Harvard Medical School’s cutting-edge microscopes have the potential to revolutionize cancer detection and lifespan research. However, a scientist who developed computer scripts to extract maximum information from the images found herself in immigration detention for two months, jeopardizing significant scientific advancements.
The scientist in question is 30-year-old Russian-born Xenia Petrova, who worked at Harvard’s renowned Kirschner Institute until her arrest at Boston Airport in mid-February. Currently detained at the Richwood Correctional Center in Monroe, Louisiana, Petrova is fighting against deportation to Russia, where she fears persecution and imprisonment due to her participation in protests against the conflict in Ukraine.
The incident involving Petrova and the detention of scholars across the country have hindered American universities’ ability to attract and retain crucial talent, a concern raised by Petrova’s colleagues. In fields where expertise is highly specialized, the loss of talent could have grave global implications for the future of medicine and scientific discovery. Scientists and faculty members are contemplating leaving institutions nationwide out of fear that their visas may be revoked or impacted by immigration enforcement actions.
“It’s like a meat grinder,” Petrova, as per a person talking to NBC News from the Louisiana facility, described her situation. “We are all in this system, regardless of having a visa, green card, or a valid reason.”
Petrova’s first immigration court hearing in Louisiana is scheduled for Tuesday morning, where she expects more clarity on her asylum case. Dr. Leon Peshkin, a prominent research scientist at Harvard University’s Faculty of Systems Biology and Petrova’s supervisor, received a call from Customs and Border Protection on February 16, notifying him of Petrova’s detention at Logan International Airport for failing to declare a sample of frog embryos used in research.
International researchers are increasingly anxious about the Trump administration’s strict stance on illegal immigration, with concerns that these policies could deter other foreign scientists from coming to Harvard. Recent surveys indicate a significant portion of scientists are contemplating relocating to Europe or Canada due to actions taken by President Donald Trump.
Iceberg calving from a Greenland glacier can carry rocks to distant coasts
Professor Ross Mitchell
The rocks transported by icebergs from Greenland to Iceland add to evidence that the European climate became much colder for a century or two in 540 AD.
This cold season in the Northern Hemisphere has been shown previously by research on tree rings and sediment cores, but is linked to many historical events around the world, from the collapse of the northern WEI dynasty in China to the decline of the city of Teotihuacan, Central America. The Justinian plague that affected the Eastern Roman Empire after the collapse of the Western Roman Empire in 476 may also have been caused in part by cold weather.
Christopher Spencer Queen’s University in Kingston, Canada and his colleagues decided to explore Iceland’s west coast beaches, as they showed it was a light colour, rather than the basalt black of almost every other beach in Iceland.
Its bright colour turned out to be due to the presence of many shells, but while walking through the area, Spencer spotted a cobblestone-sized granite stone. It was immediately clear to him that these rocks were not from Iceland. “It’s a bit embarrassing how easy it is to make a discovery,” he says.
Sure enough, analysis of the rocks confirmed that they came from various parts of Greenland. Greenland is the closest point, about 300 km from Iceland. So, Spencer must have been carried by icebergs spotted and washed away on the beach from Greenland’s glacier.
The beach formations where Greenland rocks reside were previously dated from AD 500 to AD 700, says Spencer. Greenland icebergs can still reach this area, but Greenland Rock has not been found in other layers of the beach.
An ancient rock collection analyzed in the study was traced to Greenland
Dr. Christopher Spencer
Therefore, this finding indicates that numerous Greenlandic Icebergs were washed away at this beach during the period when this layer was formed. This suggests that because of the cold conditions, Greenland’s glaciers grew larger during this period, hiding more icebergs, says Spencer.
This is neatly linked to evidence of cold seasons, sometimes known as the late antique red ice age. The cause of this event is unknown. Some people think it was caused by volcanoes, while others think it was caused by a surprising piece of Earth from a comet. Spencer believes that the solar heat is simply dependent on changes in the orbit that reaches Earth.
The extent to which climate contributed to events such as the collapse of Rome remains debated, but there is growing evidence that climate change has shaped the fate of many civilizations.
Antarctic Circulating Current (ACC), which is more than four times as strong as the Gulf Stream, is the world’s strongest ocean current and plays an unbalanced role in the climate system due to its role as a major basin conduit. Scientists at the University of Melbourne and the Research Centre in Nordic Norway have shown that ACC will slow by about 20% by 2050 in high carbon emission scenarios. This influx of freshwater into the southern ocean is expected to alter the properties such as the density (salinity) of the ocean and its circulation patterns.
Sohail et al. High-resolution ocean and sea ice simulations of ocean currents, heat transport, and other factors were analyzed to diagnose the effects of temperature changes, saltiness, and wind conditions. Image credit: Sohail et al. , doi: 10.1088/1748-9326/adb31c.
“The oceans are extremely complex, finely balanced,” says Dr. Bishakhdatta Gayen, liquid mechanic at the University of Melbourne.
“If this current ‘engine’ collapses, serious consequences, including more climate change, including extreme extreme climate variability in certain regions, will accelerate global warming due to a decline in the ability of the ocean to function as a carbon sink. “
The ACC acts as a barrier to invasive species, like the southern burkelp and marine vectors such as shrimp and mollusks, which travel in the current from other continents reaching Antarctica.
If this current slows and weakens, it is more likely that such species will head towards the fragile Antarctica, potentially serious effects on food webs, which could change the available diet of Antarctic penguins, for example.
The ACC is an important part of the marine conveyor belt around the world, moving water around the world and linking the Atlantic, Pacific and Indian seas. These are the main mechanisms of exchange of heat, carbon dioxide, chemicals and biology throughout these basins.
In their study, the authors used Gadi, the fastest supercomputer in Australia located on the Access National Research Infrastructure.
They discovered that transport of seawater from the surface to the deepest could also be slower in the future.
“If ice melting accelerates as predicted by other studies, slowdowns are predicted to be similar in low emission scenarios,” Dr. Sohail said.
“The 2015 Paris Agreement aims 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, which could have an impact on the melting of Antarctic ice, making it even hotter.”
“Cooperative efforts to limit global warming (by reducing carbon emissions) will limit the melting of Antarctic ice and avoid the expected slowdown in ACC.”
This study reveals that the effects of ice melting and ocean warming on ACC are more complicated than previously thought.
“The melted ice sheets throw a large amount of fresh water from salt water into the salty sea.”
“This sudden change in ocean salinity has a series of results, including weakening of subsidence to the depths of surface seawater (called Antarctic bottom water), and based on this study, it includes weakening of the powerful marine jets surrounding Antarctica,” Dr. Gayen said.
study Published in the journal Environmental Survey Letter.
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Taimoor Sohail et al. 2025. Decreasing the polar current in the Antarctic due to polarization. environment. res. Rent 20, 034046; doi:10.1088/1748-9326/adb31c
According to satellite measurements from the European Union’s Climate Service Copernicus, there is less sea ice covering the ocean this February.
“One of the consequences of a warm world is to melt sea ice, and both Poles’ records or near-recorded low-sea ice covers have pushed the world’s sea ice cover to the lowest ever.” Samantha Burgess The European Middle Distance Centre is forecast in a statement. According to the service, global temperatures in February this year rose 1.59°C above the pre-industrial average, making it the third security in March on record.
These high temperatures have affected the global sea ice range, including both the Arctic and Antarctic, which is currently close to the largest in the year. Satellite records from both regions date back to 1979.
In the Arctic, sea ice was 8% below average throughout February, missing an area of nearly the size of the UK ice. This was the three consecutive months of successive months that set a low monthly new record in the Arctic.
This decline in the Northern Hemisphere is combined with the long-term decline in Antarctic sea ice seen over the past two years. Antarctic ice appeared to recover to near average levels last December, but then again fell rapidly. In February, the ice reached the fourth-lowest range on record for the month, 26% below the average.
Record low ice in both hemispheres is a “cause of serious concern,” he said. Robert Larter In a statement in the UK Antarctic Survey. He says that ice shortages could harm the polar ecosystems, expose ice shelves to more seawater, and accelerate melting and rising sea levels.
The lack of ice also affects beyond the poles. Less ice means less solar radiation is reflected in the universe, increasing warming. It can also weaken global ocean currents, relying on the dense salt water that is generated when sea ice forms.
GEO Group, the largest single private contractor for U.S. Immigration Customs Enforcement (ICE), has expanded its surveillance operations to monitor hundreds of thousands or potentially millions of migrants.
Geo Group, a private prison company and parent company of Bi Inc, has been working with ICE for nearly two decades to oversee the agency’s electronic surveillance program. Currently, they are tracking approximately 186,000 immigrants using various devices like ankle monitors, smartwatches, and facial recognition apps, as reported by Public Ice Data. With the increasing demand from the administration of Donald Trump, which has promised significant deportations, company executives anticipate that this number will surpass the previous peak of 370,000 to 450,000 immigrants within the next year. This statement was made during the company’s fourth-quarter revenue call on Thursday morning.
“About two years ago, ISAP contract utilization peaked at around 370,000,” mentioned George Zorry, executive chair of GEO Group, during a revenue call discussing the ICE and GEO contract. “If the contract exceeds its previous peak usage, achieving revenues of $250 million is possible.”
The company is ramping up the production of additional GPS units in preparation for expanded ICE contracts. Executives suggest they can monitor “hundreds of thousands” of individuals and are positioning themselves to monitor even more, potentially reaching into the millions. Zoley mentioned that GEO Group and its competitor, Core Civic, will engage in conversations with ICE to expand current contracts and electronic monitoring for detention facilities.
“It’s a dynamic situation, rapidly evolving,” he stated. “We’ve shifted from initial proposals to detailed pricing and operational discussions. The procurement process is moving at an unprecedented pace. I’ve never seen anything like it.”
Established in 2004 as an alternative to detention, the company’s extensive electronic surveillance program has been entrusted to Bi Inc, a subsidiary of Geo Group. Many individuals wearing ankle monitors raised concerns about overheating, discomfort, or tightness. The company has introduced SmartLink, a Smart Watch location tracker, and a smartphone app as less intrusive monitoring methods. However, during the revenue call on Thursday, executives expressed a desire to return to relying primarily on ankle monitors.
“Our top priority is ankle monitors for high-security monitoring,” Zoley emphasized.
While the company has not received indication from ICE about reissuing a new agreement for their electronic monitoring program, the executive team is focusing on expanding the number of individuals tracked through existing programs. Geo Group plans to invest $16 million to increase federal ISAP use and build up Ankle Monitor inventory to cater to hundreds of thousands and potentially millions of participants.
Company officials believe that under the Laken Riley Act, immigrants charged with violent crimes or thefts must be monitored “indefinitely” under the ISAP program due to the risk they pose. Executives intend to expand the surveillance program to monitor an estimated 7-8 million individuals with non-decisive immigration statuses who entered the US through unauthorized routes. They are also preparing to monitor an estimated 95-100 million people in the United States.
“Given our population size, we view this as an opportunity to enhance detention capacity… The Laken Riley Act mandates a significant increase in electronic monitoring services to combat human trafficking involving individuals with non-decisive immigration statuses and ensure compliance with immigration court requirements,” Zoley stated.
There have been numerous ice age animals recovered from the world’s permafrost, ranging from woolly rhinos and wolves to urus, brown bears, and bison. Despite some being slightly damaged, they are often found in excellent condition.
One remarkable discovery was in 2017 when scientists excavated the remains of a small cave lion named Sparta from a frozen bank on the Siberian River. Although its golden fur was muddy and matted, its skin, soft tissue, and organs were all preserved. With closed eyes, it appeared more like a sleeping animal than one that had been dead for 28,000 years.
Another notable find was a two-month-old horse that died 35,000 years ago and was uncovered in Siberia in 2018. Though some fur was missing, the animal was largely intact, with hooves, skin, tail, and nostril hair preserved.
Various well-preserved woolly mammoths have also been discovered, some with grass in their mouths, milk in their bellies, and even dung on their bellies. While videos show people cutting into frozen mammoth carcasses and finding meat that looks fresh, the appearance can be deceiving.
Many animals found from the Ice Age are well preserved on the outside, but on the inside is a different story – Credit: Grafissimo
While these ice age animals and their tissues may appear well-preserved superficially, zooming in reveals a different story. The lack of antifreeze agents when freezing live cells causes ice crystals to form, leading to cell bursting.
Although tissues and organs may seem intact, the cells that form them are not. The damage to these cells has occurred over the thousands of years since the last ice age ended. While these ancient animals may seem well-preserved on a larger scale, they are damaged at a microscopic level.
The most well-preserved ice age beasts are likely those with intact cells, which died closer to the end of the last ice age and have been frozen since. One such candidate is a 9,000-year-old bison discovered in the Russian Far East in 2022, which may have cells viable for cloning attempts.
However, cloning attempts on ice age animals have so far been unsuccessful due to DNA deterioration after death. Despite the optimism, the chances of successful cloning are slim. For now, appreciating these mummified artifacts as they are offers a fascinating glimpse into the ancient past.
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Without human-induced climate change, the Earth could have been on track to enter another ice age within 11,000 years. This long-term prediction of the planet's “natural” climate is based on a new analysis of how orbital shapes and the tilt of their axis combine to change the amount of solar energy reaching Earth.
For millions of years, these orbital oscillations (known as the Milankovich cycle) entered and left the planet during the Ice Age about every 41,000 years. However, over the past 800,000 years, these ice ages, also known as ice age, have only occurred every 100,000 years. The term Ice Age, as it is currently, can be used to refer to whenever there is ice on Earth's poles, but generally refers to a wide range of ice Age periods.
The ambiguity of the record as the ice sheets were willingly retreated meant that it was not possible to explain how trajectory changes were involved in driving this long cycle.
If previous research attempted to link orbital changes to a specific period, such as onset of an ice age, Stephen Barker Cardiff University in England and his colleagues took a new tack. They came back fading during the “glacial age” where they saw the overall pattern of the ice age, also known as ice age. This allowed us to link changes in trajectories with changes in ice, despite the ambiguity of ice records over the past million years.
They discovered that these 100,000-year cycles appear to follow simple rules. For the last 900,000 years, following the most circular phase of the orbit, the planets also tilted towards the Sun, thus causing all interglacial periods after the Earth's axis wobbled at the farthest from the Sun.
This suggests that all three of these aspects of Earth's orbit (known as precession, oblique and eccentricity) are combined to create a 100,000-year glacial cycle, Barker says. “Since 900,000 years ago, this simple rule has predicted all of these major glacial end events, which says it's really very easy to predict,” he says.
Under that rule, the next ice age where you currently live is expected to begin approximately 66,000 years from the year, as there is no impact on greenhouse gas emissions. But that could only be started if there was an ice age before that,” says Barker.
The diagonal and gradual stages of precession that preceded the Holocene suggest that the glaciers are likely to be on track between 4300 and 11 and 100 years from now. We may now live in what would have been the beginning of this next ice age. “Of course, it's just a natural scenario,” says Barker.
More than 1.5 trillion tons of carbon dioxide have been released into the atmosphere as the Industrial Revolution is expected to cause sufficient warming to disrupt this long-term glacial cycle.
“The amount we've already put into the atmosphere is so big that it takes hundreds to thousands of years to pull it out through natural processes,” Barker says. However, he says more research is needed to define the planet's future natural climate in a more detailed way.
It states that this is consistent with previous modeling suggesting that anthropogenic emissions can prevent the onset of the next ice age, from dozens to hundreds of thousands of years. Andrei Ganopolsky At the Potsdam Climate Impact Research Institute in Germany.
But he says even at pre-industrial levels of CO2 in the atmosphere, it was high enough to delay the ice sheet advancement by 50,000 years. This is due to the unusually small orbital changes expected in thousands of years and the unpredictable way that Earth responds to those changes.
Tribal palm trees Trachycarpeae Fossilization analysis shows that it once flourished in Axiang Canada Phytris – Microscopic siliceous structures produced in specific tissues in many plant families – from the territory of the northwestern Canada.
Palm plant stones from the Eocene Giraffe Region (AQ) and modern plant stones extracted from Coryphoid Palm leaves Trachycarpus Fortunei. Image credit: Siver et al. , doi: 10.1093/aob/mcaf021.
“The palm is a monocot flowering plant of the Arecaceae family distributed primarily to tropical and subtropical regions around the world,” the University of Connecticut said. Professor Peter Siver And his colleague.
“It's a large family, with a particularly high variety of species, especially in Central and South America and Southeast Asia.”
“In general, the palms thrive in warm, wet conditions, so the majority of the species are found in rainforests.”
“There are significantly fewer species found in both Southern Europe and the southern regions of the United States, and families are completely lacking in more north latitudes.”
“In the southeastern US subtropical area, the palm is largely restricted to state coastal areas along the Gulf of Mexico, and some inland along the Atlantic coast that stretches north along Florida. It's growing to Tennessee.”
“The majority of the palms are found in climates marked with both high average annual temperatures and high average annual rainfall, but several species can be found under cool, dry conditions.”
Professor Siver and co-authors discovered fossilized plant matter from a tree in Trachycarpeae in ancient lakebed sediments extracted from the area of the Giraffin Balite Pipe in Canada's northwest territory.
Four aquatic organisms, largely restricted to today's warm subtropical and tropical regions, were also found in the same sediments.
These 48 million years ago (early Eocene) fossils exhibit much warmer climates than previously thought, challenging the challenge of ice that first formed in the Northern Hemisphere.
“This discovery of palm fossils in the north provides clear evidence that the Arctic Circle was once iceless and has a climate similar to today's subtropical climate,” Professor Shiver said.
“These findings provide a window into past greenhouse conditions and help refine models to predict future climate change.”
In addition to confirming records of the northernmost palms during this period, the authors established that this evolutionary characteristic appeared in the early Eocene: linear arrays of plant matter in palm leaves., Fossilized Stegmata – Fossilized Stegmata were also recorded.
The presence of multiple warm, adaptive aquatic species further strengthens the support of this prehistoric Arctic region's lush, temperate ecosystem.
“Our research contributes to a broader understanding of the extent and timing of ice formation in the Earth's climate history, particularly during the Cenozoic era,” the researchers said.
“Restructuring these past environments will give scientists valuable insight into how ecosystems respond to long-term climate change.”
Survey results It will be displayed in the journal The Anniversary of Botany.
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Peter A. Shiver et al. Palmphytris in sub-Western Canada means ice-free winter in the late Eocene period 48 million years ago. The Anniversary of BotanyPublished online on February 10th, 2025. doi:10.1093/aob/mcaf021
Greenland ice sheet algae absorb light and accelerate melting
Laura Halbach
Dark algae growing on the surface of the Arctic ice sheet are likely to expand future coverage, and tend to exacerbate melting, sea level rise and warming.
“These algae are not a new phenomenon.” James Bradley At the Institute of Oceanography in Marseille, France. “But if they bloom more intensely or the flowers bloom more widely, this is an important thing to consider in future projections of sea level rise.”
Greenland's ice sheets, which cover most of the island, are rapidly melting due to rising temperatures, making them the biggest contributor to sea level rise worldwide.
ancylonema Algae under a microscope
Natural Communication
ancylonema Algae species bloom in patches of ice called ablation zones, which are exposed as snow lines recede to the ice sheet every summer. Flowers darken the ice, reduce its reflectivity, absorbing more heat, thereby increasing melting in these regions by an estimated 10-13%.
To better understand this feedback loop, Bradley and his colleagues gathered ancylonema Samples from the southwest tip of the ice sheet were examined for cells using advanced imaging techniques.
The results reveal that algae are highly adapted to malnutritional conditions and suggest that they can invade ice at high elevations with low nutrients.
Global warming already causes snow lines to increase altitude over time, exposing more ice. Ice algae should add yet another layer to these interactions and explain it in future climate forecasts.
“We have been studying glacial algae flowers for several years, and one of the biggest questions that remains is that we can grow to such high numbers in such undernourished ice.” I say that. Christopher Williamson At the University of Bristol, UK, where he was not involved in the project. “A big part of understanding this puzzle is the amount of nutrients needed for glacial algae cells and whether it can efficiently take and store rare nutrients available in the system. This research is cutting edge. They do an amazing job of demonstrating these things using the methodology of
Ronnes Ice Shelf in the Southwest Pole survived a long time ago
Modis/Zuma Wire/Shutterstock
The main ice shelves in Antarctica seem to have survived the hot period more than 120, 00 years ago. This indicates that the Westwest Pole ice sheet is not as vulnerable as it is thought to complete the complete collapse caused by climate change. You can raise the sea surface by one meter. However, great uncertainty remains.
“It's good news and bad news.” Eric Wolf At Cambridge University in the UK. “There was no worst scenario, but I can't say that it won't happen in the next century or the second century.”
The climate change caused by humans uncertains the future of the Ice bed in the Southwest Pole. If you continue to release high -level greenhouse gases, some models will completely disappear the ice sheet over the next few centuries. The most extreme scenarios projected by the inter -government panel on climate change in 2023 can lead to up to 2 meters up to the sea level by 2100.
Wolf and his colleagues looked at Ronne's ice shelves, a large part of the ice sheet that extends to the sea, to see how they behaved from 117, 00 to 126 to 00 years. Meanwhile, it was part of the last inter -glacier, and the change in the orbital of the earth increased the temperature of the Antarctica even higher than today.
In order to judge the range of Ronne's ice shelves during the warm period, researchers measured the concentration of the sea salt of the ice core about 650 km away from the end of the shelf. When the ice shelf melted between the last glacier, the edge was approaching the core. As a result, the researchers expected that the core was much closer to the ocean, so the core salt concentration would rise 8 times. “It would have been a seaside resort,” Wolf says.
Instead, they discover that the salt concentration between the last glacier is similar to today's concentration or even lower, indicating that the edge of the ice sheet remains far. Other measurements of the coat of water in the core, which maintain evidence of weather patterns affected by the change in the ice sheet, suggest that Ronne's ice shelves lasted during the last ice age.
Wolfff suggests that ice stability in the previous warm period is unlikely that climate change will be completely collapsed as the climate change increases the global temperature. However, he and other researchers say that the rise of the sea surface due to melting of ice is still a big risk.
“That means that there was no complete removal cation in the South Pole, but we do not provide enough information to relax.” Timothy Naish At Werrington Victoria University in New Zealand.
One is that the survival of Ronnes Ice Shelf does not mean that other ice areas such as Swaites and Pine Island have not melt. In fact, Wolf says the record of the core's water level suggests what they did. The ice score used by the researcher did not cover the warmth of the last ice age.
The dynamics of glacial warming between glaciers, which change in the region, are different from today's global warming, where the temperature is rising throughout the planet. For example, Wolf says that warm seawater that reaches Antarctica can accelerate melting by invading under ice.
“This is a really important observation, but I think it will take more time to understand what it means.” Andrea Duton At Wisconsin University Madison School. She emphasizes that researchers are spending 50 years and trying to think about what happened in the Westwest Pole in the last ice age.
Melting ice in the Rocky Mountains has led to the discovery of a 5,900-year-old white bark pine forest. Scientists discovered more than 30 trees during an archaeological survey on Wyoming's Beartooth Plateau at about 3,100 meters above sea level, 180 meters above the current tree line.
This, he says, “allows us to learn about past conditions at high altitudes.'' Kathy Whitlock at Montana State University. Japanese white pine (Albicari pine) These plants needed to grow during warmer weather, she says, because they don't currently grow at this elevation.
To understand the history of the lost forests, Whitlock's team analyzed tree rings and used carbon dating to find out how old the forests were. They discovered that the tree lived between 5,950 and 5,440 years ago, a time when temperatures were steadily dropping.
Data from ice cores in places like Antarctica and Greenland suggest that these temperature drops were influenced by centuries of volcanic eruptions in the Northern Hemisphere. These produced enough aerial deposits to block sunlight and lower global temperatures until the environment became too cold for these high-altitude trees to survive.
Although the newly discovered tree was lying flat, it was in exceptional condition, indicating that it was rapidly preserved after death. Although there is no evidence of avalanche cover, there are traces consistent with the current expansion of the ice sheet.
Climate models suggest that more continuous volcanic eruptions occurred in Iceland 5,100 years ago, causing further temperature drops, team members say Joe McConnell at the Desert Research Institute in Nevada. These temperature drops led to the expansion of the ice belt, and “the fallen trees were buried in the ice and protected from the elements for the next 5,000 years,” he says.
Only in recent decades have temperatures warmed enough to free trees from their ice cellars. The current tree line is “likely to shift upward as temperatures rise in the coming decades,” Whitlock said.
“This discovery was made possible thanks to anthropogenic climate change. Rising temperatures are exposing areas that have been buried under ice for thousands of years,” she says. “While discoveries like this are scientifically interesting, they are also a sad reminder of how vulnerable alpine ecosystems are to climate change.”
“This study is a very elegant and careful use of a rare 'time capsule' that tells us not only about these mountain forests 6,000 years ago, but also about the climatic conditions that allowed them to exist.” '' he says. Kevin Antukaitis at the University of Arizona.
These trees are not the first such finds that researchers have unearthed from Rocky Mountain ice. Previous research had found “fragments of wooden shafts used for arrows and darts,” Whitlock said. One of the shafts has been radiocarbon dated to be more than 10,000 years old, “which tells us that people have been hunting in high-altitude environments for thousands of years,” she says.
Planetary scientists using ESA's Mars Express spacecraft's high-resolution stereo camera have captured stunning images of Earth's mysterious landscapes. Australe Scopri Region in the southern hemisphere of the red planet.
Frozen landscape of the Australe Skopli region on Mars' south pole. Image credit: ESA / DLR / FU Berlin.
“Here, a layer of carbon dioxide ice and dust envelops the site, turning Mars white,” ESA researchers said in a statement.
“The contrasting light and dark layers are especially striking on the exposed surfaces of hills and valleys.”
“They track the seasonal polar layered deposits characteristic of the region, which form when layers of ice freeze and trap varying amounts of dust within them. It is something that will be done.”
“It's probably better to take a sled ride, but either way, dress warmly, because it's -125 degrees Celsius (-193 Fahrenheit) outside so it's cold,” they added.
“Skiers and sledders on Mars will have to slalom around potentially hundreds of dust jets.”
“That's because ski season is almost over and it's starting to look like spring, or even summer. This image was taken on June 16, 2022, near the Antarctic summer solstice.”
If you zoom in on the image above, you can see numerous dark spots where the ice has already sublimated. This is a sure sign that the sun's warming rays have been hitting the area for some time.
“When sunlight hits the translucent upper layer of carbon dioxide ice, it warms the underlying surface,” the scientists explained.
“The ice at the bottom of the layer begins to sublimate, forming pockets of trapped gas.”
“As the pressure increases, the overlying ice suddenly cracks, causing gas to burst out from the surface.”
“These gas fountains carry black dust from below, which falls to the surface in a fan-shaped pattern depending on the prevailing wind direction.”
“Fan lengths range from tens of meters to hundreds of meters.”
“If you look more closely, it often appears that the fans follow the boundaries between polar layered deposits.”
“Perhaps these boundaries represent zones of weakness, from which escaping dust-laden jets can more easily break through the ice layer.”
“We may have missed the chance to create 'Frosty the Snowman,' but it's still a wonderful time of year on Mars.”
This year was the second hottest year on record in the Arctic, according to a new report from NOAA.
The authors said the tundra has become a carbon source rather than a carbon sink.
The North Pole is heating much faster than lower altitude locations because melting ice reflects less radiation back into space.
The Arctic just experienced its second warmest year on record. And worryingly, the region's tundra is transitioning from a carbon sink to a carbon emitter as permafrost thaws and methane is released.
This would only increase the amount of heat-trapping gas entering the atmosphere, paving the way for further global warming.
The findings, shared Tuesday in the National Oceanic and Atmospheric Administration's Arctic Report Card, show how climate change is disrupting ecosystems and altering the landscape in regions where global warming is most intense.
The Arctic, considered a leading region for the effects of climate change, is heating much faster than lower-altitude locations, depending on the baseline scientists use for comparisons and which geographies they include in their assessments. But that speed is 2-4 times faster. Each of the last nine years in the Arctic has been the hottest on record since 1900.
This dynamic is the result of a phenomenon called arctic amplification. As snow cover and sea ice are lost in the Arctic, more dark-colored water and rocks are revealed. Their dark surfaces reflect less radiation back into space, instead absorbing heat. In addition, ocean and atmospheric circulation patterns increasingly transport heat toward the Earth's poles.
Taken together, that means the Arctic is a fundamentally different place than it was just a decade ago. Twila Moon said.
“The Arctic is in a kind of new regime, not a new normal, of course, but it's definitely different than it was just a few decades ago,” she says.
Overall, the Arctic is becoming a greener landscape with more extreme precipitation, less snow and ice, the report said. As fires in the Arctic send smoke into populated areas, ice melts and sea levels rise, the effects of those changes are becoming increasingly apparent closer to American homes, scientists said.
“These problems aren't just limited to the Arctic; they affect all of us,” says Brendan Rogers, an associate scientist at the Woodwell Climate Research Center in Woods Hole, Massachusetts. .
This year's report includes a detailed explanation of how the carbon cycle in the Arctic is changing. Scientists have been closely watching what happens when permafrost thaws, releasing powerful greenhouse gases as it thaws and decomposes.
“Permafrost regions contain about twice as much carbon as is currently present in the atmosphere, and about three times as much carbon as is contained in the above-ground biomass of forests around the world. There's a lot of carbon out there,” Rogers said.
He added that permafrost areas “have been carbon sinks for thousands of years on average, primarily due to low temperatures and frozen soil.” Carbon sinks, by definition, absorb and capture more carbon dioxide than they emit. But now such areas are instead sources of greenhouse gas emissions, as they dissolve carbon and methane and release it into the atmosphere, Rogers said.
Wildfires also contribute to Arctic emissions. Last year's wildfires burned more than twice as much area in the region as the year before, and produced more emissions than Canada's economic activity.
Rogers said Canada's total wildfire emissions are “roughly three times the emissions from all other sectors in Canada.” “This is more than the annual emissions of any other country except China, the United States, India and Russia.”
Temperature records are organized by Arctic water year, so the most recent records are from October 2023 to September 2024. Every September, scientists measure the extent of Arctic sea ice at its seasonal minimum.
This year's sea ice was the sixth lowest in the 45 years since satellite measurements began. Sea ice extent has decreased by about 50% since the 1980s. Meanwhile, the Arctic tundra is the second greenest since records began in 2000, indicating more shrubs have taken root and spread into new terrain.
Measurements of Arctic permafrost taken from boreholes drilled beneath the earth's surface show that average temperatures were warmer than in all but one year.
“There are many indicators that consistently show extreme or near-extreme conditions,” Moon said.
On Earth, solar radiation can travel up to several meters into the ice, depending on its optical properties. Organisms in the ice can harness the energy from photosynthetically active radiation while being protected from harmful ultraviolet radiation. On Mars, there is no effective ozone shield, so about 30% more harmful ultraviolet radiation reaches the surface compared to Earth. However, a new study shows that despite strong surface UV radiation, mid-latitude ice on Mars contains 0.01-0.1% dust, ranging from a few centimeters deep to several centimeters deep. It has been shown that a radioactive habitable zone exists with a range of up to 3000 m. Cleaner ice.
The white edges along these canyons on Mars' Terra Sirenum are thought to be dusty water ice. cooler others. It is thought that melt water could form beneath the surface of this type of ice, providing a potential site for photosynthesis. Image credit: NASA / JPL-Caltech / University of Arizona.
“Today, if we are trying to find life anywhere in the universe, the icy outcrops on Mars are probably one of the most accessible places we should look,” said a researcher at NASA's Jet Propulsion Laboratory. said Dr. Aditya Kuler.
Mars has two types of ice: frozen water and frozen carbon dioxide.
Dr. Cooler and his colleagues investigated water ice. The ice masses were formed from snow mixed with dust that fell on Mars during a series of ice ages over the past million years.
That ancient snow has since solidified into ice and is still dusted with dust.
Dust particles can block light in deeper layers of ice, but they are the key to explaining how underground pools of water form within the ice when exposed to the sun.
The black dust absorbs more sunlight than the surrounding ice, causing the ice to warm and potentially melt several feet below the surface.
Mars scientists are divided on whether ice actually melts when exposed to the Martian surface.
It's thought to be caused by the planet's thin, dry atmosphere, where water ice sublimates and turns directly into gas, similar to dry ice on Earth.
But the atmospheric effects that make melting difficult on Mars' surface don't apply beneath the surface of dusty snowpack and glaciers.
On Earth, dust in ice can create what are called cryoconite holes. This is a small cavity that forms in the ice when windblown dust particles (called cryoconite) land there, absorb sunlight, and melt deep into the ice each summer. is.
Eventually, these dust particles stop sinking as they move away from the sun's rays, but they still generate enough heat to create pockets of melted water around them.
This pocket can foster a thriving ecosystem of simple organisms.
“This is a common phenomenon on Earth,” says Arizona State University researcher Phil Christensen.
“Rather than melting from the top down, thick snow and ice melts from the inside out, letting in sunlight that warms it like a greenhouse.”
In 2021, the authors discovered powdery water ice exposed inside canyons on Mars and proposed that many canyons on Mars are formed by erosion as ice melts into liquid water.
Their new paper suggests that powdery ice lets in enough light for photosynthesis to occur as deep as 3 meters (9 feet) below the surface.
In this scenario, the upper layer of ice prevents shallow underground pools of water from evaporating, while also protecting them from harmful radiation.
This is important because, unlike Earth, Mars does not have a protective magnetic field to protect it from both the Sun and radioactive cosmic ray particles flying through space.
“Water ice most likely to form underground pools would exist in tropical regions of Mars between 30 and 60 degrees latitude, in both the northern and southern hemispheres,” the researchers said.
of paper appear in the diary Communication Earth and Environment.
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AR cruller others. 2024. Possibility of photosynthesis on Mars in snow and ice. common global environment 5,583;doi: 10.1038/s43247-024-01730-y
This article is a version of a press release provided by NASA.
Previous studies have found signs of ice in permanently shadowed regions near the moon’s south pole, including areas within the Cabeus, Howarth, Shoemaker, and Faustini craters. A new analysis of data from NASA’s Lunar Reconnaissance Orbiter (LRO) shows there is widespread evidence of water ice outside Antarctica, at least within a permanently shadowed region toward 77 degrees south latitude. Ta.
This figure shows the distribution of permanently shadowed regions (blue) toward the moon’s poles at 80 degrees south latitude. They are overlaid on a digital elevation map of the lunar surface (gray) from the Lunar Orbiter Laser Altimeter Instrument aboard NASA’s Lunar Reconnaissance Orbiter. Image credit: NASA / GSFC / Timothy P. McClanahan.
Ice may have been embedded in the lunar regolith by comet or meteor impacts, emitted as steam (gas) from the moon’s interior, or formed by chemical reactions between hydrogen in the solar wind and oxygen in the regolith. there is.
Permanently shadowed regions (PSRs) typically occur in topographic depressions near the moon’s poles.
Due to the low angle of the sun, these regions have not seen sunlight for billions of years and are constantly in extremely cold conditions.
Ice molecules are thought to be repeatedly stripped from the regolith by meteorites, cosmic radiation, or sunlight, traveling across the lunar surface and landing on the PSR, where they become trapped in the extreme cold.
The PSR’s continuously cold surface could store ice molecules near the surface for perhaps billions of years, accumulating in sediments large enough for mining.
“Our models and analysis show that the largest ice concentrations are near the coldest parts of the PSR below 75 Kelvin (minus 198 degrees Celsius, or minus 325 degrees Fahrenheit) and on poleward-facing slopes of the PSR. It is expected to occur near the base of the Dr. Timothy McClanahan, researcher at NASA Goddard Space Flight Center.
“It is not possible to accurately measure the volume of ice deposits in the PSR or determine whether they are buried beneath a dry layer of regolith.”
“However, we expect it to be 1 m for each surface.2 If present above these deposits, there should be at least about 5 liters of ice within the top meter of the surface compared to the surrounding area. ”
McClanahan and his colleagues used LRO’s Lunar Exploration Neutron Detector (LEND) instrument to detect signs of ice deposits by measuring moderately energetic “exothermal” neutrons.
Specifically, they used LEND’s Collimating Sensor for Exothermal Neutrons (CSETN), which has a fixed field of view of 30 km (18.6 miles) in diameter.
Neutrons are produced by high-energy galactic cosmic rays that come from powerful deep space events, such as exploding stars, and impact the moon’s surface, destroying regolith atoms and scattering subatomic particles called neutrons.
Neutrons originate from depths of up to about 1 meter (3.3 feet) and ping-pong through the regolith, colliding with other atoms. Some are guided into space and detected by LEND.
Since hydrogen has approximately the same mass as a neutron, neutrons lose relatively more energy in collisions with hydrogen than in collisions with the most common regolith elements.
Therefore, if hydrogen is present in the regolith, its concentration will correspondingly reduce the number of medium-energy neutrons observed.
“We hypothesized that if all PSRs had the same hydrogen concentration, CSETN should detect hydrogen concentrations proportionally depending on their area,” Dr. McClanahan said.
“Therefore, more hydrogen should be observed towards the larger area of the PSR.”
TP McClanahan others. 2024. Evidence of widespread hydrogen sequestration within the lunar south pole cold trap. planet. Science. J 5, 217; doi: 10.3847/PSJ/ad5b55
This article has been adapted from the original release by NASA.
Climate change affects our planet and our lives in many ways. Dry the atmosphere To Increase in home runs Climate change accelerates glacial melt with each Major League Baseball season. Greenland Ice Sheet The land ice mass that covers about 80% of Greenland. When glaciers melt, icebergs form, a process called “iceberg formation.” Glacier collapse Recent climate change has increased the rate at which icebergs are flowing from the Greenland Ice Sheet into the North Atlantic.
Scientists have found that in the past, large increases in the rate of glacial collapse have disrupted important ocean current systems in the Atlantic Ocean. Atlantic Meridional Gyre Or as the AMOC, it carries warm water north and cold water south, affecting global temperatures and moving nutrients across the Atlantic Ocean, meaning that disrupting the AMOC could change the climate and destabilize marine ecosystems. Recently, scientists conducted a study to determine whether the current increase in glacier collapse could disrupt the AMOC.
For this study, the researchers developed a method to quantify glacial runoff during past periods of increased glacial collapse in the North Atlantic that disrupted the AMOC. Heinrich Event They began by looking at present-day glaciers in the North Atlantic and the Arctic. As icebergs break up, they deposit sediment. This sediment includes sand and rocks from the land below the ice sheet, as well as the remains of organisms that lived on the ice sheet. When the icebergs melt at sea, the sediment is released and sinks to the ocean floor.
Scientists observed modern glaciers melting and measured the average amount of sediment, by volume, that they released. Using this average, the researchers estimated how much ice was released during past Heinrich events, based on the amount of sediment that was deposited on the floor of the North Atlantic Ocean.
Scientists used this method to estimate the total amount of ice lost during 10 Heinrich events (the last of which) that occurred over the past 140,000 years. Glacial Cycle Previous scientists had determined the duration of Heinrich events, which allowed the researchers to estimate the ice runoff rate during each event. The researchers compared their estimated runoff rates to current ice runoff rates and found that current ice runoff rates are similar to those of previous mid-sized Heinrich events that disrupted the AMOC. However, the scientists who conducted the study also noted that the AMOC is currently stable.
The researchers suggested two factors that could help explain why the current increase in glacial collapse is not disrupting the AMOC as much as it has in the past. First, the researchers think that the AMOC was stronger when the current glacial runoff rate began to increase than it was at the start of past Heinrich events, which may make the current AMOC more resistant to disruptions. Second, each of the 10 Heinrich events the scientists used in their study lasted about 250 years, while the faster glacial collapse seen today may have been due to a slowdown in the early Heinrich events. It began in recent decades They suggested that AMOC collapse could only occur after a longer period of increased glacier calving than has happened previously.
If the rate of glacial calving continues to increase by the time the AMOC collapses, the size of the Greenland Ice Sheet may limit its influence on the AMOC. The researchers noted that if the Greenland Ice Sheet continues to melt at its current rate, the rate of calving will slow before 250 years have passed. The icebergs that caused the Heinrich events in the last glacial cycle broke off from a much larger ice sheet. Laurentide Ice Sheet It no longer exists.
The scientists who conducted the study said that freshwater runoff from the melting Greenland Ice Sheet could also disrupt the AMOC, but its impact would be less severe than ice runoff. However, they noted that freshwater runoff is likely to increase as glacial collapse slows in the coming decades, which could have unpredictable consequences. The researchers suggested that the scientific community should continue their work to model the impacts of a melting Greenland Ice Sheet as accurately as possible, because, in their words, “the fate of the AMOC remains uncertain.”
Sergio Pitamitz/VW Pics/Universal Images Group via Getty Images
Uplifting the land beneath the Antarctic ice sheet could help slow ice loss and limit sea level rise over the coming centuries, but if emissions continue to rise, it could cause more sea levels to rise than the ice melt alone.
The findings come from models that simulate Earth’s mantle, the layer beneath the crust, in greater detail than ever before. When Antarctica loses its weight as ice melts, the elastic mantle beneath it bounces back, causing the land above it to rise. When ice melts and the continents lose their weight, Earth’s elastic mantle bounces back, causing the land above it to rise. The bounced back land can slow the flow of ice sheets where they meet the ocean. This “sea-level feedback” occurs primarily because the uplifted land changes the shape of the ocean floor, limiting the thickness of the ice sheet’s edges. Thinner ice there reduces the overall inflow of ice into the ocean.
Researchers have long suspected that this effect plays a role in slowing ice loss, but it was unclear when this effect begins or how it varies in different parts of the ice sheet.
Natalia Gomez Gomes and his colleagues at McGill University in Canada modeled the relationship between the melting ice and the rebounding land, and also simulated the mantle, capturing the different viscosities beneath the continents: East Antarctica sits on a more viscous mantle and thicker crust, while West Antarctica’s rapidly melting glaciers sit on a less viscous mantle and thinner crust. This more detailed picture of Earth’s interior is based on precise measurements of ice sheet elevation changes over decades, as well as data about the mantle beneath Antarctica from seismic waves generated by earthquakes. “This is hard-earned,” Gomes says.
The researchers found that under a very low emissions scenario, compared to a model that considered the ground beneath the ice solid, land uplift would reduce Antarctica’s contribution to global mean sea level rise by more than 50 centimeters by 2500. This effect was less pronounced under a moderate emissions scenario, but still led to a large reduction in sea level rise, with effects starting to be felt as early as 2100.
But in a very high emissions scenario, the team found that land uplift in Antarctica would raise sea levels by an additional 0.8 meters by 2500. This happened because the ice sheet retreated faster than land uplift, and the rising sea floor pushed more water into the rest of the ocean.
“From a modeling perspective, this is a huge step forward.” Alexander Bradley The British Antarctic Survey’s Bradley says it’s always been thought that land uplift would limit sea-level rise, but this high-resolution modeling shows that the effect depends on emissions. “The changes that occur in the 21st and 22nd centuries will depend very much on what we do now,” he says.
Alexander Lovell Researchers at the Georgia Institute of Technology in Atlanta call it a “very good simulation,” but the scenario in which land uplift drives sea level rise is based on worst-case assumptions about emissions and the rate at which ice sheets are retreating.
Europa and Enceladus are important targets for the search for evidence of extraterrestrial life in the solar system. However, the surfaces and shallow subsurfaces of these airless icy moons are constantly exposed to ionizing radiation that can degrade chemical biosignatures. Therefore, sampling the icy surfaces in future life-searching missions to Europa and Enceladus requires a clear understanding of the required ice depths where intact organic biomolecules may exist. A team of scientists from NASA and Pennsylvania State University conducted experiments exposing individual biological and abiotic amino acids in the ice to gamma radiation to simulate conditions on these icy worlds.
Europa's surface stands out in this newly reprocessed color image. The image scale is 1.6 km per pixel. Europa's north side is on the right. Image courtesy of NASA / JPL-Caltech / SETI Institute.
“Based on our experiments, a 'safe' sampling depth for amino acids on Europa is about 20 centimetres (8 inches) at high latitudes in the trailing hemisphere (the hemisphere opposite the direction Europa moves around Jupiter), in an area where the surface has not been significantly disturbed by meteorite impacts,” said Dr. Alexander Pavlov, a research scientist at NASA's Goddard Space Flight Center.
“Detecting amino acids on Enceladus does not require subsurface sampling; these molecules survive radiolysis (breakdown by radiation) anywhere on Enceladus' surface, within a few millimeters (tenths of an inch) of the surface.”
Dr. Pavlov and his colleagues used amino acids in their radiolysis experiments as representative examples of biomolecules on icy moons.
Amino acids are produced by both living organisms and non-living processes.
But if certain types of amino acids were found on Europa or Enceladus, they could be a sign of life, as they may be used by life on Earth as building blocks of proteins.
Proteins are essential for life because they are used to create structures and to produce enzymes that speed up or control chemical reactions.
Amino acids and other compounds found underground in the ocean could be transported to the surface by geyser activity or the slow churning motion of the ice shell.
To assess the survival of amino acids on these planets, the researchers mixed amino acid samples with ice cooled to minus 196 degrees Celsius (minus 321 degrees Fahrenheit) in sealed, airless vials and exposed them to various doses of gamma rays (a type of high-energy light).
Because the ocean may harbor microorganisms, the researchers also tested the viability of amino acids contained in dead bacteria in the ice.
Finally, the researchers tested samples of amino acids in the ice mixed with silicate dust to see if meteorites or interior materials could be mixing with the surface ice.
This experiment provided vital data for determining the rate at which amino acids break down (called the radiolysis constant).
Using these, the scientists used the age and radiation environment of the icy surfaces of Europa and Enceladus to calculate drilling depths and where 10% of amino acids would survive radiolysis.
While experiments have been done before to test for the survival of amino acids in ice, this is the first to use low doses of radiation that don't completely break down the amino acids – changing or breaking them down would be insufficient to determine whether they were a sign of life.
This is also the first experiment to use Europa/Enceladus conditions to assess the survival of these compounds in microbes, and the first to test the survival of amino acids mixed with dust.
Scientists have found that amino acids break down faster when mixed with dust, but more slowly when they come from microorganisms.
“The slow rate of breakdown of amino acids in biological samples under surface conditions like those on Europa and Enceladus strengthens the case for future life detection measurements from lander missions to Europa and Enceladus,” Dr Pavlov said.
“Our results indicate that the decomposition rates of potential organic biomolecules are higher in the silica-rich regions of both Europa and Enceladus than in pure ice. Future missions to Europa and Enceladus should therefore be careful when sampling the silica-rich regions of these icy moons.”
“A possible explanation for why amino acids survive longer in bacteria is the way that ionizing radiation alters molecules, either directly by breaking chemical bonds or indirectly by creating nearby reactive compounds that alter or break down the target molecule.”
“It's possible that the bacterial cellular material protected the amino acids from reactive compounds produced by the radiation.”
Alexander A. Pavlov others2024. Effects of radiolysis on biological and abiotic amino acids in shallow subsurface ice on Europa and Enceladus. Astrobiology 24(7); doi: 10.1089/ast.2023.0120
This article has been edited based on the original NASA release.
A recent study reveals that climate change is fundamentally reshaping the Earth, impacting its core. The melting of polar ice caps and glaciers due to global warming is causing a redistribution of water towards the equator, resulting in a shift in the Earth’s rotation and leading to increased daylight hours. This phenomenon is supported by new evidence suggesting that changes in the Earth’s ice could potentially affect its axis. These alterations create feedback loops within the Earth’s molten core, as highlighted in studies published in Nature Geoscience and the Proceedings of the National Academy of Sciences.
According to Benedict Soja, an assistant professor at ETH Zurich in Switzerland, human activities are significantly influencing the Earth’s rotation. Changes in the planet’s shape and mass distribution, influenced historically by forces like the moon’s gravitational pull and rebounding of crust after ice age glaciers disappeared, are now being accelerated by rapid ice melting caused by climate change. Soja warns that continued carbon emissions could make ice loss a more significant factor in Earth’s rotation than the moon.
In addition to external factors like gravity and ice loss, fluid movements in the Earth’s core also play a role in affecting the planet’s rotation. These movements can speed up or slow down the Earth’s rotation and are currently compensating for the slowdown caused by climate change. The new study suggests that climate change is leading to small variations in polar motion due to changes in mass distribution, estimated to be about one meter per decade.
An iceberg in Antarctica on February 8th. Şebnem Coşkun / Anadolu via Getty Images File
These changes in rotation are expected to have implications for space missions, navigation, and timekeeping. Understanding how Earth’s rotation and axis are affected by climate change will be crucial for accurate space exploration and maintaining global time standards. The research emphasizes the interconnectedness of surface processes with the Earth’s core, shedding light on the complex relationship between human activities and the planet’s inner workings.
Broken sea ice in Lancaster Sound, part of the Northwest Passage
Allison Cook
Shipping companies had hoped that melting sea ice would open up shorter shipping routes through the Canadian Arctic, but thicker ice moving in from further north may dash those hopes.
“North [of the Northwest Passage] “No new routes are expected to open anytime soon.” Allison Cook At the Scottish Association for Marine Science.
For over a century, sailors have navigated the icy waters of the Canadian Arctic along the Northwest Passage, a dangerous but efficient sea route connecting the Atlantic and Pacific oceans. As climate change melts the sea ice, the southern part of the passage is less dangerous, and since 1990, voyages through the Northwest Passage have quadrupled.
The North Strait is expected to be an even shorter route, but it is ice-bound for longer periods than the South Strait, and so fewer ships use it. But because the entire route was almost ice-free in the summer of 2007, and the climate has continued to warm since then, many believe the North Strait route will soon become regularly navigable. This possibility has spurred ideas of a boom in Northern Sea Routes.
Cook and his colleagues assessed whether this vision was working using ice charts provided by the Canadian government to ship captains between 2007 and 2021. For each leg of the Northwest Passage, they calculated the number of weeks per year when ice was light enough for moderately ice-hardened ships to navigate safely.
Map showing the route of the Northwest Passage through the Canadian Arctic Islands
Allison Cook
The detailed images of the ice reveal that rather than the passage opening, the safe passage window shortened at several “choke points” along the route, particularly along the northern route. For example, the passage window in the eastern Beaufort Sea shortened from 27 weeks to 13 weeks. The passage window in McClure Strait shortened from 6.5 weeks per year to just two weeks. In other areas, passage windows increased by a few weeks or remained unchanged, but the passage window that determines the overall passage window is determined by the shortest passage window, Cook said.
Researchers believe the shortened season is primarily due to an increase in thicker sea ice flowing in from an area known as the “last ice field” north of Greenland, which is expected to become the last remaining bastion of sea ice in the Arctic Ocean as the climate warms. “Climate change is making the sea ice a little less intense and a little more mobile,” Cook says.
The findings are consistent with expectations that ice will remain in the Canadian Arctic the longest, he said. Amanda Lynch The bigger geopolitical and economic question now is how the melting ice will affect shipping on the Russian side of the Arctic, said Robert G. Schneider, a researcher at Brown University in Rhode Island who was not involved in the study.
Antarctica’s melting ice sheet could retreat faster as warmer ocean water invades underneath it, and rising ocean temperatures could trigger a “runaway” feedback effect that pushes warm water further inland, melting even more ice and accelerating sea-level rise.
As the climate warms, the future of Antarctica’s vast ice sheet remains uncertain, and predictions vary widely about how quickly it will melt and therefore how much it will contribute to sea-level rise. One dynamic that researchers have only recently begun to recognize as a key factor is the intrusion of warmer ocean water beneath the ice.
“The mechanisms of invasion are much more powerful than we previously understood.” Alexander Bradley At the British Antarctic Survey.
Such intrusions are driven by density differences between the freshwater flowing out from beneath the ice sheet and the warmer waters where the ice meets the sea floor, known as the grounding line. They are difficult to observe directly because they occur hundreds of meters beneath the ice, but simulations suggest that in some places the warm waters could extend several kilometers inland.
One model by Alexander Lovell Researchers from the Georgia Institute of Technology in Atlanta found that widespread ice-sheet intrusion could add heat from below, lubricating ice flow along bedrock and more than doubling ice loss from the ice sheet.
Bradley and his colleagues Ian Hewitt Using their model, Oxford researchers explained how the shape of cavities in the ice changes as the ice melts, altering how ocean water flows in.
The researchers found that once ocean water reaches a certain temperature threshold, ice from the ice sheet melts faster than it can be replaced by outflowing ice. If this cavity grows larger, more water could flow under the ice sheet and penetrate further inland, creating a so-called “runaway” positive feedback effect.
“Small changes in ocean temperature lead to dramatic changes in how far warm water can intrude,” Bradley said. The ocean warming needed to cause this effect is within the range expected this century, he said, but models cannot yet predict it for specific ice sheets, and not all ice sheets are equally susceptible to such intrusions.
“This positive feedback could lead to much more intrusion than we thought,” Lovell says. “Whether that’s a tipping point that leads to unrestrained intrusion of ocean water beneath the ice sheet is probably a stretch.”
Using high-resolution color images from the European Space Agency’s (ESA) Trace Gases Orbiter (TGO) and Mars Express missions, planetary researchers have found evidence of morning frost deposits in the calderas of the Tharsis volcanoes on Mars (Olympus Mons, Arsia Mons, Ascleius Mons and Ceraunius Turus).
This image, taken with the High Resolution Stereo Camera on ESA’s Mars Express spacecraft, shows Olympus Mons, the tallest volcano not only on Mars but in the entire Solar System. Image credit: ESA / DLR / Free University Berlin.
The Tharsis region of Mars contains numerous volcanoes, including Olympus Mons and the Tharsis Mountains (Ascraeus Mons, Pavonis Mons, and Arsia Mons).
Many of these volcanoes are enormous, towering above the surrounding plains at heights between one (Mont Pavonis) and three times (Mont Olympus) higher than Earth’s Mount Everest.
At the summit of these volcanoes are large cavities called calderas, which were formed when magma chambers were emptied during past eruptions.
“We thought it would be impossible for frost to form near the equator on Mars because of the relatively high temperatures both on the surface and on mountain tops, caused by a combination of sunlight and a thin atmosphere. On Earth, we would expect frost to form on mountain tops, but that would not be the case near the equator on Mars,” said Dr. Adomas Valantinas, a postdoctoral researcher at Brown University.
“Its presence here is intriguing and suggests that there are exceptional processes at work that allow frost to form.”
The frost patches appear for a few hours before and after sunrise, then evaporate in the sunlight.
Although it is thin, perhaps only one-hundredth of a millimeter thick (about the thickness of a human hair), it covers a vast area.
The amount of frost is equivalent to about 150,000 tonnes of water that moves between the earth’s surface and the atmosphere every day during the cold season, which is roughly the equivalent of filling about 60 Olympic swimming pools.
The researchers propose that air circulates in a special way above Tharsis, creating a unique microclimate within the volcano’s caldera there and allowing the frost patches to form.
“Winds move up the mountain slopes, carrying relatively moist air from close to the surface to higher altitudes, where it condenses and falls as frost,” said Dr Nicolas Thomas from the University of Bern, principal investigator of TGO’s Colour Stereo Surface Imaging System (CaSSIS).
“We actually see this happening on Earth and other parts of Mars, where the same phenomenon causes the seasonal elongated clouds on Mars’ Arsia Mons.”
“The frost we see on the summits of Martian volcanoes appears to have accumulated in the shadowed parts of the calderas, where temperatures are particularly cool.”
Scientists have found frost on the Tharsis volcanoes of Olympus, Arsia, Mount Ascraeus and Ceraunius Turus.
By modeling how these frosts form, scientists could potentially unlock more of Mars’ mysteries, like where any remaining water on Mars resides, how it moves between reservoirs, and even understanding the dynamics of the planet’s complex atmosphere.
This knowledge is essential for future exploration of Mars and the search for signs of extraterrestrial life.
“The discovery of water on the surface of Mars is always an exciting prospect, both for scientific interest and for its implications for human and robotic exploration,” said Dr Colin Wilson, ESA’s project scientist for both ExoMars TGO and Mars Express.
“Even so, this discovery is particularly intriguing because Mars’ low atmospheric pressure creates the unusual situation where Martian mountaintops are typically less cold than the plains. But moist air blowing up the mountain slopes can still condense into frost, a phenomenon that is clearly similar to Earth.”
“This discovery was made possible thanks to successful collaboration between ESA’s two Mars rovers, as well as additional modelling.”
“Understanding exactly which phenomena are the same and which are different on Earth and Mars will really test and improve our understanding of the fundamental processes occurring not only on our home planet but elsewhere in the universe.”
A. Valantinus othersEvidence for episodic morning frost accumulation at the Tharsis volcano, Mars. National GeographyPublished online June 10, 2024; doi: 10.1038/s41561-024-01457-7
Giant viruses were first discovered in the ocean in 1981, when researchers discovered them. These viruses were specialized to infect green algae in the sea. Giant viruses were later found in soil on land and even in humans. However, this is the first time that giant viruses have been found living on the surface of ice or snow, where snow algae dominate. In Greenland, these viruses probably control the growth of snow algae by infecting them on the ice.
Giant virus species Pandoravirus Salinus Image courtesy of IGS CNRS-AMU.
“Every spring in the Arctic, the sun rises after months of darkness and life returns,” said Aarhus University researcher Laura Perini and her colleagues.
“Polar bears emerge from their winter dens, arctic terns return from their long journey south, and musk oxen trek north.”
“But animals aren’t the only life awakened by the spring sun. Algae that were dormant on the ice begin to flourish in the spring, turning large areas of the ice black.”
“As the ice darkens, it loses its ability to reflect sunlight, which accelerates its melting. More melting exacerbates global warming.”
“But we may have found a way to control the growth of snow algae, and in the long term, we may be able to reduce some of the ice melt.”
In the new study, the authors found signatures of giant viruses in snow and ice samples from the Greenland Ice Sheet.
The researchers believe that these viruses feed on snow algae and may act as a natural control mechanism against algal blooms.
“Although we still do not know much about viruses, we suspect they may be useful as a means to mitigate ice melt caused by algal blooms,” the researchers said.
“We don’t yet know how specific it will be and how efficient it will be, but we’re hopeful that further investigation will help answer some of those questions.”
“We analyzed samples of black ice, red snow, and melted pits (cryoconite),” they explained.
“We found traces of an active giant virus in both the dark ice and the red snow.”
“And this is the first time they’ve been found on ice or snow surfaces that are rich in pigmented microalgae.”
“The ecosystem surrounding the algae includes bacteria, fungi, and yeasts, as well as protozoans that eat the algae, various fungi that parasitize the algae, and giant viruses that infect the algae.”
“These last three groups need to be studied to understand the biological controls that act on algal blooms.”
“We can’t pinpoint which hosts the giant viruses will infect. Some of the viruses may infect protists, others may attack snow algae. We don’t know for sure yet,” Dr Perini said.
“We are continuing our research to learn more about giant virus interactions and their role in the ecosystem.”
A pair of planetary scientists from Brown University and the SETI Institute have uncovered ancient ice deep within Arrokoth, the Kuiper Belt object (486958) that was the focus of a flyby by NASA’s New Horizons mission on January 1, 2019. They suggest that billions of years ago when the object first formed, there was a chance that ancient ice formed by comets could be present. By developing a new model to study comet evolution, the researchers found that this endurance is not unique to Arrokoth but may also be found in many other objects in the Kuiper belt.
This composite image of Ultima Thule was compiled from data acquired when NASA’s New Horizons spacecraft flew by the object on January 1, 2019. This image combines enhanced color data (close to what the human eye can see) with detailed high-resolution panchromatic data. picture. Image credit: NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute / Roman Tkachenko.
“Using a fairly simple mathematical model, we now show that primordial ice can be trapped deep inside these objects for long periods of time,” said Dr. Sam Birch, a planetary scientist at Brown University. “Most of our community thought this ice should have disappeared long ago, but now we think that may not be the case.”
Planetary scientists have long struggled to understand what happens to the ice on these space rocks over time. The new study challenges traditional thermal evolution models and suggests that highly volatile ice on these objects may persist longer than previously thought.
A model created by Birch and SETI Institute researcher Orkan Umurkhan explains this phenomenon, indicating that the ice on these objects can endure due to their extremely low temperatures. This new idea may provide insight into the explosive nature of icy objects in the Kuiper belt when they approach the sun.
Ultimately, this study presents a new perspective on comet evolution and activity, challenging existing theories and paving the way for a deeper understanding of these celestial bodies and their origins.
Birch and Dr. Umruhan are co-investigators of NASA’s Comet Astrobiology Exploration Sample Return (CAESAR) mission, which aims to collect surface material from comet 67P/Churyumov-Gerasimenko and return it to Earth for analysis, potentially shedding further light on comet evolution and activity.
The study is published in the journal Icarus, and the results could have implications for future space exploration missions and our understanding of the cosmos.
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Samuel PD Birch and Orkan M. Umruhan. 2024. 486958 CO ice and gas remain inside the Arokos. Icarus 413: 116027; doi: 10.1016/j.icarus.2024.116027
Global warming is causing the Earth’s rotation to slow slightly, which could affect the way we measure time.
A study published Wednesday found that the melting of polar ice, a trend accelerated primarily by anthropogenic climate change, is causing the Earth to spin more slowly than it would otherwise.
Study author Duncan Agnew, a geophysicist at the Scripps Institution of Oceanography at the University of California, San Diego, said melting polar ice changes where the Earth’s mass is concentrated. This change affects the planet’s angular velocity.
Agnew likened the dynamic to a figure skater spinning around on ice. He said, “If a skater starts spinning and lowers his arms or extends his legs, he will slow down.” However, if the skater’s arms are pulled inward, the skater will rotate faster.
So less solid ice at the poles means more mass around the equator, at the Earth’s waist.
“What melting ice does is take water that has solidified in places like Antarctica or Greenland, and when that frozen water melts, it moves that liquid to other parts of the planet. “Thomas Herring said. He was a professor of geophysics at the Massachusetts Institute of Technology but was not involved in the new research. “Water flows toward the equator.”
In other words, this study shows how human influence can successfully manipulate forces that have puzzled scholars, stargazers, and scientists for millennia: forces long thought to be constants beyond human control. It suggests that it has happened.
“It’s kind of impressive, even to me, that we were able to accomplish something that measurably changed the rotational speed of the Earth,” Agnew said. “Something unprecedented is happening.”
His research, published in the journal Nature, suggests that climate change is playing a significant enough role in the Earth’s rotation to delay the possibility of a “negative leap second.” If the polar ice hadn’t melted, clocks around the world might have needed to subtract one second by 2026 to synchronize universal time with the Earth’s rotation, which is influenced by a variety of factors.
Rather, the impact of climate change has delayed that outlook by an estimated three years. If timekeeping organizations ultimately decide to add negative leap seconds, the adjustment could disrupt computer networks.
A view of the Earth captured by a deep space climate observation satellite.NASA
The leap second adjustment is necessary because even without climate change, the Earth’s daily rotation tends to slow down over time, even though it appears constant.
Studies show that about 70 million years ago, days became even shorter, lasting about 23.5 hours. Implications of paleoceanography and paleoclimatology. This means that Cretaceous dinosaurs experienced 372 planetary days a year.
Several important factors influence a planet’s rotation, but they sometimes act in opposition.
Due in part to the moon’s gravitational pull, tidal friction in the oceans slows the Earth’s rotation. Meanwhile, since the last Ice Age, the Earth’s crust has been uplifting in some areas in response to the removal of ice sheet weight. This effect changes the distribution of mass, causing the planet to spin faster. Both of these processes are approximately constant and have predictable rates.
Yet another factor is the movement of fluids within Earth’s liquid inner core, a wild card that can either speed up or slow down Earth’s rotation, Agnew said.
Here, melted polar ice was added to the mix. As climate change intensifies, researchers expect melting ice to have an even more profound effect on the Earth’s rotation.
“As we predict, as melting accelerates over time, its contribution will become even larger,” Herring said. He added that the new study is a thorough and robust analysis that combines research from multiple scientific fields.
The need for timekeepers to adjust universal time to match the Earth’s rotation is not a new phenomenon. But historically, this involved adding leap seconds to the common standard for clocks. This is because astronomical time lags behind atomic time (measured by the vibrations of atoms in atomic clocks) due to the slowing of the Earth’s rotation.
But in recent decades, changes in the Earth’s core have caused the Earth to rotate faster than expected. This has led timekeepers, for the first time since Coordinated Universal Time was officially adopted in the 1960s, to consider whether it makes sense to subtract leap seconds to synchronize universal time with the Earth’s rotation. Ta.
The melting of polar ice counteracted that trend, avoiding any decision points regarding negative leap seconds. According to Agnew’s estimates, if the current rate of Earth’s rotation is maintained, it will likely be delayed by three years from 2026 to 2029.
Adding or subtracting leap seconds is troublesome because it can disrupt satellite, financial, and energy transmission systems that rely on very precise timing. For that purpose, Timekeepers around the world have voted to abolish leap seconds in 2022. By 2035, addition and subtraction will shift universal time from the pace of the Earth’s rotation.
“Since around 2000, there has been a movement to abolish leap seconds,” Agnew said.
Regardless of whether the clocks ultimately change, the idea that melting polar ice is affecting the Earth’s rotation speaks to how important an issue it has become. Studies have already shown that ice loss has significant impacts on coastal communities.
Scientists predict that sea level rise will accelerate as the climate warms, a process that will continue for hundreds of years. Last year, leading polar researchers warned in a report that parts of the major ice sheets could collapse and coastal regions should brace for several feet of sea level rise. If humans allowed global average temperatures to rise by 2 degrees Celsius, Earth could see sea levels rise by more than 40 feet.
astronomer using Mid-infrared measuring instrument The NASA/ESA/CSA James Webb Space Telescope's (MIRI) detected molecules ranging from relatively simple ones like methane to complex compounds like ethanol (alcohol) and acetic acid. interstellar ice One low-mass protostar and one high-mass protostar: toward NGC 1333 IRAS 2A and IRAS 23385+6053, respectively.
This image taken by Webb's MIRI instrument shows the region near the IRAS 23385+6053 protostar. Image credit: NASA/ESA/CSA/WRM Rocha, LEI.
Complex organic molecules (COM) are molecules with six or more atoms, including at least one carbon atom.
These materials are the raw material for future exoplanetary systems and are therefore of essential importance in understanding the chemical complexity developed in star-forming regions.
If this material becomes available in a primitive planetary system, it could facilitate the planet's habitability.
In a new study, astronomers Will Rocha, Harold Linnaerts and colleagues at Leiden University used Webb's mid-infrared instrument to determine the extent of COM ice in two protostars, NGC 1333 IRAS 2A and IRAS 23385+6053. We investigated the characteristics.
They were able to identify a variety of COMs, including ethanol (alcohol) and perhaps acetic acid (a component of vinegar).
“Our discovery contributes to one of the long-standing questions in astrochemistry,” Dr. Rocha said.
“What is the origin of COM in the Universe?” Are they created in the gas phase or in ice? Detection of COM in ice is based on the solid phase at the surface of cold dust particles It suggests that chemical reactions can build complex types of molecules. ”
“Some COMs, including those detected in the solid phase in our study, were previously detected in the warm gas phase, so they are now thought to originate from ice sublimation.”
“Sublimation is the change from a solid directly to a gas without becoming a liquid.”
“Therefore, we have hope that detecting COM in ice will improve our understanding of the origins of other, larger molecules in the universe.”
This figure shows the spectrum of the NGC 1333 IRAS 2A protostar. Image credit: NASA/ESA/CSA/Leah Hustak, STScI.
The researchers also detected simpler molecules such as formic acid, methane, formaldehyde, and sulfur dioxide.
“Sulfur-containing compounds, such as sulfur dioxide, played an important role in promoting metabolic reactions on early Earth,” the researchers said.
“Of particular interest is that one of the investigated origins, NGC 1333 IRAS 2A, is characterized as a low-mass protostar.”
“NGC 1333 IRAS 2A may resemble the early stages of our solar system.”
“Therefore, the chemicals identified around this protostar may have been present during the earliest stages of the development of the solar system and were later delivered to the proto-Earth.”
“All of these molecules could become part of comets, asteroids, and ultimately new planetary systems as icy material is transported inside planet-forming disks as protostar systems evolve.” '' said Dr. Ewain van Dyschoek, an astronomer at Leiden University.
“We look forward to using more web data in the coming years to follow this astrochemical trajectory step by step.”
of the team paper It was published in the magazine astronomy and astrophysics.
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WRM Rocha other. 2024. JWST Young Protostar Observation (JOYS+): Detection of icy complex organic molecules and ions. I.CH.FourSo2,HCOO−,OCN−,H2Colorado, Cooh, Switzerland3CH2Oh, CH3Cho, channel3Ocho and CH3Coo. A&A 683, A124; doi: 10.1051/0004-6361/202348427
Some fish species’ reproduction, shoreline erosion, and weather patterns are all at risk due to lower ice levels. This includes changing the amount of lake-effect snow that falls on nearby communities.
Research shows that the maximum annual ice area trended downward at a rate of approximately 5% for each decade from 1973 to 2023. For more information, visit NOAA’s research page.
Due to poor ice conditions, ice fishermen are turning to inland waters as their seasons on Lake Superior are impacted. Joe Friedrichs said, “In the Duluth area, their seasons don’t exist, and that definitely impacts their ability to get on the ice.”
With the lack of snowfall and above-normal temperatures, businesses that rely on snow activities are taking a hit. John Silliman of Stone Harbor Wilderness Supply said, “People aren’t coming to ski, snowshoe, or snowmobile anymore.”
The region is experiencing the warmest winter on record, and meteorologists predict this trend will continue into spring with higher than normal temperatures. Visit AccuWeather for more details.
The National Climate Prediction Center’s outlook suggests that the Great Lakes region will continue to experience higher than normal temperatures until early spring. This raises concerns about wildfire risk, particularly in parts of Minnesota, Wisconsin, and Michigan. Learn more from the National Interagency Fire Center.
This image from ESA's Mars Express shows an area close to Mars' north pole. This image consists of data collected by Mars Express' High Resolution Stereo Camera (HRSC) on April 14, 2023. Image credit: ESA / DLR / FU Berlin.
Mars' permanent north polar ice cap is a stack of water ice and dust layers up to 3 km thick and approximately 1,000 km in diameter.
These are divided into four stacked “packets” of different thicknesses, which are further composed of finer layers.
These layers contain information about the climate going back millions of years in Mars' history.
The deposits were formed by precipitation of dust and water ice in the atmosphere and by direct frost formation.
These consist primarily of water ice, with fine dust deposits accounting for 10-15% of the total.
These likely reflect changes in Mars' orbit and the tilt of Mars' axis of rotation, which is much more unstable than Earth's orientation.
It changes in several cycles with periods ranging from thousands of years to millions of years.
Changes in solar radiation cause significant changes in climate, especially in the polar regions. The Arctic ice sheet is currently thought to be growing.
“The landforms surrounding Mars' north pole, known as pranum boriumfascinating,” said a member of the Mars Express team.
“The poles themselves are covered with a layer of fine dust and water ice. These stack up several kilometers thick and extend for about 1,000 kilometers.”
“Most of this material is not visible here, but you can see the beginning of the planum boreum on the right side of the frame. There are some subtle wrinkles that indicate where layers of material are starting to accumulate.”
“The ground has also become more distinctly stepped, as most clearly seen in the topographical map of the area below.”
“The lowest elevation areas are blue/green, and the highest elevation areas are red/white/brown.”
“These layers formed as a mixture of dust, water ice, and frost that accumulated on the Martian ground over a long period of time.”
“Each layer contains valuable information about Mars' history, telling us how the planet's climate has changed over the past millions of years.”
“During the Martian winter, a thin cap of carbon dioxide ice several meters thick rests on top of that layer. This cap completely disappears into the atmosphere each year during the Martian summer.”
The left side of the image is dominated by a vast strip of undulating sand dunes, extending over 150 km within this frame alone.
This wrinkled, turbulent appearance is very different from the smoother, more primitive terrain seen on the right.
This smooth area shows no obvious signs of erosion and has been spared from being hit by rocks from space. This indicates that the surface is very young and is probably getting younger every year.
“Between these two extremes are two semicircular cliffs, the larger of which is approximately 20 km wide,” the researchers said.
“Within the curves of these cliffs are frost-covered dunes.”
“The sheer scale of the cliffs is evident from the dark shadow they cast on the ground below. Sheer walls of ice can reach up to a kilometer in height.”
“These two cliffs are located in what's called a polar trough, a landform formed when wind pushes and wears down the earth's surface.”
“These appear as wavy ridges in the landscape and are common in this region, creating the characteristic spiral pattern of the polar plateau.”
Melting ice in Greenland could worsen extreme weather across Europe
REDA & CO srl/Alamy
Europe's 10 hottest and driest summers in the past 40 years have all come after a particularly large amount of fresh water was released from the Greenland ice sheet, meaning southern Europe will experience an especially hot summer this year. Maybe you are doing it.
They say this link occurs because the excess meltwater triggers a series of amplifying feedbacks that affect the strength and position of the atmospheric jet stream over Europe. Marilena Ortmans At the UK National Marine Centre.
“2018 and 2022 were the most recent examples,” she says. 2022 saw extreme heat and numerous bushfires across Europe, with high temperatures reaching 40°C (104°F) in parts of the UK for the first time.
These feedback effects, on top of the underlying warming trend from fossil fuel emissions, mean Europe will become even hotter and drier in coming decades as the melting of the Greenland ice sheet accelerates. Then Mr. Ortmans says:
“This is on top of the warming that is already happening due to increases in greenhouse gases,” she says.
Hotter heat waves and drier droughts are expected as the planet warms, but in some regions, such as Europe, recent heat waves and droughts have been even more extreme than climate modeling projects. Several studies have linked these extreme events to changes in the strength and position of the Arctic jet stream. The Arctic jet stream is a band of upper-level winds whose location and strength have a significant impact on weather.
But it's not clear what causes these changes, Ortmans says. Now, she and her colleagues are analyzing weather observations from the past 40 years, and the results show that extreme weather is ultimately the result of a period of increased ice melt in Greenland. It is said that there is.
“Observational statistical associations are very powerful,” she says.
The excess meltwater leads to a shallow layer of freshwater that extends south of the North Atlantic Ocean. This layer does not easily mix with the warm, salty ocean water below, causing the ocean surface to be colder than normal in winter.
This makes the gradient between this colder water and warmer water further south even more extreme, strengthening the weather front aloft. As a result, wind patterns strengthen, pushing warm water flowing northward, the North Atlantic Current, further north than usual. This further amplifies the temperature gradient.
“The front that forms between an area of cold fresh water and an area of warm ocean water is the main source of energy for storms,” she says.
Now, Oltmans' team suggests that these winter changes have lasting effects into the following summer. “Two years after the freshwater anomaly occurred, we are still seeing significant signs,” she says.
The researchers found that stronger temperature gradients lead to stronger jet streams across Europe, making the weather in southern Europe even hotter and drier. Then, as the unusually cold water recedes, the jet stream moves north, bringing hot, dry weather to northern Europe.
“We have discussed the individual links in this feedback chain before,” Ortmans says. “What we did in this study is bring these links together.”
Computer models miss this chain of feedback because they don't include factors such as large fluctuations in meltwater from year to year, she says.
“The association between Atlantic freshwater anomalies and subsequent European summer weather proposed in this study is interesting and relevant to current scientific research on long-term predictions of summer weather, especially “If that relationship holds true for future summers,” he says. adam scaife He works on long-term forecasts at the UK Met Office.
“I think this study is somewhat convincing,” he says. Fei Luo At the Singapore Climate Research Center. But when it comes to predicting summer weather, looking at the previous year's snowmelt isn't as helpful as looking at winter weather conditions, Luo said.
But Oltmans is confident enough to predict that Europe will experience more heatwaves and droughts in the coming years as Greenland's ice melts further in the summer of 2023. “I think southern Europe will experience strong heat anomalies this summer,” she says.
These are likely to become even more powerful in 2025, after which they will begin to impact Northern Europe. “We expect Northern Europe to experience another strong heatwave and drought, not this year, but in the next few years.”
Scientists have faced a challenge for nearly a century: How do you detect the undetectable, like the elusive neutrino? But now, in a groundbreaking discovery, neutrinos from elsewhere in the Milky Way have been detected for the first time, shedding light on a new era of neutrino astronomy.
The discovery of neutrinos has opened up new possibilities, and researchers like Steve Sclafani from the University of Maryland are excited about this new frontier. Neutrinos, the second most abundant elementary particles in the universe, are notoriously difficult to detect due to their elusive nature. When Austrian physicist Wolfgang Pauli proposed their existence in the 1930s, he thought they could never be detected, but he was proven wrong in 1956.
The discovery of neutrinos from outside the Milky Way was made possible by the IceCube Neutrino Observatory, a massive telescope located near the South Pole. By detecting high-energy neutrinos from distant galaxies, scientists are uncovering the mysteries of cosmic particle accelerators. These accelerators, like supermassive black holes, can provide clues about the origins of cosmic rays and other cosmic phenomena.
Small particles, huge targets
The IceCube detector, operated by a collaboration of scientists from around the world, works by detecting Cherenkov radiation emitted when high-energy neutrinos interact with the ice. This innovative approach allowed researchers to distinguish Milky Way neutrinos from other background signals, leading to the detection of hundreds of neutrinos over a 10-year period.
By studying the distribution of these neutrinos, scientists hope to learn more about the origins of cosmic rays and other high-energy phenomena in our galaxy. With plans to expand the IceCube observatory and improve detection methods, the future of neutrino astronomy looks promising.
Birth of neutrino astronomy
The detection of high-energy neutrinos from the Milky Way marks a new era in astronomy, providing researchers with a unique tool to study cosmic phenomena. By tracking these neutrinos back to their sources, scientists hope to uncover the mechanisms behind cosmic particle accelerators and other cosmic mysteries.
Neutrino astronomy offers a new perspective on the universe, allowing researchers to peer into the heart of energetic and turbulent environments near supermassive black holes. This discovery opens up a whole new window on the universe, providing invaluable insights into the workings of the cosmos.
New perspective
Neutrino astronomy has the potential to revolutionize our understanding of the universe, offering a rare glimpse into the inner workings of cosmic particle accelerators and other energetic phenomena. By studying the origins of high-energy neutrinos, researchers can uncover the mysteries of the cosmos and explore new frontiers in astrophysics. Exciting times lie ahead for neutrino astronomy, with new discoveries and advancements on the horizon.
read more:
About our experts
Mirko Hünefeld from Dortmund University of Technology and Steve Sclafani from the University of Maryland are leading scientists in the field of neutrino astronomy. Their contributions to the IceCube observatory have helped advance our understanding of the universe and unlock new insights into cosmic phenomena.
Philip LeDuc and others/Carnegie Mellon University
Complex artificial organs can be created by 3D printing molds of veins, arteries, and capillaries in ice, casting them in organic materials, and melting the ice to form delicate, hollow networks. This leaves space for the complex vascular grafts required for the development of laboratory-cultured internal organs.
Researchers have been working for decades to develop artificial organs to meet the high global demand for transplants such as hearts, kidneys and livers. However, creating the vascular network necessary to keep them alive remains a challenge.
Existing technology can grow artificial skin and ears, but the meat and organ materials disappear when they are more than 200 micrometers away from blood vessels. Philippe Leduc at Carnegie Mellon University in Pennsylvania.
“It's about twice the width of a hair. Once you get through that, and you can't access nutrients anymore, your cells start dying,” he says. Therefore, new processes will be needed to produce internal organs cheaply and quickly.
LeDuc and his colleagues experimented with printing blood vessels with meltable wax, which requires fairly high temperatures and can leave behind residue. “One day, out of the blue, a student of mine said, 'What if we tried using water, the most biologically compatible substance in the world?'” he says. “And I'm like, 'Oh, yeah.' It still makes me laugh. It's that simple.”
They developed a technique that uses a 3D printer to create a mold of the inside of an organ's blood vessels in ice. In the test, they embedded them in a gelatin material that hardens when exposed to ultraviolet light before the ice melts away.
The researchers used a platform cooled to -35°C and a printer nozzle that ejected hundreds of drops of water per second, allowing them to print structures as small as 50 micrometers in diameter.
LeDuc says the process is conceptually simple, but requires complete coordination. If the droplet is ejected too quickly, the droplet will not solidify quickly enough to create the desired shape, but if it prints too slowly, it will just form a clump.
The system is also affected by weather and humidity, so researchers are looking into using artificial intelligence to adjust the printer to different conditions.
They also used a version of water in which all the hydrogen was replaced with deuterium, a stable isotope of the element. This so-called heavy water has a high freezing point and helps create a smooth structure by avoiding unwanted crystallization. Deuterium is not radioactive, unlike some isotopes, and tests have shown it to be safe for creating artificial organs, LeDuc said.
of Sturtian “Snowball Earth” Ice Age (717 million to 661 million years ago) is considered the most extreme icehouse period in Earth’s history. In a new study, geologists from the University of Sydney and the University of Adelaide used plate tectonics modeling to identify the most likely cause of the Staats Ice Age.
Artist’s impression of “Snowball Earth”. Image credit: Oleg Kuznetsov, http://3depix.com / CC BY-SA 4.0.
“Imagine if the Earth almost completely froze over, which is exactly what happened about 700 million years ago,” said lead author Dr. Adriana Dutkiewicz, a researcher at the University of Sydney. .
“The Earth was covered in ice from the poles to the equator, and temperatures plummeted. But what caused this to happen is an open question.”
“We think we have now solved the mystery. Historically, volcanic carbon dioxide emissions have been low, driven by the weathering of large volcanic rock mountains in what is now Canada. It’s a process that absorbs carbon dioxide.”
Named after Charles Sturt, a 19th-century European colonial explorer of central Australia, the Sturtsian Ice Age spanned 717 million to 660 million years, long before dinosaurs and complex plants existed on land. It continued until ten thousand years ago.
“There are many possible causes for the trigger and end of this extreme ice age, but the most mysterious one is why it lasted 57 million years. It’s hard for humans to imagine,” Dr. Dutkiewicz said.
Dr. Dutkiewicz and his colleagues used a plate tectonics model that simultaneously shows the evolution of continents and ocean basins after the breakup of the ancient supercontinent Rodina.
They connected it to a computer model that calculates the outgassing of carbon dioxide from submarine volcanoes along mid-ocean ridges, where plates diverge and new oceanic crust is born.
They soon realized that the beginning of the Starch Ice Age correlated precisely with the lowest ever levels of volcanic carbon dioxide emissions.
Additionally, carbon dioxide flux remained relatively low throughout the ice age.
“At that time, there were no multicellular animals or land plants on Earth,” Dr. Dutkiewicz said.
“Greenhouse gas concentrations in the atmosphere were determined almost entirely by carbon dioxide emitted by volcanoes and by the weathering processes of silicate rocks that consume carbon dioxide.”
“At that time, geology ruled the climate,” said co-author Professor Dietmar Müller, a researcher at the University of Sydney.
“We think the Staats Ice Age began with a double whammy: plate tectonics realigned to minimize volcanic degassing, while at the same time Canada’s continental volcanic belt began to erode, removing carbon dioxide from the atmosphere. Consumed.”
“As a result, atmospheric carbon dioxide has fallen to levels that could begin an ice age. This is estimated to be less than 200 parts per million, less than half of today’s levels.”
The team’s current research raises interesting questions about the long-term future of the planet.
Recent theories suggest that over the next 250 million years, Earth will evolve toward Pangea Ultima, a supercontinent hot enough to wipe out mammals.
However, the Earth is currently on a trajectory where volcanic carbon dioxide emissions decrease as continental collisions increase and plate velocities decrease.
So perhaps Pangea Ultima will snowball again.
“Whatever the future holds, it is important to remember that geological climate changes of the type studied here occur very slowly,” Dr. Dutkiewicz said.
“According to NASA, human-induced climate change is occurring 10 times faster than ever before.”
Adriana Dutkiewicz other. The period of the Sturtian “Snowball Earth” ice age is associated with unusually low gas emissions at mid-ocean ridges. geology, published online on February 7, 2024. doi: 10.1130/G51669.1
Killer whale trapped in ice off the coast of Japan
NHK/Screenshot
A pod of more than a dozen killer whales has gone missing after languishing in Japan's icy waters for nearly a day, trying to escape being trapped in an ice floe. It is unknown what happened to them, but they may have died.
Fishermen near Hokkaido first noticed the pods struggling in the thick mud early Tuesday morning. Images and drone video show at least 12 orcas. Several boys struggle in a small space It was trapped in heavy ice about 1 km offshore.
As of Wednesday morning, The containment area was empty.Japanese news outlet NHK said it gave hope that the animals may have escaped to the open waters of the Sea of Okhotsk.
However, late Tuesday afternoon, a pod of 17 orcas was found trapped on an ice floe 2 kilometers northeast of their original location. NHK reporting.
“Orcas are not ice-adapted whales. They are not comfortable in this area.” colin galloway at the University of Manitoba, Canada. “So they are definitely experiencing the stress of confinement and are more likely to be starving.”
Cetaceans that permanently inhabit the Arctic region, such as narwhals (Monodon Monoceros) and belugas (Delphinapterus leucas), can sometimes become trapped in ice. Killer whale (killer whale) However, they usually avoid heavy ice and avoid getting trapped.
Still, black-and-white marine mammals can end up in icy waters at the wrong time.in 2016 reviewScientists found that since 1840, there have been 17 incidents in the Northern Hemisphere where a total of 100 orcas were trapped in ice. Almost half of them occurred in the Sea of Okhotsk, Japan. Confinement usually ends in the killer whale's death, Galloway said.
Scientists believe that even the reported orcas “broken freedomAfter being trapped in the ice, they can die struggling through further ice drifts while trying to reach the open sea.
Global warming may indeed be playing a role, Galloway says. His team is currently investigating the environmental impact of killer whales' gradual northward migration. But it's also possible that entrapment incidents simply appear to be more common because people are reporting more incidents.
“Just because we've gotten better at detecting, observing, and recording climate warming, and we're more interested in it, it's very difficult to disentangle the relationship between climate warming.” “That's one of the predictions,” he says.
NASA/JPL-California Institute of Technology/Space Science I
Saturn's moon Mimas appears to have a vast global ocean beneath its icy shell, according to detailed measurements of its orbit. If other icy worlds have similar oceans, the number of planets that can support life could increase.
Mimas is the smallest of Saturn's seven major moons. For a long time, it was thought that most of it was composed of solid ice and rock, but in 2014 astronomers observed that the orbit around Saturn was unexpectedly wobbling, suggesting that this could only be explained by either a rugby ball-shaped nucleus or a liquid ocean.
Many astronomers rejected the ocean explanation, as the friction required to melt the ice would have caused visible marks on Mimas's surface. However, recent simulations suggest that this ocean may exist even without such traces.
Looking for more clues? Valerie Rainey Researchers from France's Paris Observatory analyzed observations of Mimas' orbit by NASA's Cassini spacecraft. They found that the orbit around Saturn has shifted by about 10 kilometers over 13 years.
According to the team's calculations, this orbital drift could only have been caused by an ice shell sliding over the ocean, or by wobbles from the physically impossible pancake-shaped core.
The moon's elliptical orbit and lack of surface markings also suggest that the ocean is about 30 kilometers deep and formed less than 25 million years ago. “It was very recent,” Rainey says. “We are more or less witnessing the birth of this global ocean.”
This recent activity could help explain not only the lack of traces on the surface, but also why the moon is so different from its neighbors. Enceladus has a similar shape and orbit to Mimas, and has a global ocean, but it also has a very active surface and giant spout. Rainey said the difference is simply a difference in time, and in a few million years Mimas' ice could melt and it could look similar to Enceladus.
“It would be surprising if that were true,” he says. William McKinnon at Washington University in St. Louis, Missouri. But he says there are still things that aren't perfectly aligned, such as the vast 80-mile-wide Herschel crater, which was formed by a giant impact. If Mimas' ice shell was truly only tens of kilometers deep, McKinnon said, we would have seen evidence of a distorted crater floor in the impact and aftermath. It's also unlikely, he says, that you'll be able to get a front-row seat at such a short and unique time in Mimas' long history. “I remain a Mimas ocean skeptic,” McKinnon says.
However, if Mimas has a hidden ocean, it suggests that other icy planets and moons in the solar system and elsewhere may have the same, expanding the possibility of life. “It's expanding our vision of what is and isn't a habitable world,” Rainey says. “Mimas teaches us that even a corpse that seems to have no life in it may someday come to life.”
According to a new study, Greenland’s ice sheet has lost approximately 1,965 square miles to glacier retreat since 1985, which is about the same area as the state of Delaware. The study utilized satellite images to track the retreat and discovered that iceberg collapse is accelerating in Greenland, with previous analyses potentially underestimating its impact. The authors of the study noted that the current estimates of ice sheet mass balance may underestimate recent mass loss from Greenland by up to 20%. In recent decades, nearly all of Greenland’s glaciers have thinned or retreated.
The study, published in the journal Nature, is another indication that Greenland’s ice is melting at a rapid rate. There is growing concern among scientists that global warming could trigger a major ice sheet tipping point. If Greenland’s ice completely melts, sea levels could rise by almost 7 feet and change ocean circulation patterns. Additionally, the study suggests that the United Nations Intergovernmental Panel on Climate Change may be underestimating how much ice is being lost in Greenland.
Several studies published last year highlighted Greenland’s rapid changes, including one that found the rate of glacier retreat in the 21st century to be twice as fast as the 20th century. Another study showed that floating ice shelves in northern Greenland have lost over 35% of their total volume and are weakening, which could threaten ice sheet stability.
In November, a report by 60 leading snow and ice scientists raised concerns about the fate of the world’s ice sheets, warning that if global average temperatures rise to about 2 degrees Celsius above pre-industrial baselines, the planet could see sea level rise of more than 40 feet in the coming centuries. The report also indicates that by 2 degrees Celsius, most of Greenland, most of West Antarctica, and vulnerable parts of East Antarctica will have a very long-term chance of warming, leading to relentless sea level rise and decline.
The Great Lakes, known for ice fishing and winter's frozen waves, rang out a nearly bare New Year's bell.
Less than 0.4% of ice covered the Great Lakes on New Year's Day, according to the Great Lakes Environmental Research Institute, which uses satellite data to measure ice concentrations.
“There's basically nothing,” said James Kessler, a physical scientist at the institute, part of the National Oceanic and Atmospheric Administration. “We have about 50 years of data. Today's average for January 1st is about 9%.”
Kessler said that although ice coverage is well below normal, it is not unheard of for ice concentrations to fall below 1% on January 1, still early in the season.
The amount of ice on the Great Lakes (Lake Superior, Lake Michigan, Lake Huron, Lake Erie, and Lake Ontario) determines when and how raw materials and cargo are shipped from ports in the Midwest. Fish species such as whitefish are covered in ice to protect their eggs for reproduction. Lower ice levels could increase erosion and contribute to changes in weather patterns in the region.
Kessler said temperatures have been unseasonably high this season, making it difficult for ice to form on the lake's surface. According to his research, the Great Lakes' annual ice area varies greatly from year to year, but tends to decline at a rate of about 5% every decade.
“This is certainly a sign of climate change,” he says.
Ice typically reaches its maximum extent from mid-February to early March. In a typical year, about 40% of the Great Lakes are covered in ice at peak times.
Last year, ice coverage reached about 23% and by mid-February the ice had diminished. just covered 7% of the lake.
In 2023, Earth experienced its hottest year on record, largely due to human-induced climate change. Researchers expect temperatures to rise further this year due to El Niño, a natural climate pattern that releases ocean heat into the atmosphere.El Niño winter Warmer trends across the Great Lakes region.
A recent study from Indiana University’s Department of Earth and Atmospheric Sciences suggests that utilizing stratospheric aerosol injection to scatter sunlight-reflecting particles in the atmosphere could help slow the rapid melting of West Antarctica. This strategy aims to reduce the risk of catastrophic sea level rise due to climate change. The study shows that even with efforts to limit global warming to 1.5 degrees Celsius, significant sea level rise is still expected.
The study is one of the first to explore the effects of climate engineering on Antarctica, particularly focusing on the accelerating ice loss in West Antarctica. Researchers used high-performance computers and global climate models to simulate various stratospheric aerosol injection scenarios. The data analysis for the study was conducted on Carbonate, a large-memory computer cluster at IU University Information Technology Services.
The results of the study indicate that releasing stratospheric aerosols at multiple latitudes in the tropics and subtropics, with a larger proportion in the Southern Hemisphere, could be the best strategy for preserving Antarctic land ice. The researchers also emphasize the need for further research to quantify changes in melt rates and stress the importance of understanding the potential risks associated with stratospheric aerosol injection. These risks include changes in regional precipitation patterns and the potential for global temperatures to rapidly return to pre-injection levels if treatment is interrupted.
The study expands knowledge about the potential benefits and drawbacks of intentionally cooling the Earth and contributes to a growing conversation about geoengineering in response to the effects of climate change. While more research is needed, the findings highlight the importance of understanding how stratospheric aerosol injection affects the Antarctic region.
New findings suggest that early humans arrived in North America earlier than 13,000 years ago, likely taking advantage of the “sea ice highway” along the Pacific coast. This theory is supported by paleoclimate data, challenges traditional migration theories, and emphasizes the adaptability of early humans. Credit: SciTechDaily.com
A new study suggests that some early Americans may have traveled down the coast from Beringia 24,000 years ago on winter sea ice.
One of the hottest debates in archeology is when and how humans first arrived in North America. Archaeologists have traditionally argued that people walked through temporary ice-free passages between ice sheets an estimated 13,000 years ago.
New evidence casts doubt on traditional theory
But a growing number of archaeological and genetic discoveries, such as human footprints in New Mexico dating back some 23,000 years, suggest that humans were on the continent much earlier. These early Americans likely migrated from Beringia along the Pacific coastline. Beringia is a land bridge between Asia and North America that appeared during the last ice age maximum when ice sheets trapped large amounts of water and caused sea levels to drop.
Now, in a study presented at the American Geophysical Union Annual Meeting (AGU23) in San Francisco on Friday, December 15th, paleoclimate reconstructions of the Pacific Northwest show that sea ice has grown even further south than humans. This suggests that it may have been a means of transportation.
Coastal migration theory
The idea that early Americans may have traveled along the Pacific coast is not new. People may have been south of the giant ice sheet that once covered much of the continent by at least 16,000 years ago. Given that ice-free corridors would not open for thousands of years before these early arrivals, scientists proposed that people instead migrated along a “kelp highway.” Along this path, early Americans slowly made their way down to North America by ship. Abundant supplies found in coastal waters.
Archaeologists have discovered evidence of coastal settlements in western Canada dating back 14,000 years. But in 2020, researchers noted that freshwater from melting glaciers at the time may have created strong currents, making it difficult for people to travel along the coast.
Sea ice in Nunavut, Canada. Credit: Grid-Arendel CC-BY-NC-SA
An icy highway crossing a dangerous sea
To get a more complete picture of ocean conditions during key periods of human migration, Summer Pretorius and colleagues at the U.S. Geological Survey examined climate proxies in marine sediments along the coast. Most of the data came from small fossilized plankton. Its abundance and chemistry help scientists reconstruct ocean temperatures, salinity, and sea ice cover.
Praetorius’ presentation is part of a session at AGU23 on the climate history and geology of Beringia and the North Pacific during the Pleistocene. This year, his week-long conference brought together 24,000 of his experts from all areas of earth and space sciences in San Francisco and 3,000 online participants.
Using climate models, Praetorius’ team found that at the height of the Last Glacial Maximum, about 20,000 years ago, ocean currents were more than twice as strong as they are today due to glacial winds and falling sea levels. Pretorius said it would have been very difficult to travel by boat in these conditions, although it was not impossible to row.
However, records show that much of the region had winter sea ice until about 15,000 years ago. As a cold-adapted people, “they may have been using the sea ice as a foothold instead of having to row against this terrible glacial current,” Pretorius said.
Sea ice as a migration path
People in the Arctic now travel along the sea ice on dog sleds and snowmobiles. Pretorius said early Americans may also have used the “sea ice highway” to travel and hunt marine mammals, slowly making their way into North America in the process. Climate data suggest that conditions along the coastal route may have been favorable for migration between 24,500 and 22,000 years ago and between 16,400 and 14,800 years ago, possibly due to the presence of winter sea ice.
Integration of old and new theories
It’s difficult to prove that people used sea ice for travel, given that most ruins are underwater, but the idea is that without land bridges or easy ocean travel, humans It provides a new framework for understanding how it arrived in North America.
And the Sea Ice Highway is not mutually exclusive with other human movements beyond it, Pretorius said. The researchers’ model shows that by 14,000 years ago, the Alaska Current had calmed down, making it easier for people to travel by boat along the coast.
“There’s nothing wrong with it,” she said. “We are always amazed by the ingenuity of ancient humans.”
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