The new study focused on summer lightning flashes, or “strokes,” detected above 65 degrees latitude—that includes parts of northern Canada, Alaska and Russia, as well as Greenland and the central Arctic Ocean.
The data suggests that the total number of Arctic lightning strokes has risen sharply since 2010.
Still, the scientists wanted to be sure. The World Wide Lightning Location Network has added a number of sensors over the last 10 years, and the increase in strokes could have been the simple product of better detection. So the team adjusted their data to account for the new equipment.
The study points out that summer temperatures in the Arctic have risen by about a half-degree Fahrenheit over the last decade.
While scientists know there’s a connection between air temperature and thunderstorms, the study doesn’t actually prove that warming has caused the lightning. It simply suggests there could be a link. More research would be needed to demonstrate the connection.
Still, other studies have suggested that continued climate change may cause an increase in Arctic thunderstorms. One recent paper, published in September in Climate Dynamics, projects that thunderstorms would triple in Alaska by the end of the century under a severe climate change scenario.
A follow-up study published last month in the same journal suggests that increased humidity, driven by warming and melting sea ice, is the driver.
The Arctic Ocean saw February temperatures that were warmer than the past two decades’ average, according to a report released Monday by Europe’s Copernicus Climate Change Service.
Worldwide, the month’s temperatures were close to the average for the past 30 years but included the coldest anomaly in nearly six years, according to the organization’s report.
“Conditions were much colder than its 1991-2020 average over much of Russia and North America, but much warmer than average over parts of the Arctic and in a band stretching eastward from north-western Africa and southern Europe to China,” the report states. “Temperature for Europe as a whole, for February 2021, was also close to the 1991-2020 average, though parts of Europe saw considerable variation in temperatures during the month.”
Copernicus further found that the extent of sea ice was lower than average in the arctic and Antarctic regions during February, with coverage lowest compared to years past in Canada’s northeastern regions.
Other northern regions of the globe saw colder-than-average temperatures in February, particularly the northwestern regions of Russia, although Norwegian island chain Svalbard was an exception to the trend, according to the report.
Twelve-month average temperatures were the highest above the 1991-2020 average over northern Siberia and over Canada’s far northeastern regions, according to the research. They were above the 12-month average over most of the European continent except for parts of its northwestern and eastern regions.
“The average December-February temperature for Europe was 0.6°C above the 1991-2020 average for the season,” the report states. “This is 2.3°C lower than the corresponding value for 2019/20, the warmest winter average on record. Winter 2020/21 was similar in average European temperature to the winters of 2017/18 and 2018/19, but nine of the earlier winters since 1979/1980 were warmer.”
Scientists have said the warming of the earth’s poles are in part to blame for extreme weather events such as the winter weather that battered the Great Plains and Texas in February.
“It’s no secret that extreme weather events are happening more frequently,” Jennifer Francis, a senior scientist at the Woodwell Climate Research Center in Woods Hole, Mass., told Bloomberg News. “Climate scientists have been predicting this behavior for years, maybe decades, so it comes as no surprise whatsoever that we’re seeing back-to-back extremes of various types around the globe.”
Winter Storm Uri brought snow and freezing temperatures to Texas this week, causing multiple deaths and damage to infrastructure.
Climate scientists have spent years exploring the relationship between extreme winter weather and warming temperatures in the Arctic Circle.
Some studies suggest that the warming Arctic disrupts a natural phenomenon known as the polar vortex, which normally contains cold air in the north.
Winter Storm Uri battered the southern U.S. this week with frigid temperatures and unusually high snowfall. In Texas, the cold weather brought widespread power outages and damage to infrastructure, contributing to at least several dozen deaths.
But while the consequences of the storm are evidence, its causes are more of a mystery. In the context of climate change, the recent weather raises an obvious question: If the climate is warming, why are some parts of the world experiencing bouts of extreme cold?
It’s a topic climate scientists have been exploring for years.
But warm weather can disrupt this system. When temperatures rise, the jet stream weakens and becomes wobbly, sometimes allowing cold air to shoot out across the planet. What may be contributing to disruptions in the polar vortex is a phenomenon called Arctic amplification, which describes how the Arctic has warmed by more than twice the global average in recent decades.
Although some studies suggest relationships between the warming Arctic and increased winter storms, scientists still aren’t exactly sure how Arctic climate change might be reshaping winters around the world. For example, the polar vortex is a natural phenomenon, and so some of its fluctuations could be attributed to natural variability. What’s more, other factors, like changes to Arctic atmosphere and sea ice, might also play a role.
Given the complexity of climate systems, it’s difficult for scientists to determine how changing temperatures in one region may affect weather patterns in another. But that’s not to say they’re all in complete disagreement. A 2020 paper published in Nature, for example, commented on the “divergent consensuses” between various observational and model studies on the topic of Arctic warming and severe winter weather.
“The divide on the influence of Arctic change has contributed to the impression that this research topic is controversial and lacking consensus,” the authors wrote. “An alternative interpretation is that the wide range of results should be expected, owing to the varying approaches to studying the problem and the complexity and intermittency of Arctic/midlatitude connection.”
While scientists continue to study the relationship between the Arctic and weather patterns across the globe, other climate trends are relatively clear.
The average surface temperature of the planet has risen about 2.12 degrees Fahrenheit since the late 19th century, warming at a rate nearly 10 times faster than the planet did after the Ice Age, according to NASA. And despite warmer temperatures, the NOAA reports that the U.S. was hit by nearly twice the amount of extreme winter storms during the later half of the 20th century than the first.
For many, especially folks who live in the South, the arctic outbreak that has gripped the nation’s heartland for the past week is the kind of cold that only happens once in a century. Countless record cold temperatures were set. Conditions overwhelmed the Texas power grid, cutting off electricity to millions and bursting water pipes, creating a humanitarian crisis.
But with climate change making for generally warmer winters and causing heat records to outnumber cold records by 2 to 1 globally over the past decade, this historic cold snap may seem counterintuitive. It’s not. In fact, paradoxically, a warmer climate may have actually contributed to the extreme cold.
CBS News previewed the wild winter weather in this January 7th article, explaining how over the course of just a few days in late December and early January, temperatures in the atmosphere high above the North Pole warmed by 100 degrees Fahrenheit — jumping from minus-110 degrees Fahrenheit to minus-10.
SSW’s are a natural occurrence which happen every couple of winters and portend extreme weather in the weeks following them. That’s because when the Arctic warms rapidly it disrupts a spinning mass of cold air — the polar vortex — a semi-permanent weather system which is present each winter.
Normally the jet stream winds around the vortex and acts as a lasso of sorts, keeping the cold air trapped inside. But when it gets warm in the Arctic, the jet stream weakens and elongates, allowing the cold air to plunge south.
What made this particular situation historic was that the core of the cold air — a piece of the polar vortex — plunged much further south than it really ever does: a full 4,000 miles from its usual home near the North Pole.
While this extreme cold paired with extreme heat may seem odd, it’s actually what meteorologists would expect of a wavy jet stream. Think of it this way: what goes up must come down. When the atmosphere forces cold air south, there must be an equal and opposite reaction forcing warm air north. When air masses are displaced into places they don’t typically visit, weather extremes and the impacts they bring to society follow.
A number of climate scientists think that climate change may not only be making sudden stratospheric warming more likely, but that climate change itself may have a similar effect in the Arctic, because it is also causing significant warming. Due to human-caused climate change, the Arctic is warming at three times the pace of the global average.
The wavy jet stream theory, as it relates to climate change, was pioneered by Dr. Jennifer Francis at Woodwell Climate Research Center. The theory makes logical sense: Arctic warming reduces the gradient between warm and cold air, and thus weakens the temperature contrast mechanism which powers the strength of the jet stream. That results in a weaker, more wavy jet stream, which is more likely to spill its cold air southward.
The theory has since been adopted by many other climate scientists, who view the apparent increasing extremes, like this latest bitter blast, as sign the theory has merit. But a sizable group of other scientists have their doubts about the impact of climate change and Arctic amplification on the jet stream.
That’s partly because the atmosphere is very noisy and climate models are not quite yet capable of reproducing the finer details of a complex system. Thus, finding evidence to definitively prove or disprove the theory has been a challenge. But many long-time meteorologists believe the logic, the research and the qualitative evidence they have observed is enough to make the case.
What all meteorologists and climate scientists can agree on is this extreme event was set in motion by a Sudden Stratospheric Warming. That was the driving force.
For those tired of cold and snow, good news: it seems the extreme pattern has about run its course. The globe is about to return to a more normal pattern. That does not preclude cold air outbreaks and snowstorms for the U.S. as we head into spring, but it should allow the weather to return to some degree of normalcy.
The polar vortex has become synonymous with winter’s most brutal cold. For days, the weather system has been sitting and spinning right along the U.S.-Canada border, with temperatures as low as 43 degrees below zero in northern Minnesota.
But now, there are signs it is about to surge south, bringing with it record-shattering cold air from the far reaches of Alaska and Northern Canada. By the weekend, temperatures in Kansas City and St. Louis will be below what’s normal for Fairbanks, Alaska.
This bitter airmass landed there because of a phenomenon called a sudden stratospheric warming, a natural event that occurs 50,000 to 100,000 feet above the Arctic every couple of years, throwing weather patterns off-kilter. This event is often followed by a mountain of unusually warm air near the Arctic circle that acts to reroute pieces of the cold polar vortex southward.
From Friday through Monday, more than 100 record low readings will be in jeopardy in the heartland, with temperatures as low as 40 degrees below zero in the northern Plain States and wind chills as low as 60 below on Sunday morning.
Temperatures will drop to near zero as far south as North Texas. On Sunday, temperatures in Kansas City and St. Louis, Missouri, will not climb out of the single digits, colder than the normal high temperature of 7 degrees in Fairbanks, Alaska, this time of year.
Extreme cold will not be the only hazard. Disturbances will ride along the frontal boundary separating bitter cold to the north and warm, moist air to the south. From Wednesday through Friday snow, ice and rain will straddle the boundary, with some areas from Dallas, Texas, to Little Rock, Arkansas, to Lexington, Kentucky, getting a glaze of treacherous ice.
Washington, D.C., will be just north of the front, and for the nation’s capital, that means mainly snow. From Wednesday afternoon through Friday morning, the area will pick up an extended period of intermittent light to moderate snowfall. In total, from West Virginia to Roanoke and Northern Virginia a general 5 to 10 inches will accumulate.
Further north in New York City, the cold-dry airmass will block the storm system, keeping it to the south. While snow showers will fly on Thursday and Friday, they will not amount to much. That is, until Sunday, when a stronger storm looks to take aim at the rest of the Northeast. If it materializes, another significant snow and ice storm may be in the cards.
After Trump’s sell off, the Arctic Refuge gets a reprieve
Just hours after being sworn into office, President Biden took a number of monumental actions to protect public lands, address the climate crisis and combat systemic racism, including an executive order that places a moratorium on all oil and gas activity in the Arctic National Wildlife Refuge.
This occurred only one day after the previous administration issued leases for drilling in the refuge’s coastal plain in a rushed, flawed and likely illegal process.
Biden’s action was met with great enthusiasm, particularly by many Gwich’in and Iñupiat peoples who have depended on and protected the refuge for thousands of years and rely on the caribou and other resources in the refuge to sustain their communities and cultures.
“Mashi’ choo, President Biden,” said Bernadette Demientieff, executive director of the Gwich’in Steering Committee. “The Gwich’in Nation is grateful to the president for his commitment to protecting sacred lands and the Gwich’in way of life.”
The executive order also reinstated President Obama’s withdrawal of most of the Arctic Ocean and parts of the Bering Sea from oil and gas drilling—an order that had been reversed by the Trump administration. Protecting offshore areas from the threat of a major oil spill benefits not only marine species such as fish, seals and bowhead whales, but the coastlines of sensitive lands like the Arctic Refuge, too.
We are grateful to President Biden for his commitment to protect the refuge, address the climate crisis and respect the human rights of Indigenous peoples. We are also grateful to the millions of people who made today’s announcement possible by putting the climate and social justice first. This action is a result of years of advocacy from people across the United States, including members and supporters of The Wilderness Society, who refused to stay silent as oil corporations and their friends sought to put drilling rigs in the Arctic Refuge.
This action is a result of years of advocacy from people across the United States, including members and supporters of The Wilderness Society.
This does not mean the fight to protect the Arctic Refuge and the calving grounds of the Porcupine Caribou Herd is over. The moratorium is temporary. But it’s a huge first step in Biden’s plan to review the legality of the Jan. 6 Arctic Refuge lease sale and the issuance of leases to the winning bidders.
We will continue to work with our Gwich’in and Iñupiat partners—as well as the Biden administration and our allies in the Congress and the conservation community—as we explore all options for ensuring that drilling never occurs on the coastal plain of the Arctic Refuge. We’ll also keep putting pressure on corporations like banks and insurers.
But today we rest, raise a glass and celebrate a new day for the Arctic.
Researchers from the Universities of Bristol, Exeter, and Bath have come up with a new way to predict the knock-on effects of various changes to this major air current high up in the stratosphere, 10 to 50 kilometres (6 to 30 miles) overhead.
Ironically, the cause of this chill is a sudden burst of heat seeping into the whirling currents over a window of just 24 to 48 hours.
With its temperature surging by as much as 40 degrees Celsius, the vortex undergoes some rapid changes, changing course or dramatically breaking apart into daughter vortices that shove against surrounding atmosphere.
The results can be devastating. Just a few years ago, a sudden stratospheric warming (SSW) event nudged frigid polar air from Siberia into Europe, delivering a snow-laden cell of high pressure the media dubbed The Beast from the East.
That said, not all shifts in this polar vortex end in freezing conditions. Two years ago, warming of stratospheric polar winds preceded one of the warmest winter days in United Kingdom’s recorded history.
Knowing which deviations are portents of winter fury, and which will fizzle, will go a long way in making weather forecasting more accurate.
Surprisingly, such stratospheric warming events themselves aren’t exactly rare, with records suggesting an average of around half a dozen of them occur in the Arctic’s polar vortex every decade.
“While an extreme cold weather event is not a certainty, around two thirds of SSWs have a significant impact on surface weather,” says Richard Hall, University of Bristol meteorologist and lead author of the new study.
Observations dating back more than six decades have provided the researchers with 40 such examples of wobbles and splits in the northern stratospheric polar vortex, which inform a tracking algorithm that attempts to predict the impact each kind of change will have on weather systems across the northern hemisphere.
The results suggest any time the polar vortex splits into two smaller winds we can expect more severe cooling events, compared with other SSW anomalies.
It’s a timely result, with forecast changes to the air currents appearing over the weekend.
“As predicted, atmospheric observations are now showing that the Arctic stratosphere is undergoing a sudden warming event associated with a weakening stratospheric polar vortex,” says Adam Scaife, head of long-range prediction at the UK Met Office.
What’s more, the change has all the hallmarks of the more dangerous kind of SSW, meaning there’s a good chance that the predicted drop in temperature will be significant.
Having informed climate models certainly helps improve the odds of knowing what to expect. But while modelling on this scale benefits from improved algorithms, there’s still room for plenty of uncertainty when it comes to nailing down the precise details in coming days.
Oddly, it might even turn out that Europe sweats instead of shivers.
The UK experienced record-setting winter warmth after a SSW in February 2019 after all, so the Met Office doesn’t rule out the possibility of a similar swelter in coming weeks.
“Although the prolonged cold spell and snow events in February and March of 2018 – dubbed the ‘Beast from the East’ by the UK media – were linked to a sudden stratospheric warming, the record warm spell that occurred in February 2019 also followed such an event,” says meteorologist Matthew Lehnert.
We’ve got some way to go before we can promise with confidence which way the weather will go in the wake of these polar changes.
But tools like this new algorithm will improve the odds of guessing, and continue to do so the more we learn about our atmosphere.
“Despite this advance many questions remain as to the mechanisms causing these dramatic events, and how they can influence the surface, and so this is an exciting and important area for future research,” says mathematician William Seviour from the University of Exeter.
Millions of tons of organic carbon and methane beneath the Arctic Ocean thaw out and ooze to the surface each year. And climate change could speed up this release of greenhouse gases, new research suggests.
The carbon tied up in organic matter and methane (a carbon atom bound to four hydrogen atoms) are currently trapped in subsea permafrost, which is frozen sediment that became covered by 390 feet (120 meters) of seawater toward the end of the Paleolithic ice age about 1,800 to 1,400 years ago, according to the U. S. Geological Survey (USGS). Most subsea permafrost sits on the continental shelf under the Arctic Ocean, said study author Sayedeh Sara Sayedi, a doctoral student in the department of plant and wildlife science at Brigham Young University in Salt Lake City.
Because that sediment is in such an inaccessible spot, there’s only a little bit of patchy data on how much carbon and methane lie buried there and how quickly those gases are escaping into the ocean and atmosphere above, Sayedi added.
Somescientists consider this greenhouse gas reservoir to be a ticking time bomb, one that could suddenly spew into the atmosphere and trigger a climate catastrophe. But Sayedi and her colleagues propose a different scenario: Rather than a sudden release, these gases have been slowly and steadily oozing from the permafrost for centuries. Human-caused climate change could still make the situation worse by accelerating the rate of release, but this acceleration would occur over the course of several centuries, not decades or years.
“Still, the decisions we make today will make a difference in how it’s going to be affected,” Sayedi told Live Science.
In their new study, published Dec. 22 in the journal Environmental Research Letters, the team attempted to assemble a comprehensive picture of the subsea permafrost using all the piecemeal data currently available; they also asked 25 permafrost scientists to use their expertise to estimate how much organic carbon is hidden in each specific layer of subsea permafrost. By compiling their perspectives, the team captured a more detailed picture of the ecosystem as a whole, and they estimated that the permafrost currently holds about 60 billion tons (544 metric tons) of methane and 560 billion tons (508 metric tons) of organic carbon.
Each year, about 140 million tons (128 metric tons) of carbon dioxide and 5.3 million tons (4.8 metric tons) of methane escape from the permafrost into the atmosphere, they estimated. That’s roughly equivalent to the carbon footprint of Spain, according to a statement. That said, due to the paucity of data, these emissions estimates remain highly uncertain, the authors noted. RELATED CONTENT
The authors also concluded that, rather than being driven primarily by recent human activity, much of these greenhouse gas emissions began after the Last Glacial Maximum, when ice sheets were at their greatest extent. However, human-driven changes may still drive up these emissions “several hundreds or thousands of years from now,” they wrote.
In fact, over the next 300 years, the experts expect the rate of greenhouse gas emission from subsea permafrost to increase substantially if carbon emissions from human activity continue as usual. If emissions rise throughout the 21st century, the permafrost would release four times more greenhouse gas than if emissions started declining by the end of this year and reached net-zero by 2100.
In the business-as-usual scenario, the increase in emissions would ramp up over the next several centuries, but still not enough to create a so-called “methane bomb.”
By overlooking subsea permafrost in models of climate change, scientists run the risk of miscalculating the amount of greenhouse gas being emitted into the atmosphere, which may skew where we set our targets for reducing emissions, Sayedi said. In the next five to 10 years, Sayedi said that she hopes additional research into subsea permafrost can help fill the gaps in our knowledge and provide more certainty about how much carbon is actually down there — and how much is getting out. Other factors, such as the extent of sea-ice cover, may also affect how much gas leaks into the atmosphere, since the ice can act as a ceiling trapping the gas underneath, she said.
By JENNIFER CHU, MASSACHUSETTS INSTITUTE OF TECHNOLOGY DECEMBER 17, 2020
New study suggests waters will become more turbulent as Arctic loses summertime ice.
Eddies are often seen as the weather of the ocean. Like large-scale circulations in the atmosphere, eddies swirl through the ocean as slow-moving sea cyclones, sweeping up nutrients and heat, and transporting them around the world.
In most oceans, eddies are observed at every depth and are stronger at the surface. But since the 1970s, researchers have observed a peculiar pattern in the Arctic: In the summer, Arctic eddies resemble their counterparts in other oceans, popping up throughout the water column. However, with the return of winter ice, Arctic waters go quiet, and eddies are nowhere to be found in the first 50 meters beneath the ice. Meanwhile, deeper layers continue to stir up eddies, unaffected by the abrupt change in shallower waters.
This seasonal turn in Arctic eddy activity has puzzled scientists for decades. Now an MIT team has an explanation. In a paper published on December 15, 2020, in the Journal of Physical Oceanography, the researchers show that the main ingredients for driving eddy behavior in the Arctic are ice friction and ocean stratification.
By modeling the physics of the ocean, they found that wintertime ice acts as a frictional brake, slowing surface waters and preventing them from speeding into turbulent eddies. This effect only goes so deep; between 50 and 300 meters deep, the researchers found, the ocean’s salty, denser layers act to insulate water from frictional effects, allowing eddies to swirl year-round.
The results highlight a new connection between eddy activity, Arctic ice, and ocean stratification, that can now be factored into climate models to produce more accurate predictions of Arctic evolution with climate change.
“As the Arctic warms up, this dissipation mechanism for eddies, i.e. the presence of ice, will go away, because the ice won’t be there in summer and will be more mobile in the winter,” says John Marshall, professor of oceanography at MIT. “So what we expect to see moving into the future is an Arctic that is much more vigorously unstable, and that has implications for the large-scale dynamics of the Arctic system.”
Marshall’s co-authors on the paper include lead author Gianluca Meneghello, a research scientist in MIT’s Department of Earth, Atmospheric and Planetary Sciences, along with Camille Lique, Pal Erik Isachsen, Edward Doddridge, Jean-Michel Campin, Healther Regan, and Claude Talandier.
This image shows the activity of eddies simulated in the Arctic Ocean. The left panel shows seasonal changes in eddy activity at the surface of the ocean, compared to the right panel, where eddy behavior is unaffected by the seasons, and remains the same at deeper levels of the ocean. Credit: Courtesy of: Gianluca Meneghello
Beneath the surface
For their study, the researchers assembled data on Arctic ocean activity that were made available by the Woods Hole Oceanographic Institution. The data were collected between 2003 and 2018, from sensors measuring the velocity of the water at different depths throughout the water column.
The team averaged the data to produce a time series to produce a typical year of the Arctic Ocean’s velocities with depth. From these observations, a clear seasonal trend emerged: During the summer months with very little ice cover, they saw high velocities and more eddy activity at all depths of the ocean. In the winter, as ice grew and increased in thickness, shallow waters ground to a halt, and eddies disappeared, whereas deeper waters continued to show high-velocity activity.
“In most of the ocean, these eddies extend all the way to the surface,” Marshall says. “But in the Arctic winter, we find that eddies are kind of living beneath the surface, like submarines hanging out at depth, and they don’t get all the way up to the surface.”
To see what might be causing this curious seasonal change in eddy activity, the researchers carried out a “baroclinic instability analysis.” This model uses a set of equations describing the physics of the ocean, and determines how instabilities, such as weather systems in the atmosphere and eddies in the ocean, evolve under given conditions.
An icy rub
The researchers plugged various conditions into the model, and for each condition they introduced small perturbations similar to ripples from surface winds or a passing boat, at various ocean depths. They then ran the model forward to see whether the perturbations would evolve into larger, faster eddies.
The researchers found that when they plugged in both the frictional effect of sea ice and the effect of stratification, as in the varying density layers of the Arctic waters, the model produced water velocities that matched what the researchers initially saw in actual observations. That is, they saw that without friction from ice, eddies formed freely at all ocean depths. With increasing friction and ice thickness, waters slowed and eddies disappeared in the ocean’s first 50 meters. Below this boundary, where the water’s density, i.e. its stratification, changes dramatically, eddies continued to swirl.
When they plugged in other initial conditions, such as a stratification that was less representative of the real Arctic ocean, the model’s results were a weaker match with observations.
“We’re the first to put forward a simple explanation for what we’re seeing, which is that subsurface eddies remain vigorous all year round, and surface eddies, as soon as ice is around, get rubbed out because of frictional effects,” Marshall explains.
Now that they have confirmed that ice friction and stratification have an effect on Arctic eddies, the researchers speculate that this relationship will have a large impact on shaping the Arctic in the next few decades. There have been other studies showing that summertime Arctic ice, already receding faster year by year, will completely disappear by the year 2050. With less ice, waters will be free to swirl up into eddies, at the surface and at depth. Increased eddy activity in the summer could bring in heat from other parts of the world, further warming the Arctic.
At the same time, the wintertime Arctic will be ice covered for the foreseeable future, notes Meneghello. Whether a warming Arctic will result in more ocean turbulence throughout the year or in a stronger variability over the seasons will depend on sea ice’s strength.
Regardless, “if we move into a world where there is no ice at all in the summer and weaker ice during winter, the eddy activity will increase,” Meneghello says. “That has important implications for things moving around in the water, like tracers and nutrients and heat, and feedback on the ice itself.”
Reference: “Genesis and decay of mesoscale baroclinic eddies in the seasonally ice-covered interior Arctic Ocean” by Gianluca Meneghello, John Marshall, Camille Lique, Pål Erik Isachsen, Edward Doddridge, Jean-Michel Campin, Heather Regan and Claude Talandier, 15 December 2020, Journal of Physical Oceanography. DOI: 10.1175/JPO-D-20-0054.1
The moon could be affecting how much methane is released from the Arctic Ocean seafloor, a new study finds.
The tides, which are controlled by the moon, affect how much methane is released from seafloor sediments: Low tides mean less pressure and more methane released, while high tides create more pressure, and therefore less methane emission.
The research was conducted in the west-Svalbard region of the Arctic, with the findings published Oct. 9 in the journal Nature Communications.
“It is the first time that this observation has been made in the Arctic Ocean. It means that slight pressure changes can release significant amounts of methane. This is a game-changer and the highest impact of the study,” study coauthor, Jochen Knies, a marine geologist at the Centre for Arctic Gas Hydrate, Environment and Climate (CAGE), said in a statement.
Methane is a greenhouse gas, which contributes to global warming by trapping and holding heat in the atmosphere. Huge methane reserves lurk beneath the seafloor and ocean warming is expected to unlock some of that trapped methane. So understanding how the tides impact these seafloor methane emissions is important for future climate predictions.
To find this tidal effect, the team measured the pressure and temperature inside the sediments and found that gas levels near the seafloor rise and fall with the tides.
By using a permanent monitoring tool they were able to identify methane release in an area of the Arctic Ocean where it has not previously been observed.
“This tells us that gas release from the seafloor is more widespread than we can see using traditional sonar surveys,” study co-author, Andreia Plaza Faverola, a marine geologist and geophysicist at CAGE, said in the statement. Image 1 of 2
Their discovery implies that scientists have been underestimating greenhouse gas emissions in the Arctic. RELATED CONTENT
“What we found was unexpected and the implications are big. This is a deep-water site. Small changes in pressure can increase the gas emissions but the methane will still stay in the ocean due to the water depth. But what happens in shallower sites? This approach needs to be done in shallow Arctic waters as well, over a longer period. In shallow water, the possibility that methane will reach the atmosphere is greater,” Knies said.
This newly discovered phenomenon also raises questions about how rising sea levels and ocean warming, both of which are caused by climate change, will interact. Because high tides reduce methane emissions, it’s possible rising sea levels, which come with higher tides, might partially counterbalance the threat of increased gas emissions being caused by a warming ocean.