scholarly journals Galactic Cosmic-Ray Anisotropy During Forbush Decreases: Evidence for Diffusive Barriers and Large-Scale Flow

2019 ◽  
Author(s):  
Grace Ihongo ◽  
D. Ruffolo ◽  
A. Saiz ◽  
U. Tortermpun ◽  
A. C-L. Chian
Keyword(s):  
Large Scale ◽  
Cosmic Ray ◽  
Forbush Decreases ◽  
Large Scale Flow ◽  
Galactic Cosmic Ray

A comparison of catalogues of Forbush decreases identified from individual and a network of neutron monitors: a critical perspective

2021 ◽  
Vol 503 (4) ◽  
pp. 5675-5691
Author(s):  
O Okike ◽  
J A Alhassan ◽  
E U Iyida ◽  
A E Chukwude
Keyword(s):  
Cosmic Ray ◽  
Radiowave Propagation ◽  
Current Work ◽  
Survey Method ◽  
Critical Perspective ◽  
Short Term ◽  
Forbush Decreases ◽  
Academy Of Sciences ◽  
Galactic Cosmic Ray ◽  
Monitor Data

ABSTRACT Short-term rapid depressions in Galactic cosmic ray (GCR) flux, historically referred to as Forbush decreases (FDs), have long been recognized as important events in the observation of cosmic ray (CR) activity. Although theories and empirical results on the causes, characteristics, and varieties of FDs have been well established, detection of FDs, from either isolated detectors' or arrays of neutron monitor data, remains a subject of interest. Efforts to create large catalogues of FDs began in the 1990s and have continued to the present. In an attempt to test some of the proposed CR theories, several analyses have been conducted based on the available lists. Nevertheless, the results obtained depend on the FD catalogues used. This suggests a need for an examination of consistency between FD catalogues. This is the aim of the present study. Some existing lists of FDs, as well as FD catalogues developed in the current work, were compared, with an emphasis on the FD catalogues selected by the global survey method (GSM). The Forbush effects and interplanetary disturbances database (FEID), created by the Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation Russian Academy of Sciences (IZMIRAN), is the only available comprehensive and up to date FD catalogue. While there are significant disparities between the IZMIRAN FD and other event lists, there is a beautiful agreement between FDs identified in the current work and those in the FEID. This may be a pointer to the efficiency of the GSM and the automated approach to FD event detection presented here.

Force-field parameterization of the galactic cosmic ray spectrum: Validation for Forbush decreases

2015 ◽  
Vol 55 (12) ◽  
pp. 2940-2945 ◽  
Author(s):  
I.G. Usoskin ◽  
G.A. Kovaltsov ◽  
O. Adriani ◽  
G.C. Barbarino ◽  
G.A. Bazilevskaya ◽  
...  
Keyword(s):  
Force Field ◽  
Cosmic Ray ◽  
Forbush Decreases ◽  
Force Field Parameterization ◽  
Galactic Cosmic Ray

scholarly journals Large-Scale Sidereal Anisotropy of Galactic Cosmic-Ray Intensity Observed by the Tibet Air Shower Array

2005 ◽  
Vol 626 (1) ◽  
pp. L29-L32 ◽  
Author(s):  
M. Amenomori ◽  
S. Ayabe ◽  
S. W. Cui ◽  
Danzengluobu ◽  
L. K. Ding ◽  
...  
Keyword(s):  
Large Scale ◽  
Cosmic Ray ◽  
Cosmic Ray Intensity ◽  
Air Shower ◽  
Galactic Cosmic Ray ◽  
Shower Array ◽  
Sidereal Anisotropy ◽  
Air Shower Array

Testing the Impact of Coronal Mass Ejections on Cosmic Ray Intensity Modulation with Algorithm selected Forbush Decreases

2020 ◽  
Author(s):  
O Okike ◽  
O C Nwuzor ◽  
F C Odo ◽  
E U Iyida ◽  
J E Ekpe ◽  
...  
Keyword(s):  
Coronal Mass Ejections ◽  
Cosmic Ray ◽  
Forbush Decreases ◽  
Cosmic Ray Intensity ◽  
Event Identification ◽  
Diurnal Anisotropy ◽  
Current Article ◽  
Galactic Cosmic Ray ◽  
The Impact ◽  
The Relationship

Abstract The relationship between coronal mass ejections (CMEs) and Forbush decreases (FDs) has been investigated in the past. But selection of both solar events are difficult. Researchers have developed manual and automated methods in efforts to identify CMEs as well as FDs. While scientists investigating CMEs have made significant advancement, leading to several CME catalogues, including manual and automated events catalogues, those analyzing FDs have recorded relatively less progress. Till date, there are no comprehensive manual FD catalogues, for example. There are also paucity of Automated FD lists. Many investigators, therefore, attempt to manually select FDs which are subsequently used in the analysis of the impact of CMEs on galactic cosmic ray (GCR) flux depressions. However, some of the CME versus FD correlation results might be biased since manual event identification is usually subjective, unable to account for the presence of solar-diurnal anisotropy which characterizes GCR flux variations. The current article investigates the relation between CMEs and FDs with emphasis on accurate and careful Forbush event selection.

scholarly journals Possible effects on Earth's climate due to reduced atmospheric ionization by GCR during Forbush Decreases

2016 ◽  
Vol 12 (S328) ◽  
pp. 298-300
Author(s):  
Williamary Portugal ◽  
Ezequiel Echer ◽  
Mariza Pereira de Souza Echer ◽  
Alessandra Abe Pacini
Keyword(s):  
Surface Temperature ◽  
Chemical Properties ◽  
Cosmic Ray ◽  
Galactic Cosmic Rays ◽  
Forbush Decreases ◽  
First Results ◽  
Earth’S Climate ◽  
Galactic Cosmic Ray ◽  
Cosmic Ray Flux ◽  
Atmospheric Ionization

AbstractThis work presents the first results of a study about possible effects on the surface temperature during short periods of lower fluxes of Galactic Cosmic Rays at Earth, called Forbush Decreases. There is a hypothesis that the Galactic Cosmic Ray flux decreases cause changes on the physical-chemical properties of the atmosphere. We have conducted a study to investigate these possible effects on several latitudinal regions, around the ten strongest FDs occurred from 1987 to 2015. We have found a possible increase on the surface temperature at middle and high latitudes during the occurence of these events.

scholarly journals Study of Galactic Cosmic-Ray Flux Modulation by Interplanetary Plasma Structures for the Evaluation of Space Instrument Performance and Space Weather Science Investigations

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 749 ◽  
Author(s):  
Catia Grimani ◽  
Daniele Telloni ◽  
Simone Benella ◽  
Andrea Cesarini ◽  
Michele Fabi ◽  
...  
Keyword(s):  
Large Scale ◽  
European Space Agency ◽  
Cosmic Ray ◽  
High Energy ◽  
Interplanetary Coronal Mass Ejections ◽  
Particle Detectors ◽  
Space Agency ◽  
Interplanetary Plasma ◽  
Galactic Cosmic Ray ◽  
Science Investigations

The role of high-energy particles in limiting the performance of on-board instruments was studied for the European Space Agency (ESA) Laser Interferometer Space Antenna (LISA) Pathfinder (LPF) and ESA/National Astronautics and Space Administration Solar Orbiter missions. Particle detectors (PD) placed on board the LPF spacecraft allowed for testing the reliability of pre-launch predictions of galactic cosmic-ray (GCR) energy spectra and for studying the modulation of proton and helium overall flux above 70 MeV n − 1 on a day-by-day basis. GCR flux variations up to approximately 15% in less than a month were observed with LPF orbiting around the Lagrange point L1 between 2016 and 2017. These variations appeared barely detected or undetected in neutron monitors. In this work the LPF data and contemporaneous observations carried out with the magnetic spectrometer AMS-02 experiment are considered to show the effects of GCR flux short-term variations with respect to monthly averaged measurements. Moreover, it is shown that subsequent large-scale interplanetary structures cause a continuous modulation of GCR fluxes. As a result, small Forbush decreases cannot be considered good proxies for the transit of interplanetary coronal mass ejections and for geomagnetic storm forecasting.

Is the large-scale sidereal anisotropy of the galactic cosmic-ray intensity really instable at TeV energies?

2012 ◽  
Vol 36 (1) ◽  
pp. 237-241 ◽  
Author(s):  
M. Amenomori ◽  
X.J. Bi ◽  
D. Chen ◽  
W.Y. Chen ◽  
S.W. Cui ◽  
...  
Keyword(s):  
Large Scale ◽  
Cosmic Ray ◽  
Cosmic Ray Intensity ◽  
Galactic Cosmic Ray ◽  
Sidereal Anisotropy
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