. | . |
Coronal mass ejections and cosmic ray observations at Syowa Station in the Antarctic by Staff Writers Matsumoto, Japan (SPX) Jun 16, 2021
Solar activities, such as CME(Coronal Mass Ejection), cause geomagnetic storm that is a temporary disturbance of the Earth's magnetosphere. Geomagnetic storms can affect GPS positioning, radio communication, and power transmission system. Solar explosions also emit radiation, which can affect satellite failures, radiation exposure to aircraft crew, and space activity. Therefore, it is important to understand space weather phenomena and their impact on the Earth. Space weather research by continuous observation of cosmic rays on the ground is mainly conducted using observation data from neutron monitors and multi-directional muon detectors. Since the phenomenon of space weather is on a short-term, days-long scale, it is effective to investigate changes in the flow of cosmic rays for several hours, which requires a total sky monitor of cosmic rays. In the muon detector, the global muon detector network (GMDN) has been observing space weather phenomena since 2006, and in the neutron monitor, the Spaceship Earth project constitutes a similar observation network and the role of the all-sky monitor. Until now, observations by neutron monitors and muon detectors have been performed independently, and progress has been made in space weather research. In February 2018, Professor Chihiro Kato of Shinshu University took the lead in acquiring simultaneous observations of the neutron monitor and muon detector at Syowa Station in the Antarctic in order to acquire bridging data of observations by the neutron monitor and muon detector. In the polar regions, unlike low latitude regions on the earth, it is possible to observe cosmic rays coming from the same direction with a neutron monitor and a muon detector due to the weaker deflection by the geomagnetism. This is the reason why Syowa Station was selected as the observation point. Syowa muon detector and neutron monitor observed small fluctuation in CR count like a Forbush decrease on 2018.8. The research group including researchers from Shinshu University and the National Polar Research Institute found curious cosmic-ray density variation on this event by analyzing GMDN data. On the CME event, a huge amount of coronal material released with a bundle of the solar magnetic field, called Magnetic Flux Rope (MFR), into the interplanetary space. MFR moves through interplanetary space as expanding. CR density is low inside of it because it is originally coronal material. When the Earth enters the MFR, CR counts on the ground decreases. This is called Forbush Decrease. Normally, when MFR arrives on Earth, CR density observed at the ground level decreases rapidly, and then turns to increase recovering to the original level while the Earth is in the MFR. On this event, however, the CR exceeds the original level before the Earth exits the MFR. This event attracts interest from researchers because 1) The solar activity is currently near the minimum and the scale of the event itself is small, 2) It causes a disproportionately large geomagnetic storm, and 3) There is high-speed solar wind catching up the MFR expected to interact with it. By analysis of the GMDN and solar plasma data, it is concluded that the high-speed solar wind causes the unusual enhancement of the CR density by compressing the rear part of the MFR locally. Cosmic ray observation data is closely related not only to space weather research but also to atmospheric phenomena such as sudden stratospheric temperature rise and is expected to be used in a wide range of fields in the future. The cosmic ray observation data at Syowa Station, including the phenomenon in August 2018, which was the subject of this research, is published on the website and updated daily here
Dark matter particle explorer measures cosmic ray helium energy spectrum Beijing, China (SPX) May 31, 2021 Dark Matter Particle Explorer (DAMPE) Collaboration directly observed a spectral softening of helium nuclei at about 34TeV for the first time. This work was based on measurements data of the helium spectrum with kinetic energies from 70 GeV to 80 TeV (17.5 GeV/n to 20 TeV/n for per nucleon) recorded by the DAMPE. Galactic cosmic rays (GCRs) offers important ways to deeply understand the astrophysical particle origin and accelerators and the interstellar medium of the Galaxy. Helium nuclei, the second ... read more
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |