On Facebook ads, users may dislike ‘likes’

Lots of ‘likes’ can lead to fewer clicks — depending on who does the liking

University of Texas at Austin

AUSTIN, Texas — Scroll through your Facebook feed, and you’ll get pelted by advertisements begging for a click. Like any other type of post, these ads allow you to react. Often, you’ll notice that one or more of your friends has already “liked” them.

Advertisers hope that a high number of such endorsements, especially from familiar faces, might make users more likely to click. But new research from Texas McCombs finds it depends on the type of ad — and the type of friend.

The wrong ads and friends could have the opposite effect, making a viewer less likely to click. So say Ashish Agarwal, associate professor of information, risk, and operations management (IROM), and Andrew Whinston, professor of IROM. Whinston is also the Hugh Roy Cullen Centennial Chair in Business Administration and director of the Center for Research in Electronic Commerce at The University of Texas at Austin.

Agarwal, Whinston, and Shun-Yang Lee of Northeastern University focused on call-to-action (CTA) ads. Such ads use assertive wording to urge users to do something specific, such as purchase a product or download a mobile app. They’re different from the passive wording of informational ads, which politely invite users to click to “learn more.”

Advertisers tend to prefer CTA ads, Agarwal says, because they put social media users “directly into purchase mode.” But past research had shown a downside to CTA ads: They often rubbed users the wrong way, especially when people felt manipulated.

The researchers wondered whether an accumulation of “likes” could overcome that resistance. Says Agarwal, “Given that these are assertive ads, how would these social cues help or hurt?”

They conducted two rounds of studies.

• In a field experiment, they teamed up with a mobile app developer to place a CTA ad on Facebook, asking users to download an app. It appeared 710,445 times, resulting in 799 “likes” and 4,052 clicks.
• For a lab test, they evaluated different combinations of ads and cues: informational vs. CTA and generic “likes” vs. “likes” from friends. Each of the 982 study participants provided the names of five friends.

The studies found that users had different responses, depending on the ad and the cue. For informational ads, more “likes” led to more clicks. The odds of a click rose 3% for every 100 generic likes and even more — 21% — for each “like” by a friend.

For CTA ads, the opposite was true. The overall number of “likes” had no meaningful impact on clicks.

But “likes” from friends did have effects — both ways. They were positive or negative, depending on whether a user believed a friend had similar or dissimilar interests.

• Having similar interests increased odds of a click 180%.
• Having dissimilar interests decreased odds 66%.

Why the difference? In a follow-up lab study, the team found that users responded negatively to CTA ads, because they felt advertisers were trying to manipulate them. They saw the highlighting of “likes” as part of that strategy.

They set aside that resistance, though, when they saw that friends with similar interests “liked” an ad. They saw the ad as having higher credibility.

By contrast, they found informational ads less intrusive than CTAs. They felt less resistance and were more open to being swayed by “likes.”

The team’s findings have implications for advertisers, Agarwal says, as well as for social media companies that rely on advertising revenue. Displaying “likes” may be effective for informational ads but not for CTAs.

“You have to be a bit careful about the value of these endorsements,” Agarwal says. “Maybe social media companies can make their presence optional. Maybe advertisers should have a choice: Do I want my content to be promoted with these endorsements or not?”

“The Effect of Popularity Cues and Peer Endorsements on Assertive Social Media Ads” is published online in Information Systems Research.

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Journal

Information Systems Research

DOI

10.1287/isre.2021.0606 

Article Title

The Effect of Popularity Cues and Peer Endorsements on Assertive Social Media Ads

GREENWASHING  

Rice Sustainability Institute and Chevron partner to empower next-gen sustainable energy leaders

Rice University

 

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This year’s fellows are tackling critical energy challenges.

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Credit: Photo by Brandon Martin/Rice University.

By Loren Wilkerson
Special to Rice News

The Rice University Sustainability Institute (RSI) is pleased to announce the inaugural recipients of the newly created Rice Chevron Energy Graduate Fellowship. Funded by Chevron, this fellowship is a commitment to fostering the next generation of leaders who are developing the sustainable technologies that will shape our future.

“We are excited about our partnership with Chevron, which broadens our students’ opportunities to develop advanced solutions for carbon dioxide management and sustainable energy generation,” said Caroline Masiello, director of the RSI and the W. Maurice Ewing Professor in Earth, Environmental and Planetary Sciences.

Meet the 2024 Chevron Fellows

This year’s fellows are tackling critical energy challenges, focusing on creating real-world solutions that could transform how we live, work and interact with our environment.

Xi Chen, a doctoral student in materials science and nanoengineering, is using microwave-assisted techniques to revolutionize how we recycle lithium-ion batteries. “Recycling lithium-ion batteries in an environmentally and economically sustainable way is essential for global energy security,” Chen said.

Enina Egiebor, a doctoral student in chemical and biomolecular engineering, is working on cost-effective solar-driven technologies to produce green hydrogen, an eco-friendly alternative to fossil fuels. “The fellowship has taken my research beyond the lab. I’m excited to share progress on what could be the next generation of clean energy production,” Egiebor said.

Miriam Gammerman, a doctoral student in Earth, environmental and planetary sciences, is exploring the role of soil minerals in the global carbon cycle. Her research is vital in understanding how climate change affects soil processes and how we can enhance soil carbon storage to combat climate change. “Receiving this fellowship has boosted my confidence in my work and its potential to connect fundamental science with real human impacts,” Gammerman said.

Wesley Hungbui, an MBA student, works at the intersection of business and renewable energy. His research is focused on developing financial models that make it easier for companies to invest in sustainable energy projects. Wesley’s work highlights how smart economic strategies can accelerate the transition to a greener future.

Alexander Lathem, a doctoral student in applied physics, is developing innovative carbon-free methods to produce ammonia, a crucial agricultural fertilizer and an energy-efficient way of storing energy. Lathem’s research demonstrates the potential of novel chemical processes in achieving sustainability goals.

Ziran Wang, a doctoral student in civil and environmental engineering, is focused on understanding the resilience of our power grids and pipelines, even in the face of threats like natural disasters and hardware failures. “This fellowship also provides a valuable opportunity to connect with industry experts, which will enhance both my academic and professional development,” Wang said.

Other fellows include Ahmad El Gazzar and Zina Deriche, doctoral students in chemical and biomolecular engineering, whose research addresses various aspects of renewable fuel production and carbon-capture technologies. Travis Seamons, a doctoral student in systems, synthetic and physical biology, focuses on advanced biological systems to sequester carbon dioxide. Stan Kannegieter, a doctoral student in economics, investigates economic models and policies that can facilitate the transition to a decarbonized industry.

A partnership for a sustainable future

“Rice University is at the forefront of developing scalable, practical, lower carbon solutions that the world needs, and Chevron is proud to support emerging leaders focused on innovative solutions,” said Chris Powers, vice president of carbon capture, utilization and storage at Chevron New Energies.

By partnering with the RSI, Chevron is investing in original solutions and supporting the future leaders who will drive the energy evolution.

The RSI, in partnership with Chevron, established the Rice Chevron Energy Graduate Fellowship program to advance cutting-edge sustainable energy solutions and to nurture the development of future leaders in this critical field.

For more information about the program and the groundbreaking research being conducted by this year’s fellows, please visit the website.

 

Substituting lower-wage staff for hospital RNs is a poor business model

A 500-bed hospital with average occupancy rate is projected to lose $5 million annually

Wolters Kluwer Health

August 28, 2024 — When hospitals replace registered nurses (RNs) with licensed practical nurses and unlicensed assistive personnel, patients are more likely to die, experience readmissions, and have longer hospital stays, and Medicare must bear millions of dollars annually in avoidable costs. Moreover, there is no business case for this practice—hospitals actually experience a negative return on investment. Those conclusions come from a study in the latest issue of Medical Care, the official journal of the Medical Care Section of the American Public Health Association, published in the Lippincott portfolio by Wolters Kluwer. 

Multiple state and federal laws are proposing minimum hospital nurse staffing levels to improve safety. Yet many hospital leaders—and national organizations—are instead resurrecting the outdated "team nursing" model that was adopted as a stopgap measure after World War II. "'Team' in this context is not a multidisciplinary team of professionals, which research shows enhances patient outcomes, but substitutes lower-wage workers for RNs, the effect of which is a reduction of RN care to patients," Karen B. Lasater, PhD, RN, FAAN, Associate Professor of Nursing at the University of Pennsylvania, and colleagues explain. 

Quantifying the harms of reducing RN care 

Dr. Lasater’s group evaluated the effects on patients, payers, and hospitals of reducing RN care. They analyzed data from the American Hospital Association, Medicare, and the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS, which collects patient satisfaction ratings). 

Based on the experience of 6,559,704 Medicare patients admitted to 2,676 general acute care hospitals in 2019, they found that a 10-percentage-point reduction in the proportion of RNs to total hospital nursing staff is associated with: 

• 7% higher odds of in-hospital mortality 
• 4% higher odds of death within 30 days 
• 1% higher odds of hospital readmission within 30 days 
• 2% increase in the number of days per hospital stay 
• 23% higher odds of losing a star on "overall hospital rating" in the HCAHPS 

Using projected figures, the researchers also estimated that with a 10-percentage-point reduction in RN care: 

• 10,947 avoidable patient deaths would occur annually 
• 5,207 avoidable readmissions would occur annually, costing Medicare $68.5 million extra 
• Hospitals would miss out on $2.9 billion in cost savings annually because of longer patient stays 
• Hospitals would save $31.94 per patient day in labor costs, but they would lose $66.03 per patient day due to longer stays; for a 500-bed hospital with average occupancy rate, this translates to a $5 million loss annually 

"Though substituting lower-wage nursing staff for RNs is associated with reductions in hospital labor costs, those savings will likely be much reduced, if not nullified, by longer expected patient stays, unfavorable performance on value-based purchasing metrics, and added costs of RN turnover and labor actions," Dr. Lasater and her co-authors conclude. "The cost is ultimately paid by patients who are more likely to die, be readmitted, have longer hospital stays, and experience less satisfactory care." 

"With roughly half of hospital RNs reporting high levels of burnout, hospitals should focus on fixing the root causes of their burnout—chronic understaffing and poor work environments—not replacing RNs with lesser trained nursing staff that the evidence shows is likely dangerous to patients," Dr. Lasater noted. 

Read Article: Alternative Models of Nurse Staffing May Be Dangerous in High-Stakes Hospital Care 

Wolters Kluwer provides trusted clinical technology and evidence-based solutions that engage clinicians, patients, researchers and students in effective decision-making and outcomes across health care. We support clinical effectiveness, learning and research, and clinical surveillance and compliance, as well as data solutions. For more information about our solutions, visit https://www.wolterskluwer.com/en/health. 

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About Wolters Kluwer 

Wolters Kluwer (EURONEXT: WKL) is a global leader in information, software, and services for professionals in health care, tax and accounting, financial and corporate compliance, legal and regulatory, and corporate performance and ESG. We help our customers make critical decisions every day by providing expert solutions that combine deep domain knowledge with specialized technology and services. 

Wolters Kluwer reported 2023 annual revenues of €5.6 billion. The group serves customers in over 180 countries, maintains operations in over 40 countries, and employs approximately 21,400 people worldwide. The company is headquartered in Alphen aan den Rijn, the Netherlands.  

For more information, visit www.wolterskluwer.com, follow us on LinkedIn, Facebook, and YouTube.

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Journal

Medical Care

Article Title

Alternative Models of Nurse Staffing May Be Dangerous in High-Stakes Hospital Care

Article Publication Date

28-Aug-2024

 

New vaccine created by Mizzou researchers protects cattle from deadly tick-borne disease

MizzouForward researcher Roman Ganta has created the first effective vaccine proven to protect cattle from bovine anaplasmosis, benefiting both cattle health and the agricultural economy.

University of Missouri-Columbia

 

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Cattle

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Credit: University of Missouri

COLUMBIA, Mo. -- University of Missouri researchers are working to develop the first-ever vaccine proven to protect cattle from a devastating tick-borne cattle disease known as bovine anaplasmosis. The research is vital to the state’s economy as it aims to protect Missouri’s $1.6 billion cattle industry.

Bovine anaplasmosis — which is common in Missouri — infects the red blood cells of cattle and causes hundreds of millions of dollars in economic losses nationwide each year and nearly $1 billion in losses worldwide, primarily due to reduced cattle production, treatment costs and deaths.

Roman Ganta, a McKee endowed professor in Mizzou’s College of Veterinary Medicine and a Bond Life Sciences Center researcher, led the study that created the new vaccine. The work involved genetically modifying the pathogen Anaplasma marginale — which causes bovine anaplasmosis — in a lab. By deleting a specific gene and then injecting the modified pathogen into cattle, the vaccinated cattle were successfully immunized against the disease.

“I often receive calls from cattle producers who are excited about our research and want to know how soon they can get the vaccine,” Ganta said. “There is currently no effective, widely available, vaccine for the disease, and cattle farmers are very worried about the disease harming or killing their cattle. We want to help farmers in Missouri and around the world and are working hard to come up with a viable solution.”

Moving the needle forward

Ganta, who has been researching molecular genetics and vector-borne diseases for more than 30 years, was hired at Mizzou in 2023 as part of MizzouForward, a 10-year, $1.5 billion transformational effort that focuses on faculty expansion, infrastructure growth and student success. 

Throughout his career, Ganta has published more than 100 studies in peer-reviewed journals and earned more than $22 million in grants from organizations such as the National Institutes of Health, the U.S. Department of Agriculture, the Centers for Disease Control and Prevention, industry partners and foundations. He is an example of why Mizzou is a leading research university and a member of the prestigious Association for American Universities.

Working at a land-grant university, Ganta’s research will ultimately help improve the health of cattle — and the agricultural economy — throughout Missouri, particularly in rural areas.

“Missouri is a hotbed for tick-borne diseases, and bovine anaplasmosis causes massive economic losses both here in Missouri and around the world,” Ganta said. “Mizzou has already made substantial contributions to protecting cattle against ticks. For example, many farmers currently give their cattle an antibiotic called chlortetracycline, which was first discovered at Mizzou’s Sanborn Field in 1945. While effective, that medicine doesn’t fully eliminate the infection, so this new vaccine is an innovative step forward to fully eliminate the infection.”

Ganta said the new vaccine has been proven to give immunized cattle protection against bovine anaplasmosis for at least a month, and he and his team are eager to conduct additional research to determine how long the genetically modified pathogen can provide immunity for cattle. Ganta is also collaborating with industry partners to discuss future distribution of the new vaccine — which has been patented — to cattle producers.

“The genetically modified live vaccine offers protective immunity against wild-type Anaplasma marginale tick-transmission challenge” was published recently in Vaccine. Funding for the study was provided by the National Institutes of Health and Russell L. Rustici Rangeland and Cattle Research Endowment, University of California, Davis.

Leading the charge in tick research

Mizzou — the state of Missouri’s flagship and most prominent research university — has been on the frontlines of tick research for years. A 2021 Mizzou study found recent increases in both the number and severity of tick-borne diseases in the Midwest, particularly in the humid climates of Missouri, Kansas, Oklahoma and Arkansas. The documentation of what, when and where ticks are present helps public health officials better understand the threat of tick-borne diseases to people, pets and livestock.

Researchers in Mizzou’s College of Veterinary Medicine and College of Health Sciences also were the first to identify the invasive longhorned tick in northern Missouri in 2022 and in Boone County, Missouri, in 2023. Mizzou’s Veterinary Medical Diagnostic Laboratory assists livestock producers who notice various health issues in their cattle with tracking down the causes of such signs in an effort to support Missouri’s agriculture industry.

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Journal

Vaccine

DOI

10.1016/j.vaccine.2024.06.036 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Genetically modified live vaccine offers protective immunity against wild-type Anaplasma marginale tick-transmission challenge

 

MSU researchers contribute to study revealing salamanders are surprisingly abundant in eastern North American forests

Michigan State University

Michigan State University researchers contributed to a recent amphibian-focused study that shed light on the ecological importance of red-backed salamanders.

Scientists knew that red-backed salamanders were abundant in eastern North America, but a recent study found their densities and biomass, or their total quantity across the region, were much higher than expected.

The study, conducted by the U.S. Geological Survey and many partner institutions including Michigan State University and Penn State University, marks the first time that the densities and biomass for this common, but rarely seen, species were calculated across the extent of its range.

The study authors estimated an average of 5,300 salamanders in every patch of forest the size of a football field in the Northeast. Even though each individual s a mere 3 inches long, the sheer number of red-backed salamanders means that they also have some of the highest biomass estimated for animals other than insects in the Northeast, similar to or greater than white-tailed deer.

“The red-backed salamander, plethodon cinereus, is a relatively common and small salamander,” said Louise Mead, a professor in the College of Natural Science and the Ecology, Evolution and Behavioral Biology Program at MSU. “Given estimates of its density in forests across its range and the extensive research already done on physiology, behavior, territoriality, and evolutionary history, the red-backed salamander provides a unique opportunity to study a small but mighty species, further examining local adaptation and possible impacts of landscape and climate changes.”

The incredible magnitude of red-backed salamander presence in the eastern North American captured in this study suggests that red-backed salamanders, and likely amphibians in general, play a more prevalent role in terrestrial temperate ecosystems than previously suspected.  

“The very large biomass of red-backed salamanders tells us that they are likely ‘small but mighty’ in terms of their role in the ecological health of northeastern forests,” said Evan Grant, a research wildlife biologist at the USGS and lead author on the paper. “If red-backed salamanders disappeared, there would probably be some pretty large ecosystem-level consequences.

Many salamanders, like the red-backed salamander, are tiny and spend the majority of their time underground, so it's easy for most people to overlook them. In fact, Grant commonly refers to salamanders and other amphibians as “hidden biodiversity” because, though they are often abundant, they hide well. But that doesn't mean people should overlook their ecological roles. Salamanders eat things that bigger consumers can’t eat and are themselves prey for other animals, meaning salamanders punch above their weight in an ecosystem’s food web.

“Salamanders serve a vital function in forest ecosystems,” explained David Miller, associate professor of wildlife population ecology at Penn State and co-author of the study. “They are at the top of the food chain on the forest floor, where everything is breaking down into the soil that sustains this entire network of life. In fact, salamanders are so important to this life cycle that we can use them as a barometer for forest health.”

Unfortunately, just as scientists are beginning to understand the true magnitude of salamanders’ hidden biodiversity and ecological importance, a new wildlife disease that is particularly hard on salamanders is a looming threat and a serious concern for scientists and wildlife managers.

Batrachochytrium salamandrivorans, or Bsal for short, is a fungal disease closely related to the chytrid fungus that is already devastating amphibian populations around the world. It was first found in the Netherlands in 2013. Sadly, since its introduction, Bsal has decimated the salamander populations in central Europe and continues to spread across Europe.

Bsal hasn’t been detected in the U.S. yet, so scientists and wildlife managers are preparing for its arrival. There is a North American Bsal Task Force, which Warwick and Grant serve on, whose mission is to limit the invasion and reduce the impact of Bsal in North America.

MSU’s contribution to the study also provided an opportunity for students.

“MSU joined the Salamander Population Adaptation Research Collaboration Network, or SPARCnet, in 2016 and, since 2017, students, postdocs and community members have been collecting and contributing data from six plots located at Rose Lake State Wildlife Research Area,” said Alexa Warwick, an assistant professor in the College of Agriculture and Natural Resources. “We have integrated sampling, data collection and analysis into the ecology labs taught by Mead in both the fall and spring engaging upwards of 200 students each year.”

Warwick also engages students in another amphibian project looking at ways to mitigate disease spread through the pet amphibian trade.

“With a new understanding of how incredibly prevalent salamanders are in an ecosystem, and with the empirical justification for the benefits of proactive management for salamander populations threatened by Bsal, it is more critical than ever to protect the hidden biodiversity of amphibians,” said Bletz.

This research was recently published in the journal Biology Letters.

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Journal

Biology Letters

Article Publication Date

26-Aug-2024

Breaking open the AI black box, team finds key chemistry for solar energy and beyond

University of Illinois at Urbana-Champaign, News Bureau

 

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Illinois researchers have opened up the AI "black box" to gain valuable new insight about chemistry for solar energy applications. Pictured, from left: Professor Charles Schroeder, Changhyun Hwang, Seungjoo Yi, professor Ying Diao, professor Nick Jackson, Tiara Charis and Torres Flores.

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Credit: Photo by Michelle Hassel

CHAMPAIGN, Ill. — Artificial intelligence is a powerful tool for researchers, but with a significant limitation: The inability to explain how it came to its decisions, a problem known as the “AI black box.” By combining AI with automated chemical synthesis and experimental validation, an interdisciplinary team of researchers at the University of Illinois Urbana-Champaign has opened up the black box to find the chemical principles that AI relied on to improve molecules for harvesting solar energy. 

The result produced light-harvesting molecules four times more stable than the starting point, as well as crucial new insights into what makes them stable — a chemical question that has stymied materials development.

The interdisciplinary team of researchers was co-led by U. of I. chemistry professor Martin Burke, chemical and biomolecular engineering professor Ying Diao, chemistry professor Nicholas Jackson and materials science and engineering professor Charles Schroeder, in collaboration with along with University of Toronto chemistry professor Alán Aspuru-Guzik. They published their results in the journal Nature.

“New AI tools have incredible power. But if you try to open the hood and understand what they’re doing, you’re usually left with nothing of use,” Jackson said. “For chemistry, this can be very frustrating. AI can help us optimize a molecule, but it can’t tell us why that’s the optimum — what are the important properties, structures and functions? Through our process, we identified what gives these molecules greater photostability. We turned the AI black box into a transparent glass globe.”

The researchers were motivated by the question of how to improve organic solar cells, which are based on thin, flexible materials, as opposed to the rigid, heavy, silicon-based panels that now dot rooftops and fields. 

“What has been hindering commercialization of organic photovoltaics is problems with stability. High-performance materials degrade when exposed to light, which is not what you want in a solar cell,” said Diao. “They can be made and installed in ways not possible with silicon and can convert heat and infrared light to energy as well, but the stability has been a problem since the 1980s.”

The Illinois method, called “closed-loop transfer,” begins with an AI-guided optimization protocol called closed-loop experimentation. The researchers asked the AI to optimize the photostability of light-harvesting molecules, Schroeder said. The AI algorithm provided suggestions about what kinds of chemicals to synthesize and explore in multiple rounds of closed-loop synthesis and experimental characterization. After each round, the new data were incorporated back into the model, which then provided improved suggestions, with each round moving closer to the desired outcome.

The researchers produced 30 new chemical candidates over five rounds of closed-loop experimentation, thanks to building block-like chemistry and automated synthesis pioneered by Burke’s group. The work was done at the Molecule Maker Lab housed in the Beckman Institute for Advanced Science and Technology at the U. of I.  

“The modular chemistry approach beautifully complements the closed-loop experiment. The AI algorithm requests new data with maximized learning potential, and the automated molecule synthesis platform can generate the new required compounds very quickly. Those compounds are then tested, the data goes back into the model, and the model gets smarter — again and again,” said Burke, who also is a professor in the Carle Illinois College of Medicine. “Until now, we’ve been largely focused on structure. Our automated modular synthesis now has graduated to the realm of exploring function.”

Instead of simply ending the query with the final products singled out by the AI, as in a typical AI-led campaign, the closed-loop transfer process further sought to uncover the hidden rules that made the new molecules more stable. 

As the closed-loop experiment ran, another set of algorithms was continuously looking at the molecules made, developing models of chemical features predictive of stability in light, Jackson said. Once the experiment concluded, the models provided new lab-testable hypotheses. 

“We're using AI to generate hypotheses that we can validate to then spark new human-driven campaigns of discovery,” Jackson said. “Now that we have some physical descriptors of what makes molecules photostable, that makes the screening process for new chemical candidates dramatically simpler than blindly searching around chemical space.” 

To test their hypothesis about photostability, the researchers investigated three structurally different light-harvesting molecules with the chemical property they identified — a particular high-energy region — and confirmed that choosing the proper solvents made the molecules up to four times more light-stable.

“This is a proof of principle for what can be done. We’re confident we can address other material systems, and the possibilities are only limited by our imagination. Eventually, we envision an interface where researchers can input a chemical function they want and the AI will generate hypotheses to test,” Schroeder said. “This work could only happen with a multidisciplinary team, and the people, resources and facilities we have at Illinois, and our collaborator in Toronto. Five groups came together to generate new scientific insight that would not have been possible with any one of the sub teams working in isolation.”

This work was supported by the Molecule Maker Lab Institute, an AI Research Institutes program supported by the U.S. National Science Foundation under grant no. 2019897 . 

Editor’s note:   

To reach Nick Jackson, email jacksonn@illinois.edu. To reach Martin Burke, email mdburke@illinois.edu.  

The paper, “Closed-loop transfer enables AI to yield chemical knowledge,” is available online. 

DOI: 10.1038/s41586-024-07892-1

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Journal

Nature

DOI

10.1038/s41586-024-07892-1 

Method of Research

Experimental study

Article Title

Closed-loop transfer enables AI to yield chemical knowledge

Article Publication Date

28-Aug-2024

 

NASA discovers a long-sought global electric field on earth

NASA/Goddard Space Flight Center

 

video: 

Youtube video: https://www.youtube.com/watch?v=UCM1MaYC5lM

Downloadable files: https://svs.gsfc.nasa.gov/14628

High above the Earth’s North and South Poles, a steady stream of particles escapes from our atmosphere into space. Scientists call this mysterious outflow the “polar wind,” and for almost 60 years, spacecraft have been flying through it as scientists have theorized about its cause. The leading theory was that a planet-wide electric field was drawing those particles up into space. But this so-called ambipolar electric field, if it exists, is so weak that all attempts to measure it have failed – until now. In 2022, scientists traveled to Svalbard, a small archipelago in Norway, to launch a rocket in an attempt to measure Earth’s ambipolar electric field for the first time. This was NASA’s Endurance rocketship mission, and this is its story.

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Credit: NASA's Goddard Space Flight Center/Lacey Young

Using observations from a NASA suborbital rocket, an international team of scientists has, for the first time, successfully measured a planet-wide electric field thought to be as fundamental to Earth as its gravity and magnetic fields. Known as the ambipolar electric field, scientists first hypothesized over 60 years ago that it drove how our planet’s atmosphere can escape above Earth’s North and South Poles. Measurements from the rocket, NASA’s Endurance mission, have confirmed the existence of the ambipolar field and quantified its strength, revealing its role in driving atmospheric escape and shaping our ionosphere — a layer of the upper atmosphere — more broadly.

Understanding the complex movements and evolution of our planet’s atmosphere provides clues not only to the history of Earth but also gives us insight into the mysteries of other planets and determining which ones might be hospitable to life. The paper was published Wednesday, Aug. 28, 2024, in the journal Nature.

An Electric Field Drawing Particles Out to Space

Since the late 1960s, spacecraft flying over Earth’s poles have detected a stream of particles flowing from our atmosphere into space. Theorists predicted this outflow, which they dubbed the “polar wind,” spurring research to understand its causes. 

Some amount of outflow from our atmosphere was expected. Intense, unfiltered sunlight should cause some particles from our air to escape into space, like steam evaporating from a pot of water. But the observed polar wind was more mysterious. Many particles within it were cold, with no signs they had been heated — yet they were traveling at supersonic speeds.

“Something had to be drawing these particles out of the atmosphere,” said Glyn Collinson, principal investigator of Endurance at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the paper. Scientists suspected a yet-to-be-discovered electric field could be at work.

The hypothesized electric field, generated at the subatomic scale, was expected to be incredibly weak, with its effects felt only over hundreds of miles. For decades, detecting it was beyond the limits of existing technology. In 2016, Collinson and his team got to work inventing a new instrument they thought was up to the task of measuring Earth’s ambipolar field.

Launching a Rocket from the Arctic

The team’s instruments and ideas were best suited for a suborbital rocket flight launched from the Arctic. In a nod to the ship that carried Ernest Shackleton on his famous 1914 voyage to Antarctica, the team named their mission Endurance. The scientists set a course for Svalbard, a Norwegian archipelago just a few hundred miles from the North Pole and home to the northernmost rocket range in the world.

“Svalbard is the only rocket range in the world where you can fly through the polar wind and make the measurements we needed,” said Suzie Imber, a space physicist at the University of Leicester, UK, and co-author of the paper.

On May 11, 2022, Endurance launched and reached an altitude of 477.23 miles (768.03 kilometers), splashing down 19 minutes later in the Greenland Sea. Across the 322-mile altitude range where it collected data, Endurance measured a change in electric potential of only 0.55 volts.

“A half a volt is almost nothing — it’s only about as strong as a watch battery,” Collinson said. “But that’s just the right amount to explain the polar wind.”

Hydrogen ions, the most abundant type of particle in the polar wind, experience an outward force from this field 10.6 times stronger than gravity. “That’s more than enough to counter gravity — in fact, it’s enough to launch them upwards into space at supersonic speeds,” said Alex Glocer, Endurance project scientist at NASA Goddard and co-author of the paper.

Heavier particles also get a boost. Oxygen ions at that same altitude, immersed in this half-a-volt field, weigh half as much. In general, the team found that the ambipolar field increases what’s known as the “scale height” of the ionosphere by 271%, meaning the ionosphere remains denser to greater heights than it would be without it.

“It’s like this conveyor belt, lifting the atmosphere up into space,” Collinson added.

Endurance’s discovery has opened many new paths for exploration. The ambipolar field, as a fundamental energy field of our planet alongside gravity and magnetism, may have continuously shaped the evolution of our atmosphere in ways we can now begin to explore. Because it’s created by the internal dynamics of an atmosphere, similar electric fields are expected to exist on other planets, including Venus and Mars.

“Any planet with an atmosphere should have an ambipolar field,” Collinson said. “Now that we’ve finally measured it, we can begin learning how it’s shaped our planet as well as others over time.”

By Miles Hatfield and Rachel Lense
NASA’s Goddard Space Flight Center, Greenbelt, Md.

Endurance was a NASA-funded mission conducted through the Sounding Rocket Program at NASA’s Wallops Flight Facility in Virginia. The Svalbard Rocket Range is owned and operated by Andøya Space. The European Incoherent Scatter Scientific Association (EISCAT) Svalbard radar, located in Longyearbyen, made ground-based measurements of the ionosphere critical to interpreting the rocket data. The United Kingdom Natural Environment Research Council (NERC) and the Research Council of Norway (RCN) funded the EISCAT radar for the Endurance mission. EISCAT is owned and operated by research institutes and research councils of Norway, Sweden, Finland, Japan, China, and the United Kingdom (the EISCAT Associates). The Endurance mission team encompasses affiliates of the Catholic University of America, Embry-Riddle Aeronautical University, the University of California, Berkeley, the University of Colorado at Boulder, the University of Leicester, U.K., the University of New Hampshire, and Penn State University.

 

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Journal

Nature

DOI

10.1038/s41586-024-07480-3 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Earth’s ambipolar electrostatic field and its role in ion escape to space

Article Publication Date

28-Aug-2024