scholarly journals DISTURBED MAGNETOSPHERE ON NOVEMBER 7–8, 2004AND VARIATIONS OF COSMIC RAY CUTOFF RIGIDITY: LATITUDE EFFECTS

2020 ◽  
Vol 6 (3) ◽  
pp. 40-47
Author(s):  
Olga Danilova ◽  
Natalia Ptitsyna ◽  
Marta Tyasto ◽  
Valeriy Sdobnov
Keyword(s):  
Magnetic Field ◽  
Interplanetary Magnetic Field ◽  
Neutron Monitor ◽  
Cosmic Ray ◽  
Recovery Phase ◽  
Survey Method ◽  
Cutoff Rigidity ◽  
Strong Magnetic Storm ◽  
Current Systems ◽  
Activity Indices

We have studied the latitude behavior of cosmic ray cutoff rigidity and their sensitivity to Bz and By components of the interplanetary magnetic field and geomagnetic activity indices Dst and Kp for different phases of the November 7–8, 2004 strong magnetic storm. Cutoff rigidities have been calculated using two methods: the spectrographic global survey method in which the cutoff rigidity is determined from observational data, acquired by the neutron monitor network, and the method in which particle trajectories are calculated numerically in a model magnetic field of the magnetosphere. We have found that the sensitivity of observed cutoff rigidities to Dst changes with latitude (threshold rigidity of stations) is in antiphase with changes in the sensitivity to By. During the recovery phase of the storm, the Dst correlation with By is significantly greater than that with Bz, and the Kp correlation with Bz is greater than that with By. The By component is shown to be a predominant driver of the current systems that determine the Dst evolution during the recovery phase.

scholarly journals DISTURBED MAGNETOSPHERE ON NOVEMBER 7–8, 2004AND VARIATIONS OF COSMIC RAY CUTOFF RIGIDITY: LATITUDE EFFECTS

2020 ◽  
Vol 6 (3) ◽  
pp. 34-39
Author(s):  
Olga Danilova ◽  
Natalia Ptitsyna ◽  
Marta Tyasto ◽  
Valeriy Sdobnov
Keyword(s):  
Magnetic Field ◽  
Interplanetary Magnetic Field ◽  
Neutron Monitor ◽  
Cosmic Ray ◽  
Recovery Phase ◽  
Survey Method ◽  
Cutoff Rigidity ◽  
Strong Magnetic Storm ◽  
Current Systems ◽  
Activity Indices

We have studied the latitude behavior of cosmic ray cutoff rigidity and their sensitivity to Bz and By components of the interplanetary magnetic field and geomagnetic activity indices Dst and Kp for different phases of the November 7–8, 2004 strong magnetic storm. Cutoff rigidities have been calculated using two methods: the spectrographic global survey method in which the cutoff rigidity is determined from observational data, acquired by the neutron monitor network, and the method in which particle trajectories are calculated numerically in a model magnetic field of the magnetosphere. We have found that the sensitivity of observed cutoff rigidities to Dst changes with latitude (threshold rigidity of stations) is in antiphase with changes in the sensitivity to By. During the recovery phase of the storm, the Dst correlation with By is significantly greater than that with Bz, and the Kp correlation with Bz is greater than that with By. The By component is shown to be a predominant driver of the current systems that determine the Dst evolution during the recovery phase.

The second spherical harmonic of the diurnal variation and the orientation of the interplanetary magnetic field

1968 ◽  
Vol 46 (10) ◽  
pp. S973-S975 ◽  
Author(s):  
G. V. Skeipin ◽  
P. A. Krivoshapkin ◽  
G. F. Krymsky ◽  
A. I. Kuzmin
Keyword(s):  
Magnetic Field ◽  
Diurnal Variation ◽  
Interplanetary Magnetic Field ◽  
Neutron Monitor ◽  
Spherical Harmonic ◽  
Cosmic Ray ◽  
Vector Information ◽  
Neutron Monitor Data ◽  
Distribution Vector ◽  
Monitor Data

The super neutron monitor data from Goose Bay and Deep River for 1965 have been analyzed to give month-to-month changes of the first and second harmonics of the solar-diurnal variation. Using these results together with various suppositions about the nature of the cosmic-ray distribution vector, information is obtained concerning the orientation of the interplanetary magnetic field.

Variations of geomagnetic thresholds of cosmic rays and magnetospheric parameters during different phases  of the storm of November 20, 2003

2021 ◽  
Author(s):  
Elena Vernova ◽  
Natalia Ptitsyna ◽  
Olga Danilova ◽  
Marta Tyasto
Keyword(s):  
Solar Wind ◽  
Cosmic Rays ◽  
Hysteresis Loop ◽  
Magnetic Storm ◽  
Cosmic Ray ◽  
Recovery Phase ◽  
Main Phase ◽  
Cutoff Rigidity ◽  
The Relationship ◽  
Current Systems

<div> <p>The correlations between variations in the geomagnetic cutoff rigidity of cosmic rays and the Dst and Kp geomagnetic indices and solar-wind and IMF parameters are calculated for the three phases of the magnetic storm of November 20–21, 2003: before the storm and during its main and recovery phases. The correlations are the strongest between variations in the cutoff rigidity and the Dst index during all stages. A significant correlation was recorded with the By component of IMF and the field magnitude B; the correlation with By dominated during the main phase, and the correlation with B was dominant during the recovery phase. There is also a high correlation with the dynamic parameters of solar activity during the main phase, especially with the solar-wind speed.</p> <div> <p>As far as we know, hysteresis phenomena have been discovered for the first time in the relationship between the cosmic-ray cutoff rigidities and the parameters of the helio- and magnetosphere on the scale of the magnetic storm (with Moscow station as an example). Loop-like patterns formed, because the trajectories of variations in the cutoff rigidities versus the studied parameters during storm intensification (development of current systems) did not coincide with the trajectories during the recovery phase (decay of current systems). The correlations of the cutoff rigidities with Dst and Kp indices were characterized by a narrow hysteresis loop, and their correlations with the IMF parameters were characterized by a wide hysteresis loop. The hysteresis loops for the relationship between the cutoff rigidities and solar-wind density and pressure were disordered.</p> </div> </div>

scholarly journals Variations in cosmic ray cutoff rigidities during the greatgeomagnetic storm of November 2004

10.12737/7890 ◽  
2015 ◽  
Vol 1 (2) ◽  
pp. 97-105 ◽  
Author(s):  
Марта Тясто ◽  
Marta Tyasto ◽  
Ольга Данилова ◽  
Olga Danilova ◽  
Наталия Птицына ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Correlation Coefficients ◽  
Cosmic Ray ◽  
Survey Method ◽  
Cutoff Rigidity ◽  
Low Latitude ◽  
Inner Magnetosphere ◽  
Global Survey ◽  
Dst Index ◽  
Tracing Method

Very strong interplanetary and magnetospheric disturbance observed on 7–13 November 2004 can be regarded as one of the strongest events during the entire period of space observations. In this paper, we report on the studies of cosmic ray cutoff rigidity variations during 7–13 November 2004 showing how storm conditions can affect the direct cosmic ray access to the inner magnetosphere. Effective cutoff rigidities have been calculated for selected points on the ground by tracing trajectories of cosmic ray particles through the magnetospheric magnetic field of the “storm-oriented” Tsyganenko 2003 model [Tsyganenko, 2002a, b; Tsyganenko et al., 2003]. Cutoff rigidity variations have also been determined by the spectrographic global survey method on the basis of experimental data of the neutron monitor network. Correlations between the calculated and experimental cutoff rigidities, as well as between geomagnetic Dst index and interplanetary parameters have been investigated. Correlation coefficients between the cutoff rigidities obtained by the trajectory tracing method and the spectrographic global survey method have been found to be in the limits of 0.76–0.89 for all stations except the low-latitude station Tokyo (0.35). The most pronounced correlation has been revealed between the cutoff rigidities that exhibited a very large variation of 1–1.5 GV during the magnetic storm, and the Dst index.

Periodic cosmic-ray variations associated with the sector structure of the interplanetary magnetic field

1968 ◽  
Vol 46 (10) ◽  
pp. S966-S969 ◽  
Author(s):  
V. L. Patel ◽  
R. L. Chasson
Keyword(s):  
Magnetic Field ◽  
Interplanetary Magnetic Field ◽  
Neutron Monitor ◽  
Cosmic Ray ◽  
Sector Structure ◽  
Cosmic Ray Intensity ◽  
The Earth ◽  
Neutron Monitor Data ◽  
Monitor Data

Observations by IMP-1 satellite have established that the interplanetary magnetic field is divided into sectors of opposing polarity. These observations have been confirmed by observations with IMP-2 and Mariner 4. The effect of this sector structure on the cosmic-ray intensity observed on the earth has been studied using daily averages of pressure-corrected neutron monitor data from several locations. These data have been analyzed using the method of superposition of epochs, beginning at the edge of the observed sector. The results indicate periodic variations of 6–8-day periods and 0.5 to 1.0% amplitude in cosmic-ray intensity, associated with the passage of positive and negative sectors moving past the earth, including a weak recurrence at 27 days. Theoretical implications of these observations are discussed.

Correlation between the variations of cosmic ray geomagnetic thresholds and interplanetary parameters during various phases of solar disturbance in November 2004

2020 ◽  
Author(s):  
Elena Vernova ◽  
Natalia Ptitsyna ◽  
Olga Danilova ◽  
Marta Tyasto
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Magnetic Fields ◽  
Interplanetary Magnetic Field ◽  
Particle Flux ◽  
Cosmic Ray ◽  
Dynamic Interaction ◽  
Cutoff Rigidity ◽  
Geomagnetic Cutoff Rigidity ◽  
Geomagnetic Cutoff

<p>The geomagnetic cutoff rigidity R (momentum per unit charge) is the threshold rigidity below which the particle flux becomes zero due to geomagnetic shielding. The properties of the geomagnetic screen vary greatly during magnetic storms, depending on the dynamic interaction of the solar wind (SW) magnetic fields with the magnetospheric fields and currents. The correlation between the variations of geomagnetic cutoff rigidity ΔR and interplanetary parameters and geomagnetic activity indexes during various phases of the superstorm on November 7 – 8, 2004 has been calculated. On the scale of the entire storm the most geoeffеctive parameters were Dst, Kp, and SW speed, while other parameters, including total interplanetary magnetic field B and Bz component, were effective at different phases of the storm.</p>

scholarly journals Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the Sun

2018 ◽  
Vol 120 (3) ◽  
Author(s):  
M. Amenomori ◽  
X. J. Bi ◽  
D. Chen ◽  
T. L. Chen ◽  
W. Y. Chen ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Interplanetary Magnetic Field ◽  
Magnetic Field Strength ◽  
Cosmic Ray ◽  
The Sun

scholarly journals Kinematic models of the interplanetary magnetic field

2019 ◽  
Vol 37 (3) ◽  
pp. 299-314 ◽  
Author(s):  
Christoph Lhotka ◽  
Yasuhito Narita
Keyword(s):  
Magnetic Field ◽  
Interplanetary Magnetic Field ◽  
Current Knowledge ◽  
Cosmic Ray ◽  
Charged Dust ◽  
Cosmic Ray Modulation ◽  
Latitudinal Dependence ◽  
Magnetic Field Model ◽  
Kinematic Models ◽  
Turbulence Effect

Abstract. Current knowledge on the description of the interplanetary magnetic field is reviewed with an emphasis on the kinematic approach as well as the analytic expression. Starting with the Parker spiral field approach, further effects are incorporated into this fundamental magnetic field model, including the latitudinal dependence, the poleward component, the solar cycle dependence, and the polarity and tilt angle of the solar magnetic axis. Further extensions are discussed in view of the magnetohydrodynamic treatment, the turbulence effect, the pickup ions, and the stellar wind models. The models of the interplanetary magnetic field serve as a useful tool for theoretical studies, in particular on the problems of plasma turbulence evolution, charged dust motions, and cosmic ray modulation in the heliosphere.

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