Latest news with #AntarcticCircumpolarCurrent
Yahoo
29-03-2025
- Science
- Yahoo
New research suggests troubling phenomenon brewing in Antarctic waters — here's what we should prepare for
The Antarctic Circumpolar Current may be moving 20% slower by 2050, according to research described in The Conversation. Surrounding Antarctica in a ring, the Antarctic Circumpolar Current is the strongest ocean current in the world. However, its remote location has historically made it challenging to study, so it's not as well-understood as other currents of its caliber, as the researchers noted. However, modern technology has allowed researchers to delve into this subject further. Australia-based researchers Taimoor Sohail and Bishakhdatta Gayen, along with their colleague Andreas Klocker, used a supercomputer and climate simulator to predict future patterns of currents. "The model captures features others often miss, such as eddies," Sohail and Gayen explain in the Conversation. "So it's a far more accurate way to assess how the current's strength and behaviour will change. … It picks up the intricate interactions between ice melting and ocean circulation." The results weren't encouraging. The projection predicted that fresh water from newly melted Antarctic ice would flow northward and penetrate the deep sea, ultimately slowing the current. As the researchers detailed, the Antarctic Circumpolar Current keeps things in balance. Its chilly temperatures protect the Antarctic from warm water that could melt its shores and disturb its ecosystem. It links the Pacific, Atlantic, and Indian currents, and plays a crucial role in regulating the current climate. If the current slows down, a lot could change. A weaker current would harm fisheries that are important to coastal communities. Pesky invasive species could also worm their way into Antarctic ecosystems, pushing native species out and disrupting the ecosystem's already delicate balance. Such increased competition for resources can lead to the extinction of marine species. Polar ice melting can also trigger domino effects across the rest of the globe, even contributing to droughts and heat waves. Yes, this prediction is bad. No, it's not hopeless. If this comes to pass, it won't happen until 2050. There's still time to limit the melting and keep the Antarctic Circumpolar Current intact. Many organizations are dedicated to combating critical climate issues like this one. For instance, one Dutch startup, Arctic Reflections, is looking to restore Arctic sea ice by pumping cool water onto the ocean's surface. Should we be harnessing the ocean to power our homes? Absolutely Leave it be It depends I'm not sure Click your choice to see results and speak your mind. If you want to do your part to slow the planet's warming, you could install solar panels, upgrade to an induction stove, or donate to climate causes, among many other possibilities designed around the primary goal of helping yourself while helping the planet that are covered in the TCD Guide. However, it's important to remember that big issues like this can't be fully addressed without policy changes. Sohail and Gayen explained in the Conversation that "proactive and coordinated international actions" are the key to the planet's healthy future. Join our free newsletter for good news and useful tips, and don't miss this cool list of easy ways to help yourself while helping the planet.
CBC
18-03-2025
- Science
- CBC
In Antarctica, Canadian scientists have a 'momentous' chance to learn more about climate change
Social Sharing In the middle of an active volcano at the bottom of the world, dozens of fur seals bask in blowing wet snow. They are mostly unfussed by their two-legged guests. Around them lie cockeyed iron tanks and wooden boats from an early 20th-century whaling settlement, so weathered they're nearly absorbed by the black sand beach. Traces of Chilean and British bases appear just as humbled. On the surface, Deception Island's Whalers Bay is still humanity's biggest imprint on Antarctica, outside of its 80 or so research stations. But a climate scientist might say otherwise. Studies on this fragile continent have documented how temperatures, glaciers, oceans and wildlife are reacting to the warming consequences of fossil fuel emissions. A place this remote and isolated makes a perfect laboratory for grasping the past, present and future of the Earth's climate, according to many scientists drawn to Antarctica. It's a case study with high stakes, says Natural Resources Canada scientist Thomas James, who is leading the first all-Canadian expedition to the region. "What happens in Antarctica doesn't stay here," he said, while recently walking the beach at Whalers Bay, as scientists gathered samples from the sand, snow and air around him. Climate shifts ripple beyond Antarctica It's understood that climate change doesn't acknowledge politically drawn borders. But James explains that Antarctica's ice and cold oceans play an outsized role in regulating our climate. Just this month, researchers identified that melting freshwater from Antarctica's glaciers is altering the water chemistry of the Southern Ocean. They predict that the changed salinity will slow the vital Antarctic Circumpolar Current by 20 per cent by 2050. The strongest current on Earth, the ACC's influence extends to the Atlantic, Pacific and Indian oceans, pumping water, heat and nutrients around the world. The current also protects Antarctica's ice sheets — large masses of land-based ice — from warmer northern waters, preventing sea level rise, which would impact coastal communities around the globe. "We know that the Antarctic ice sheet is potentially unstable and could provide larger amounts of sea level change than the present models currently predict," said James. "It's a huge reservoir of fresh water." He's studied Antarctica for more than 30 years, but his field work has mainly been in the northern polar region; this is only James's second time in Antarctica. "We think that spending some time understanding the Antarctic ice sheet and the implications for sea level change is very important for Canadians." It's not just ice sheets that are melting. Sea ice (frozen sea water) at the poles has reached record lows three months in a row. "The fact that we're now seeing a reduction in Antarctic sea ice is really just one of many, many indicators that global climate change is happening," said James. "It's happening in all facets of the environment, and in many cases it appears to be accelerating." Team of strangers contribute to climate science James's team of 15 scientists — many of them strangers before this expedition — cross numerous disciplines of science. They are studying not only the ice sheet but glacial melt, the ocean floor, contaminants like microplastics and the sea water itself. Aboard the HMCS Margaret Brooke, they are supported by the Royal Canadian Navy, which runs the winches, cranes and boats to help the scientists collect a mass of samples around the South Shetland Islands off the tip of the Antarctic Peninsula. It is part of the RCN's larger Operation PROJECTION, to circumnavigate South America, strengthening alliances with other southern navies and gathering experience in the southern polar region. Militaries may only enter Antarctica's boundaries if they are supporting scientific research, a rule set out in the Antarctic Treaty, which governs the continent. The Arctic and offshore patrol ship will only cover a small fraction of the continent over four weeks of maritime transit from Chile's Punta Arenas, but the voyage and science work takes enormous effort. From early-morning trips on zodiac boats to glacier-lined coasts to late-night, deep-water collection using an elaborate crane, winch and boom system designed in Halifax, the science team is putting in long hours, determined to maximize their rare Antarctic access. Brent Else is one of the scientists, here to study the ocean's chemical properties. "It turns out that oceans absorb a lot of carbon dioxide from the atmosphere," said the University of Calgary researcher. "If you look back over time, sort of since industrialization, they've probably taken up about the equivalent of about 40 per cent of all of the emissions that humans put into the atmosphere. So that gives us a huge break on climate change. What we really need to understand is, will the oceans continue to do that?" Because of its cold temperatures, the Southern Ocean has the ability to sink carbon to significant depths — and keep it out of the atmosphere — for hundreds of years. "It's really important that we understand what's going on in polar oceans, especially because they're changing the fastest," said Else. "So in an area like Antarctica, as we start to get more ice sheet melting, that's going to put more freshwater into the Southern Ocean. And that might affect how all of these things interact." WATCH | This Antarctic island holds clues about future climate change: Antarctic island may hold clues about the climate's next century 7 days ago Duration 2:15 On Antarctica's Deception Island, Canadian scientists study the links between melting ice sheets and rising global sea levels, saying what happens in Antarctica doesn't stay there. It's why the interdisciplinary approach of this expedition is so advantageous. "Most science, by its nature, is incremental. And what we're doing is adding to that body of knowledge," said James. The team will take back thousands of samples for analysis over the coming weeks and months. Many of them will go to other researchers back home in Canada.
Yahoo
17-03-2025
- Science
- Yahoo
The 'heart' of the ocean is slowing down, study finds
When you buy through links on our articles, Future and its syndication partners may earn a commission. Melting Antarctic ice is slowing Earth's strongest ocean current, according to a new study. The influx of cold meltwater could slow the Antarctic Circumpolar Current by up to 20% by 2050, researchers reported March 3 in the journal Environmental Research Letters. The slowdown could affect ocean temperatures, sea level rise and Antarctica's ecosystem, the team said. The Antarctic Circumpolar Current, which swirls clockwise around Antarctica, transports around a billion liters (264 million gallons) of water per second. It keeps warmer water away from the Antarctic Ice Sheet and connects the Atlantic, Pacific, Indian and Southern oceans, providing a pathway for heat exchange between these bodies of water. Climate change has caused Antarctic ice to melt rapidly in recent years, adding an influx of fresh, cold water to the Southern Ocean. To explore how this influx will affect the Antarctic Circumpolar Current's strength and circulation, Bishakhdatta Gayen, a fluid mechanist at the University of Melbourne in Australia, and his colleagues used Australia's fastest supercomputer and climate simulator to model interactions between the ocean and the ice sheet. Related: Are Atlantic Ocean currents weakening? A new study finds no, but other experts aren't so sure. Fresh, cold meltwater likely weakens the current, the team found. The meltwater dilutes the surrounding seawater and slows convection between surface water and deep water near the ice sheet. Over time, the deep Southern Ocean will warm as convection brings less cold water from the surface. Meltwater also makes its way farther north before sinking. Together, these changes affect the density profile of the world's oceans, which drives the slowdown. Such a slowdown could allow more warm water to reach the Antarctic Ice Sheet, thereby exacerbating the melting that's already been observed. In addition to contributing to sea level rise, this could add even more meltwater to the Southern Ocean and weaken the Antarctic Circumpolar Current further. The Antarctic Circumpolar Current also acts as a barrier against invasive species by directing non-native plants — and any animals hitching a ride on them — away from the continent. If the current slows or weakens, this barrier could become less effective. RELATED STORIES —Zoom through a 'spectacular' chain of ancient underwater volcanoes on Antarctic ocean floor —'We are approaching the tipping point': Marker for the collapse of key Atlantic current discovered —Gulf Stream's fate to be decided by climate 'tug-of-war' "It's like a merry-go-round. It keeps on moving around and around, so it takes a longer time to come back to Antarctica," Gayen said. "If it slows down, what will happen is, things can migrate very quickly to the Antarctic coastline." It's difficult to say when we'll start to feel the effects — if we haven't started feeling them already. The Antarctic Circumpolar Current hasn't been monitored very long because it's in such a remote location, Gayen told Live Science. To better differentiate warming-induced changes from baseline conditions, "we need a long-term record," he said. The effects of the slowdown will be felt even in other oceans. "This is where the ocean heart sits," Gayen said. "If something stops there, or something different is happening, it's going to impact each and every ocean circulation."
Yahoo
05-03-2025
- Science
- Yahoo
World's strongest ocean current becoming weaker due to melting Antarctic ice: Study
Recent studies show the melting ice sheets surrounding Antarctica are having repercussions on the Antarctic Circumpolar Current (ACC), the world's strongest ocean current. This change could perturb integrated climate systems on a global scale, altering sea levels, ocean temperatures, or even marine ecosystems. According to a study conducted by the University of Melbourne and NORCE Norway Research Centre, if carbon emissions are not controlled, the ACC may decelerate by up to 20% by 2050. Increases in freshwater due to melting ice are changing patterns of saltiness and circulation in the ocean, and this is affecting the balance that allows currents to circulate around the globe. 'The ocean is extremely complex and finely balanced. If this current 'engine' breaks down, there could be severe consequences, including more climate variability, with greater extremes in certain regions, and accelerated global warming due to a reduction in the ocean's capacity to act as a carbon sink,' said Bishakhdatta Gayen, one of the study authors. The ACC is a major player in the world's ocean movement, acting as a key component of the "ocean conveyor belt," responsible for maintaining the movement of water between the Atlantic, Pacific, and Indian Oceans. Furthermore, it assists in climate control, including the distribution of heat, carbon dioxide, and nutrients to different ocean basins. The ACC is over four times as powerful as the Gulf Stream. As a result, the ACC significantly controls the migration of a number of species across the ocean. With the current weakening, there is a potential risk of certain species, such as bull kelp, shrimps, and mollusks, invading the Antarctic waters and putting the fragile ecosystems and food chains in grave danger. The possible shifts in available prey could affect the population of penguins, thereby affecting the biodiversity of the entire region. Researchers analyzed these microdetails through Australia's fastest supercomputer, GADI, using which they simulated the ocean currents and climatic changes. The model incorporated the change in monsoon patterns, intake of saline water, and other free atmospheric wind conditions to determine the ice melt effect on oceanic circulation. These findings contradict earlier research that said that the ACC had been accelerating owing to the growing range in temperature across oceanic latitudinal regions. The study's major finding, instead, was that large quantities of freshwater from melting ice sheets reduce the ocean's salinity, which weakens the process that drives cold, dense water to sink and circulate—a key mechanism behind ACC strength. The research reveals it isn't just the high emissions scare – even in a scenario predicated on weaker emissions where the ice continues to melt. The severity of change is still imminent. 'The 2015 Paris Agreement aimed to limit global warming to 1.5 degrees Celsius above pre-industrial levels. Many scientists agree that we have already reached this 1.5-degree target, and it is likely to get hotter, with flow-on impacts on Antarctic ice melting,' said Taimoor Sohail, one of the study authors. The scientists believe that there is more work required, such as climatograph modeling and animation simulations, to consider the complete ACC slowdown effects caused by climate change. 'Ocean models have historically been unable to adequately resolve the small-scale processes that control current strength. This model resolves such processes, and shows a mechanism through which the ACC is projected to actually slow down in the future. However, further observational and modelling studies of this poorly-observed region are necessary to definitively discern the current's response to climate change,' concluded Gayen. The study has been published in Environmental Research Letters.
Ammon
05-03-2025
- Science
- Ammon
Melting Antarctic ice sheets will slow Earth's strongest ocean current
Ammon News - Melting ice sheets are slowing the Antarctic Circumpolar Current (ACC), the world's strongest ocean current, researchers have found. This melting has implications for global climate indicators, including sea level rise, ocean warming and viability of marine ecosystems. The researchers, from the University of Melbourne and NORCE Norway Research Centre, have shown the current slowing by around 20 per cent by 2050 in a high carbon emissions scenario. This influx of fresh water into the Southern Ocean is expected to change the properties, such as density (salinity), of the ocean and its circulation patterns. University of Melbourne researchers, fluid mechanist Associate Professor Bishakhdatta Gayen and climate scientist Dr Taimoor Sohail, and oceanographer Dr Andreas Klocker from the NORCE Norwegian Research Centre, analysed a high-resolution ocean and sea ice simulation of ocean currents, heat transport and other factors to diagnose the impact of changing temperature, saltiness and wind conditions. Associate Professor Gayen said: "The ocean is extremely complex and finely balanced. If this current 'engine' breaks down, there could be severe consequences, including more climate variability, with greater extremes in certain regions, and accelerated global warming due to a reduction in the ocean's capacity to act as a carbon sink." The ACC works as a barrier to invasive species, like rafts of southern bull kelp that ride the currents, or marine-borne animals like shrimp or molluscs, from other continents reaching Antarctica. As the ACC slows and weakens, there is a higher likelihood such species will make their way onto the fragile Antarctic continent, with a potentially severe impact on the food web, which may, for example, change the available diet of Antarctic penguins. More than four times stronger than the gulf stream, the ACC is a crucial part of the world's "ocean conveyor belt," which moves water around the globe linking the Atlantic, Pacific and Indian Oceans and is the main mechanism for the exchange of heat, carbon dioxide, chemicals and biology across these ocean basins. Science Daily
