Arctic sheds huge chunks of ice

Two masses of ice together measuring almost 20 square kilometers (seven square miles) have broken off an Arctic ice shelf, the biggest breakup of Arctic ice in three years, Canadian officials announced.

The chunks broke off from the Ward Hunt Ice Shelf on the coast of Ellesmere Island in the Canadian Arctic Archipelago, forming two floating islands of ice measuring four to five square kilometers (1.9 square miles) and 14 square kilometers (5.4 square miles), officials said.

“The first broke off sometime around July 22 and the second in the night of July 23 to 24,” Luc Desjardins, a senior iceberg forecaster for the Canadian Ice Service, told AFP Tuesday, noting that beads of smaller slabs also detached from the ice shelf and are now adrift.

Scientists confirmed the schism in a fly-over of one of the resulting masses of ice and by analyzing satellite data.

It was the largest breakup of an ice shelf in the Arctic since the Ayles Ice Shelf split off Ellesmere Island in 2005 and formed a floating island roughly the size of New York city’s Manhattan, or about 66 square kilometers (25 square miles).

The August 2005 rupture caused such a splash, the burst was detected by Canadian seismology equipment 250 kilometers (155 miles) away, but it was not until scientists analyzed satellite data that they realized what had happened.

Five vast ice shelves gird the north side of Ellesmere Island in Canada’s Nunavut territory. Ward Hunt is considered the largest, with a surface area of 443 square kilometers (171 square miles).

The ice shelves, vast plateaus of thick ice floating on the ocean but attached to land, began to form more than 4,000 years ago, scientists believe.

“We ascertained that in the 20th century 90 percent of the ice surface area (in the region) has been lost,” said Derek Mueller, a Polar specialist at Trent University in Peterborough.

“So, this phenomena has been ongoing on for a long time, but we’re now seeing punctuated events,” he said.

He pointed to the Petersen Ice Shelf which lost a third of its surface area between 2005 and 2007, as an example.

This calving is emblematic of the far north’s warming, say other scientists.

A fissure formed at the center of the Ward Hunt Ice Shelf in 2002, leaving a lip of ice clinging to Ellesmere Island. A new crack measuring 18 kilometers (11 miles) long and 40 meters (131 feet) deep was discovered earlier this year.

But “it doesn’t look like the latest breakup of ice is directly tied to the fracture that was detected in the spring,” said Desjardins.

“The 2002 fissure cut the ice shelf in two pieces. I believe over time the shelf’s integrity, its entire structure, was simply weakened,” Mueller explained.

Arctic seafloor said littered with plastic

The seabed in the arctic deep ocean is increasingly strewn with litter and plastic waste, a German researcher says, with twice as much debris as ten years ago.

Marine biologist Melanie Bergmann of the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven examined some 2,100 seafloor photographs taken near a deep-sea observatory in the arctic’s eastern Fram Strait between Greenland and the Norwegian island of Spitsbergen.

“The study was prompted by a gut feeling. When looking through our images I got the impression that plastic bags and other litter on the seafloor were seen more frequently in photos from 2011 than in those dating back to earlier years,” she said.

“For this reason I decided to go systematically through all photos from 2002, 2004, 2007, 2008 and 2011.”

“Waste can be seen in around 1 percent of the images from 2002, primarily plastic. In the images from 2011 we made the same discovery on around 2 percent of the footage. The quantity of waste on the sea bed has therefore doubled,” she said.

The increasing plastic contamination of the seafloor is affecting deep-sea inhabitants at risk, she said.

“Almost 70 percent of the plastic litter that we recorded had come into some kind of contact with deep-sea organisms. For example we found plastic bags entangled in sponges, sea anemones settling on pieces of plastic or rope, cardboard and a beer bottles colonized by sea lilies.”

Bergmann’s study has been published in the journal Marine Pollution Bulletin.

Arctic seafloor methane releases double previous estimates

The seafloor off the coast of Northern Siberia is releasing more than twice the amount of methane as previously estimated, according to new research results published in the Nov. 24 edition of the journal Nature Geoscience.

The East Siberian Arctic Shelf is venting at least 17 teragrams of the methane into the atmosphere each year. A teragram is equal to 1 million tons.

“It is now on par with the methane being released from the arctic tundra, which is considered to be one of the major sources of methane in the Northern Hemisphere,” said Natalia Shakhova, one of the paper’s lead authors and a scientist at the University of Alaska Fairbanks. “Increased methane releases in this area are a possible new climate-change-driven factor that will strengthen over time.”

Methane is a greenhouse gas more than 30 times more potent than carbon dioxide. On land, methane is released when previously frozen organic material decomposes. In the seabed, methane can be stored as a pre-formed gas or asmethane hydrates. As long as the subsea permafrost remains frozen, it forms a cap, effectively trapping the methane beneath. However, as the permafrost thaws, it develops holes, which allow the methane to escape. These releases can be larger and more abrupt than those that result from decomposition.

The findings are the latest in an ongoing international research project led by Shakhova and Igor Semiletov, both researchers at the UAF International Arctic Research Center. Their twice-yearly arctic expeditions have revealed that the subsea permafrost in the area has thawed much more extensively than previously thought, in part due to warming water near the bottom of the ocean.

The warming has created conditions that allow the subsea methane to escape in much greater amounts than their earlier models estimated. Frequent storms in the area hasten its release into the atmosphere, much in the same way stirring a soda releases the carbonation more quickly.

“Results of this study represent a big step forward toward improving our understanding of methane emissions from the East Siberian Arctic Shelf,” said Shakhova. She noted that while the ESAS is unusual in its expansive and shallow nature, the team’s findings there speak to the need for further exploration of the subsea Arctic. “I believe that all other arctic shelf areas are significantly underestimated and should be paid very careful attention to.”

The East Siberian Arctic Shelf is a methane-rich area that encompasses more than 2 million square kilometers of seafloor in the Arctic Ocean. It is more than three times as large as the nearby Siberian wetlands, which have been considered the primary Northern Hemisphere source of atmospheric methane. Previous estimates performed for the ESAS suggested that the area was releasing 8 teragrams of methane into the atmosphere yearly.

During field expeditions, the research team used a variety of techniques-including sonar and visual images of methane bubbles in the water, air and water sampling, seafloor drilling and temperature readings-to determine the conditions of the water and permafrost, as well as the amount of methane being released.

Methane is an important factor in global climate change, because it so effectively traps heat. As conditions warm, global research has indicated that more methane is released, which then stands to further warm the planet. Scientists call this phenomenon a positive feedback loop.

“We believe that the release of methane from the Arctic, and in particular this part of the Arctic, could impact the entire globe,” Shakhova said. “We are trying to understand the actual contribution of the ESAS to the global methane budget and how that will change over time.”

Arctic sea ice volume up from record low

Measurements from ESA’s CryoSat satellite show that the volume of Arctic sea ice has significantly increased this autumn. The volume of ice measured this autumn is about 50% higher compared to last year. In October 2013, CryoSat measured about 9000 cubic km of sea ice – a notable increase compared to 6000 cubic km in October 2012.

Over the last few decades, satellites have shown a downward trend in the area of Arctic Ocean covered by ice. However, the actual volume of sea ice has proven difficult to determine because it moves around and so its thickness can change.

CryoSat was designed to measure sea-ice thickness across the entire Arctic Ocean, and has allowed scientists, for the first time, to monitor the overall change in volume accurately.

About 90% of the increase is due to growth of multiyear ice – which survives through more than one summer without melting – with only 10% growth of first year ice. Thick, multiyear ice indicates healthy Arctic sea-ice cover.

This year’s multiyear ice is now on average about 20%, or around 30 cm, thicker than last year.

“One of the things we’d noticed in our data was that the volume of ice year-to-year was not varying anything like as much as the ice extent – at least in 2010, 2011 and 2012,” said Rachel Tilling from the UK’s Centre for Polar Observation and Modelling, who led the study.

“We didn’t expect the greater ice extent left at the end of this summer’s melt to be reflected in the volume. But it has been, and the reason is related to the amount of multiyear ice in the Arctic.”

While this increase in ice volume is welcome news, it does not indicate a reversal in the long-term trend.

“It’s estimated that there was around 20 000 cubic kilometres of Arctic sea ice each October in the early 1980s, and so today’s minimum still ranks among the lowest of the past 30 years,” said Professor Andrew Shepherd from University College London, a co-author of the study.

The findings from a team of UK researchers at the Centre for Polar Observation and Modelling were presented last week at the American Geophysical Union’s autumn meeting in San Francisco, California.

“We are very pleased that we were able to present these results in time for the conference despite some technical problems we had with the satellite in October, which are now completely solved,” said Tommaso Parrinello, ESA’s CryoSat Mission Manager.

In October, CryoSat’s difficulties with its power system threatened the continuous supply of data, but normal operations resumed just over a week later.

With the seasonal freeze-up now underway, CryoSat will continue its routine measurement of sea ice. Over the coming months, the data will reveal just how much this summer’s increase has affected winter ice volumes.

Arctic sea ice summertime minimum is fourth lowest on record

According to a NASA analysis of satellite data, the 2015 Arctic sea ice minimum extent is the fourth lowest on record since observations from space began.

The analysis by NASA and the NASA-supported National Snow and Ice Data Center (NSIDC) at the University of Colorado at Boulder showed the annual minimum extent was 1.70 million square miles (4.41 million square kilometers) on Sept. 11. This year’s minimum is 699,000 square miles (1.81 million square kilometers) lower than the 1981-2010 average.

Arctic sea ice cover, made of frozen seawater that floats on top of the ocean, helps regulate the planet’s temperature by reflecting solar energy back to space. The sea ice cap grows and shrinks cyclically with the seasons. Its minimum summertime extent, which occurs at the end of the melt season, has been decreasing since the late 1970s in response to warming temperatures.

In some recent years, low sea-ice minimum extent has been at least in part exacerbated by meteorological factors, but that was not the case this year.

“This year is the fourth lowest, and yet we haven’t seen any major weather event or persistent weather pattern in the Arctic this summer that helped push the extent lower as often happens,” said Walt Meier, a sea ice scientist with NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “It was a bit warmer in some areas than last year, but it was cooler in other places, too.”

In contrast, the lowest year on record, 2012, saw a powerful August cyclone that fractured the ice cover, accelerating its decline.

The sea ice decline has accelerated since 1996. The 10 lowest minimum extents in the satellite record have occurred in the last 11 years. The 2014 minimum was 1.94 million square miles (5.03 million square kilometers), the seventh lowest on record. Although the 2015 minimum appears to have been reached, there is a chance that changing winds or late-season melt could reduce the Arctic extent even further in the next few days.

“The ice cover becomes less and less resilient, and it doesn’t take as much to melt it as it used to,” Meier said. “The sea ice cap, which used to be a solid sheet of ice, now is fragmented into smaller floes that are more exposed to warm ocean waters. In the past, Arctic sea ice was like a fortress. The ocean could only attack it from the sides. Now it’s like the invaders have tunneled in from underneath and the ice pack melts from within.”

Some analyses have hinted the Arctic’s multiyear sea ice, the oldest and thickest ice that survives the summer melt season, appeared to have recuperated partially after the 2012 record low. But according to Joey Comiso, a sea ice scientist at Goddard, the recovery flattened last winter and will likely reverse after this melt season.

“The thicker ice will likely continue to decline,” Comiso said. “There might be some recoveries during some years, especially when the winter is unusually cold, but it is expected to go down again because the surface temperature in the region continues to increase.”

This year, the Arctic sea ice cover experienced relatively slow rates of melt in June, which is the month the Arctic receives the most solar energy. However, the rate of ice loss picked up during July, when the sun is still strong. Faster than normal ice loss rates continued through August, a transition month when ice loss typically begins to slow. A big “hole” appeared in August in the ice pack in the Beaufort and Chukchi seas, north of Alaska, when thinner seasonal ice surrounded by thicker, older ice melted. The huge opening allowed for the ocean to absorb more solar energy, accelerating the melt.

It’s unclear whether this year’s strong El Nino event, which is a naturally occurring phenomenon that typically occurs every two to seven years where the surface water of the eastern equatorial Pacific Ocean warms, has had any impact on the Arctic sea ice minimum extent.

“Historically, the Arctic had a thicker, more rigid sea ice that covered more of the Arctic basin, so it was difficult to tell whether El Nino had any effect on it,” said Richard Cullather, a climate modeler at Goddard. “Although we haven’t been able to detect a strong El Nino impact on Arctic sea ice yet, now that the ice is thinner and more mobile, we should begin to see a larger response to atmospheric events from lower latitudes.”

In comparison, research has found a strong link between El Nino and the behavior of the sea ice cover around Antarctica. El Nino causes higher sea level pressure, warmer air temperature and warmer sea surface temperature in west Antarctica that affect sea ice distribution. This could explain why this year the growth of the Antarctic sea ice cover, which currently is headed toward its yearly maximum extent and was at much higher than normal levels throughout much of the first half of 2015, dipped below normal levels in mid-August.

Starting next week, NASA’s Operation IceBridge, an airborne survey of polar ice, will be carrying science flights over sea ice in the Arctic, to help validate satellite readings and provide insight into the impact of the summer melt season on land and sea ice.

Arctic sea ice still too thick for regular shipping through Northwest

Despite climate change, sea ice in the Northwest Passage (NWP) remains too thick and treacherous for it to be a regular commercial Arctic shipping route for many decades, according to new research out of York University.

Prior to this research, there was little information about the thickness of sea ice in the NWP, which meanders through the Canadian Arctic Archipelago. Yet, next to ice coverage and type, sea ice thickness plays the most important role in assessing shipping hazards and predicting ice break-up.

“While everyone only looks at ice extent or area, because it is so easy to do with satellites, we study ice thickness, which is important to assess overall changes of ice volume, and helps to understand why and where the ice is most vulnerable to summer melt,” says lead researcher York Professor Christian Haas, the Canada Research Chair for Arctic Sea Ice Geophysics.

The research paper, “Ice Thickness in the Northwest Passage”, was published in the journal Geophysical Research Letters .

Haas and his team, including Stephen Howell of Environment Canada, measured first-year and multiyear ice thickness in the Canadian Arctic Archipelago using an airplane equipped with an electromagnetic induction sounder or EM bird. They surveyed the ice in April and May of 2011 and again in 2015. It is considered the first large-scale assessment of ice thickness in the area.

The surveys found a modal thickness of 1.8 to two metres in most regions of the NWP and mean thickness of between two and three metres. Ice originating from the Arctic Ocean showed a mean thickness of more than three metres on average. Some multiyear ice regions contained much thicker, deformed ice that was more than 100 m wide and more than four metres thick.

“This is the first-ever such survey in the Northwest Passage, and we were surprised to find this much thick ice in the region in late winter, despite the fact that there is more and more open water in recent years during late summer,” says Haas. “This points to the importance of ice transport from the high Arctic and melt processes during the spring season, which critically depend on weather conditions and how they affect the melting of thick ice.”

Although the results were obtained in late winter when no ships travel the route, they will impact how ice break-up and summer ice conditions develop and are currently predicted, and help forecast the opening and navigability of the NWP during summer. It will also affect how sea ice hazards are assessed during the shipping season and provide baseline data going forward.

The NWP, comprised of a series of gulfs, straits, sounds and channels that connect the Beaufort Sea in the west with Baffin Bay in the east, is a much shorter route for moving goods between the Pacific and Atlantic regions than the Panama and Suez Canals. At the moment, this year’s annual summer minimum Arctic-wide ice coverage is the fourth lowest on record, with similar low coverage in the NWP, according to information provided by the Canadian Ice Service.

How climate change will affect the summer ice in the NWP in the future, however, is difficult to predict, says Haas. Further melting could cause more multiyear ice from the Arctic Ocean to drift into the NWP, making it less, not more passable.

Arctic sea ice shrinks to third lowest area on record

Arctic sea ice melted over the summer to cover the third smallest area on record, US researchers said Wednesday, warning global warming could leave the region ice free in the month of September 2030.

Last week, at the end of the spring and summer “melt season” in the Arctic, sea ice covered 4.76 million square kilometers (1.84 million square miles), the University of Colorado’s National Snow and Ice Data Center said in an annual report.

“This is only the third time in the satellite record that ice extent has fallen below five million square kilometers (1.93 million square miles), and all those occurrences have been within the past four years,” the report said.

A separate report by the National Oceanic and Atmospheric Administration (NOAA) found that in August, too, Arctic sea ice coverage was down sharply, covering an average of six million square kilometers (2.3 million square miles), or 22 percent below the average extent from 1979 to 2000.

The August coverage was the second lowest for Arctic sea ice since records began in 1979. Only 2007 saw a smaller area of the northern sea covered in ice in August, NOAA said.

The record low for Arctic sea ice cover at the end of the spring and summer “melt season” in September, was also in 2007, when ice covered just 4.13 million square kilometers (1.595 million square miles).

Mark Serreze, director of the NSIDC, said climate-change skeptics might seize the fact that Arctic sea ice did not hit a record-low extent this year, but said they would be barking up the wrong tree if they claimed the shrinkage had been stopped.

“Only the third lowest? It didn’t set a new record? Well, right. It didn’t set a new record but we’re still headed down. We’re not looking at any kind of recovery here,” he told AFP.

In fact, Serreze said, Arctic sea ice cover is shrinking year-round, with more ice melting in the spring and summer months and less ice forming in the fall and winter.

“The Arctic, like the globe as a whole, is warming up and warming up quickly, and we’re starting to see the sea ice respond to that. Really, in all months, the sea ice cover is shrinking — there’s an overall downward trend,” Serreze told AFP.

“The extent of Arctic ice is dropping at something like 11 percent per decade — very quickly, in other words.

“Our thinking is that by 2030 or so, if you went out to the Arctic on the first of September, you probably won’t see any ice at all. It will look like a blue ocean, we’re losing it that quickly,” he said.

Losing sea ice cover in the Arctic would affect everything from the obvious, such as people who live in the far north and polar bears, to global weather patterns, said Serreze.

“The Arctic acts as a sort of refrigerator of the northern hemisphere. As we lose the ice cover, we start to change the nature of that refrigerator, and what happens up there affects what happens down here in the middle latitudes,” he said.

“We might have less cold outbreaks, which you might say is a good thing, but it’s not such a good thing in regions that depend on snowfall for their water supply.”

NOAA noted in its report that the first eight months of 2010 were in equal first place with the same period in 1998 for the warmest combined land and ocean surface temperatures on record worldwide, and the summer months were the second warmest on record globally, after 1998.

earlier related report

Arctic sea ice shrinks to lowest level on record: US

Arctic sea ice has shrunk to its smallest surface area since record-keeping began, taking the world into “uncharted territory” as climate change intensifies, US scientists warned Wednesday.

Satellite images show the ice cap has melted to 1.32 million square miles (3.4 million square kilometers) as of September 16, the predicted lowest point for the year.

That’s the smallest Arctic ice cover since record-keeping began in 1979, according to the National Snow and Ice Data Center.

“We are now in uncharted territory,” NSIDC director Mark Serreze said in a statement.

“While we’ve long known that as the planet warms up, changes would be seen first and be most pronounced in the Arctic, few of us were prepared for how rapidly the changes would actually occur.”

Arctic sea ice expands and contracts seasonally, with the lowest extent usually occurring in September.

This year’s minimum followed a season already full of records for shrinking ice, with the lowest ever extents recorded on August 26 and again on September 4.

And in the last two weeks, the ice cover melted by more than 200,000 square miles, a large margin for the end of the summer.

“The strong late season decline is indicative of how thin the ice cover is,” said NSIDC scientist Walt Meier.

“Ice has to be quite thin to continue melting away as the sun goes down and fall approaches.”

Scientists use Arctic sea ice extent as a gauge of the overall climate. Despite year-to-year fluctuations from natural weather variations, the ice cap has shown a clear trend toward shrinking over the last 30 years, according to the NSIDC.

“This year’s minimum will be nearly 50 percent lower than the 1979 to 2000 average,” it said.

The Colorado-based center said the Arctic is shifting in composition. Whereas most of the ice previously stayed frozen through several summers, much of it now melts and refreezes each season.

“Twenty years from now in August, you might be able to take a ship right across the Arctic Ocean,” once blocked year-round by ice, said NSIDC scientist Julienne Stroeve.

Climate models predict “ice free conditions” before 2050, she added, but said the decline appears to be happening faster than predicted.

The NSIDC warned that increased heat and moisture from the melting Arctic ice cover could have global climate implications.

“This will gradually affect climate in the areas where we live,” he said. “We have a less polar pole — and so there will be more variations and extremes.”

Environmental activist group Greenpeace lamented the announcement, expressing hope it would trigger a sense of urgency for action to slow the trend.

“In just over 30 years, we have altered the way our planet looks from space, and soon the North Pole may be completely ice free in summer,” Greenpeace chief Kumi Naidoo said in a statement.

“I hope that future generations will mark this day as a turning point, when a new spirit of global cooperation emerged to tackle the huge challenges we face.”

Scientists say climate change is caused when carbon dioxide and other human-produced gases rise into the atmosphere and make it more difficult for the planet to reflect the sun’s heat back into space, creating a greenhouse effect.

As the ice cap melts over Greenland vast amounts of methane — a greenhouse gas — trapped in the permafrost are likely to be released.

The methane comes from the remains of the region’s plant and animal life trapped in sediment and later covered by ice sheets in the last Ice Age.

Methane is 25 times more efficient at trapping solar heat than carbon dioxide.

As the methane is released into the atmosphere and the planet warms further due to the greenhouse effect, more ice in turn melts, freeing up locked-up carbon.

Arctic sea ice reaches minimum 2011 extent

The blanket of sea ice that floats on the Arctic Ocean appears to have reached its lowest extent for 2011, the second lowest recorded since satellites began measuring it in 1979, according to the University of Colorado Boulder’s National Snow and Ice Data Center.

The Arctic sea ice extent fell to 1.67 million square miles, or 4.33 million square kilometers on Sept. 9, 2011. This year’s minimum of 1.67 million square miles is more than 1 million square miles below the 1979-2000 monthly average extent for September – an area larger than Texas and California combined.

While this year’s September minimum extent was greater than the all-time low in 2007, it remains significantly below the long-term average and well outside the range of natural climate variability, according to scientists involved in the analysis.

Most scientists believe the shrinking Arctic sea ice is tied to warming temperatures caused by an increase in human-produced greenhouse gases pumped into Earth’s atmosphere.

“Every summer that we see a very low ice extent in September sets us up for a similar situation the following year,” said NSIDC Director Mark Serreze, also a professor in CU-Boulder’s geography department.

“The Arctic sea ice cover is so thin now compared to 30 years ago that it just can’t take a hit anymore. This overall pattern of thinning ice in the Arctic in recent decades is really starting to catch up with us.”

Serreze said that in 2007, the year of record low Arctic sea ice, there was a “nearly perfect” set-up of specific weather conditions. Winds pushed in more warm air over the Arctic than usual, helping to melt sea ice, and winds also pushed the floating ice chunks together into a smaller area.

“It is interesting that this year, the second lowest sea ice extent ever recorded, that we didn’t see that kind of weather pattern at all,” he said.

The last five years have been the five lowest Arctic sea ice extents recorded since satellite measurements began in 1979, said CU-Boulder’s Walt Meier, an NSIDC scientist. “The primary driver of these low sea ice conditions is rising temperatures in the Arctic, and we definitely are heading in the direction of ice-free summers,” he said. “Our best estimates now indicate that may occur by about 2030 or 2040.”

There still is a chance the sea ice extent could fall slightly due to changing winds or late season melt, said Meier. During the first week of October, CU-Boulder’s NSIDC will issue a full analysis of the 2011 results and a comparison to previous years.

Arctic sea ice minimum ties record for second lowest

Only a month ago, scientists were suggesting the rate of sea ice melting in the Arctic had slowed and the 2016 minimum was unlikely to break any records.

Fast-forward to early September, as Arctic sea ice levels reached their summertime minimum, and 2016 has joined 2007 for the second lowest minimum on record.

“It was a stormy, cloudy, and fairly cool summer,” Mark Serreze, director of the National Snow and Ice Data Center, said in a news release. “Historically, such weather conditions slow down the summer ice loss, but we still got down to essentially a tie for second lowest in the satellite record.”

At its low point on September 10, the NSIDC reports Arctic sea ice covered just 1.6 million square miles. The all-time record belongs to 2012, with a minimum coverage of just 1.3 million square miles.

Between 1981 and 2010, Arctic sea ice lost an average of 8,100 square miles per day during its melting months. In 2016, Arctic sea ice lost an average of 13,200 square miles per day.

Melting rates slowed in midsummer as cool, cloudy weather stalled over the North Pole, but that period of respite was bookended by record high temperatures and accelerated melting. Even so, scientists were surprised by this year’s minimum.

Researchers suggest a plethora of especially thin ice at the end of the winter — a winter that also set a record low — contributed to the record melt. Water temperatures were above average in the upper ocean during the late summer months, contributing to accelerated ice loss to end the melt season.

Researchers say they’ll now begin to explore the causes for this year’s melt.