PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

The origin of bifurcated current sheets explained

The origin of bifurcated current sheets explained
2021-07-20
(Press-News.org) A Korean research team has identified the origin of bifurcated current sheets, considered one of the most unsolved mysteries in the Earth's magnetosphere and in magnetized plasma physics.

A POSTECH joint research team led by Professor Gunsu S. Yun of the Department of Physics and Division of Advanced Nuclear Engineering and Dr. Young Dae Yoon from the Pohang Accelerator Laboratory has theoretically established the process of collisionless equilibration of disequilibrated plasma current sheets. In addition, by comparing this with particle simulations and satellite data from NASA, the origin of the bifurcated current sheets - which had remained largely unknown - has been revealed.

In the Earth's magnetosphere, a sheet-shaped plasma is observed that is trapped between two regions of opposing magnetic fields. Because current flows inside it, it is also called a current sheet. According to the conventional theory, the current sheet exists as a single bulk in which the magnetic pressure due to the magnetic field generated by the current and the thermal pressure of the plasma balance one another, thereby forming an equilibrium. However, in 2003, the European Space Agency's Cluster mission observed a bifurcated current sheet in Earth's magnetosphere. Since then, similar phenomena have been observed.

On the other hand, extensive research has been accumulated on the condition in which the magnetic force and thermal pressure are perfectly balanced with each other in the current sheet. But the process through which a disequilibrated current sheet equilibrates remains largely unknown. Since plasma systems generally do not start from an equilibrium state, comprehension of the equilibration process is desired to better understand the current sheet plasma dynamics.

The joint research team thoroughly analyzed the process in which the disequilibrated sheet achieves equilibrium by considering the orbit classes and phase-space distributions of particles that constitute the current sheet and found that the current sheets can naturally bifurcate during the equilibration process. It was then confirmed that these theoretical predictions were consistent with the particle-in-cell simulation results performed by the KAIROS supercomputer at the Korea Institute of Fusion Energy. In addition, the simulation data were compared and verified with NASA's Magnetospheric Multiscale (MMS) measurements.

This achievement has enhanced the comprehension of magnetized plasma dynamics by incorporating theoretical analyses, supercomputer simulations, and satellite observations. Since the Earth's magnetospheric plasma has similar characteristics as other magnetized plasmas such as nuclear fusion plasmas in various ways, it is anticipated to contribute to a wide range of fields.

"This study has a significant academic value in that it simultaneously resolved two mysteries: the process through which disequilibrated current sheet equilibrates and the origin of bifurcated current sheets," explained Professor Gunsu S. Yun of POSTECH who participated as a co-corresponding author in the study. "We are trying to extend the analysis framework for plasmas with strong guide fields and hope to understand similar phenomena that occur in fusion plasmas."

INFORMATION:

Supported by the National Research Foundation of Korea, this study was published in Nature Communications on June 18, 2021.


[Attachments] See images for this press release:
The origin of bifurcated current sheets explained

ELSE PRESS RELEASES FROM THIS DATE:

Synthesis of new red phosphors with a smart material as a host material

Synthesis of new red phosphors with a smart material as a host material
2021-07-20
Overview: Professor Hiromi Nakano of Toyohashi University of Technology used a material with a unique periodical structure (smart material: Li-M-Ti-O [M = Nb or Ta]) as a host material to synthesize new Mn4+-activated phosphors that exhibit red light emissions at 685 nm when excited at 493 nm. Because the valence of the Mn ions in the material changes from Mn4+ to Mn3+ according to the sintering temperature, composition, and crystal structure, there is a difference in the photoluminescence intensity of the phosphors. XRD, TEM, and XANES were used to clarify the relationship between the photoluminescence intensity and the sintering temperature, ...

Tree-ring records reveal Asian monsoon variability

2021-07-20
Chinese researchers along with international colleagues recently reported a 6,700-year-long, precisely dated and well-calibrated tree-ring stable isotope chronology from the Northeastern Tibetan Plateau. It reveals full-frequency precipitation variability in the Asian Summer Monsoon (ASM) from interannual to multimillennial timescales with a long-term decreasing trend and several abrupt climate change events. The international research team comprised 20 scientists from research groups based in China, Norway, Germany, United Kingdom, USA, Sweden, Canada, and Switzerland ...

No IgA leads to intestinal inflammation in mice

No IgA leads to intestinal inflammation in mice
2021-07-20
Tokyo, Japan - While researchers have known for years that immunoglobulin A (IgA) is important for gut health, it has remained unclear exactly what role it plays in preventing infection and disease. But now, researchers from Japan have found that eliminating IgA disrupts the balance of the intestinal ecosystem, making it susceptible to disease. In a study published online in May in Gut, researchers from Tokyo Medical and Dental University (TMDU) have revealed that IgA deficiency results in substantial inflammation of the ileum, a specific part of the small intestine. IgA is present in large quantities in the small intestine, where it helps protect the body against microorganisms that could potentially cross the lining of the gut to cause ...

Farm consolidation has negative effect on wild pollinators

Farm consolidation has negative effect on wild pollinators
2021-07-20
A new study by a team of researchers has found that the consolidation of traditional smallholder farms in China has a devastating effect on the biodiversity of wild pollinators in the area. Pollinators play an essential role when it comes to supporting global food production. However, wild pollinators are on the decline for several reasons, including the loss of floral resources and nesting sites. This loss of biodiversity could have far-reaching consequences for global food production in future. "Biodiversity is essential for all life, with pollinators being one of the most important groups," says Dr Yi Zou from Xi'an Jiaotong-Liverpool ...

Removal of barred owls slows decline of iconic spotted owls in Pacific Northwest, study finds

2021-07-20
CORVALLIS, Ore. - A 17-year study in Oregon, Washington and California found that removal of invasive barred owls arrested the population decline of the northern spotted owl, a native species threatened by invading barred owls and the loss of old-forest habitats. The conservation and management of northern spotted owls became one of the largest and most visible wildlife conservation issues in United States history after the U.S. Fish and Wildlife Service listed the spotted owl as threatened under the Endangered Species Act in 1990 because of rapid declines in the owl's old-forest habitats. Four years later, the Northwest Forest Plan was adopted and reduced the rate of logging of old-growth forests on federal lands. Despite more ...

Strong signals

2021-07-20
Tsukuba, Japan - Scientists from the department of Anatomy and Embryology at the Faculty of Medicine of the University of Tsukuba created a computer model to simulate the development of complex structures based on the Delta-Notch signaling pathway. This work may lead to a more comprehensive picture of the process that results in the formation of organs and other physiological systems. The development of a tiny embryo consisting of undifferentiated cells into a healthy fetus with spatially defined organs depends on the complex interplay between genetic instructions and signaling molecules. For example, "Notch" genes are ...

A machine learning breakthrough: using satellite images to improve human lives

A machine learning breakthrough: using satellite images to improve human lives
2021-07-20
Berkeley -- More than 700 imaging satellites are orbiting the earth, and every day they beam vast oceans of information -- including data that reflects climate change, health and poverty -- to databases on the ground. There's just one problem: While the geospatial data could help researchers and policymakers address critical challenges, only those with considerable wealth and expertise can access it. Now, a team based at the University of California, Berkeley, has devised a machine learning system to tap the problem-solving potential of satellite imaging, using low-cost, ...

Millions of dollars saved when scheduled travel providers adapt to on-demand scheduling

2021-07-20
CATONSVILLE, MD, July 20, 2021 - Uber and Lyft are popular on-demand ways to travel, but does that mean trains and buses are a thing of the past? Travelers prefer different modes of transportation at different times. So how can all these modes co-exist and do so successfully? New research in the INFORMS Journal Transportation Science has created a model and an algorithm to redistribute transit resources based on commuter preferences resulting in millions in savings. "Based on case study experiments in New York City, our optimized transit schedules consistently lead to 0.4%-3% system-wide cost reduction. This amounts to rush hour savings of millions of dollars per day, while simultaneously reducing costs to passengers and transportation service ...

New method for uninterrupted monitoring of solid-state milling reactions

New method for uninterrupted monitoring of solid-state milling reactions
2021-07-20
A team of chemists from the Croatian Ruđer Bošković Institute (RBI) described a new, easy-to-use method for uninterrupted monitoring of mechanochemical reactions. These reactions are conducted in closed milling devices, so in order to monitor the reaction one has to open the reaction vessel, thus interfering with the process. The new method uses Raman spectroscopy to get deeper insight into solid-state milling reactions, without the usual interruption of the chemical reaction process. Mechanochemical synthesis by milling is used today to prepare all ...

Public health summer program increases STEM career interests in high schoolers

2021-07-20
High school students who participated in summer programs about public health increased their interest in pursuing careers in science, technology, engineering and mathematics (STEM), according to a Rutgers study. Published in the journalPedagogy in Health Promotion, the study explored whether increasing public health awareness would motivate high school students to pursue public health careers. Researchers found that the summer program, Public Health: Outbreaks, Communities, and Urban Studies (PHocus) offered in 2018 and 2019 increased the students' knowledge in public health, epidemiology, urban public health and global public health. "Including interdisciplinary, authentic ...

LAST 30 PRESS RELEASES:

KAIST Develops Retinal Therapy to Restore Lost Vision​

Adipocyte-hepatocyte signaling mechanism uncovered in endoplasmic reticulum stress response

Mammals were adapting from life in the trees to living on the ground before dinosaur-killing asteroid

Low LDL cholesterol levels linked to reduced risk of dementia

Thickening of the eye’s retina associated with greater risk and severity of postoperative delirium in older patients

Almost one in ten people surveyed report having been harmed by the NHS in the last three years

Enhancing light control with complex frequency excitations

New research finds novel drug target for acute myeloid leukemia, bringing hope for cancer patients

New insight into factors associated with a common disease among dogs and humans

Illuminating single atoms for sustainable propylene production

New study finds Rocky Mountain snow contamination

Study examines lactation in critically ill patients

UVA Engineering Dean Jennifer West earns AIMBE’s 2025 Pierre Galletti Award

Doubling down on metasurfaces

New Cedars-Sinai study shows how specialized diet can improve gut disorders

Making moves and hitting the breaks: Owl journeys surprise researchers in western Montana

PKU Scientists simulate the origin and evolution of the North Atlantic Oscillation

ICRAFT breakthrough: Unlocking A20’s dual role in cancer immunotherapy

How VR technology is changing the game for Alzheimer’s disease

A borrowed bacterial gene allowed some marine diatoms to live on a seaweed diet

Balance between two competing nerve proteins deters symptoms of autism in mice

Use of antifungals in agriculture may increase resistance in an infectious yeast

Awareness grows of cancer risk from alcohol consumption, survey finds

The experts that can outsmart optical illusions

Pregnancy may reduce long COVID risk

Scientists uncover novel immune mechanism in wheat tandem kinase

Three University of Virginia Engineering faculty elected as AAAS Fellows

Unintentional drug overdoses take a toll across the U.S. unequally, study finds

A step toward plant-based gelatin

ECMWF unveils groundbreaking ML tool for enhanced fire prediction

[Press-News.org] The origin of bifurcated current sheets explained