It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Wednesday, October 02, 2024
Smoke from megafires puts orchard trees at risk
Effects last months, reducing nut crop yields
University of California - Davis
By Amy Quinton | October 2, 2023
Long-term smoke exposure from massive wildfires lowers the energy reserves of orchard trees and can cut their nut production by half, researchers at the University of California, Davis, found. The smoke can affect trees for months after a megafire, depressing their bloom and the next season’s harvest. This finding reveals a new danger from wildfires that could affect plant health in both agricultural and natural environments.
Nature Plants published the study today (Oct. 2).
“A lot of research focuses on the impact of smoke on humans but there is less study on the effects of smoke on plant health,” said lead author Jessica Orozco, a postdoctoral researcher with the UC Davis Department of Plant Sciences. “Our study suggests that trees are just as vulnerable as humans.”
Dark skies, less energy for trees
Scientists studied almond, pistachio and walnut trees at 467 orchard sites in California’s Central Valley from 2018 to 2022. In 2020, megafires scorched more than 4.2 million acres in California, filling the skies with smoke and ash. At the time, researchers were studying how trees store energy, in the form of carbohydrates, to cope with heat and drought. But Orozco said the team saw an opportunity to study how smoke affects carbohydrate levels.
“Photosynthesis produces carbohydrates, which are critical elements for tree survival,” said Orozco. “Trees need carbohydrates not just to grow but to store energy for when they’re under stress or when photosynthesis isn’t happening.”
Photosynthesis changes under smoke-filled skies. Smoke particles block some sunlight but also reflect light, creating more diffused light. The diffused light can help trees make more carbohydrates. However, Orozco said the study found that while diffused light increased, the smoke was so thick that it likely didn’t compensate for the loss of direct light.
Lingering effects, less yield
The team found that megafire smoke not only reduced the amount of carbohydrates in trees but also caused losses that continued even after the fires were out. This led to nut yield decreases of 15% to as much as 50% in some orchards. The most active time for wildfires also coincides with the time trees start storing carbohydrates to sustain them through winter dormancy and spring growth.
“We were expecting to see some impact especially in the months when the smoke was really dense, but we weren’t expecting the smoke to have such a lingering effect and result in a significant drop in yield,” Orozco said.
Orozco said researchers still don’t know what components in megafire smoke caused the decrease in tree carbohydrates. During the 2020 megafires, the smoke reduced light and increased both ozone and particulate matter levels, all of which affect photosynthesis. One or a combination of these factors could have led to the drop in tree carbohydrates.
Additional authors on the study are Professor Maciej A. Zwieniecki and postdoctoral researcher Paula Guzmán-Delgado of the UC Davis Department of Plant Sciences.
The Almond Board of California, the California Pistachio Research Board, the California Walnut Board and the California Department of Food and Agriculture supported the research.
Megafire smoke exposure jeopardizes tree carbohydrate reserves and yield
Article Publication Date
2-Oct-2024
The rate of climate change threatens to exceed the adaptive capacity of species
University of Helsinki
image:
The study revealed that the Siberian primrose may only be able to adapt to climate change if the warming can be limited in accordance with the goals of the Paris Agreement on climate change.
A recent study from the University of Helsinki focusing on the Arctic Siberian primrose underscores the critical need to curb climate change to allow species time to adapt through evolution.
A research group at the Finnish Museum of Natural History is investigating the adaptive potential of plant species amid a warming climate. Their recent study investigates the Siberian primrose, a plant species that occurs on the coasts of the Bothnian Bay and Arctic Ocean. Climate change is threatening the viability of the species.
“The Siberian primrose is a good example of a species threatened by rapidly advancing climate change. It cannot migrate to more favourable conditions due to geographic constraints, leaving adaptation in its current habitat as its only survival option,” says Adjunct Professor Marko Hyvärinen from the Finnish Museum of Natural History.
The study revealed that the Siberian primrose may only be able to adapt to climate change if the warming can be limited in accordance with the goals of the Paris Agreement on climate change. This requires effective mitigation of climate change. Otherwise, the flowers and other important traits of the Siberian primrose are unlikely to have the time to evolve quickly enough to survive the changing conditions.
Many wild species have limited capacity to adapt to warming climate
“Our research suggests that the evolutionary potential of wild species is seriously limited in the face of rapidly advancing climate change. This means that the future of many species is at stake, unless climate change is effectively curbed,” says Postdoctoral Researcher Anniina Mattilafrom the Finnish Museum of Natural History.
Particularly in the case of geographically restricted species, such as many specialised plant species surrounded by unsuitable habitats, conservation measures may be necessary to prevent extinction.
The study emphasizes the needs for proactive measures to protect species threatened by climate change. For example, translocations may help species to adapt to new conditions. Knowledge on the adaptive capacity of species from studies such as the one on the Siberian primrose can help in targeting conservation measures and motivates the development of methods to conserve species threated by climate change. However, according to the researchers, the most critical action is to strive to limit climate change, thus allowing species to adapt naturally.
Background:
Importance of the Paris Agreement on species adaptation
The Paris Agreement aims to keep the global average temperature increase well below two degrees Celsius. According to the latest report by the Intergovernmental Panel on Climate Change (IPCC), the global temperature has already risen by 1.1 degrees since the pre-industrial era, with the Arctic warming up to four times faster. Meeting these objectives is increasingly challenging, but essential for enabling species to adapt.
Journal
Proceedings of the Royal Society B Biological Sciences
PHILADELPHIA – Driven by political partisanship, public trust in the U.S. Supreme Court has continued a downward slide since the court’s 2022 Dobbs decision overturning the Roe v. Wade ruling that established a constitutional right to abortion, according to a new survey by the Annenberg Public Policy Center (APPC) of the University of Pennsylvania.
More than half of Americans (56%) now disapprove of the Supreme Court, saying they trust it either “a little” or “not at all” to act in the best interest of “people like you,” according to the nationally representative panel survey conducted in July and August 2024.
Support for the court stands at 44%, with 8% expressing “a great deal” of trust, 11% “a lot” of trust, and 25% “a moderate amount” of trust in the court to act in the best interest of people like you. It is the lowest overall level of trust since APPC began surveying the American public on this issue in 2005, when 75% of the public trusted the court.
Highlights
The new survey, conducted among a nationally representative sample of 1,395 adult U.S. citizens, was fielded July 12-August 12, 2024, following the court’s 2023-24 term, which concluded on July 1 with the court’s ruling in the Capitol insurrection case that Donald Trump has immunity from criminal prosecution for official acts he took as president. The same sample of respondents was previously surveyed in May 2024, during the court term.
In August 2024, 44% overall have trust in the Supreme Court, about the same as 45% in May. But the 40-point spread in trust seen in May between Republicans and Democrats widened significantly to 47 points in August, with 71% of Republicans, 41% of independents, and 24% of Democrats having trust in the court to act in their best interest. Download the topline here.
Earlier APPC surveys found that trust in the court plummeted 22 points after the Dobbs decision, from 68% in 2019 to 46% in 2022. The current survey shows that after a modest rebound, trust has continued to slip, hitting 44% in August 2024. It also finds:
Growing numbers have no trust in the court: Asked how much, if at all, do you trust the court to act in the best interest of people like you, 1 in 3 people (34%) in August say “not at all,” up from 30% in May. In a 2005 APPC survey, only 7% did “not at all” trust the court, which shows a stunning increase in distrust over the past two decades.
Partisan split growing even wider: Over the three-month period from May to August, partisan divisions in views of the court increased significantly. In May, the parties were divided, with Republicans seeing the Supreme Court more favorably, trusting it more, vesting greater legitimacy in it, and being less willing to endorse potential reforms to the court than Democrats and independents. After the court term, the gap separating Republicans from both Democrats and independents grew on each of these dimensions.
Favorability drops in key swing states: Since 2021, APPC has reinterviewed the same set of respondents in Michigan, Pennsylvania, and Wisconsin. These data allow us to compare views of the court from 2021, before the court’s Dobbs decision, to today, two years after that landmark ruling. Over that time, we have seen a dramatic decline in the public’s view of the court – mostly from a decrease in support from both Democrats and independents.
“This underscores how Dobbs has fundamentally shifted views of the court,” said University of Pennsylvania political science professor Matthew Levendusky, the Stephen and Mary Baran Chair in the Institutions of Democracy at the Annenberg Public Policy Center and director of the survey. “For many years, the court was held in high esteem by all Americans across partisan lines, but no more – that polarization emerged after Dobbs, and the court’s rulings since then have done little to change these perceptions.”
Partisan differences in attitudes toward the court
For decades, the Supreme Court had been seen as one of the few institutions respected by Republicans and Democrats alike. In a journal article this year, Annenberg Public Policy Center researchers said the court had been primarily regarded as a legal institution, not a political one, strengthened by its “norms, processes, symbols, and independence,” and was therefore afforded greater public trust and legitimacy than other institutions. (See “Has the Supreme Court become just another political branch? Public perceptions of court approval and legitimacy in a post-Dobbs world” in Science Advances.)
A second article this year by APPC researchers found that declining trust in the Supreme Court was mirrored in the federal judiciary, with the percentage of Americans with either “a great deal” or “a fair amount” of trust and confidence in the judicial branch falling to under 50% in 2022 from 75% in 2000. (See “The withering of public confidence in the courts” in Judicature.)
This year, APPC surveyed a nationally representative sample of adult U.S. citizens during and after the most recent Supreme Court term in, respectively, May and August 2024. These national surveys found that:
Favorability increased slightly among Republicans but decreased among both independents and Democrats.
Trust: Republicans placed greater trust in the court, though trust dropped among Democrats and independents.
Reform: Support for a half-dozen proposed reforms to the U.S. Supreme Court, taken as a group, increased among Democrats and independents, but decreased slightly among Republicans. Overall, a majority of the public shows strong support for several potential reforms to the Supreme Court, including prohibiting justices from participating in cases in which they have personal or financial interests (83% support); creation of a formal ethics code that allows justices to be investigated if they are accused of an ethical violation (75% support); a mandatory retirement age (71%) and term limits (68%). In addition, half of those surveyed (50%) support allowing the public to vote to overturn Supreme Court decisions on controversial issues and a third (32%) support increasing the number of justices on the current nine-member court.
For further details on support for potential reforms to the court, see our news release issued in early September, based on the May 2024 findings.
Legitimacy: Institutional support for the court
In addition to the three measures of support described above, the APPC surveys also asked a set of questions which tap into deeper institutional support for the U.S. Supreme Court. Respondents were asked whether they agreed or disagreed with the following statements:
If the Supreme Court started making a lot of rulings that most Americans disagreed with, it might be better to do away with the Court altogether.
The U.S. Supreme Court gets too mixed up in politics.
The U.S. Supreme Court ought to be made less independent so that it listens a lot more to what the people want.
The right of the Supreme Court to decide certain types of controversial issues should be reduced.
Justices on the U.S. Supreme Court who consistently make unpopular decisions should be removed from their position as Justice.
In our analysis, conducted by APPC research analyst Shawn Patterson Jr., we use the average of each panelists’ responses to these questions as a measure of institutional legitimacy. While the effects are smaller than for favorability or trust, here, too, we see that Republicans viewed the court as more legitimate than Democrats and independents in May, and that the gap between the parties grew significantly over the following three months
Evidence from three swing states
Surveys conducted in three swing states – Michigan, Pennsylvania, and Wisconsin – bolster these findings. Panelists were asked about their favorability toward the court on six occasions from November 2021 through August 2024. These results show that:
Before and after Dobbs, there is a dramatic decline in the public’s view of the court. In 2021, before the decision, the average respondent had a “neither favorable nor unfavorable” view of the court, but post-Dobbs in 2022, that fell 31%, to just more than “somewhat unfavorable” on average and it has remained below pre-Dobbs levels since.
This decrease in support for the court comes mostly from changes among Democrats and independents. In 2021, the difference between the two parties was relatively small, with little partisan polarization in views of the court. Today the gap in favorability between the parties has more than doubled, a 101% increase.
About the surveys
The most recent findings are based on two ongoing Annenberg Institutions of Democracy (AIOD) panel studies, surveys that interview the same sets of voters over time. One is a nationally representative sample of adult U.S. citizens, while the other is a sample of adult U.S. citizens living in Michigan, Pennsylvania, and Wisconsin (the sample in each state is drawn to be representative of adults living in that state). Both sets of respondents were interviewed from May 1-23, 2024, and from July 12-August 12, 2024. The swing state samples have also been interviewed roughly quarterly since May 2020.
Data collection for the national panel was conducted from May 1-23, 2024, among a sample of 1,620 adult U.S. citizens, divided in three subgroups. The margin of sampling error (MOE) for the complete set of weighted data is ± 3.3 percentage points at the 95% confidence level. The panel survey was conducted again July 12-August 12, 2024, among a sample of 1,395 U.S. adult citizens, with a margin of error of ± 3.6 percentage points.
For more information on the sampling of the swing state panel, see the Appendix for the book “Democracy Amid Crises,”available at https://osf.io/487jk/.
The battery of survey questions about court reform was developed under the supervision of Matt Levendusky, director of the AIOD national panel at the Annenberg Public Policy Center. The analysis and graphics were prepared by APPC research analyst Shawn Patterson Jr. The team supervising the survey also includes Kathleen Hall Jamieson, the director of APPC, and Ken Winneg, APPC’s managing director of survey research.
The Annenberg Public Policy Centerwas established in 1993 to educate the public and policy makers about communication’s role in advancing public understanding of political, science, and health issues at the local, state, and federal levels.
THAT'S DIALECTICS
Do NFTs create value in games? There are at least three ways to look at it
When blockchain is introduced into video gaming, the economy and sometimes the entire design of such games focus on artificial scarcity and ownership of game items. However, this approach overlooks some of the most important aspects of value creation in games, according to Alesha Serada’s research at the University of Vaasa. The value of game items is derived from manifold social relations in gaming communities, in the ways that frequently disregard rarity or price of digital assets.
Alesha Serada's doctoral dissertation demonstrates how the value of Non-Fungible Tokens (NFTs) is constructed in games, using the example of one of the first popular and longest-running blockchain-based games, CryptoKitties.
The processes of value creation and extraction in games are well familiar to industry practitioners, but they are rarely studied by academic researchers. This continues to be a problem, because consumer awareness is often low, and corporate responsibility in the gaming industry is lacking. Back in 2017, NFTs on blockchain were promised to liberate gamers from corporate greed of major game publishers. As of 2024, this promise is not fulfilled yet.
According to their early adopters, NFTs would ensure property rights in virtual worlds and create new types of value based on unique properties of blockchain technology. After eight years of creative evolution, only very few blockchain-based games have reached a noticeable level of adoption, and even those are critically panned. This indicates the lack of value in such games to their players.
However, games are one of very few blockchain applications beyond cryptocurrencies that saw at least some level of adoption. So-called ‘crypto games’ made an important contribution to the development of blockchain platforms, as Serada argues in their doctoral dissertation, to be defended on October 4 at the University of Vaasa.
– I chose CryptoKitties as my primary case for studying value on blockchain, because it was the first of this kind to reach overnight fame, says Serada. – Besides, this is also one of the very few blockchain-based games to have a friendly and vibrant community. Thanks to it, the game managed to survive several ‘crypto winters’ on the cryptocurrency market. Throughout the years, a wealth of quantitative data has been accumulated both on blockchain and off-chain, which I combined with qualitative data from the game community and the game itself.
A holistic model of value creation in games before and after blockchain
Despite the many inefficiencies of blockchain, game designers can learn valuable lessons from blockchain-based games. Based on research, Serada suggests a three-dimensional model that takes into account different types of value: the value as designed by game creators, the subjective value of items projected by an individual player, and the value that is collectively created by the game community. The last type of value is the fundamental and most sustainable way of value creation in games, and yet blockchain-based games are particularly low on it. The dissertation also includes a decision flowchart, which can be used to determine what kind of value, if any, is constructed in a game item represented by an NFT.
Public defence
The public examination of Master of Sociology Alesha Serada’s doctoral dissertation “Value Creation and Price Negotiation on the Blockchain-Based Marketplace: The Case of CryptoKitties" will be held at the University of Vaasa, in Auditorium Nissi, on Friday October 4, 2023, at noon. It is possible to participate in the defence also online via Zoom, password: 697917
Professor Juho Lindman (University of Gothenburg) will act as an opponent and Professor Tanja Sihvonen as a custos. The defence will be held in English.
Dissertation
Serada, Alesha (2024) Value Creation and Price Negotiation on the Blockchain-Based Marketplace: The Case of CryptoKitties. Acta Wasaensia 533. Doctoral dissertation. University of Vaasa
Dolphins are extremely playful, but little is known about how they—and other marine mammals—communicate during playtime. New research publishing October 2 in the Cell Press journal iScience shows that bottlenose dolphins (Tursiops truncates) use the “open mouth” facial expression—analogous to a smile—to communicate during social play. The dolphins almost always use the facial expression when they are in their playmate’s field of view, and when playmates perceived a “smile,” they responded in kind 33% of the time.
“We’ve uncovered the presence of a distinct facial display, the open mouth, in bottlenose dolphins, and we showed that dolphins are also able to mirror others’ facial expression,” says senior author and evolutionary biologist Elisabetta Palagi (@bettapalagi) of the University of Pisa. “Open-mouth signals and rapid mimicry appear repeatedly across the mammal family tree, which suggests that visual communication has played a crucial role in shaping complex social interactions, not only in dolphins but in many species over time.”
Dolphin play can include acrobatics, surfing, playing with objects, chasing, and playfighting, and it’s important that these activities aren’t misinterpreted as aggression. Other mammals use facial expressions to communicate playfulness, but whether marine mammals also use facial expressions to signal playtime hasn’t been previously explored.
“The open mouth gesture likely evolved from the biting action, breaking down the biting sequence to leave only the ‘intention to bite’ without contact,” says Palagi. “The relaxed open mouth, seen in social carnivores, monkeys’ play faces, and even human laughter, is a universal sign of playfulness, helping animals—and us—signal fun and avoid conflict.”
To investigate whether dolphins visually communicate playfulness, the researchers recorded captive bottlenose dolphins while they were playing in pairs and while they were playing freely with their human trainers.
They showed that dolphins frequently use the open mouth expression when playing with other dolphins, but they don’t seem to use it when playing with humans or when they’re playing by themselves. While only one open mouth event was recorded during solitary play, the researchers recorded a total of 1,288 open mouth events during social play sessions, and 92% of these events occurred during dolphin-dolphin play sessions. Dolphins were also more likely to assume the open mouth expression when their faces were in the field of view of their playmate—89% of recorded open mouth expressions were emitted in this context—and when this “smile” was perceived, the playmate smiled back 33% of the time.
“Some may argue that dolphins are merely mimicking each other’s open mouth expressions by chance, given they’re often involved in the same activity or context, but this doesn’t explain why the probability of mimicking another dolphin’s open mouth within 1 second is 13 times higher when the receiver actually sees the original expression,” says Palagi. “This rate of mimicry in dolphins is consistent with what’s been observed in certain carnivores, such as meerkats and sun bears.”
The researchers didn’t record the dolphins’ acoustic signals during playtime, and they say that future studies should investigate the possible role of vocalizations and tactile signals during playful interactions.
“Future research should dive into eye-tracking to explore how dolphins see their world and utilize acoustic signals in their multimodal communication during play,” says corresponding author and zoologist Livio Favaro (@LivioF_80). “Dolphins have developed one of the most intricate vocal systems in the animal world, but sound can also expose them to predators or eavesdroppers. When dolphins play together, a mix of whistling and visual cues helps them cooperate and achieve goals, a strategy particularly useful during social play when they’re less on guard for predators.”
iScience (@iScience_CP) is an open access journal from Cell Press that provides a platform for original research and interdisciplinary thinking in the life, physical, and earth sciences. The primary criterion for publication in iScience is a significant contribution to a relevant field combined with robust results and underlying methodology. Visit https://www.cell.com/iscience. To receive Cell Press media alerts, contact press@cell.com.
Smiling underwater: exploring playful signals and rapid mimicry in bottlenose dolphins
Article Publication Date
2-Oct-2024
Most tropical lightning storms are radioactive
New observations from a retrofitted U2 spy plane reveal a surprising amount and variety of gamma radiation is produced in large tropical thunderstorms
Duke University
DURHAM, N.C. – In the 1990s, NASA satellites built to spot high-energy particles coming from supernovas and other celestial-sized objects discovered a surprise — high energy gamma radiation bursts coming from right here on Earth.
While it didn’t take long for researchers to figure out that these radioactive supercharged particles were coming from thunderstorms, how commonly the phenomenon happened remained a mystery. Satellites weren’t built to find gamma radiation coming from Earth, and they had to be in just the right place at just the right time to do so.
After years of making do with platforms not ideal for the task, a group of scientists secured an opportunity to fly a retrofitted U2 spy plane owned by NASA over storms to take a proper look. In two new papers published October 3 in Nature, the team discovered that gamma radiation produced in thunderstorms is far more common than anyone thought and that the dynamics creating the radiation hold a treasure trove of mysteries yet to be solved.
“There is way more going on in thunderstorms than we ever imagined,” said Steve Cummer, the William H. Younger Distinguished Professor of Engineering at Duke University, who was a coauthor on both papers. “As it turns out, essentially all big thunderstorms generate gamma rays all day long in many different forms.”
The general physics behind how thunderstorms create high-energy flashes of gamma radiation is not a mystery. As thunderstorms develop, swirling drafts drive water droplets, hail and ice into a mixture that creates an electric charge much like rubbing a balloon on your shirt. Positively charged particles end up at the top of the storm while negatively charged particles drop to the bottom, creating an enormous electric field that can be as strong as 100 million AA batteries stacked end-to-end.
When other charged particles — such as electrons — find themselves in such a strong field, they accelerate. If they accelerate to high enough speeds and happen to strike an air molecule, they knock off more high-energy electrons. The process cascades until the collisions have enough energy to create nuclear reactions, producing extremely strong and extremely fast flashes of gamma rays, antimatter and other forms of radiation.
But that’s not the end of the thunderstorm gamma radiation story. Aircraft flying close to thunderstorms have also seen a faint glow of gamma radiation coming from clouds. These storms seem to have enough energy to produce a low-level simmering of gamma radiation, but something prevents it from creating an explosive burst like a popping corn kernel.
“A few aircraft campaigns tried to figure out if these phenomena were common or not, but there were mixed results, and several campaigns over the United States didn’t find any gamma radiation at all,” Cummer said. “This project was designed to address these questions once and for all.”
The research group secured the use of a NASA ER-2 High-Altitude Airborne Science Aircraft. A retrofitted U2 spy plane left over from the Cold War, it flies over twice as high as commercial aircraft and about three miles above most thunderstorms. It’s also extremely fast, giving the team the opportunity to pick the exact thunderstorms they thought were most likely to produce results.
“The ER-2 aircraft would be the ultimate observing platform for gamma-rays from thunderclouds,” said Nikolai Østgaard, professor of space physics at the University of Bergen in Norway and lead investigator of the project. “Flying at 20 km [12.4 miles], we can fly directly over the cloud top, as close as possible to the gamma-ray source.”
Because the ER-2 was the perfect solution and the team was going to fly over the right storms, the researchers figured that if these phenomena were rare, then they’d barely see any at all. But if they were common, then they’d see a lot.
And they saw a lot.
Over the course of a month, the ER-2 flew 10 flights over large storms in the tropics south of Florida, and 9 of them yielded observations of this simmer of gamma radiation, which was also more dynamic than expected.
“The dynamics of gamma-glowing thunderclouds starkly contradicts the former quasi-stationary picture of glows, and rather resembles that of a huge gamma-glowing boiling pot both in pattern and behavior,” said Martino Marisaldi, professor of physics and technology at the University of Bergen.
Given the size of a typical thunderstorm in the tropics, which get much larger than storms at other latitudes, this suggests that more than half of all thunderstorms in the tropics are radioactive. The researchers postulate that this low-level production of gamma radiation acts like steam boiling off a pot of water and limits how much energy can be built up inside.
The researchers were equally excited to see numerous examples of short duration and intense gamma radiation bursts coming from the same thunderstorms. Some of these were precisely like those that were originally detected by the NASA satellites. These almost always occurred in conjunction with an active lightning discharge. This suggests that the large electric field created by lightning is likely supercharging the already high-energy electrons, enabling them to create high-energy nuclear reactions.
But there were also at least two other types of short gamma radiation bursts that had never been seen before. One type is incredibly short, less than a thousandth of a second, while the other is a sequence of about 10 individual bursts that repeat over the course of about a tenth of a second.
“Those two new forms of gamma radiation are what I find most interesting,” Cummer said. “They don’t seem to be associated with developing lightning flashes. They emerge spontaneously somehow. There are hints in the data that they may actually be linked to the processes that initiate lightning flashes, which are still a mystery to scientists.”
If there is anybody out there worried about getting turned into the Hulk by all of this gamma radiation, Cummer added, they shouldn’t be. The amount of radiation being produced would only be dangerous if a person or object were quite close to the origination source.
“The radiation would be the least of your problems if you found yourself there. Airplanes avoid flying in active thunderstorm cores due to the extreme turbulence and winds,” Cummer said. “Even knowing what we now know, I don’t worry about flying any more than I used to.”
This research was supported by the European Research Council under the European Union's Seventh Framework Programme (FP7/2007–2013)/ERC grant agreement no. 320839 and the Research Council of Norway under contracts 223252/F50 (CoE) and contract 325582.
CITATIONS: Østgaard N., Mezentsev A., Marisaldi M., Grove J. E., Quick M., et al., Flickering Gamma-Ray Flashes, the Missing Link between Gamma Glows and TGFs. Nature Letter, DOI: 10.1038/s41586-024-07893-0 (2024)
Marisaldi, M., Østgaard, N., Lang, T., Sarria D., Mezentsev, A., et al. Highly dynamic gamma-ray emissions are common in tropical thunderclouds, Nature Letter, DOI: 10.1038/s41586-024-07936-6 (2024)
Credit: «Artistic view of ALOFT observations» by University of Bergen / Mount Visual, licensed under CC BY 4.0
Groundbreaking Discoveries in Gamma-Ray Emissions from Thunderstorms
In the recent edition of Nature, groundbreaking results about the gamma-ray emissions produced during thunderstorms are presented. Overall, these findings reveal that gamma-ray emission from thunderclouds is much more complex, diverse, and dynamic than previously thought. Understanding these phenomena is crucial to uncovering the secrets of lightning.
Flickering Gamma-Ray Flashes: A New Discovery
Entitled “Flickering Gamma-Ray Flashes, the Missing Link between Gamma Glows and TGFs,” the paper by Østgaard et al. [2024] reports unique observations of a new phenomenon called Flickering Gamma-Ray Flashes (FGFs).
During thunderclouds, two different hard radiation phenomena have so far been known to originate: Terrestrial Gamma-ray Flashes (TGFs) and gamma-ray glows. This third phenomenon, observed and named FGFs by Østgaard et al. [2024] resembles the other two, while at the same time revealing certain characteristics separating FGFs from the others. Most noteworthy may be that FGFs are pulses of gamma-rays not associated with any detectable optical or radio signals.
The Missing Link Found?
«We think that FGFs could be the missing link between TGFs and gamma-ray glows, whose absence has been puzzling the atmospheric electricity community for two decades», says lead author and Professor Nikolai Østgaard at the University of Bergen.
Dynamic Gamma-Ray Emissions in Tropical Thunderclouds
In another study presented in this edition of Nature, Marisaldi et al. [2024] focus on the phenomenon referenced above and known as gamma-ray glows. The paper, entitled «Highly dynamic gamma-ray emissions are common in tropical thunderclouds», shows that contrary to what has been believed until now, tropical thunderclouds over ocean and coastal regions commonly emit gamma rays for hours over areas up to a few thousand square kilometers.
A New Understanding of Gamma-Ray Glows
«The dynamics of gamma-glowing thunderclouds starkly contradicts the former quasi-stationary picture of glows, and resembles that of a huge gamma-glowing boiling pot both in pattern and behavior», says Professor Martino Marisaldi at the University of Bergen.
The ALOFT Campaign
The groundbreaking results presented by Østgaard et al. [2024] and Marisaldi et al. [2024] are based on observations from the ALOFT (Airborne Lightning Observatory for FEGS and TGFs) campaign.
ALOFT, a collaboration between NASA and the University of Bergen, involved flying the NASA ER-2 aircraft from the MacDill Air Force Base, Florida, over tropical thunderstorms around the Gulf of Mexico, Central America, and the Caribbean in the summer of 2023. The payload included lightning detectors, gamma-ray scintillators, and a mix of passive and/ or active microwave sensors. A total of 10 flights were conducted above thunderclouds around Mexico, El Salvador, Nicaragua, and Florida.
The ALOFT campaign was financed by the Research Council of Norway and led by Professor Nikolai Østgaard and Professor Martino Marisaldi from the University of Bergen, Timothy Lang (Marshall Space Flight Center, NASA), and Franzeska Becker (ER-2 Mission Management).
The instrumentation on Board ER-2 during the ALOFT campaign included:
Gamma-ray detectors UIB-BGO (PI: Nikolai Østgaard, UiB) and iStorm (PI: Eric Grove, NRL)
An optical instrument named FEGS (PI: Mason Quick, Marshall Space Flight Center, NASA)
Two electric field sensors known as EFCM (PI: Hugh Christian, University of Alabama, Huntsville) and LIP (PI: Christopher Schultz, Marshall Space Flight Center, NASA)
Four cloud characterization instruments: AMPR (PI: Timothy Lang, Marshall Flight Center, NASA), CRS and EXRAD (PI: Gerry Heymsfield, Goddard Space Flight Center, NASA), and CoSSIR (PI: Rachael Kroodsma, Goddard Space Flight Center, NASA)
The flight campaign was coordinated with ground-based radio observations managed by a large network of collaborators.
«Flickering Gamma-Ray Flashes, the Missing Link Between Gamma Glows and TGFs» by Østgaard et al. & «Highly dynamic gamma-ray emissions are common in tropical thunderclouds» by Marisaldi et al.
