier analysis shows, the rise in mean global temperatures from preindustrial could be more than 10°C in a matter of years, as illustrated by the images below.

A 2°C rise in temperature alone is devastating, especially when considering that the speed at which this rise could occur leaves little or no time for plants and animals to adapt.

The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.


• Climate Plan

• Feedbacks in the Arctic

• Extinction

• Ten Dangers of Global Warming

IPCC seeks to downplay global warming

The graph below shows global warming for a 30-year period centered on January 2018, using NASA 2003 to January 2018 LOTI anomalies from 1951-1980, adjusted by 0.59°C to cater for the rise from preindustrial to 1951-1980, and with a polynomial trend added.

From: ECMWF Nino Plumes
Above graph shows that the 1.5°C guardrail, set at the Paris Agreement, was crossed in 2016 and that a 10°C (18°F) warming could eventuate within a decade or so.

The variations in above temperature data are strongly influenced by El Niño/La Niña. We currently are in a La Niña period, during which surface temperatures are suppressed, whereas surface temperatures in 2016 were much above the trendline, due to El Niño.

The ECMWF forecast from 1 February 2018 on the right indicates that we're heading for another El Niño, i.e. surface temperatures will be rising strongly over the coming months.

The IPCC seeks to downplay the amount of global warming that has already occurred and that looks set to eventuate over the next decade or so. A leaked draft of the IPCC 'Special Report on 1.5°C above pre-industrial' (First Order Draft of SR1.5 SPM) estimates that the global mean temperature reached approximately 1°C above pre-industrial levels around 2017/2018. The IPCC appears to have arrived at this estimate using an extrapolation or near term predictions of future warming so that the level of anthropogenic warming is reported for a 30 year period centered on today.

This 1°C IPCC estimate looks quite incredible when calculating the temperature rise using NASA's data for the two most recent years for which data are available (2016/2017), which shows a warming of 0.95°C when using a baseline of 1951-1980 and a warming of 1.23°C when using a baseline of 1890-1910.

Indeed, the temperature rise differs depending on which baseline is used, and when using preindustrial as a baseline, i.e. the baseline agreed to at the Paris Agreement, indications are that temperatures have already risen by more than 1.5°C, as also discussed in an earlier post.

Furthermore, when using a 30-year period centered on January 2018, the current temperature will have to be calculated over the past 15 years and estimated for the next 15 years, i.e. up to the year 2033.

To arrive at a 1°C rise for the 30-year period, the IPCC must somehow assume that temperatures will magically fall dramatically over the next 15 years, whereas indications are that temperatures will instead rise dramatically over the next decade or so.

The image on the right shows that 10°C (18°F) warming from preindustrial could eventuate within one decade when taking into full account the warming that could result from the elements depicted in the stacked bar. Each of these warming elements is discussed in more detail at the extinction page.

The image below shows the rise from 1750 to 2030, in surface temperatures (land+ocean), rather than in anomalies.

The situation is dire and calls for comprehensive and effective action, as described in the Climate Plan.