Unknown details identified in the Lions' Courtyard at the Alhambra

by University of Seville

A novel methodology was followed based on three complementary graphic analyses: first, outstanding images from the seventeenth to the twentieth centuries were reviewed; then new computer drawings were made of their muqarnas, following the theoretical principles of their geometrical grouping; and finally, a three-dimensional scan was made to ascertain their precise current state from the point cloud obtained. Credit: Universidad de Sevilla

Through drawings, researchers from the University of Seville, the École Polytechnique Fédérale de Lausanne (Switzerland) and the University of Granada have identified details hitherto unknown in the muqarnas of the temples of the Lions' Courtyard at the Alhambra in Granada, a UNESCO World Heritage Site.


In order to better understand and facilitate the conservation of these fourteenth-century architectural elements, following a review of numerous repairs performed over the intervening centuries, a novel methodology was followed based on three complementary graphic analyses: first, outstanding images from the seventeenth to the twentieth centuries were reviewed; then new computer drawings were made of their muqarnas, following the theoretical principles of their geometrical grouping; and finally, a three-dimensional scan was made to ascertain their precise current state from the point cloud obtained.

The comparison of drawings has allowed us to verify for the first time that the muqarnas of the two temples have a different configuration and different number of pieces. In addition, geometric deformations have been detected in the original Nasrid design, identifying hitherto unknown pieces, plus other deformations due to the various repairs from major threats that the temples and their muqarnas have survived for centuries, despite their fragile construction.

"For the first time, this article documents and analyses details that were hitherto practically absent from the scientific literature", says Antonio Gámiz, professor at the University of Seville and co-author of this work.

The muqarnas are one of the most unique architectural episodes of the Nasrid Alhambra and of medieval Islamic art because of their sophisticated three-dimensional geometrical construction. They are small prisms that are grouped together and create a great diversity of spatial configurations, adapting their composition to very diverse architectural situations in cornices, arches, capitals and vaults. They reached a virtuous zenith during the reign of Muhammad V (1354-1359 and 1362-1391) when crucial works were undertaken in the palaces of the Alhambra.


Explore furtherArchitects have recreated the Puerta de Triana (Triana Gate) in Seville

More information: Antonio Gámiz-Gordo et al, The Pavilions at the Alhambra's Court of the Lions: Graphic Analysis of Muqarnas, Sustainability (2020). DOI: 10.3390/su12166556

Provided by University of Seville

Momentum of unprecedented Chilean uprising stalled by COVID-19 pandemic

by Binghamton University

Credit: CC0 Public Domain

The uprising that erupted in fall 2019 in Chile against the post-dictatorship government may be diminished by the impact of the COVID-19 pandemic, according to faculty at Binghamton University, State University of New York.


Despite a reputation for equitable development and robust democratic institutions, post-dictatorship Chile proved incapable of guaranteeing economic and social protections for vast swaths of the population and of adequately representing their needs and policy preferences, according to René Rojas, assistant professor of human development at Binghamton University. Over the last 10 years, stagnation, intensified insecurity and oligarchic politics promoted an upsurge in popular protests that finally erupted in October 2019, as a furious and seemingly uncontainable rebellion. The COVID-19 pandemic, however, may give the post-authoritarian regime a new lease on life, as it undermines possibilities for ongoing collective action and places the prospects for meaningful reform on hold.

"As the insurgency set about to resolve its differences and confront inevitable exhaustion, the arrival of the coronavirus and its recent surge have placed mobilizations on hold, threatening to restore the fragile balance of the pre-rebellion order," wrote Rojas in a new paper in New Labor Forum. "In one swoop, the pandemic snatched from the movement its crucial weapon for securing concessions—its capacity for disruption."

Fear of the virus and its economic consequences has stymied the uprising, and Chileans have redirected their energies toward holding on to work and whatever income they might secure. Whether the uprising can find its momentum again amidst the ongoing pandemic remains to be seen. Some developments indicate that as the pandemic reveals the inadequacy of official relief measures and re-exposes deep inequalities at the heart of the Chilean governing model, mass mobilization might retake center stage, wrote Rojas.

"The question in coming months will be whether Chile's new mass movement can regroup and win the reforms it forced onto the national agenda or whether neoliberal elites will succeed in reviving the developed world's least representative and most unequal political system," said Rojas.


Explore further COIVD-19: A barometer for social justice in New York City  

More information: René Rojas, Can the Chilean Uprising Survive the Pandemic?, New Labor Forum (2020). DOI: 10.1177/1095796020949487

Provided by Binghamton University
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Mobile phone radiation may be killing insects: German study

Credit: Unsplash/CC0 Public Domain

Radiation from mobile phones could have contributed to the dramatic decline in insect populations seen in much of Europe in recent years, a German study showed Thursday.


On top of pesticides and habitat loss, increased exposure to electromagnetic radiation is "probably having a negative impact on the insect world", according to the study presented in Stuttgart, which is yet to be peer reviewed.

The analysis of 190 scientific studies was carried out by Germany's Nature and Biodiversity Conservation Union (NABU) together with two NGOs, one from Germany and one from Luxembourg.

Of the 83 studies deemed scientifically relevant, 72 showed that radiation had a negative effect on bees, wasps and flies.

These effects ranged from a reduced ability to navigate due to the disturbance of magnetic fields to damage to genetic material and larvae.

Mobile phone and Wi-Fi radiation in particular opens the calcium channels in certain cells, meaning they absorb more calcium ions.

This can trigger a biochemical chain reaction in insects, the study said, disrupting circadian rhythms and the immune system.

"The study shows that we must keep our eyes open in all directions when analysing the causes of the dramatic insect decline," said Johannes Enssle, head of NABU in the state of Baden-Wuerttemberg.

"The subject is uncomfortable for many of us because it interferes with our daily habits and there are powerful economic interests behind mobile communication technology," Enssle said.

Peter Hensinger of the German consumer protection organisation Diagnose Funk said closer attention must be paid to the possible negative effects of radiation on both animals and humans, particularly with regard to the introduction of 5G technology.

Networks equipped with 5G are expected to offer speeds 100 times faster than existing 4G networks, but the technology has been met with strong opposition from some quarters, especially among environmental campaigners.


Explore further Germany plans to dim lights at night to save insects

© 2020 AFP

How environmental cues can affect behavior

by Raleigh McElvery, Marine Biological Laboratory

Hydra in control media before contraction (left) and during contraction (right). 

Credit: Wataru Yamamoto

Although it may seem counterintuitive, researchers are turning to an animal without a brain to crack the neural code underlying behavior.

Hydra vulgaris, a tiny, tentacled, freshwater organism, uses "nets" of neurons dispersed throughout its tube-like body to coordinate stretching, contracting, somersaulting, and feeding movements. This simple nervous system is one reason that Hydra is well suited for studying how electrical activity translates into motion.

In a study published in eNeuro, a duo from Columbia University and the Marine Biological Laboratory (MBL) has begun to crack the neural code behind Hydra's simplest behavior, called contraction bursts (when the torso shrinks down and expands outward, over and over again). The scientists found that the concentration of dissolved particles in the surrounding water—a property known as osmolarity—affects the activity of a neural circuit in one of Hydra's nerve nets, which can trigger a specific set of muscle cells to contract the torso.

"One by one, we want to decipher the neural and muscular activity behind each of Hydra's behaviors," says senior author and MBL Whitman Center Fellow, Rafael Yuste of Columbia University. "This paper is the beginning of our journey."

Five Hydra freely behaving in 50mM sucrose (high osmolarity) solution. This video is sped up 300-fold. Credit: Wataru Yamamoto

Yuste and first author Wataru Yamamoto conducted their experiments in Woods Hole during the summers of 2017 and 2018, in consultation with their MBL Hydra Lab research consortium. They used whole-body calcium imaging to visualize Hydra's neurons and muscles, and tested whether tweaking various environmental conditions such as water temperature, body size, nutritional state, and osmolarity would affect contractions. They were surprised to find that just one of those parameters, osmolarity, had an impact.

Boosting the concentration of sugar particles in the water triggered fewer contractions and decreased activity in the "contraction burst" (CB) neural circuit as well as in one set of muscles. Lowering particle concentration had the opposite effect, increasing cellular activity and contractions. Although additional experiments are needed to confirm their theory, the researchers propose that CB neurons respond to changes in osmolarity by altering muscle activity, which in turn influences contraction frequency.

Hydra ectoderm muscle activity during contraction in control media. The animal was allowed to move between coverslips in the mounted configuration. This video is sped up 20-fold. Credit: Wataru Yamamoto

Reacting to changes in particle concentration could mean the difference between life and death for Hydra—especially if salt is involved. As freshwater dwellers lacking advanced excretory systems, Hydra are not well-equipped to maintain the proper balance of salinity inside and outside their bodies. Water is constantly flowing in and out of their gastrovascular cavities, and too much internal salty solution causes them to balloon and literally explode. The researchers surmise that Hydra contract in response to high osmolarity to "wring" themselves out and expel excess water.

Freely-behaving Hydra vulgaris exhibiting different motor behaviors (elongation, contraction, somersaulting). Credit: Wataru Yamamoto

In addition to affecting contractions, osmolarity also influenced how often Hydra detached and repositioned its tube foot, likely preparing to move to a new location. Yamamoto plans to continue to investigate how and why this happens. He hopes his line of inquiry will eventually help decode a more complex behavior: somersaulting, when Hydra flips tentacles-over-tube foot, like a circus acrobat.

Explore further 

How does the nervous system create behavior? Muscle activity map in Hydra gives insight

More information: Wataru Yamamoto et al, Whole-Body Imaging of Neural and Muscle Activity during Behavior in Hydra vulgaris: Effect of Osmolarity on Contraction Bursts, eneuro (2020). DOI: 10.1523/ENEURO.0539-19.2020

Provided by Marine Biological Laboratory

Brexit: Ireland's land bridge to the continent boosts air pollution in the UK

by John Bryson, Omid Ghaffarpasand, William Bloss, The Conversation

Credit: Duncan Andison/Shutterstock

A no-deal Brexit could cost up to 5,000 jobs in Ireland's fisheries, but it's not just access to the UK's coastal waters that the country is hoping to hold on to in any post-Brexit arrangement. Perhaps more important to Ireland is the UK's motorway network.


Every year, more than 150,000 trucks transport over 3 million tons of freight to and from Ireland to the rest of the single market across the UK land bridge. One route involves goods being shipped from Dublin to Holyhead by ferry and then by road to Dover before being shipped to Calais.

It's difficult to overestimate the importance of this land bridge for Ireland. A 2017 study found that 40% of Ireland's exports to the EU reached the continent via the UK's roads, with an estimated value of €18.2 billion (£16.3 billion). Journey times to the EU market are less than 20 hours by the land bridge, but up to 40 to 60 hours by sea. That's why it's the preferred route for companies moving food, live animals and other high-value goods, such as heavy machinery and transport equipment.

A no-deal outcome could sever Ireland's most important route to EU markets. But what might the loss of Ireland's land bridge mean for the UK? Our research has found that it could entail substantial benefits for air quality and roads throughout the country.

Irish freight, British pollution

From January 1 2021, British goods will be treated as third-country freight by the EU, meaning they will be subject to customs and regulatory controls at European ports. These ports aren't yet able to differentiate between British and Irish freight, but once they are, a two-speed processing system would ensure Irish trucks are fast tracked through the system and UK trucks subject to regulatory delays. The Irish government is keen to ensure that the land bridge isn't considered a major negotiating point in UK-EU trade negotiations.


But for the UK, there is another dimension to the land bridge that has been completely overlooked. All the benefits that come from it accrue to Ireland and the EU, while all the negatives are borne by British citizens and companies.

The 150,000 truck journeys that Ireland's imports and exports add to the UK's road network often cause local congestion. Lorries also cause more damage to road surfaces than most other vehicles, with one study calculating that a six-axle, 44-ton truck is over 138,000 times more damaging to the foundations of a road than a small, one-ton car with two axles. These extra costs are covered by the UK taxpayer.

For the UK, the land bridge means that a third country is directly contributing to national air pollution, with all the health consequences that entails. Exposure to nitrogen dioxide pollution can trigger and exacerbate asthma symptoms, and it's also associated with heart disease and birth complications. Inhaling fine particulate matter (often called "PM2.5," as these particles are smaller than 2.5 micrometers) is linked to a host of medical conditions, including lung cancer.

We calculated the quantities of nitrogen oxides (NOx) and PM2.5 produced from 150,000 heavy goods vehicle journeys from Holyhead to Felixstowe (329 miles, or 529 kilometers) and found that it results in an additional 34 tons of NOx and 0.7 tons of PM2.5 per year being emitted across Wales and England. The PM2.5 calculation is based on exhaust emissions only though, it excludes particulates shed from brakes and tires. Total UK road transport NOx emissions in 2018 were 258,000 tons.

The Irish lorry fleet is also quite a lot older than the UK's. By 2020, 90% of UK lorries were at Euro VI standard and none were Euro III. In comparison, the latest data for the Irish fleet reveals that almost 20% is Euro III and only 22% Euro VI. This matters, as Euro III engines emit about 30 times more NOx than Euro VI.

Brexit has made visible a source of UK air pollution that is unrelated to the UK economy. The UK-EU trade negotiations should include air pollution and any agreement should include regulations that prevent highly polluting heavy goods vehicles from using the land bridge.

Perhaps one of the strangest outcomes of a no-deal Brexit may be that, for all the potential economic consequences for both Ireland and the UK, Britain's air pollution problem might substantially improve.


Explore further Research finds air pollution in Ireland associated with strokes

Provided by The Conversation

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Additional warming of just 0.5 C has a huge effect on global aridity

by University of Tokyo
Credit: CC0 Public Domain

In a new climate modeling study, researchers from the Institute of Industrial Science, The University of Tokyo have revealed major implications for global drought and aridity when limiting warming to 1.5°C rather than 2°C above pre-industrial levels. Drought has serious negative impacts on both human society and the natural world and is generally projected to increase under global climate change. As a result, assessment of the risk of drought under climate change is a critical area of climate research.


In the 2015 Paris Agreements, the United Nations Framework Convention on Climate Change (UNFCCC) proposed that the increase in global average temperature should be limited to between 1.5°C and 2°C above pre-industrial levels to limit the effects of severe climate change. However, there have been few studies focusing on the relative importance of this 0.5°C of global average temperature rise and what effect it might have on drought and aridity around the world.

"We wanted to contribute to the understanding of how important that 0.5°C could be, but it such a study is not easy to conduct based on previous modeling approaches," explains corresponding author Hyungjun Kim. "This is mainly because most models look at the extreme high levels and you cannot simply take a slice out of the data while the model spins up to this maximum. Therefore, we used data from the specially designed Half a degree Additional warming Prognosis and Projected Impacts (HAPPI) project to assess the impacts on aridity based on estimations of the balance between water and energy at the Earth's surface."

The study revealed that 2°C of warming led to more frequent dry years and more severe aridification in most areas of the world compared with 1.5°C, which emphasizes that efforts should be made to limit warming to 1.5°C above pre-industrial levels.

"There is a really strong message that some parts of the world could have more frequent drought at 2°C than at 1.5°C. This situation could be especially severe in the Mediterranean, western Europe, northern South America, the Sahel region, and southern Africa," says lead author Akira Takeshima. "However, this situation is highly regional. In some parts of the world, like Australia and some of Asia, the opposite situation was simulated, with a wetter climate at 2°C than at 1.5°C."

These findings show the importance of considering the regional impacts of the additional 0.5°C of warming, especially with respect to any future relaxation of the 1.5°C target.


Explore furtherLatest climate models show more intense droughts to come

More information: Akira Takeshima et al, Global aridity changes due to differences in surface energy and water balance between 1.5 °C and 2 °C warming, Environmental Research Letters (2020). DOI: 10.1088/1748-9326/ab9db3

Journal information: Environmental Research Letters


Provided by University of Tokyo 

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What the wildfires tell us about the shortcomings of California's electric grid

by Sean Brenner, University of California, Los Angeles

Fournier said the grid's operations depend heavily on transmission infrastructure to move power around. Credit: Sean Brenner

In addition to the vast destruction they have caused, the wildfires that have engulfed California in recent weeks have laid bare serious concerns about the state's electric grid.

In an email interview, UCLA's Eric Fournier explains why the architecture of California's grid isn't well suited for such extreme conditions and what it would take to improve it. Fournier has been research director of the California Center for Sustainable Communities at the UCLA Institute of the Environment and Sustainability since 2018—he joined UCLA as a postdoctoral researcher in 2016—and his research involves analyzing energy systems and the mechanics of the electric power system.

What are the core issues that the wildfires have exposed about our power grid?

The wildfires are exposing some of the inherent weaknesses of the grid's current architecture, which relies upon highly centralized sources of power generation.

The grid has historically been designed to support the unidirectional flow of power from a few large generator stations to many smaller consumers. That architecture seeks to take advantage of the economies of scale in power production that come from building generator stations as large as possible.

One thing that happens under this approach, however, is that these large generator stations tend to be built far away from the consumers. For fossil fuel–based generator plants, that's because their operations produce large amounts of harmful air emissions that can negatively affect public health. For renewable generator plants, it's because they need to be on sites with access to renewable energy flows—whether that's wind, sun or hydraulic potential, for example—and those locations are typically remote.

As a result, the grid's operations depend heavily on transmission infrastructure to move power around. If this infrastructure becomes compromised either due to age or some other external hazard—like extremely high heat or wildfire—grid operators have a difficult time maintaining reliable service.

The public safety power shut-offs in response to wildfires and other high-risk weather conditions are attempts to mitigate the grid's exposure to these hazards. These measures are obviously not ideal, however, because power outages result in significant disruptions to the lives of large numbers of people.


Ideally, we should be taking a longer-term view on how we can mitigate both these underlying hazards as well as the extent of the grid's exposure to them.

What are some ways California could realistically address those problems?

Adopting distributed renewable energy generation and storage would have a number of potential benefits, in terms of both mitigating hazards and reducing exposures.

In the former case, generating energy renewably avoids the emissions of greenhouse gases. This would help slow the rate of climate change and reduce the likelihood of more severe wildfires occurring in the future. In the latter case, generating energy in a distributed way helps reduce our reliance upon transmission infrastructure, and it would provide some capacity to continue making power available to consumers in the event of a transmission infrastructure failure.

What would it take to make those things happen?

There are a number of barriers to achieving a more renewable, more decentralized energy future. Some of them are technical and some are legal and administrative.

On the technical side, the grid will require extensive modernization upgrades to support higher levels of distributed energy resource penetration and, even further down the road, fully bi-directional power flows. These efforts will need to be supported by a dramatic expansion in the grid's capacity to store and share the energy that is produced by renewable sources—such as with batteries. This will be necessary to address problems related to many types of renewables' only intermittent ability to produce electric power.

On the legal and administrative side, there needs to be a recognition of the benefits associated with decentralized energy solutions. And these benefits should be considered during long-term energy system planning.

Utility companies have extensive experience building, operating and maintaining the grid as it currently exists. The proposed alternative represents a paradigm shift within this sector and will have to be supported with strong policy mandates. Otherwise, it is highly likely that in the future we will simply replace our existing, large-scale, remote, fossil fuel generation facilities with new, large-scale, remote, renewable generation facilities. That would mean that we would be retaining all of the same systemic vulnerabilities to climate change and wildfire that are inherent to the current system.

Finally, relative to this idea that we should promote greater decentralization: It is crucial that questions of equity be considered in the process. These solutions will fundamentally not work if they are only the provenance of the rich. Thus, we need to be forceful about ensuring that residents of disadvantaged communities are not left behind due to the cost or other difficulties associated with the adoption of these types of new technologies.


Explore further  Inertia and the power grid: A guide without the spin

Provided by University of California, Los Angeles

New method adds and subtracts for sustainability's true measure

by Michigan State University

The captive giant pandas in China's Wolong National Nature are a huge tourist draw. Credit: Michigan State University Center for Systems Integration and Sustainability

From loaning pandas to welcoming tourists to hike to sacred monuments, to regulating the sale of wild animals for meat, policies across the world seek to forge clear paths to sustainability.


A group of sustainability scientists at Michigan State University (MSU) examined those policies and discovered they sometimes have more success than intended to achieve some of the United Nations' Sustainable Development Goals (SDGs). Yet in some cases, those paths have created roadblocks and detours to success. The example of such unintended sidesteps is starkly illustrated in wildlife trading that provides economic benefits but has resulted in outbreaks of diseases that jump to humans, such as the current novel coronavirus.

The work is published in this week's open-access journal Sustainability.

"Today's world is extremely connected, and decisions are not created in a bubble," said Jianguo "Jack" Liu, MSU Rachel Carson Chair in Sustainability. "Our analysis has shown how important it is not just to look at the direct relationship between an action and a specific problem. It's crucial to look far and wide to see what else has been affected. Sometimes there are more wins. Sometimes, a problem solved in one place creates another elsewhere. We are learning the hard way how an action in one part of the world can have consequences thousands of miles away."

The scientists looked at 22 cases of tourism and instances of wildlife being relocated for various reasons across six continents. They looked at these cases through the lens of metacoupling—a new framework that helps scientists examine an action from the perspective of human-nature interactions across space and time.

In this paper, they lined up these cases with the 17 SDGs, adopted by world leaders from 193 countries and identify synergies—cases where success begat more success—or trade-offs, in which gaining ground in an SDG in one place meant losing ground on another SDG elsewhere.

The scorecard: they found 33 synergies and 14 trade-offs among 10 SDGs within the systems between which tourism, trade or animal movement happened—and across spillover systems—the places between.

Tourism accounts for one in 11 jobs worldwide (in the time frame of this study, before the pandemic) and is specifically called out in SDG 8 (decent work and economic growth). They found in the 12 cases they studied that beyond SDG 8, tourism in protected areas enhanced or compromised other SDGs, including SDGs 2 (zero hunger), 9 (industry, innovation and infrastructure), 12 (responsible consumption and production), 14 (life below water), 15 (life on land) and 17 (partnerships) within focal systems, and 1 (no poverty).

Examples of synergy can be found in Sagarmatha National Park of Nepal and Serengeti National Park in Tanzania, where tourism not only fulfilled SDG 8, but also contributed management funds for the parks—a win for SDG 15. But things were different in Peru's Machu Picchu, where the 900,000 visitors limited access for indigenous peoples and degradation of the site—a blow to SDG 12.

Moving animals around by trade, as a method of conservation or animal management—can have great benefits or harms. When raccoons were moved from their Florida homes to West Virginia to boost the local population, an SDG 15 win, SDG 3's good health and wellbeing took a hit when the Florida coons brought rabies with them.

The current pandemic is a dramatic call to better understand how the world works, and how to scrutinize actions for possible outcomes, according to the paper's first author Zhiqiang Zhao, who was a postdoctoral associate at MSU's Center for Systems Integration and Sustainability (CSIS). Liu is CSIS director.

The trade of bats in China may not have seemed relevant to people in Europe or America, yet it shows us it's just one stark reminder that it both is critical to do better to pursue global sustainability and to make sure our good intentions continue to result in good," Zhao said. "We are following the flows and working to show ways to quickly see all sides of a story."


Explore furtherStriving and stumbling towards sustainability amongst pandas and people

More information: Zhiqiang Zhao et al, Metacoupled Tourism and Wildlife Translocations Affect Synergies and Trade-Offs among Sustainable Development Goals across Spillover Systems, Sustainability (2020). DOI: 10.3390/su12187677

Provided by Michigan State University

Hubble captures crisp new portrait of Jupiter's storms

by NASA's Goddard Space Flight Center

This latest image of Jupiter, taken by NASA's Hubble Space Telescope on Aug. 25, 2020, was captured when the planet was 406 million miles from Earth. A unique and exciting detail of Hubble's snapshot appears at mid-northern latitudes as a bright, white, stretched-out storm traveling around the planet at 350 mph. Hubble shows that the Great Red Spot, rolling counterclockwise in the planet's southern hemisphere, is plowing into the clouds ahead of it, forming a cascade of white and beige ribbons. Jupiter's icy moon Europa, thought to hold potential ingredients for life, is visible to the left of the gas giant. Credit: NASA, ESA, STScI, A. Simon (Goddard Space Flight Center), M.H. Wong (University of California, Berkeley), and the OPAL team

This latest image of Jupiter, taken by NASA's Hubble Space Telescope on Aug. 25, 2020, was captured when the planet was 406 million miles from Earth. Hubble's sharp view is giving researchers an updated weather report on the monster planet's turbulent atmosphere, including a remarkable new storm brewing, and a cousin of the famous Great Red Spot region gearing up to change color—again.


A unique and exciting detail of Hubble's snapshot appears at mid-northern latitudes as a bright, white, stretched-out storm traveling around the planet at 350 miles per hour (560 kilometers per hour). This single plume erupted on Aug. 18, 2020—and ground-based observers have discovered two more that appeared later at the same latitude.

While it's common for storms to pop up in this region every six years or so, often with multiple storms at once, the timing of the Hubble observations is perfect for showing the structure in the wake of the disturbance, during the early stages of its evolution. Trailing behind the plume are small, rounded features with complex "red, white, and blue" colors in Hubble's ultraviolet, visible, and near-infrared light image. Such discrete features typically dissipate on Jupiter, leaving behind only changes in cloud colors and wind speeds, but a similar storm on Saturn led to a long-lasting vortex. The differences in the aftermaths of Jupiter and Saturn storms may be related to the contrasting water abundances in their atmospheres, since water vapor may govern the massive amount of stored-up energy that can be released by these storm eruptions.

Hubble shows that the Great Red Spot, rolling counterclockwise in the planet's southern hemisphere, is plowing into the clouds ahead of it, forming a cascade of white and beige ribbons. The Great Red Spot is currently an exceptionally rich red color, with its core and outermost band appearing deeper red.

An image of Jupiter taken by NASA's Hubble Space Telescope in ultraviolet, visible, and near-infrared light on Aug. 25, 2020, is giving researchers an entirely new view of the giant planet and offers insights into the altitude and distribution of the planet's haze and particles. This complements Hubble's visible-light pictures that show the ever-changing cloud patterns. In this photo, the parts of Jupiter's atmosphere that are at higher altitude, especially over the poles, look red from atmospheric particles absorbing ultraviolet light. Conversely, the blue-hued areas represent the ultraviolet light being reflected off the planet. A new storm at upper left, which erupted on Aug. 18, 2020, is grabbing the attention of scientists in this image. The "clumps" trailing the white plume appear to be absorbing ultraviolet light, similar to the center of the Great Red Spot, and Red Spot Jr. directly below it. This provides researchers with more evidence that this storm may last longer on Jupiter than most storms. Credit: NASA, ESA, STScI, A. Simon (Goddard Space Flight Center), M.H. Wong (University of California, Berkeley), and the OPAL team

Researchers say the Great Red Spot now measures about 9,800 miles across, big enough to swallow Earth. The super-storm is still shrinking as noted in telescopic observations dating back to 1930, but the reason for its dwindling size is a complete mystery.

Another feature researchers are noticing has changed is Oval BA, nicknamed by astronomers as Red Spot Jr., which appears just below the Great Red Spot in this image. For the past few years, Red Spot Jr. has been fading in color to its original shade of white after appearing red in 2006. However, now the core of this storm appears to be darkening slightly. This could hint that Red Spot Jr. is on its way to turning to a color more similar to its cousin once again.

Hubble's image shows that Jupiter is clearing out its higher altitude white clouds, especially along the planet's equator, where an orangish hydrocarbon smog wraps around it.

The icy moon Europa, thought to hold potential ingredients for life, is visible to the left of the gas giant.

This Hubble image is part of yearly maps of the entire planet taken as part of the Outer Planets Atmospheres Legacy program, or OPAL. The program provides annual Hubble global views of the outer planets to look for changes in their storms, winds, and clouds.


Explore furtherHubble showcases new portrait of Jupiter

Provided by NASA's Goddard Space Flight Center

 

Sea ice triggered the Little Ice Age, finds a new study

by University of Colorado at Boulder

The map shows Greenland and adjacent ocean currents. Colored circles show where some of the sediment cores used in the study were obtained from the seafloor. The small historical map from the beginning of the 20th century shows the distribution of Storis, or sea ice from the Arctic Ocean, which flows down the east coast of Greenland. The graphs show the reconstructed time series of changes in the occurrence of sea ice and polar waters in the past. The colors of the curves correspond to the locations on the map. The blue shading represents the period of increased sea ice in the 1300s. Credit: The figures are modified from Miles et al., 2020.

A new study finds a trigger for the Little Ice Age that cooled Europe from the 1300s through mid-1800s, and supports surprising model results suggesting that under the right conditions sudden climate changes can occur spontaneously, without external forcing.

The study, published in Science Advances, reports a comprehensive reconstruction of sea ice transported from the Arctic Ocean through the Fram Strait, by Greenland, and into the North Atlantic Ocean over the last 1400 years. The reconstruction suggests that the Little Ice Age—which was not a true ice age but a regional cooling centered on Europe—was triggered by an exceptionally large outflow of sea ice from the Arctic Ocean into the North Atlantic in the 1300s.

While previous experiments using numerical climate models showed that increased sea ice was necessary to explain long-lasting climate anomalies like the Little Ice Age, physical evidence was missing. This study digs into the geological record for confirmation of model results.

Researchers pulled together records from marine sediment cores drilled from the ocean floor from the Arctic Ocean to the North Atlantic to get a detailed look at sea ice throughout the region over the last 1400 years.

"We decided to put together different strands of evidence to try to reconstruct spatially and temporally what the sea ice was during the past one and a half thousand years, and then just see what we found," said Martin Miles, an INSTAAR researcher who also holds an appointment with NORCE Norwegian Research Centre and Bjerknes Centre for Climate Research in Norway.

The cores included compounds produced by algae that live in sea ice, the shells of single-celled organisms that live in different water temperatures, and debris that sea ice picks up and transports over long distances. The cores were detailed enough to detect abrupt (decadal scale) changes in sea ice and ocean conditions over time.

The records indicate an abrupt increase in Arctic sea ice exported to the North Atlantic starting around 1300, peaking in midcentury, and ending abruptly in the late 1300s.

"I've always been fascinated by not just looking at sea ice as a passive indicator of climate change, but how it interacts with or could actually lead to changes in the climate system on long timescales," said Miles. "And the perfect example of that could be the Little Ice Age."


"This specific investigation was inspired by an INSTAAR colleague, Giff Miller, as well as by some of the paleoclimate reconstructions of my INSTAAR colleagues Anne Jennings, John Andrews, and Astrid Ogilvie," added Miles. Miller authored the first paper to suggest that sea ice played an essential role in sustaining the Little Ice Age.

Scientists have argued about the causes of the Little Ice Age for decades, with many suggesting that explosive volcanic eruptions must be essential for initiating the cooling period and allowing it to persist over centuries. One the hand, the new reconstruction provides robust evidence of a massive sea-ice anomaly that could have been triggered by increased explosive volcanism. One the other hand, the same evidence supports an intriguing alternate explanation.

Climate models called "control models" are run to understand how the climate system works through time without being influenced by outside forces like volcanic activity or greenhouse gas emissions. A set of recent control model experiments included results that portrayed sudden cold events that lasted several decades. The model results seemed too extreme to be realistic—so-called Ugly Duckling simulations—and researchers were concerned that they were showing problems with the models.

Miles' study found that there may be nothing wrong with those models at all.

"We actually find that number one, we do have physical, geological evidence that these several decade-long cold sea ice excursions in the same region can, in fact do, occur," he said. In the case of the Little Ice Age, "what we reconstructed in space and time was strikingly similar to the development in an Ugly Duckling model simulation, in which a spontaneous cold event lasted about a century. It involved unusual winds, sea ice export, and a lot more ice east of Greenland, just as we found in here." The provocative results show that external forcing from volcanoes or other causes may not be necessary for large swings in climate to occur. Miles continued, "These results strongly suggest...that these things can occur out of the blue due to internal variability in the climate system."

The marine cores also show a sustained, far-flung pulse of sea ice near the Norse colonies on Greenland coincident with their disappearance in the 15th century. A debate has raged over why the colonies vanished, usually agreeing only that a cooling climate pushed hard on their resilience. Miles and his colleagues would like to factor in the oceanic changes nearby: very large amounts of sea ice and cold polar waters, year after year for nearly a century.

"This massive belt of ice that comes streaming out of the Arctic—in the past and even today—goes all the way around Cape Farewell to around where these colonies were," Miles said. He would like to look more closely into oceanic conditions along with researchers who study the social sciences in relation to climate.


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More information: Martin W. Miles et al, Evidence for extreme export of Arctic sea ice leading the abrupt onset of the Little Ice Age, Science Advances (2020). DOI: 10.1126/sciadv.aba4320
Journal information: Science Advances


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