scholarly journals The heliospheric magnetic flux, solar wind proton flux, and cosmic ray intensity during the coming solar minimum

Space Weather ◽  
2014 ◽  
Vol 12 (7) ◽  
pp. 499-507 ◽  
Author(s):  
Charles W. Smith ◽  
K. G. McCracken ◽  
Nathan A. Schwadron ◽  
Molly L. Goelzer
Keyword(s):  
Solar Wind ◽  
Magnetic Flux ◽  
Solar Minimum ◽  
Cosmic Ray ◽  
Proton Flux ◽  
Solar Wind Proton ◽  
Cosmic Ray Intensity

scholarly journals Responses and Periodic Variations of Cosmic Ray Intensity and Solar Wind Speed to Sunspot Numbers

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Jacob Oloketuyi ◽  
Yu Liu ◽  
Amobichukwu Chukwudi Amanambu ◽  
Mingyu Zhao
Keyword(s):  
Solar Wind ◽  
Wind Speed ◽  
Solar Wind Speed ◽  
Phase Relationship ◽  
Cosmic Ray ◽  
Strong Negative Correlation ◽  
Cosmic Ray Intensity ◽  
Sunspot Numbers ◽  
Daily Data ◽  
Wide Range

To investigate the periodic behaviour and relationship of sunspot numbers with cosmic ray intensity and solar wind speed, we present analysis from daily data generated from 1995 January to 2018 December. Cross-correlation and wavelet transform tools were employed to carry out the investigation. The analyses confirmed that the cosmic ray intensity correlates negatively with the sunspot numbers, exhibiting an asynchronous phase relationship with a strong negative correlation. The trend in cosmic ray intensity indicates that it undergoes the 11-year modulation that mainly depends on the solar activity in the heliosphere. On the other hand, the solar wind speed neither shows a clear phase relationship nor correlates with the sunspot numbers but shows a wide range of periodicities that could possibly be connected to the pattern of coronal hole configuration. A number of short and midterm variations were also observed from the wavelet analysis, i.e., 64–128 and 128–256 days for the cosmic ray intensity, 4–8, 32–64, 128–256, and 256–512 days for the solar wind speed, and 16–32, 32–64, 128–256, and 256–512 days for the sunspot numbers.

Solar Wind Effects on the Transport of 3–10 MeV Cosmic‐Ray Electrons from Solar Minimum to Solar Maximum

2003 ◽  
Vol 594 (1) ◽  
pp. 552-560 ◽  
Author(s):  
S. E. S. Ferreira ◽  
M. S. Potgieter ◽  
D. M. Moeketsi ◽  
B. Heber ◽  
H. Fichtner
Keyword(s):  
Solar Wind ◽  
Solar Minimum ◽  
Solar Maximum ◽  
Cosmic Ray ◽  
Wind Effects

Neutron monitor latitude survey of cosmic ray intensity during the 1986/1987 solar minimum

1989 ◽  
Vol 94 (A2) ◽  
pp. 1459 ◽  
Author(s):  
H. Moraal ◽  
M. S. Potgieter ◽  
P. H. Stoker ◽  
A. J. van der Walt
Keyword(s):  
Neutron Monitor ◽  
Solar Minimum ◽  
Cosmic Ray ◽  
Cosmic Ray Intensity

Solar wind proton flux extremes and their association with pseudostreamers

2013 ◽  
Author(s):  
Liang Zhao ◽  
Sarah E. Gibson ◽  
Lennard A. Fisk
Keyword(s):  
Solar Wind ◽  
Proton Flux ◽  
Solar Wind Proton

scholarly journals The Galactic cosmic ray intensity at the evolving Earth and young exoplanets

2020 ◽  
Author(s):  
Donna Rodgers-Lee ◽  
Aline Vidotto ◽  
Andrew Taylor ◽  
Paul Rimmer ◽  
Turlough Downes
Keyword(s):  
Solar Wind ◽  
Cosmic Rays ◽  
Cosmic Ray ◽  
Galactic Cosmic Rays ◽  
The Sun ◽  
Cosmic Ray Intensity ◽  
Chemical Signature ◽  
Exoplanetary Systems ◽  
Life On Earth ◽  
Galactic Cosmic Ray

<p>Cosmic rays may have contributed to the start of life on Earth. Cosmic rays also influence and contribute to atmospheric electrical circuits, cloud cover and biological mutation rates which are important for the characterisation of exoplanetary systems. The flux of Galactic cosmic rays present at the time when life is thought to have begun on the young Earth or in other young exoplanetary systems is largely determined by the properties of the stellar wind. </p> <p>The spectrum of Galactic cosmic rays that we observe at Earth is modulated, or suppressed, by the magnetised solar wind and thus differs from the local interstellar spectrum observed by Voyager 1 and 2 outside of the solar system. Upon reaching 1au, Galactic cosmic rays subsequently interact with the Earth’s magnetosphere and some of their energy is deposited in the upper atmosphere. The properties of the solar wind, such as the magnetic field strength and velocity profile, evolve with time. Generally, young solar-type stars are very magnetically active and are therefore thought to drive stronger stellar winds. </p> <p>Here I will present our recent results which simulate the propagation of Galactic cosmic rays through the heliosphere to the location of Earth as a function of the Sun's life, from 600 Myr to 6 Gyr, in the Sun’s future. I will specifically focus on the flux of Galactic cosmic rays present at the time when life is thought to have started on Earth (~1 Gyr). I will show that the intensity of Galactic cosmic rays which reached the young Earth, by interacting with the solar wind, would have been greatly reduced in comparison to the present day intensity. I will also discuss the effect that the Sun being a slow/fast rotator would have had on the flux of cosmic rays reaching Earth at early times in the solar system's life.</p> <p>Despite the importance of Galactic cosmic rays, their chemical signature in the atmospheres’ of young Earth-like exoplanets may not be observable with instruments in the near future. On the other hand, it may instead be possible to detect their chemical signature by observing young warm Jupiters. Thus, I will also discuss the HR 2562b exoplanetary system as a candidate for observing the chemical signature of Galactic cosmic rays in a young exoplanetary atmosphere with upcoming missions such as JWST.</p>

scholarly journals Study of the Very Slow Speed Solar Wind Streams with Cosmic Ray Intensity and Ae Index for Solar Cycle 24 (2008-2013)

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Meena Pokharia ◽  
Lalan Prasad
Keyword(s):  
Solar Wind ◽  
Solar Cycle ◽  
Cosmic Ray ◽  
Magnetic Activity ◽  
Slow Speed ◽  
Cosmic Ray Intensity ◽  
Ae Index ◽  
Solar Cycle 24 ◽  
Speed Solar Wind ◽  
Cycle 24

The aim of this paper is to investigate the association of the variation of very slow speed solar wind streams (VSSSWS) with the cosmic ray intensity (CRI) and Ae index for solar cycle 24 (2008-2013). A Chree analysis by the superposed epoch method has been done in the study. The results of the present analysis showed that VSSSWS are not able to produce decreases in CRI. The prime source of the variation in magnetic activity near aurora zone is the wind interaction with the magnetosphere, but the speed of VSSSWS is low enough to produce any significant impact on aurora zone magnetic activity.

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