scholarly journals Heliospheric modulation of cosmic rays: model and observation

2017 ◽  
Vol 3 (1) ◽  
pp. 78-102 ◽  
Author(s):  
Сардаана Герасимова ◽  
Sardaana Gerasimova ◽  
Петр Гололобов ◽  
Peter Gololobov ◽  
Владислав Григорьев ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Wide Energy Range ◽  
Interstellar Gas ◽  
Cosmic Ray Intensity ◽  
Basic Model ◽  
Electrical Neutrality ◽  
Cosmic Ray Modulation ◽  
Wide Energy ◽  
Activity Cycles ◽  
Zero Potential

This paper presents the basic model of cosmic ray modulation in the heliosphere, developed in Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy of the Siberian Branch of RAS. The model has only one free modulation parameter: the ratio of the regular magnetic field to the turbulent one. It may also be applied to the description of cosmic ray intensity variations in a wide energy range from 100 MeV to 100 GeV. Possible mechanisms of generation of the mentioned turbulence field are considered. The primary assumption about the electrical neutrality of the heliosphere appears to be wrong, and the zero potential needed to match the model with observations in the plane of the solar equator can be achieved if the frontal point of the heliosphere, which is flowed around by interstellar gas, lies near the mentioned plane. We have revealed that the abnormal rise of cosmic ray intensity at the end of solar cycle 23 is related to the residual modulation produced by the subsonic solar wind behind the front of a standing shock wave. The model is used to describe features of cosmic ray intensity variations in several solar activity cycles.

scholarly journals Heliospheric modulation of cosmic rays: model and observation

2017 ◽  
Vol 3 (1) ◽  
pp. 63-78
Author(s):  
Сардаана Герасимова ◽  
Sardaana Gerasimova ◽  
Петр Гололобов ◽  
Peter Gololobov ◽  
Владислав Григорьев ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Wide Energy Range ◽  
Interstellar Gas ◽  
Cosmic Ray Intensity ◽  
Basic Model ◽  
Electrical Neutrality ◽  
Cosmic Ray Modulation ◽  
Wide Energy ◽  
Activity Cycles ◽  
Zero Potential

This paper presents the basic model of cosmic ray modulation in the heliosphere, developed in Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy of the Siberian Branch of RAS. The model has only one free modulation parameter: the ratio of the regular magnetic field to the turbulent one. It may also be applied to the description of cosmic ray intensity variations in a wide energy range from 100 MeV to 100 GeV. Possible mechanisms of generation of the mentioned turbulence field are considered. The primary assumption about the electrical neutrality of the heliosphere appears to be wrong, and the zero potential needed to match the model with observations in the plane of the solar equator can be achieved if the frontal point of the heliosphere, which is flowed around by interstellar gas, lies near the mentioned plane. We have revealed that the abnormal rise of cosmic ray intensity at the end of solar cycle 23 is related to the residual modulation produced by the subsonic solar wind behind the front of a standing shock wave. The model is used to describe features of cosmic ray intensity variations in several solar activity cycles.

COSMIC RAY FLUXES IN THE MAXIMUM PHASE OF SOLAR ACTIVITY CYCLES

2005 ◽  
Vol 20 (29) ◽  
pp. 6669-6671
Author(s):  
G. A. BAZILEVSKAYA ◽  
V. S. MAKHMUTOV ◽  
Y. I. STOZHKOV ◽  
A. K. SVIRZHEVSKAYA ◽  
N. S. SVIRZHEVSKY
Keyword(s):  
Solar Activity ◽  
Cosmic Rays ◽  
Cosmic Ray ◽  
Lebedev Physical Institute ◽  
Activity Maximum ◽  
Cosmic Ray Intensity ◽  
Cosmic Ray Modulation ◽  
Wide Energy ◽  
Activity Cycles ◽  
Solar Activity Cycles

The homogeneous series of primary cosmic ray intensity with energy > 100 MeV is obtained in the long-term balloon measurements of charged particle fluxes performed by Lebedev Physical Institute. Supplementing these data with those of neutron monitors enables us to study the cosmic ray modulation on the wide energy base during more than four solar activity cycles. In the periods of solar activity maximum a transition from cosmic ray decrease to recovery occurs. Changes in fluxes of cosmic rays of lower energy lag behind the changes in fluxes of cosmic rays of higher energy producing an energy hysteresis. After a while cosmic ray fluxes of all energies start to recover. In the cycles 20 and 22 the periods of transition from decline to recovery were shorter than in the cycles 21 and 23. This may be indicative of more complicated passage from the cosmic ray drift in the A > 0 conditions to the drift in the A < 0 conditions than vice versa.

scholarly journals Reconstructing the long-term cosmic ray intensity: linear relations do not work

2003 ◽  
Vol 21 (4) ◽  
pp. 863-867 ◽  
Author(s):  
K. Mursula ◽  
I. G. Usoskin ◽  
G. A. Kovaltsov
Keyword(s):  
Cosmic Ray ◽  
Geomagnetism And Paleomagnetism ◽  
Cosmic Ray Intensity ◽  
Linear Relations ◽  
Cosmic Ray Modulation ◽  
Interplanetary Physics ◽  
Long Time ◽  
Time Variations ◽  
Cosmic Ray Flux

Abstract. It was recently suggested (Lockwood, 2001) that the cosmic ray intensity in the neutron monitor energy range is linearly related to the coronal source flux, and can be reconstructed for the last 130 years using the long-term coronal flux estimated earlier. Moreover, Lockwood (2001) reconstructed the coronal flux for the last 500 years using a similar linear relation between the flux and the concentration of cosmogenic 10 Be isotopes in polar ice. Here we show that the applied linear relations are oversimplified and lead to unphysical results on long time scales. In particular, the cosmic ray intensity reconstructed by Lockwood (2001) for the last 130 years has a steep trend which is considerably larger than the trend estimated from observations during the last 65 years. Accordingly, the reconstructed cosmic ray intensity reaches or even exceeds the local interstellar cosmic ray flux around 1900. We argue that these unphysical results obtained when using linear relations are due to the oversimplified approach which does not take into account the complex and essentially nonlinear nature of long-term cosmic ray modulation in the heliosphere. We also compare the long-term cosmic ray intensity based on a linear treatment with the reconstruction based on a recent physical model which predicts a considerably lower cosmic ray intensity around 1900.Key words. Interplanetary physics (cosmic rays; heliopause and solar wind termination) – Geomagnetism and paleomagnetism (time variations, secular and long-term)

scholarly journals Galactic Cosmic Ray Modulation Up to Recent Solar Cycles

2011 ◽  
Vol 48 (4) ◽  
pp. 66-70
Author(s):  
R. Agarwal ◽  
R. Mishra
Keyword(s):  
Solar Cycle ◽  
Solar Radio ◽  
Cosmic Ray ◽  
Radio Flux ◽  
Solar Cycles ◽  
Cosmic Ray Intensity ◽  
Cosmic Ray Modulation ◽  
Solar Radio Flux ◽  
Yearly Average ◽  
Galactic Cosmic Ray

Galactic Cosmic Ray Modulation Up to Recent Solar Cycles Cosmic ray neutron monitor counts obtained by different ground-based detectors have been used to study the galactic cosmic ray modulation during the last four solar activity cycles. Since long, systematic correlative studies have been per-formed to establish a significant relationship between the cosmic ray intensity and different helio-spheric activity parameters, and the study is extended to a recent solar cycle (23). In the present work, the yearly average of 10.7 cm solar radio flux and the interplanetary magnetic field strength (IMF, B) have been used to find correlation of the yearly average cosmic ray intensity derived from different neutron monitors. It is found that for four solar cycles (20-23) the cosmic ray intensity is anti-correlated with the 10.7 cm solar radio flux and the IMF, B value with some discrepancy. However, this is in a good positive correlation with the flux of mentioned wavelength for four different solar cycles. The IMF, B shows a weak correlation with cosmic rays for solar cycle 20, and a good anti-correlation for solar cycles 21-23.

scholarly journals Variations of Interplanetary Parameters and Cosmic-Ray Intensities

1980 ◽  
Vol 91 ◽  
pp. 393-398
Author(s):  
A. Geranios
Keyword(s):  
Solar Flare ◽  
Recovery Time ◽  
Propagation Speed ◽  
Cosmic Ray ◽  
Interplanetary Shocks ◽  
Fast Solar Wind ◽  
Neutron Monitors ◽  
Cosmic Ray Intensity ◽  
Cosmic Ray Modulation ◽  
Modulation Region

Observations of cosmic ray intensity depressions by earth bound neutron monitors and measurements of interplanetary parameter's variations aboard geocentric satellites in the period January 1972-July 1974 are analysed and grouped according to their correlation among them. From this analysis of about 30 cases it came out that the majority of the depressions correlates with the average propagation speed of interplanetary shocks as well as with the amplitude of the interplanetary magnetic field after the eruption of a solar flare. About one fourth of the events correlates with corotating fast solar wind streams. As the recovery time of the shock-related depressions depends strongly on the heliographic longitude of the causitive solar flare, it seems that the cosmic ray modulation region has a corotative-like feature.

Observation of heavy cosmic-ray primaries over the wide energy range from ∼100 GeV/particle to ∼100 TeV/particle: Is the celebrated ‘‘knee’’ actually so prominent?

1993 ◽  
Vol 48 (5) ◽  
pp. 1949-1975 ◽  
Author(s):  
Masakatsu Ichimura ◽  
Masataka Kogawa ◽  
Shuichi Kuramata ◽  
Hiroyuki Mito ◽  
Takayuki Murabayashi ◽  
...  
Keyword(s):  
Energy Range ◽  
Cosmic Ray ◽  
Wide Energy Range ◽  
Wide Energy

scholarly journals ARGO-YBJ: STATUS AND HIGHLIGHTS

2013 ◽  
Vol 53 (A) ◽  
pp. 646-651
Author(s):  
Giuseppe Di Sciascio
Keyword(s):  
Energy Range ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
Current Status ◽  
Wide Energy Range ◽  
Open Problems ◽  
Direct Measurements ◽  
Wide Energy ◽  
First Time ◽  
Gathering Data

The ARGO-YBJ experiment has been gathering data steadily since November 2007 at the YangBaJing Cosmic Ray Laboratory (Tibet, P.R. China, 4300m a.s.l., 606 g/cm2). ARGO-YBJ is confronting various open problems in Cosmic Ray (CR) physics. The search for CR sources is carried out by observing TeV gamma-ray sources, both galactic and extra-galactic. The CR spectrum, composition and anisotropy are measured in a wide energy range (TeV ÷ PeV), thus overlapping direct measurements for the first time. This paper summarizes the current status of the experiment and describes some of the scientific highlights since 2007.

scholarly journals Cosmic Ray Extremely Distributed Observatory

2020 ◽  
Author(s):  
Piotr Homola ◽  
Dmitriy Beznosko ◽  
Gopal Bhatta ◽  
Łukasz Bibrzycki ◽  
Łukasz Bratek ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Cosmic Ray ◽  
Wide Energy Range ◽  
Air Showers ◽  
Arrival Times ◽  
Classical Models ◽  
Wide Energy ◽  
Partially Observable ◽  
Photon Interactions ◽  
Detection Strategies

The Cosmic Ray Extremely Distributed Observatory (CREDO) is a newly formed, global collaboration dedicated to observing and studying cosmic rays (CR) and cosmic ray ensembles (CRE): groups of a minimum of two CR with a common primary interaction vertex or the same parent particle. The CREDO program embraces testing known CR and CRE scenarios, and preparing to observe unexpected physics, it is also suitable for multi-messenger and multi-mission applications. Perfectly matched to CREDO capabilities, CRE could be formed both within classical models (e.g. as products of photon-photon interactions), and exotic scenarios (e.g. as results of decay of Super Heavy Dark Matter particles), their fronts might be significantly extended in space and time, and they might include cosmic rays of energies spanning the whole cosmic ray energy spectrum. CRE are expected to be partially observable on Earth even if the initiating interaction or process occurs as far as ~1 Gpc away. They would have a footprint composed of at least two extensive air showers with correlated arrival directions and arrival times. Since CRE are mostly expected to be spread over large areas and, because of the expected wide energy range of the contributing particles, CRE detection might only be feasible when using available cosmic ray infrastructure collectively, i.e. as a globally extended network of detectors. Thus, with this review article, the CREDO Collaboration invites the astroparticle physics community to actively join or to contribute to the research dedicated to CRE, and in particular to share any cosmic ray data useful for the specific CRE detection strategies.

Long Duration Solar Flare Events and Cosmic Ray Modulation (1969-1992)

1994 ◽  
Vol 144 ◽  
pp. 499-502
Author(s):  
A. Antalová ◽  
K. Kudela ◽  
D. Venkatesan ◽  
J. Rybák
Keyword(s):  
Solar Cycle ◽  
Solar Flare ◽  
Solar Flares ◽  
Cosmic Ray ◽  
Flare Activity ◽  
Cosmic Ray Intensity ◽  
Cosmic Ray Modulation ◽  
Long Duration ◽  
Flare Index ◽  
Galactic Cosmic Ray

AbstractWe present here the results of the correlation analysis between the galactic cosmic ray intensity decrease p (as observed on Calgary neutron monitor station) and the occurence of SXR long-lasting (LDE-type) solar flares, represented by the LDE-type flare index FI. It is shown, that for the solar cycle with the lower monthly values of FI (the 21-st solar cycle) the correlation coefficient is slighter (about 0.4) comparing to the cycles with the higher LDE-type flare activity (about 0.6, in the 20-th and the 22-nd cycles).

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