Latest news with #EarthandSpaceScience
Yahoo
02-05-2025
- Science
- Yahoo
How California's farmers can recharge the aquifers they've drained
In parts of California's Central Valley, so much groundwater has been pumped out of the ground to deal with the region's persistent drought that the land is starting to sink in. Underground aquifers — layers of sand, gravel, clay, and water — are vital resources that communities can turn to when surface water is scarce. But when more water is pumped out of aquifers than is put back in — as is happening in the southern part of the valley — it can cause the ground to slowly contract, like a drying sponge. After studying this phenomenon, Rosemary Knight, a professor of geophysics at the Stanford Doerr School of Sustainability, became interested in identifying the fastest ways to replenish California's groundwater using managed aquifer recharge. This technique involves flooding a piece of land with excess surface water and allowing that water to seep through the ground and into aquifers, where it can be stored for later use. Armed with a massive electromagnetic dataset, Knight and a team of researchers set out to analyze sediment types below the surface in the California Central Valley and map out the quickest routes to refilling aquifers. Their research, published last month in the journal Earth and Space Science, found that between 2 million and 7 million acres of land in the Central Valley are suitable for recharge — or between 19 and 56 percent of the valley's total area. Most of the rechargeable land is currently used to grow crops. Many farmers are enthused about the data, according to Knight — and keen to implement it. As climate change continues to exacerbate water challenges in California, her team's research points to how agricultural producers can help to ensure sustainable water access for all. 'They want to be part of the solution,' said Knight. Since 2000, the U.S. Southwest has been in the driest 25-year period the region has seen in over a millennium, according to researchers at the University of California, Los Angeles, who found that climate change has supercharged these dry conditions. Part of the way rising global temperatures exacerbate water challenges is by increasing the evaporation of surface water, or water in rivers, lakes, and reservoirs. Scientists are also eyeing how climate change could impact snowpack in the Sierra Nevada mountain range, which forms a critical part of California's annual water supply every spring as it melts and moves into rivers and streams. In 2015, a multiyear drought in California led to an unprecedented decline in snowpack in the Sierra Nevada; researchers have also predicted that global warming could cause snowlines on the Sierra Nevada to rise towards the end of the century, meaning snow would only form at higher elevations, reducing the overall amount of snow on the mountain range. Water is critical for the region because the Central Valley is an agricultural powerhouse, producing one-fourth of the nation's food, according to the U.S. Geological Survey. It's home to more than 250 different crops — from hay and cotton to rice and corn to tomatoes and olives. But the state's agricultural industry has also been blamed for depleting groundwater while wells run dry in nearby rural communities. Over the past two decades, groundwater levels in California have been steadily falling, despite aquifers being periodically recharged naturally by snowmelt and rainfall, according to a 2022 study in Nature Communications. 'Natural recharge was not keeping pace with the rate of extraction,' said Knight. In order to determine how water would flow through sediments below the ground, Knight and her colleagues used a large set of electromagnetic data acquired by the California Department of Water Resources. The data was collected by helicopters flying over the Central Valley in a grid formation, with flightlines spaced a few miles apart. Using special equipment that sends an electromagnetic signal into the ground, the choppers were able to determine how the current is conducted through layers of soil at a depth of up to 300 meters. Areas full of coarse materials like sand and gravel — where water flows seamlessly — can't conduct electricity easily. By interpreting these results, the researchers were able to construct a 3D model of the subsurface and pinpoint 'fastpaths' for water to travel down into aquifers. This kind of information could be vital for regional California agencies, which have been instructed to develop plans for using groundwater more efficiently under the state's Sustainable Groundwater Management Act. The data that Knight and her colleagues produced — which they've made available online — can also help agricultural producers decide whether or not to implement groundwater recharge on their lands. Their analysis reveals which specific croplands are best suited for recharging aquifers (like the ones used to grow fruits, nuts, and field crops, as well as vineyards) and which aren't (those used for rice and citrus). This level of soil data can help farmers make decisions about whether managed recharge is right for their land. 'Growers really want to have confidence that if their land is being flooded for recharge, that water is going to very rapidly move below the ground surface,' said Knight. Better guidance for agricultural producers has already been circulating; the Almond Board of California has been recommending groundwater recharge for a few years now and published an introductory guide for growers. Christine Gemperle, a longtime almond grower who sits on the Almond Board of California, has flooded one of her orchards twice for groundwater recharge — and said she has seen numerous benefits beyond raising groundwater levels in her area. They include flushing gophers out of her fields (they love her cover crops, Gemperle said) and pushing salts that accumulate from irrigation further down into the soil. Although she wasn't able to do it this winter, due to dry conditions lowering the amount of surface water available, she feels optimistic that this kind of data can empower other farmers to explore recharge. 'There's so much opportunity,' she said. Like many farmers in the state, Gemperle already had access to canals that transport water from a reservoir to her fields for irrigation. This made recharge fairly straightforward: When she saw the canals were full of water during a particularly wet year, she got permission from her local irrigation district to open the canal gates and flood her land. The prevalence of this kind of infrastructure is an advantage for California farmers interested in recharge, according to Shimon Anisfeld, a professor at the Yale School of the Environment focused on water management who was not involved in Knight's study. Managed recharge can provide some 'environmental win-wins,' said Anisfeld. When farmers face wet winters and dry summers, recharge can help store excess surface water, making it accessible during the growing season. In certain instances, like when farmlands are restored into floodplains, aquifer recharge can also double as habitat restoration for wildlife. Farmers are likely to be motivated to dedicate some of their land to aquifer recharge, said Anisfeld, especially if they can reap the benefits later. Still, he suggested, Californians will likely need to tackle its water challenges by decreasing demand as much as boosting supply. 'I'm not convinced that recharge is going to be a substitute for reducing water use,' he said. 'I don't think it can, on its own, solve the whole problem.' Managed aquifer recharge may be a more attractive option for farmers than the alternative of changing their agricultural practices. 'If you can recharge groundwater, that gives you more to work with,' Anisfeld said. 'It means you can keep on farming and keep on growing water-intensive crops.' Knight agreed that growers don't 'want to stop pumping' groundwater or have to fallow their fields. She hopes that by publishing a version of their data online and making it accessible to the public, her team will help empower individual stakeholders to explore the options that are best for their soil. 'I care about actionable data presented in a way that is helpful to end users, such as growers, managers of water districts,' she said. That way, 'the user can make their own decisions about how best to use the results.' As for Gemperle, she sees flooding her farmland as a way to ensure that her community continues to have access to water. 'I see it as something that really points to how connected we are in this agricultural landscape,' she said. 'We are more connected than disconnected.' This story was originally published by Grist with the headline How California's farmers can recharge the aquifers they've drained on May 2, 2025.
Ammon
13-04-2025
- Science
- Ammon
Mysterious ocean glow reported for over 400 years has stumped scientists
Ammon News - For over 400 years, sailors have reported a mysterious phenomenon in which the ocean appears to glow as far as the eye can see. 'The sea from horizon to horizon in all directions took on a phosphorescence glow … the moon had just set and the whole sea was several shades lighter than the sky,' wrote J. Brunskill, an officer aboard a ship called the SS Ixion that had sailed through the Arabian Sea in 1967. Nearly 10 years later, another crew aboard a vessel named the MV Westmorland experienced a similar event in the Arabian Sea as it sailed through a 'large area of bioluminescence,' according to the ship's captain, P. W. Price. 'The sea … glared a brilliant and bright green. So brilliant in fact that neither white caps nor swell waves could be distinguished from what appeared to be a perfectly flat sea,' he wrote in a letter in 1976. These events, dubbed 'milky seas' by the sailors who have been lucky enough to come across them, have been notoriously hard to study due to their rare occurrences in remote regions of the ocean where many humans are not around to see them. Now, scientists hoping to better investigate the peculiar events are one step closer to predicting when and where these mysterious bioluminescent displays will occur. Justin Hudson, a doctoral student in Colorado State University's department of atmospheric science, has compiled over 400 known sightings of 'milky seas,' including those from Brunskill and Price, to create a new database that will help scientists one day get a research vessel to an event, according to a study published Wednesday in the journal Earth and Space Science. 'My hope is that with this database … more people will be able to start studying 'milky seas' and start unraveling this mystery that's been around for centuries,' said Hudson, who is the lead author of the new research. CNN
Yahoo
12-04-2025
- Science
- Yahoo
‘Milky sea' events mysteriously cause the ocean to glow. Scientists are trying to track them
Sign up for CNN's Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. For over 400 years, sailors have reported a mysterious phenomenon in which the ocean appears to glow as far as the eye can see. 'The sea from horizon to horizon in all directions took on a phosphorescence glow … the moon had just set and the whole sea was several shades lighter than the sky,' wrote J. Brunskill, an officer aboard a ship called the SS Ixion that had sailed through the Arabian Sea in 1967. Nearly 10 years later, another crew aboard a vessel named the MV Westmorland experienced a similar event in the Arabian Sea as it sailed through a 'large area of bioluminescence,' according to the ship's captain, P. W. Price. 'The sea … glared a brilliant and bright green. So brilliant in fact that neither white caps nor swell waves could be distinguished from what appeared to be a perfectly flat sea,' he wrote in a letter in 1976. These events, dubbed 'milky seas' by the sailors who have been lucky enough to come across them, have been notoriously hard to study due to their rare occurrences in remote regions of the ocean where many humans are not around to see them. Now, scientists hoping to better investigate the peculiar events are one step closer to predicting when and where these mysterious bioluminescent displays will occur. Justin Hudson, a doctoral student in Colorado State University's department of atmospheric science, has compiled over 400 known sightings of 'milky seas,' including those from Brunskill and Price, to create a new database that will help scientists one day get a research vessel to an event, according to a study published Wednesday in the journal Earth and Space Science. 'My hope is that with this database … more people will be able to start studying 'milky seas' and start unraveling this mystery that's been around for centuries,' said Hudson, who is the lead author of the new research. He added that further study of 'milky seas' can answer the many questions that remain on the phenomenon, such as why they happen and what they could mean for ocean life. 'Milky seas could be a sign of something like a very good, healthy ecosystem. They could be a sign of an unhealthy ecosystem, and we just don't know,' he added. 'And so by being able to predict when and where they're going to happen, we can start answering those questions about … where it fits in our whole global, interconnected Earth system.' Observers often describe 'milky seas' as similar in color to glow-in-the-dark stars put on the ceilings of children's bedrooms. The glow the phenomenon emits has been reported by sailors to be strong enough to read by — a stark contrast to the dark ocean typically seen when there is no sun or moonlight. These events, which can last for months on end, stretch as wide as 100,000 square kilometers (about 39,000 square miles), and the larger ones can be seen from space, according to the study. While scientists do not know exactly why this rare glow occurs, it is likely a byproduct of high concentrations of microscopic bioluminescent bacteria called Vibrio harveyi, according to the study. This hypothesis is based on a 1985 chance encounter by a research vessel that had collected and tested a water sample during a 'milky sea' event. 'But besides that, the circumstances for how they form and how they set about causing the entire ocean to glow like that is still highly unknown,' said Dr. Steven Miller, study coauthor and a professor in Colorado State University's department of atmospheric science. Miller, who has studied the phenomenon for decades, was the lead author of a 2021 study that found the larger 'milky seas' could be detected via satellites. After compiling all known records of 'milky sea' sightings, which included historical records of eyewitness reports from sailors and satellite data, the study authors noted several trends related to the mysterious sea occurrences: Milky seas primarily appear in the Arabian Sea and Southeast Asian waters, and they may be impacted by certain global climate events, such as the Indian Ocean Dipole and the El Niño Southern Oscillation, Hudson said. The regions where 'milky seas' mostly occur tend to experience upwelling in the ocean, which is when the cooler, nutrient-rich water from the deep ocean is brought up to the surface due to strong winds. He predicts in these regions there are about one or so instances of 'milky seas' a year. 'They are spots that are primed for lots of biological activity to happen,' Hudson said. 'But there's lots of places on Earth that are like that. So what actually makes (these regions) special is a huge, open question.' 'Milky seas' are different from the more common bioluminescent ocean events caused by a type of phytoplankton known as dinoflagellates. These organisms emit a blue glow when disturbed, such as when fish swim by or waves crash on the shore, in contrast to the steady glow emitted in the 'milky seas' event. While the phytoplankton flash in a defense mechanism, researchers theorize that the 'milky sea' bacteria glow instead to attract fish — which then will eat the bacteria and allow the bacteria to thrive in the creature's gut, said Miller, who is also the director of the Cooperative Institute for Research in the Atmosphere (CIRA) at Colorado State University. Like many other scientists who have studied bioluminescence, Miller hopes to one day see the mysterious event for himself. Dr. Edith Widder, an oceanographer and marine biologist who was not involved with the study, has the same goal. 'I have spent my career observing and measuring bioluminescence in the ocean. I have seen some amazing light shows but I've never seen a milky sea. I really want to,' Widder said in an email. 'By assembling this data base the authors bring us that much closer to being able to predict where and when a milky sea may occur.' Widder, who is also the CEO and senior scientist for the Ocean Research & Conservation Association, wonders what effect the bioluminescent event has on other life in the ocean, particularly on the creatures that hide in the dark depths during the day and come up to eat only in the darkness. 'Light is a critical determinant of animal distributions and behaviors in the ocean. … What happens to that daily game of hide and seek when the animals that need to hide are illuminated by all that glowing bioluminescence? What is the impact on the carbon cycle? This is a natural experiment that has the potential to reveal a lot about the workings of life in the ocean,' she added. There have been previous attempts at compiling databases of milky sea events, but each of these were eventually lost to time. With the new database, it 'resets the benchmark for us in terms of our knowledge and awareness of where 'milky seas' are happening globally and over time,' Miller said. During these mysterious bioluminescent ocean events, 'the bacterial population is responding in this way that is so dramatic, and in a way that we hadn't really anticipated could be possible,' Miller added. Amongst the many unanswered questions that remain: Scientists don't know how climate change affects the occurrence of the glow events, and how that can impact the ecosystem, he noted. 'We need to understand how that process is working … because, among many other things, bacteria and phytoplankton are associated with the bottom of the oceanic food chain — all the higher order species and fish are reliant on that food chain to exist. And changes in that food chain, based on changes in circulations of our planet, are things that we need to know about.'
CNN
12-04-2025
- Science
- CNN
‘Milky sea' events mysteriously cause the ocean to glow. Scientists are trying to track them
For over 400 years, sailors have reported a mysterious phenomenon in which the ocean appears to glow as far as the eye can see. 'The sea from horizon to horizon in all directions took on a phosphorescence glow … the moon had just set and the whole sea was several shades lighter than the sky,' wrote J. Brunskill, an officer aboard a ship called the SS Ixion that had sailed through the Arabian Sea in 1967. Nearly 10 years later, another crew aboard a vessel named the MV Westmorland experienced a similar event in the Arabian Sea as it sailed through a 'large area of bioluminescence,' according to the ship's captain, P. W. Price. 'The sea … glared a brilliant and bright green. So brilliant in fact that neither white caps nor swell waves could be distinguished from what appeared to be a perfectly flat sea,' he wrote in a letter in 1976. These events, dubbed 'milky seas' by the sailors who have been lucky enough to come across them, have been notoriously hard to study due to their rare occurrences in remote regions of the ocean where many humans are not around to see them. Now, scientists hoping to better investigate the peculiar events are one step closer to predicting when and where these mysterious bioluminescent displays will occur. Justin Hudson, a doctoral student in Colorado State University's department of atmospheric science, has compiled over 400 known sightings of 'milky seas,' including those from Brunskill and Price, to create a new database that will help scientists one day get a research vessel to an event, according to a study published Wednesday in the journal Earth and Space Science. 'My hope is that with this database … more people will be able to start studying 'milky seas' and start unraveling this mystery that's been around for centuries,' said Hudson, who is the lead author of the new research. He added that further study of 'milky seas' can answer the many questions that remain on the phenomenon, such as why they happen and what they could mean for ocean life. 'Milky seas could be a sign of something like a very good, healthy ecosystem. They could be a sign of an unhealthy ecosystem, and we just don't know,' he added. 'And so by being able to predict when and where they're going to happen, we can start answering those questions about … where it fits in our whole global, interconnected Earth system.' Observers often describe 'milky seas' as similar in color to glow-in-the-dark stars put on the ceilings of children's bedrooms. The glow the phenomenon emits has been reported by sailors to be strong enough to read by — a stark contrast to the dark ocean typically seen when there is no sun or moonlight. These events, which can last for months on end, stretch as wide as 100,000 square kilometers (about 39,000 square miles), and the larger ones can be seen from space, according to the study. While scientists do not know exactly why this rare glow occurs, it is likely a byproduct of high concentrations of microscopic bioluminescent bacteria called Vibrio harveyi, according to the study. This hypothesis is based on a 1985 chance encounter by a research vessel that had collected and tested a water sample during a 'milky sea' event. 'But besides that, the circumstances for how they form and how they set about causing the entire ocean to glow like that is still highly unknown,' said Dr. Steven Miller, study coauthor and a professor in Colorado State University's department of atmospheric science. Miller, who has studied the phenomenon for decades, was the lead author of a 2021 study that found the larger 'milky seas' could be detected via satellites. After compiling all known records of 'milky sea' sightings, which included historical records of eyewitness reports from sailors and satellite data, the study authors noted several trends related to the mysterious sea occurrences: Milky seas primarily appear in the Arabian Sea and Southeast Asian waters, and they may be impacted by certain global climate events, such as the Indian Ocean Dipole and the El Niño Southern Oscillation, Hudson said. The regions where 'milky seas' mostly occur tend to experience upwelling in the ocean, which is when the cooler, nutrient-rich water from the deep ocean is brought up to the surface due to strong winds. He predicts in these regions there are about one or so instances of 'milky seas' a year. 'They are spots that are primed for lots of biological activity to happen,' Hudson said. 'But there's lots of places on Earth that are like that. So what actually makes (these regions) special is a huge, open question.' 'Milky seas' are different from the more common bioluminescent ocean events caused by a type of phytoplankton known as dinoflagellates. These organisms emit a blue glow when disturbed, such as when fish swim by or waves crash on the shore, in contrast to the steady glow emitted in the 'milky seas' event. While the phytoplankton flash in a defense mechanism, researchers theorize that the 'milky sea' bacteria glow instead to attract fish — which then will eat the bacteria and allow the bacteria to thrive in the creature's gut, said Miller, who is also the director of the Cooperative Institute for Research in the Atmosphere (CIRA) at Colorado State University. Like many other scientists who have studied bioluminescence, Miller hopes to one day see the mysterious event for himself. Dr. Edith Widder, an oceanographer and marine biologist who was not involved with the study, has the same goal. 'I have spent my career observing and measuring bioluminescence in the ocean. I have seen some amazing light shows but I've never seen a milky sea. I really want to,' Widder said in an email. 'By assembling this data base the authors bring us that much closer to being able to predict where and when a milky sea may occur.' Widder, who is also the CEO and senior scientist for the Ocean Research & Conservation Association, wonders what effect the bioluminescent event has on other life in the ocean, particularly on the creatures that hide in the dark depths during the day and come up to eat only in the darkness. 'Light is a critical determinant of animal distributions and behaviors in the ocean. … What happens to that daily game of hide and seek when the animals that need to hide are illuminated by all that glowing bioluminescence? What is the impact on the carbon cycle? This is a natural experiment that has the potential to reveal a lot about the workings of life in the ocean,' she added. There have been previous attempts at compiling databases of milky sea events, but each of these were eventually lost to time. With the new database, it 'resets the benchmark for us in terms of our knowledge and awareness of where 'milky seas' are happening globally and over time,' Miller said. During these mysterious bioluminescent ocean events, 'the bacterial population is responding in this way that is so dramatic, and in a way that we hadn't really anticipated could be possible,' Miller added. Amongst the many unanswered questions that remain: Scientists don't know how climate change affects the occurrence of the glow events, and how that can impact the ecosystem, he noted. 'We need to understand how that process is working … because, among many other things, bacteria and phytoplankton are associated with the bottom of the oceanic food chain — all the higher order species and fish are reliant on that food chain to exist. And changes in that food chain, based on changes in circulations of our planet, are things that we need to know about.'
Yahoo
12-04-2025
- Science
- Yahoo
Scientists Investigating Patches of Ocean With Otherworldly Glow
We're inching ever closer towards unearthing the secrets behind one of the most enduring marine mysteries: the fabled "milky seas" — glowing stretches of water that cast the ocean in an otherworldly haze of green and white, spanning to the horizon and beyond. The nocturnal phenomenon has haunted and mystified sailors for centuries. But they're incredibly rare, and scientists have struggled to determine what causes them. The milky seas are believed to be produced by some form of bioluminescence, but by what creature? To learn more, researchers have created a database of every recorded sighting over the past 400 years, in the hope of predicting when and where the next display will pop up. As detailed in a new paper published in the journal Earth and Space Science, by teasing out an underlying pattern to the phenomenon, the effort could provide scientists a chance to observe the milky seas and collect samples that have so far eluded them. "It is really hard to study something if you have no data about it," study lead author Justin Hudson, an atmospheric scientist at Colorado State University, said in a statement about the work. "To this point, there is only one known photograph at sea level that came from a chance encounter by a yacht in 2019." The serendipitous photo was taken off the coast of Indonesia and was published in a 2022 paper led by Steven Miller, Hudson's colleague at CSU. Along with the photo, the other sacred piece of evidence is a water sample collected by a research vessel's chance encounter in 1985 near the Yemeni island of Socotra, which was found to contain the bacteria Vibrio harveyi. Today, the strain, which is known to be bioluminescent, remains the prime suspect. But it's far from conclusive evidence. Perhaps it doesn't act alone — and regardless, there are other nagging questions. For one, it remains unclear what role milky seas play in the ocean ecosystem, or how they fit into the carbon cycle. Stretching for tens of thousands of square miles and glowing for up to months at a time, their influence could be incalculably vast. "It seems possible that milky seas represent an understudied aspect of the large-scale movement of carbon and nutrients through the Earth system," Hudson said. Based on insights gleaned from modern satellite imagery, combined with mapping hundreds of years of accounts, it appears the milky seas are concentrated around the Arabian Sea and Southeast Asian waters. Intriguingly, the work revealed that the timing of the sightings are statistically related to the Indian Ocean Dipole and the El Niño Southern Oscillation, recurring climate patterns that involve changes to the temperature of the waters. Perhaps the milky seas are the result of a biological response by the bacteria, but it's anyone's guess if it's a healthy sign or a bad one. "The regions where this happens the most are around the northwest Indian Ocean near Somalia and Socotra, Yemen, with nearly 60 percent of all known events occurring there," Hudson explained. "At the same time, we know the Indian monsoon's phases drive biological activity in the region through changes in wind patterns and currents." Whatever the cause, Miller, who authored the 2022 paper and contributed to this latest one, is confident they're onto something big. "Milky seas are incredible expressions of our biosphere whose significance in nature we have not yet fully determined," Miller said in the statement. "Their very existence points to unexplored connections between the surface and the sky, and between microscopic to the global scale roles of bacteria in the Earth system. More on the ocean: Iceberg Breaks Off Antarctica, Revealing Tentacled Creatures Beneath
