scholarly journals Corotating interaction regions and the 27 day variation of galactic cosmic rays intensity at 1 AU during the cycle 23/24 solar minimum

2014 ◽  
Vol 119 (4) ◽  
pp. 2411-2429 ◽  
Author(s):  
X. Guo ◽  
V. Florinski
Keyword(s):  
Cosmic Rays ◽  
Solar Minimum ◽  
Galactic Cosmic Rays ◽  
Corotating Interaction Regions ◽  
Interaction Regions

scholarly journals Galactic Cosmic Rays Modulation in the Vicinity of Corotating Interaction Regions: Observations During the Last Two Solar Minima

2019 ◽  
Vol 882 (1) ◽  
pp. 54 ◽  
Author(s):  
Keyvan Ghanbari ◽  
Vladimir Florinski ◽  
Xiaocheng Guo ◽  
Qiang Hu ◽  
Richard Leske
Keyword(s):  
Cosmic Rays ◽  
Galactic Cosmic Rays ◽  
Corotating Interaction Regions ◽  
Interaction Regions

scholarly journals Latitudinal and radial variation of >2 GeV/n protons and alpha-particles at solar maximum: ULYSSES COSPIN/KET and neutron monitor network observations

2003 ◽  
Vol 21 (6) ◽  
pp. 1295-1302 ◽  
Author(s):  
A. V. Belov ◽  
E. A. Eroshenko ◽  
B. Heber ◽  
V. G. Yanke ◽  
A. Raviart ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Neutron Monitor ◽  
Solar Minimum ◽  
Latitudinal Gradient ◽  
Solar Maximum ◽  
Cosmic Ray ◽  
Galactic Cosmic Rays ◽  
Alpha Particles ◽  
Polar Regions

Abstract. Ulysses, launched in October 1990, began its second out-of-ecliptic orbit in September 1997. In 2000/2001 the spacecraft passed from the south to the north polar regions of the Sun in the inner heliosphere. In contrast to the first rapid pole to pole passage in 1994/1995 close to solar minimum, Ulysses experiences now solar maximum conditions. The Kiel Electron Telescope (KET) measures also protons and alpha-particles in the energy range from 5 MeV/n to >2 GeV/n. To derive radial and latitudinal gradients for >2 GeV/n protons and alpha-particles, data from the Chicago instrument on board IMP-8 and the neutron monitor network have been used to determine the corresponding time profiles at Earth. We obtain a spatial distribution at solar maximum which differs greatly from the solar minimum distribution. A steady-state approximation, which was characterized by a small radial and significant latitudinal gradient at solar minimum, was interchanged with a highly variable one with a large radial and a small – consistent with zero – latitudinal gradient. A significant deviation from a spherically symmetric cosmic ray distribution following the reversal of the solar magnetic field in 2000/2001 has not been observed yet. A small deviation has only been observed at northern polar regions, showing an excess of particles instead of the expected depression. This indicates that the reconfiguration of the heliospheric magnetic field, caused by the reappearance of the northern polar coronal hole, starts dominating the modulation of galactic cosmic rays already at solar maximum.Key words. Interplanetary physics (cosmic rays; energetic particles) – Space plasma physics (charged particle motion and acceleration)

scholarly journals Solar minimum spectra of galactic cosmic rays and their implications for models of the near-Earth radiation environment

2001 ◽  
Vol 106 (A12) ◽  
pp. 29979-29987 ◽  
Author(s):  
A. J. Davis ◽  
R. A. Mewaldt ◽  
C. M. S. Cohen ◽  
A. C. Cummings ◽  
J. S. George ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Solar Minimum ◽  
Galactic Cosmic Rays ◽  
Radiation Environment ◽  
Earth Radiation

Anomalous and Galactic Cosmic Rays at 1 AU During the Cycle 23/24 Solar Minimum

2011 ◽  
Vol 176 (1-4) ◽  
pp. 253-263 ◽  
Author(s):  
R. A. Leske ◽  
A. C. Cummings ◽  
R. A. Mewaldt ◽  
E. C. Stone
Keyword(s):  
Cosmic Rays ◽  
Solar Minimum ◽  
Galactic Cosmic Rays

Cosmic ray modulation in high and middle latitudes during solar cycles 22 and 23

2015 ◽  
Vol 93 (1) ◽  
pp. 100-104 ◽  
Author(s):  
Kingsley Chukwudi Okpala ◽  
Francisca Nneka Okeke ◽  
Anselem Ikechukwu Ugwuoke
Keyword(s):  
Cosmic Rays ◽  
Dynamic Pressure ◽  
Cosmic Ray ◽  
Galactic Cosmic Rays ◽  
Proton Density ◽  
Solar Cycles ◽  
Middle Latitudes ◽  
Cosmic Ray Modulation ◽  
Interaction Regions

Galactic cosmic rays are modulated in the heliosphere primarily by the global merged interaction regions with intense magnetic fields, which leads to a decrease in galactic cosmic rays throughout the heliosphere. Using long-term averages of solar wind (SW) component parameters in addition to cosmic ray count rates of four neutron monitors with different rigidity cutoffs, we analyzed the effect of these SW components on the count rates under different interplanetary magnetic field (IMF) disturbance levels. From first-order partial correlation, we found that the IMF-B was the most dominant modulating parameter, especially during quiet conditions and the SW dynamic pressure was more effective during disturbed conditions. The influence of more subtle parameters like wind speed, Bz component, and proton density were masked by these dominant parameters: IMF total B, and SW dynamic pressure.

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