SPACE/COSMOS
Spacecraft data reveals surprising detail about Saturn's magnetic "shield"
Lancaster University
image:
Saturn's equinox captured by Cassini in 2009
view moreCredit: NASA/JPL/Space Science Institute
Scientists analysing data from the Cassini-Huygens mission have uncovered a significant structural surprise in Saturn’s protective magnetic bubble.
Researchers say this discovery confirms that giant planets operate under a different magnetospheric regime from the Earth’s.
The study in Nature Communications includes Dr Licia Ray and Dr Sarah Badman from Lancaster University with Dr Chris Arridge, formerly of Lancaster.
Cassini was sent to study the planet Saturn and its system, including its rings, natural satellites and local space environment, as part of a research mission by NASA, the European Space Agency (ESA) and the Italian space agency (ASI). It was in orbit between 2004 and 2017.
This latest research backs up a longstanding scientific theory that the rapid spin of massive planets like Saturn would replace the solar wind – the stream of charged particles from the Sun - as the dominant force sculpting their “magnetospheres”.
A magnetosphere is the region in the near-space environment where a planetary magnetic field acts as a shield against the solar wind. However, near the planetary poles, funnel-shaped openings called "magnetospheric cusps" allow charged particles from the Sun to leak directly into a planetary atmosphere.
Researchers analysed Cassini data collected between 2004 and 2010 to determine the precise location of Saturn’s magnetospheric cusp. The results showed a clear difference from similar measurements at Earth.
Saturn's immense rotational forces "drag" the cusp away from noon, skewing its average location significantly toward the afternoon sector, specifically between 13:00 and 15:00 local time while sometimes extending toward 20:00 local time. The dusk-oriented location of Saturn’s cusp confirms that a planet’s rotation rate can fundamentally change the structure of its near space environment
The shifted cusp location fundamentally alters models of magnetic reconnection, high-energy particle acceleration, and Saturn’s powerful auroral activity.
Dr Licia Ray of Lancaster University said: “This result allows us to move forward with new and improved theories on how planetary magnetospheres interact with the solar wind.”
Earth spins quite slowly compared to gas giants like Saturn. With one terrestrial day lasting 24 hours, the dominant factor driving the shape of the magnetosphere is the balance between the pressure from the Sun - the solar wind- and pressure from Earth’s magnetic field. This balance aligns the cusp towards local high noon.
At Saturn, one day lasts approximately 10.7 hours and its magnetosphere is full of ionised material from its moon Enceladus. These two effects mean that for Saturn, pressure from the magnetic field and a rapidly spinning disk of ionised material must balance the solar wind pressure.
Dr Ray said: “In particular, the afternoon cusp locations have implications for how we interpret Saturn’s bright aurora and where we expect magnetic reconnection, an explosive process that accelerates particles to very high energies of keV and more, to occur. It also highlights the rich science that can still be done with Cassini data more than eight years after the end of mission.”
Journal
Nature Communications
Method of Research
Data/statistical analysis
Subject of Research
Not applicable
Article Title
Dawn-dusk Asymmetrical Distribution of Saturn’s Cusp
Article Publication Date
1-Apr-2026
Saturn’s magnetic bubble is lopsided compared to Earth’s
University College London
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Schematic showing the position of Saturn's cusp compared to Earth's.
view moreCredit: SUSTech
Saturn's magnetic shield is asymmetrical compared to Earth’s, suggests a new study involving University College London (UCL) researchers, and this is likely a result of its fast rotation coupled with the heavy material it pulls around it.
Planetary magnetic fields (magnetospheres) shield planets from the highly charged particles of the solar wind. Saturn’s field is vast, more than 10 times wider than the planet itself.
The new study, published in Nature Communications, looked at six years of data from the Cassini space mission to determine the precise location of Saturn’s cusp - where magnetic field lines start to curve back into the planet’s poles and funnel charged particles down into the atmosphere.
The team found that the cusp was dragged to the right as viewed from the Sun, and was located most often between 13:00 and 15:00 (as it might appear on a clockface), compared to 12:00 as it would be on Earth.
The researchers said this was likely because of Saturn’s extremely fast rotation (a Saturn day is 10.7 hours) and the heavy “soup” of plasma (ionised gas) it pulls around it, a product of gases emitted by Saturn’s moons, especially Enceladus. Together, these are thought to drag the magnetic field lines to the right. But more simulations are needed to confirm this interpretation.
The environment around Saturn is of particular interest given that its moon Enceladus, which has icy plumes emanating from a subsurface ocean, may even host life and is the planned destination of a major European Space Agency mission proposed for launch in the 2040s.
Co-author Professor Andrew Coates (Mullard Space Science Laboratory at UCL) said: “The cusp is the place where the solar wind can slip directly into the magnetosphere. Knowing the location of Saturn’s cusp can help us better understand and map the whole magnetic bubble.
“A better understanding of Saturn’s environment is especially urgent now as plans for our return to Saturn and its moon Enceladus start to be developed. These results feed into the excitement that we are going back there. This time we will look for evidence of habitability and for potential signs of life.
“This study also provides critical evidence for a long-held theory – that the rapid spin of massive planets like Saturn with active moons replaces the solar wind as the dominant force shaping magnetospheres. It shows that Saturn’s magnetosphere, as well as the magnetospheres of other rapidly spinning gas giants, likely differ fundamentally from Earth’s.”
“Enceladus itself is a key driver of this environment, releasing huge amounts of water vapour that gets ionised, loading the magnetosphere with heavy plasma that is then pulled around as the planet spins.”
The international study team was led by researchers at the Chinese Academy of Sciences, the Southern University of Science and Technology, and the University of Hong Kong.
Corresponding author Professor Zhonghua Yao (The University of Hong Kong) said: “The differences between Saturn’s magnetic structure and that of Earth point to a unified fundamental process governing solar wind interaction across different planets. Comprehensive terrestrial observations reveal the working mechanisms of Earth, while comparative studies between planets inform us of the fundamental laws that can be applied to understand other systems, such as exoplanets.”
Lead author Dr Yan Xu (Southern University of Science and Technology in China) said: “By combining Cassini observations with simulations, we found that Saturn's rapid rotation and the plasma from its moon Enceladus together shape the asymmetric global distribution of the cusps. We hope this gives some useful reference for future exploration of Jupiter's and Saturn's space environments.”
The researchers looked at data from two of Cassini’s instruments (the Cassini Magnetometer, or MAG, and Cassini Plasma Spectrometer, CAPS) to detect moments where the spacecraft flew through Saturn’s cusp. They found 67 such events in total across the years 2004 to 2010, indicated through such clues as the energy levels of electrons the sensors detected.
Drawing on this data, the researchers carried out simulations of the magnetic field, finding that interactions between the magnetic field and solar wind at the edge of the magnetosphere closely resembled that of Jupiter’s.
A key source of data for the study came from the CAPS’s electron sensor, which was developed by a team led by Professor Coates at the Mullard Space Science Laboratory at UCL.
The researchers received funding from the UK’s Science & Technology Facilities Council and the National Natural Science Foundation of China, among other institutions.
Journal
Nature Communications
DOI
Gravitational waves as possible candidates for the origin of dark matter
New calculations explore the early universe
image:
Illustration that visualizes the stages of evolution of our universe and the stages at which stochastic gravitational waves are formed.
view moreCredit: Azadeh Maleknejad, Swansea University
Gravitational waves could be responsible for the production of dark matter during the early phases of our universe’s formation, according to results of a new study by Professor Joachim Kopp from Johannes Gutenberg University Mainz (JGU) and the PRISMA++ Cluster of Excellence in cooperation with Dr. Azadeh Maleknejad from Swansea University. Their work, published in Physical Review Letters, presents new calculations that explore a novel mechanism for the formation of dark matter through so-called stochastic gravitational waves.
In this way, they contribute to answering a fundamental question in particle physics. Planets, stars, and even life on Earth are all composed of visible matter. This type of matter only makes up about four percent of our universe. The vast majority is invisible, consisting of dark matter and dark energy. For instance, dark matter makes up about 23 percent of our universe. Astrophysical observations confirm that dark matter permeates the whole universe and forms galaxies as well as the largest known structures in the cosmos. However, the particles that make up dark matter are still unknown. Many theories and ongoing experiments are looking for an answer to this open question.
A new method for particle formation
Gravitational waves are a type of ripple in spacetime usually originating in some of the most intense and energetic processes in the universe, for example when two black holes or neutron stars merge. On the other hand, stochastic gravitational waves are caused by different phenomena without the participation of massive cosmological objects. Accordingly, their weaker signal forms part of the background noise of the numerous waves moving through our universe. However, they often are extremely old. Many of their originating phenomena occurred in the earliest stages of our universe's development, such as so-called phase transitions of matter, as the universe cooled down following the hot Big Bang, or primordial magnetic fields.
"In this article, we investigate the possibility of gravitational waves – which are believed to have been ubiquitous in the early universe – being partially converted into dark matter particles," Kopp explained. "This leads to a new mechanism of dark matter production that has not been researched before."
Kopp and Maleknejad show in their study that gravitational waves may well have led to the formation of mass-free or nearly mass-free fermions. The fermion family of particles includes electrons, protons, and neutrons, among others. These fermions from the early universe would then acquire mass and form the dark matter particles that still exist today.
"The next step in developing this line of research is to go beyond our analytical estimates and conduct numerical calculations to improve the accuracy of our predictions. Another avenue for future research is the investigation of further possible effects of gravitational waves in the early universe. One example for this would be a mechanism that could account for the well-known difference in particles and antiparticles produced," said Kopp.
Journal
Physical Review Letters
Article Title
Gravitational-wave induced freeze-in of fermionic dark matter
Article Publication Date
31-Mar-2026
Two's company: ISTA scientists identify new class of star remnants
Researchers at the Institute of Science and Technology Austria (ISTA) say two white dwarfs, Gandalf and Moon-Sized, define a new class of star remnants because they share five properties, including X-ray emission, despite being isolated objects.
image:
New class of star remnants. Researchers at the Institute of Science and Technology Austria (ISTA) find two isolated, ultra-massive, X-ray emitting, highly magnetic, and rapidly rotating white dwarfs. Left to right: PhD student Andrei Cristea, Assistant Professor Ilaria Caiazzo, and PhD student Aayush Desai. © ISTA
view moreCredit: © ISTA
In the vastness of the Universe, any new object with interesting properties can spur the search for similar objects, potentially establishing a new class of stars. In a paper published in Astronomy & Astrophysics and an arXiv preprint, researchers from the Institute of Science and Technology Austria (ISTA) describe two stellar remnants that share five properties, including X-ray emission, despite being isolated objects. According to the team, these two remnants are sufficient to define a new class of stars.
In about five to eight billion years, our Sun is expected to evolve into a white dwarf—an extremely dense, Earth-sized stellar remnant that has exhausted its fuel and shed its outer layer. But while our Sun is a solitary star, research over the past 15 years has demonstrated that binary or multi-star systems are far more common than astronomers once thought. When a dense and compact remnant like a white dwarf is involved in a binary system, it often ‘snatches away’ material from its companion star. This process, called accretion, usually emits X-rays in what is considered a ‘signature’ signal.
Now, scientists from the group of Ilaria Caiazzo, assistant professor at the Institute of Science and Technology Austria (ISTA), confirm the detection of an X-ray signal in not just one, but two isolated objects called Gandalf and Moon-Sized. Highly magnetic and rapidly rotating, these two objects are called “merger remnants” as they each formed as a result of a violent cosmic collision. By emitting X-rays in the absence of a companion, they now form a new class of their own.
Gandalf—the Lord of the Half Rings?
Gandalf is not exactly a fresh discovery. Caiazzo first observed it during her postdoctoral research and classified it as an interesting object due to signals that hint at the presence of material around it.
“We initially thought it was a binary system,” says Andrei Cristea, a PhD student in the Caiazzo group and first author of the paper published in Astronomy & Astrophysics, about Gandalf. “At the remnant’s extremely high level of magnetism, its spin should be synchronized with its companion’s orbit, similarly to Earth’s rotation with the Moon’s orbit,” he adds. However, the fastest orbit period observed to date is 80 minutes. Gandalf, on the other hand, rotates on its axis every six minutes. According to Cristea, this is but one of its puzzling features.
“If Gandalf were involved in a binary system, it would have been highly unsynchronized, which might have made it even more puzzling than it already is. But we never found a companion. So, where does the circumstellar material come from?”
To help answer this question, the team drew on a clue from optical emission spectra, an observation technique widely used in astronomy.
“We saw hydrogen emission spectra that exhibited a double-peaked signature, similar to cat ears,” says Cristea. “Usually, this signature indicates the presence of a disk of material surrounding a merger remnant. However, by examining the signal more closely, we realized that it was alternating between the two peaks over the remnant’s six-minute spin period.” This curious observation matched the existence of a half-ring of material circling the star. “We have never seen anything like that before in any white dwarf,” he adds.
The team went on to argue that for the material surrounding the merger remnant to be trapped asymmetrically in a half-ring configuration, the object must have a strong and asymmetric magnetic field.
“To note, white dwarfs of similar age and evolutionary stage are typically nonmagnetic,” says Cristea. “While highly magnetic white dwarf remnants are already an exception, Gandalf is now one of only two known merger remnants to feature asymmetric magnetization.” All these puzzling reasons led Cristea to name this stellar object after the famous protagonist in J.R.R. Tolkien’s novels, who likes to speak in riddles.
Moon-Sized—Gandalf’s more evolved twin?
Even though the team did not find a companion for Gandalf, it might still have a ‘twin’ in a completely different area of the Universe.
When Caiazzo published her discovery of a white dwarf she called “Moon-Sized” in 2021, this stellar object presented a range of unique properties. In addition to being very highly magnetic and rotating rapidly, it also packed a mass equivalent to the Sun into a size comparable to that of the Moon—or slightly larger, as the new evidence in an arXiv preprint led by Aayush Desai, another PhD student in the Caiazzo group, shows.
The ISTA astronomers found that Moon-Sized and Gandalf share five distinct characteristics. In addition to being ultra-massive, highly magnetic, and rapidly rotating, these two remnants are also companionless, and they both emit X-rays. These five common properties led the ISTA scientists to propose Gandalf and Moon-Sized as two members of a new class of remnants.
However, the two objects also differ significantly: unlike Gandalf, Moon-Sized shows no signs of material surrounding it. In addition, while Gandalf is the result of a collision that happened 60 to 70 million years ago, Moon-Sized is seven to eight times older, as its merger event took place around 500 million years ago. Another important difference is that Gandalf’s X-ray emissions are 100 times brighter, suggesting that Moon-Sized might be an older, more evolved ‘twin’ that may be losing its source of X-rays.
What are the criteria for defining a new class of stars or remnants?
Astronomers agree that the closer an object is to us in the Universe, the more likely it is to be common. Nevertheless, any new object could spark interest in the community.
Caiazzo explains: “If we find one new object in the vastness of the Universe, what are the chances of it being the only one? Usually, one stellar object with new characteristics is more than enough for us to start looking for similar ones. But here, we actually found two objects with five overlapping features. This is plenty for a new class of star remnants!”
X-rays and the mysteries of stellar evolution
The team proposes several scenarios to explain their findings, particularly the source of the X-rays.
In the first scenario, a highly magnetized star could rotate rapidly enough to generate a powerful force that extracts material from itself. “This is my favorite scenario because it only accounts for the white dwarf itself rather than material originating from outside the star remnant,” says Desai. According to the team, this so-called outflow scenario is known from highly magnetized neutron stars called pulsars, though it has never been modeled in a white dwarf remnant.
In their second scenario—this time involving an “inflow” of material— they propose that a ‘leftover’ trail of material originating from the merger event may not have completely accreted onto the star remnant following the blast. By orbiting around the merger remnant at high eccentricity—meaning moving away over a large orbit, far from the star, before returning closely—this trail could ‘fall back’ on the remnant over hundreds of millions of years.
In their third scenario, the team explores another source of “inflow” of external material.
“We know that a third of white dwarfs are ‘polluted,’” says Desai. “They are so dense that we would expect external material, such as asteroids or even disrupted planetary bodies, to collapse onto them.” While Gandalf shows some signs of pollution, possibly through carbon- or silicon-rich materials, the team did not detect such signals from the considerably older Moon-Sized. “This scenario seems less likely, as it does not fully explain why we see the X-rays in both objects right now,” Desai explains.
Although the team has uncovered key insights about Moon-Sized and Gandalf, further research is needed to understand how these stars might influence their planetary systems.
“The two objects we identified so far have lots of similarities, but also differences,” explains Desai. “Finding more such remnants will help us exclude scenarios and perhaps find other explanations altogether.”
For now, the challenge remains to determine whether any of the five overlapping parameters is decisive for belonging to this new class.
Gandalf—the Lord of the Half Rings? Hydrogen emission spectra alternating between two peaks over the remnant’s six-minute spin period indicate a half-ring of material circling the star. © Aayush Desai / Andrei Cristea / ISTA
Journal
Astronomy and Astrophysics
Method of Research
Observational study
Subject of Research
Not applicable
Article Title
A half ring of ionized circumstellar material trapped in the magnetosphere of a white dwarf merger remnant.
SwRI-led research indicates a more complex Sun’s magnetic engine
Close observation reveals protons and heavy ions defying expectations
image:
NASA’s Parker Solar Probe is the first spacecraft to fly through the corona, the Sun’s upper atmosphere, and offers a unique perspective on solar processes. Using Parker Solar Probe data, SwRI-led research has revealed a complex system of magnetic forces and kinetic energy associated with protons and heavy ions accelerated by magnetic reconnection.
view moreCredit: NASA
SAN ANTONIO — March 31, 2026 — A Southwest Research Institute-led study found that protons and heavy ions react differently to solar magnetic reconnection events, revealing a more complex magnetic engine powering the solar wind.
Magnetic reconnection converts magnetic energy into explosive kinetic energy, powering solar events and causing space weather that impacts Earth. Magnetic reconnection energizes protons and heavy ions, sending them shooting out from the Sun at high speeds.
Current models assume all these particles react the same way, but new data obtained by NASA’s Parker Solar Probe shows distinct differences in particle acceleration. While heavy ions shoot out straight like a laser beam, protons create waves that scatter subsequent particles in a dispersed pattern, more like a flashlight.
“This new data rewrites our understanding of reconnection,” said SwRI’s Dr. Mihir Desai, lead author of a new paper about this research. “Protons and heavy ions show distinct spectra that contradict current models. Protons generate waves that scatter them more efficiently, while the heavy ions stay beam-like and retain their accelerated spectral shapes.”
Magnetic reconnection is a ubiquitous phenomenon in the universe, where magnetic field lines converge, break apart and reconnect. At the Sun, the explosive physical process energizes particles and generates high-speed flows, driving space weather events such as solar flares and coronal mass ejections. Space weather drives disturbances in Earth’s space environment, producing spectacular auroras but can also disrupt operations of electrical power grids, satellite-based communication and navigation systems. Understanding how magnetic reconnection works is critical for predicting hazardous events and protecting life and technological assets on Earth and in space.
“What we are learning is that the Sun’s ‘magnetic engine’ is far more complex than we imagined,” Desai said. “This is incredibly exciting because it demonstrates that our own star acts as a local, accessible laboratory for the same high-energy physics — like particle acceleration and magnetic snapping — that powers the most violent and mysterious phenomena in the universe, from black holes to supernovae.”
Parker Solar Probe’s record-breaking proximity to the Sun collects unique measurements as it flies through the corona three times a year. Developed as part of NASA’s Living With a Star program, Parker explores aspects of the Sun-Earth system that directly affect life and society. The Living With a Star program is managed by the agency’s Goddard Space Flight Center in Greenbelt, Maryland, for NASA’s Science Mission Directorate in Washington. The Johns Hopkins University Applied Physics Laboratory designed, built and operates the spacecraft and manages the mission for NASA.
To read The Astrophysical Journal Letters paper titled “Proton and Heavy Ion Acceleration by Magnetic Reconnection at the near-Sun Heliospheric Current Sheet,” go to DOI: 10.3847/1538-4357/ae48f2.
For more information, visit https://www.swri.org/markets/earth-space/space-research-technology/space-science/heliophysics.
Journal
The Astrophysical Journal Letters
Method of Research
Data/statistical analysis
Subject of Research
Not applicable
Article Title
Proton and Heavy Ion Acceleration by Magnetic Reconnection at the Near-Sun Heliospheric Current Sheet
Article Publication Date
31-Mar-2026
Why satellite positioning can suddenly go wrong
Aerospace Information Research Institute, Chinese Academy of Sciences
image:
The geographic distribution of a GNSS Receivers and b IPPs
view moreCredit: Satellite Navigation
Satellite navigation can fail not only during dramatic space weather events, but also when the ionosphere develops sharp regional structures that standard correction models fail to resolve. This study shows that steep longitudinal gradients in total electron content (TEC) can appear within a narrow band over Asia, creating positioning errors for standard point positioning. It also finds that storm-time ionospheric irregularities can either amplify or reduce precise positioning errors, depending on how electric fields reshape plasma motion after sunset. By linking these regional structures to specific positioning outcomes, the research offers a clearer picture of when and why GNSS accuracy breaks down—and how warning systems could become more useful for real-world users.
The ionosphere is one of the largest natural error sources in Global Navigation Satellite System applications, especially during periods of strong solar activity. Existing global ionosphere models help correct part of that error, but their spatial resolution is often too coarse to capture sharp, localized gradients. At the same time, irregular plasma structures can trigger signal scintillation, cycle slips, and sudden drops in positioning stability. Earlier studies documented these hazards, yet key gaps remained: how different ionosphere models perform under steep regional gradients, and how storm-time electrodynamic processes physically connect to irregularities and positioning degradation. Based on these challenges, deeper research is needed on regional ionospheric structures and their impacts on GNSS positioning.
Researchers from the Institute of Geology and Geophysics, Chinese Academy of Sciences, together with collaborators from the Aerospace Information Research Institute of CAS, Nanjing University of Information Science and Technology, and Shandong University, reported (DOI: 10.1186/s43020-026-00191-2) in Satellite Navigation in 2026 that regional ionospheric structures in the Asian sector can strongly alter both standard point positioning (SPP) and precise point positioning (PPP), with sharp TEC gradients and storm-driven post-sunset irregularities emerging as two major sources of error.
Using observations from more than 300 GNSS receivers across Asia, along with ionosonde and incoherent scatter radar measurements at Sanya, the team traced how medium-scale and small-scale ionospheric structures affect positioning in different ways. They identified steep TEC gradients exceeding 2 TECU per degree, concentrated mainly between 20°N and 30°N. Those gradients exposed a major weakness in widely used global ionosphere models: most were too coarse to reproduce the real structure. CASG and JPLG performed better than other products, but even JPLG left more than half of the strongest gradients unresolved. When such gradients appeared, SPP errors increased, while CASG reduced those errors by about 0.5 to 2 meters compared with many alternatives. The study then turned to two geomagnetic storms. During the 1 December 2023 event, an under-shielding penetration electric field drove upward plasma drift, intensified post-sunset irregularities, and degraded kinematic PPP accuracy from under 10 centimeters to beyond 1 meter, in some cases reaching meter-level to 10-meter-scale errors. In contrast, during the 10 May 2024 storm, an over-shielding electric field drove downward drift, suppressed the usual post-sunset irregularities, and prevented the extra PPP errors they normally trigger.
“This study shows that the ionosphere is not just background noise for satellite navigation,” the findings suggest. “Its regional structures can rapidly reorganize positioning conditions, and storm-time electric fields can push the system in opposite directions—either amplifying errors or suppressing them.” That insight matters because it shifts the focus from simply asking whether a geomagnetic storm is occurring to asking what kind of electrodynamic process is unfolding, where, and at what time of day.
The work has clear operational value. It suggests that GNSS users in Asia—from surveying systems to transport platforms and autonomous technologies—could benefit from warnings that track not only storm intensity but also steep TEC gradients and the direction of storm-time electric fields. It also points to practical model improvements: finer longitudinal resolution, better use of multi-constellation data, and more realistic multi-layer ionosphere representations. Rather than treating all space weather as uniformly harmful, the study shows that some storm-time conditions may actually prevent daily irregularity-related positioning failures. That makes the future of GNSS forecasting not just more accurate, but more nuanced and more actionable.
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References
DOI
Original Source URL
https://doi.org/10.1186/s43020-026-00191-2
Funding Information
This work was supported by National Natural Science Foundation of China (42530201), National Key R&D Program (2022YFF0504400), Basic Research Program of Jiangsu (BK20250747), and National Key R&D Program of China (2025YFF0512302).
About Satellite Navigation
Satellite Navigation (E-ISSN: 2662-1363; ISSN: 2662-9291) is the official journal of Aerospace Information Research Institute, Chinese Academy of Sciences. The journal aims to report innovative ideas, new results or progress on the theoretical techniques and applications of satellite navigation. The journal welcomes original articles, reviews and commentaries.
Journal
Satellite Navigation
Subject of Research
Not applicable
Article Title
Study of regional ionospheric structures and their impacts on SPP and PPP with multi-instrument observations in the Asian sector
