Climate pollution is making GPS and communications satellites even more vulnerable to solar storms
Andrew Freedman
, CNN
A monitor displays satellites in orbit and real-time communications across the globe.
Photo:
Justin Ide/Bloomberg/Getty Images via CNN Newsource
Satellites, including those used for GPS and communications, will face greater risks in coming decades during solar-triggered geomagnetic storms because of the effect climate pollution has on Earth's atmosphere, a new study found.
The increasing volume of planet-warming carbon dioxide in the upper atmosphere is likely to make the air less dense, while geomagnetic storms have the opposite effect: The ensuing rapid changes in density as a result could cause serious troubles for satellite operations.
This study, published in the journal Geophysical Research Letters, comes at a time when the world is growing more dependent on satellite networks for everything from internet access to navigation, as well as military applications.
Geomagnetic storms occur when charged particles from the Sun interact with the Earth's upper atmosphere. Their most visible impact is the auroras that light up the sky with green, purple and pink light. But strong storms can wreak havoc on satellite operations and communication.
They can increase how dense the air is in these thin upper layers, making it difficult for satellites to maintain their speed and altitude and potentially make them sink, cutting down on their operational lifetimes.
Geomagnetic storms later this century that are of similar intensity to those today will cause bigger spikes in atmospheric density because Earth's upper atmosphere will be less dense overall, the researchers found, using a supercomputer to model changes in the entirety of Earth's atmosphere.
"For the satellite industry, this is an especially important question because of the need to design satellites for specific atmospheric conditions," lead author Nicholas Pedatella of the National Center for Atmospheric Research told CNN.
A less dense atmosphere means satellites in the future would experience less drag, and that could lengthen their lifespan - and would also exacerbate the problem of more space junk in low Earth orbit, Pedatella said.
People visit St Mary's lighthouse in Whitley Bay, England, to see the northern lights in May 2024.
Photo:via CNN Newsource
Scientists already knew that the upper atmosphere is likely to become less dense as the climate warms, with a lower concentration of non-ionized particles such as oxygen and nitrogen. It's partly because of how higher concentrations of carbon dioxide affect temperatures in the upper atmosphere, which in turn affects the density of the air.
But this study breaks new ground by showing how much the atmosphere's density could change during strong geomagnetic storms.
The researchers used last May's strong geomagnetic storm as a case study. At that time, a series of powerful coronal mass ejections from the Sun interacted with the Earth's atmosphere, disrupting and even damaging satellites and leading to brilliant displays of the Northern Lights unusually far south.
The scientists analyzed how the atmosphere would respond to the same event in different years: 2040, 2061 and 2084.
To perform the experiment, they used a supercomputer that can simulate the entirety of the Earth's atmosphere, including the thinner, upper layers, to show how changes in the composition of the lower levels can alter the characteristics at much higher altitudes.
The researchers found that by later this century, the upper atmosphere would be 20% to 50% less dense at the peak of a solar storm similar to the 2024 event. The relative change would be greater, going from a doubling of density during such an event to a potential tripling.
Such a rapid throttling up of atmospheric density could damage critical satellite networks and thereby cause problems for society at the Earth's surface.
The bigger the spike, the bigger the impact on a satellite's orbit, Pedatella told CNN: "If you have a really big increase in density, then the satellite kind of comes down closer to Earth."
The satellites being designed today need to take these climate change-related impacts into account, rather than basing their engineering on historical calculations, he added.
"You would think, 'Okay, for this magnitude of a (geomagnetic) storm, I would expect this density response.' But in 30 years from now, that magnitude of storm will have a potentially different magnitude of response," Pedatella said.
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Climate pollution is making GPS and communications satellites even more vulnerable to solar storms
By Andrew Freedman , CNN A monitor displays satellites in orbit and real-time communications across the globe. Photo: Justin Ide/Bloomberg/Getty Images via CNN Newsource Satellites, including those used for GPS and communications, will face greater risks in coming decades during solar-triggered geomagnetic storms because of the effect climate pollution has on Earth's atmosphere, a new study found. The increasing volume of planet-warming carbon dioxide in the upper atmosphere is likely to make the air less dense, while geomagnetic storms have the opposite effect: The ensuing rapid changes in density as a result could cause serious troubles for satellite operations. This study, published in the journal Geophysical Research Letters, comes at a time when the world is growing more dependent on satellite networks for everything from internet access to navigation, as well as military applications. Geomagnetic storms occur when charged particles from the Sun interact with the Earth's upper atmosphere. Their most visible impact is the auroras that light up the sky with green, purple and pink light. But strong storms can wreak havoc on satellite operations and communication. They can increase how dense the air is in these thin upper layers, making it difficult for satellites to maintain their speed and altitude and potentially make them sink, cutting down on their operational lifetimes. Geomagnetic storms later this century that are of similar intensity to those today will cause bigger spikes in atmospheric density because Earth's upper atmosphere will be less dense overall, the researchers found, using a supercomputer to model changes in the entirety of Earth's atmosphere. "For the satellite industry, this is an especially important question because of the need to design satellites for specific atmospheric conditions," lead author Nicholas Pedatella of the National Center for Atmospheric Research told CNN. A less dense atmosphere means satellites in the future would experience less drag, and that could lengthen their lifespan - and would also exacerbate the problem of more space junk in low Earth orbit, Pedatella said. People visit St Mary's lighthouse in Whitley Bay, England, to see the northern lights in May 2024. Photo:via CNN Newsource Scientists already knew that the upper atmosphere is likely to become less dense as the climate warms, with a lower concentration of non-ionized particles such as oxygen and nitrogen. It's partly because of how higher concentrations of carbon dioxide affect temperatures in the upper atmosphere, which in turn affects the density of the air. But this study breaks new ground by showing how much the atmosphere's density could change during strong geomagnetic storms. The researchers used last May's strong geomagnetic storm as a case study. At that time, a series of powerful coronal mass ejections from the Sun interacted with the Earth's atmosphere, disrupting and even damaging satellites and leading to brilliant displays of the Northern Lights unusually far south. The scientists analyzed how the atmosphere would respond to the same event in different years: 2040, 2061 and 2084. To perform the experiment, they used a supercomputer that can simulate the entirety of the Earth's atmosphere, including the thinner, upper layers, to show how changes in the composition of the lower levels can alter the characteristics at much higher altitudes. The researchers found that by later this century, the upper atmosphere would be 20% to 50% less dense at the peak of a solar storm similar to the 2024 event. The relative change would be greater, going from a doubling of density during such an event to a potential tripling. Such a rapid throttling up of atmospheric density could damage critical satellite networks and thereby cause problems for society at the Earth's surface. The bigger the spike, the bigger the impact on a satellite's orbit, Pedatella told CNN: "If you have a really big increase in density, then the satellite kind of comes down closer to Earth." The satellites being designed today need to take these climate change-related impacts into account, rather than basing their engineering on historical calculations, he added. "You would think, 'Okay, for this magnitude of a (geomagnetic) storm, I would expect this density response.' But in 30 years from now, that magnitude of storm will have a potentially different magnitude of response," Pedatella said. - CNN
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In a series of experiments reported Wednesday in the journal Nature, researchers at Harvard and Rush universities found that depleting lithium in the diet of normal mice caused their brains to develop inflammation and changes associated with accelerated ageing. In mice that were specially bred to develop the same kinds of brain changes as humans with Alzheimer's disease, a low-lithium diet revved the buildup of sticky proteins that form plaques and tangles in the brains that are hallmarks of the disease. It also sped up memory loss. Maintaining normal lithium levels in mice as they aged, however, protected them from brain changes associated with Alzheimer's. If further research supports the findings, it could open the door to new treatments and diagnostic tests for Alzheimer's, which affects an estimated 6.7 million older adults in the United States, according to the US Centres for Disease Control and Prevention. The research provides a unifying theory that helps explain so many of the puzzle pieces scientists have been trying to fit together for decades. "It is a potential candidate for a common mechanism leading to the multisystem degeneration of the brain that precedes dementia," said Dr. Bruce Yankner, a professor of genetics at Harvard Medical School, who led the study. "It will take a lot more science to determine whether this is a common pathway ... or one of several pathways," to Alzheimer's, he added. "The data are very intriguing." In an editorial published in Nature, Dr. Ashley Bush, a neuroscientist who directs the Melbourne Dementia Research Centre at the University of Melbourne in Australia, said the researchers "present compelling evidence that lithium does in fact have a physiological role and that normal ageing might impair the regulation of lithium levels in the brain." He was not involved in the study. Close examination of human and animal brain tissues, along with genetic investigations in the study, found the mechanism that appears to be at play: Beta amyloid plaques - the sticky deposits that gum up the brains of Alzheimer's patients - bind to lithium and hold it, including the type that's normally present in the body, as well as the commonly prescribed form. This binding depletes lithium available for nearby cells, including important scavengers known as microglia. When the brain is healthy and functioning normally, microglia are waste managers, clearing away beta amyloid before it can accumulate and can cause harm. In the team's experiments, microglia from the brains of lithium-deficient mice showed a reduced ability to sweep away and break down beta amyloid. Yankner believes this creates a downward spiral. The accumulation of beta amyloid soaks up more and more lithium, further crippling the brain's ability to clear it away. He and his colleagues tested different lithium compounds and found one - lithium orotate - that doesn't bind to amyloid beta. When they gave lithium orotate to mice with signs of Alzheimer's in their brains, these changes reversed: Beta amyloid plaques and tangles of tau that were choking the memory centres of the brain were reduced. Mice treated with lithium were once again able to navigate mazes and learn to identify new objects, whereas those who got placebos showed no change in their memory and thinking deficits. In its natural form, lithium is an element, a soft, silvery-white metal that readily combines with other elements to form compounds and salts. It's naturally present in the environment, including in food and water. Scientists have never fully known how it works to improve mood - only that it does. The original formula for 7Up soda included lithium - it was called 7Up Lithiated Lemon Soda - and touted as a hangover cure and mood lifter "for hospital or home use." 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Consistently finding lower lithium levels in the brains of people with memory loss amounted to a smoking gun, Yankner said. "At first, frankly, we were sceptical of the result because it wasn't expected," said Yankner. But it held up even when they checked samples from other brain banks at Massachusetts General Hospital, Duke and Washington universities. "We wanted to know whether this drop in lithium was biologically meaningful, so we devised an experimental protocol where we could take lithium selectively out of the diet of mice and see what happens," Yankner said. When they fed the mice a low-lithium diet, simply dropping their natural levels by 50 percent, their brains rapidly developed features of Alzheimer's. "The neurons started to degenerate. The immune cells in the brain went wild in terms of increased inflammation and worse maintenance function of the neurons around them, and it looked more like an advanced Alzheimer patient," Yankner said. 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All of this poses challenges for vaccine design. Ideally, potential vaccines must not only induce strong, long-lasting immunity, but also maintain efficacy across the vast genetic diversity of circulating noroviruses. Progress in norovirus vaccinology has accelerated over the past couple of decades. While researchers are considering multiple strategies to formulate and deliver vaccines, a technology called VLP-based vaccines is at the forefront. VLP stands for virus-like particles. These synthetic particles, which scientists developed using a key component of the norovirus (called the major caspid protein), are almost indistinguishable from the natural structure of the virus. When given as a vaccine, these particles elicit an immune response resembling that generated by a natural infection with norovirus - but without the debilitating symptoms of gastro. One bivalent VLP vaccine ("bivalent" meaning it targets two different norovirus genotypes) has progressed through multiple clinical trials. This vaccine showed some protection against moderate to severe gastroenteritis in healthy adults. However, its development recently suffered a significant setback. A phase two clinical trial in infants failed to show it effectively protected against moderate or severe acute gastroenteritis. The efficacy of the vaccine in this trial was only 5 percent. In another recent phase two trial, an oral norovirus vaccine did meet its goals. Participants who took this pill were 30 percent less likely to develop norovirus compared to those who received a placebo. This oral vaccine uses a modified adenovirus to deliver the norovirus VLP gene sequence to the intestine to stimulate the immune system. With the success of mRNA vaccines during the Covid-19 pandemic, scientists are also exploring this platform for norovirus. 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Developing a safe and effective norovirus vaccine is one of the most pressing and under-addressed needs in infectious disease prevention. A licensed norovirus vaccine could drastically reduce workplace and school absenteeism, hospitalisations and deaths. It could also bolster our preparedness against future outbreaks of gastrointestinal pathogens. This story was originally published on The Conversation.
