Corotational solar streams and cosmic-ray diurnal anisotropy

1991 ◽  
Vol 69 (8-9) ◽  
pp. 981-983
Author(s):  
A. G. Ananth ◽  
D. Venkatesan
Keyword(s):  
Solar Activity ◽  
Magnetic Fields ◽  
Geomagnetic Activity ◽  
Cosmic Ray ◽  
Activity Cycle ◽  
Solar Activity Cycle ◽  
Detailed Comparison ◽  
Secondary Peak ◽  
Solar Magnetic Fields ◽  
Diurnal Anisotropy

A detailed comparison of the behavior of cosmic-ray diurnal anisotropy with the solar activity cycle indicates that the amplitude of the diurnal anisotropy is significantly modulated by the corotational streams that produce the secondary peak in geomagnetic activity. However, the time of the maximum of diurnal anisotropy does not show any systematic changes with solar activity but indicates a shift towards earlier hours (~12:00 LT), corresponding to the reversal of polarity of solar magnetic fields.

scholarly journals Global evolution of solar magnetic fields and prediction of activity cycles

2019 ◽  
Vol 15 (S354) ◽  
pp. 147-156
Author(s):  
Irina N. Kitiashvili
Keyword(s):  
Solar Activity ◽  
Magnetic Fields ◽  
Activity Cycle ◽  
Dynamo Model ◽  
Solar Magnetic Fields ◽  
Solar Cycles ◽  
Multiscale Dynamics ◽  
Activity Cycles ◽  
Solar Dynamics ◽  
Solar Activity Cycles

AbstractPrediction of solar activity cycles is challenging because physical processes inside the Sun involve a broad range of multiscale dynamics that no model can reproduce and because the available observations are highly limited and cover mostly surface layers. Helioseismology makes it possible to probe solar dynamics in the convective zone, but variations in differential rotation and meridional circulation are currently available for only two solar activity cycles. It has been demonstrated that sunspot observations, which cover over 400 years, can be used to calibrate the Parker-Kleeorin-Ruzmaikin dynamo model, and that the Ensemble Kalman Filter (EnKF) method can be used to link the modeled magnetic fields to sunspot observations and make reliable predictions of a following activity cycle. However, for more accurate predictions, it is necessary to use actual observations of the solar magnetic fields, which are available only for the last four solar cycles. In this paper I briefly discuss the influence of the limited number of available observations on the accuracy of EnKF estimates of solar cycle parameters, the criteria to evaluate the predictions, and application of synoptic magnetograms to the prediction of solar activity.

The change in the energy spectrum of galactic cosmic rays over the 11-year solar activity cycle

1968 ◽  
Vol 46 (10) ◽  
pp. S927-S929
Author(s):  
Yu. Stozhkov ◽  
T. N. Charakhchyan
Keyword(s):  
Diffusion Coefficient ◽  
Solar Activity ◽  
Energy Spectrum ◽  
Cosmic Rays ◽  
Cosmic Ray ◽  
Activity Cycle ◽  
Solar Activity Cycle ◽  
Galactic Cosmic Rays ◽  
Ray Diffusion

The energy spectrum of galactic cosmic rays has been investigated for various periods of the solar activity. In the framework of commonly used ideas about the mechanism of the 11-year variation according to Parker the dependence of the cosmic-ray diffusion coefficient, D, on the particle rigidity, P, was determined. For the form D ≈ vpα the parameter α is found to change during the cycle of the solar activity.[Formula: see text]

Galactic Cosmic Ray Intensity in the Upcoming Minimum of the Solar Activity Cycle

2018 ◽  
Vol 58 (2) ◽  
pp. 169-177 ◽  
Author(s):  
M. B. Krainev ◽  
G. A. Bazilevskaya ◽  
M. S. Kalinin ◽  
A. K. Svirzhevskaya ◽  
N. S. Svirzhevskii
Keyword(s):  
Solar Activity ◽  
Cosmic Ray ◽  
Activity Cycle ◽  
Solar Activity Cycle ◽  
Cosmic Ray Intensity ◽  
Galactic Cosmic Ray

scholarly journals Deriving the solar activity cycle modulation on cosmic ray intensity observed by Nagoya muon detector from October 1970 until December 2012

2016 ◽  
Vol 12 (S328) ◽  
pp. 130-133 ◽  
Author(s):  
Rafael R. S. de Mendonça ◽  
Carlos. R. Braga ◽  
Ezequiel Echer ◽  
Alisson Dal Lago ◽  
Marlos Rockenbach ◽  
...  
Keyword(s):  
Solar Activity ◽  
Cosmic Ray ◽  
Activity Cycle ◽  
Solar Activity Cycle ◽  
Atmospheric Temperature ◽  
Muon Detector ◽  
Natural Phenomena ◽  
Cosmic Ray Intensity ◽  
Temperature Changes ◽  
Muon Intensity

AbstractIt is well known that the cosmic ray intensity observed at the Earth's surface presents an 11 and 22-yr variations associated with the solar activity cycle. However, the observation and analysis of this modulation through ground muon detectors datahave been difficult due to the temperature effect. Furthermore, instrumental changes or temporary problems may difficult the analysis of these variations. In this work, we analyze the cosmic ray intensity observed since October 1970 until December 2012 by the Nagoya muon detector. We show the results obtained after analyzing all discontinuities and gaps present in this data and removing changes not related to natural phenomena. We also show the results found using the mass weighted method for eliminate the influence of atmospheric temperature changes on muon intensity observed at ground. As a preliminary result of our analyses, we show the solar cycle modulation in the muon intensity observed for more than 40 years.

Variations of the cosmic-ray intensity andK p data in the solar-activity cycle no. 19

1974 ◽  
Vol 11 (1) ◽  
pp. 29-32
Author(s):  
O. Filisetti ◽  
G. Lovera ◽  
C. Oldano ◽  
P. G. Tedde
Keyword(s):  
Solar Activity ◽  
Cosmic Ray ◽  
Activity Cycle ◽  
Solar Activity Cycle ◽  
Cosmic Ray Intensity
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