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.

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.

scholarly journals Monitoring of geomagnetic disturbances using the global survey method in real time

2019 ◽  
Vol 5 (3) ◽  
pp. 93-97 ◽  
Author(s):  
Владислав Григорьев ◽  
Vladislav Grigoryev ◽  
Сергей Стародубцев ◽  
Sergei Starodubtsev ◽  
Петр Гололобов ◽  
...  
Keyword(s):  
Real Time ◽  
Geomagnetic Storms ◽  
Interplanetary Medium ◽  
Three Dimensional ◽  
Cosmic Ray ◽  
Temporal Variations ◽  
Survey Method ◽  
Geomagnetic Disturbances ◽  
Global Survey ◽  
Worldwide Network

A method for forecasting geomagnetic storms using the realization of the global survey method in real time is presented. The method is based on data from the worldwide network of neutron monitors NMDB. Using this method, we analyze the behavior of components of three-dimensional angular distribution of cosmic rays in the interplanetary medium, which were due to the first two spherical harmonics, over the period from 2013 to 2018. We have established that the main parameters that respond to the arrival of geoeffective disturbances of the interplanetary medium at Earth are changes in amplitudes of zonal (north-south) components of cosmic ray distribution. In order to select effective criteria for identifying predictors of geomagnetic disturbances and their possible temporal variations, we have made a retrospective analysis of the relationship between behaviors of the above components and geomagnetic disturbances occurring during the period of interest.

scholarly journals REAL-TIME MONITORING OF COSMIC RAY ANISOTROPY PARAMETERS AND SHORT-TERM FORECASTING OF GEOMAGNETIC DISTURBANCES

2020 ◽  
pp. 37-39
Author(s):  
Anton Zverev ◽  
Vladislav Grigoryev ◽  
Peter Gololobov ◽  
Sergei Starodubtsev
Keyword(s):  
Real Time ◽  
Cosmic Ray ◽  
Geomagnetic Disturbance ◽  
Survey Method ◽  
Geomagnetic Disturbances ◽  
Global Survey ◽  
Measured Time ◽  
Distribution Parameters ◽  
Using Data ◽  
Short Term Forecasting

SB RAS, using data from the NMDB database, has implemented continuous monitoring of the dynamics of cosmic ray (CR) distribution parameters and the automatic forecasting of geomagnetic disturbance. Monitoring is based on the global survey method, which considers the world-wide network of neutron monitors as a single device oriented in different directions at each measured time. This method provides real-time parameters of nine components of the first two angular moments of the CR distribution function for each hour of observation. This paper discusses methodological aspects related to the use of the global survey method and some results of the forecasting of geomagnetic disturbances for 2017–2018.

scholarly journals REAL-TIME MONITORING OF COSMIC RAY ANISOTROPY PARAMETERS AND SHORT-TERM FORECASTING OF GEOMAGNETIC DISTURBANCES

2020 ◽  
Vol 6 (4) ◽  
pp. 42-45
Author(s):  
Anton Zverev ◽  
Vladislav Grigoryev ◽  
Peter Gololobov ◽  
Sergei Starodubtsev
Keyword(s):  
Real Time ◽  
Cosmic Ray ◽  
Geomagnetic Disturbance ◽  
Survey Method ◽  
Geomagnetic Disturbances ◽  
Global Survey ◽  
Measured Time ◽  
Distribution Parameters ◽  
Using Data ◽  
Short Term Forecasting

SB RAS, using data from the NMDB database, has implemented continuous monitoring of the dynamics of cosmic ray (CR) distribution parameters and the automatic forecasting of geomagnetic disturbance. Monitoring is based on the global survey method, which considers the world-wide network of neutron monitors as a single device oriented in different directions at each measured time. This method provides real-time parameters of nine components of the first two angular moments of the CR distribution function for each hour of observation. This paper discusses methodological aspects related to the use of the global survey method and some results of the forecasting of geomagnetic disturbances for 2017–2018.

The Global Survey Method Applied to Ground-level Cosmic Ray Measurements

Solar Physics ◽  
2018 ◽  
Vol 293 (4) ◽  
Author(s):  
A. Belov ◽  
E. Eroshenko ◽  
V. Yanke ◽  
V. Oleneva ◽  
A. Abunin ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Ground Level ◽  
Survey Method ◽  
Global Survey

scholarly journals Influence of the terrestrial magnetic field geometry on the cutoff rigidity of cosmic ray particles

2013 ◽  
Vol 31 (10) ◽  
pp. 1637-1643 ◽  
Author(s):  
K. Herbst ◽  
A. Kopp ◽  
B. Heber
Keyword(s):  
Magnetic Field ◽  
Geographical Location ◽  
Cosmic Ray ◽  
Virgin Islands ◽  
Cutoff Rigidity ◽  
Earth’S Magnetic Field ◽  
Simple Geometry ◽  
Earth's Magnetic Field ◽  
Field Geometry ◽  
Definition Of

Abstract. Studies of the propagation of charged energetic particles in the Earth's magnetic field go back to Carl Størmer. In the end, his investigations finally lead to the definition of the so-called cutoff rigidity RC; that is, the minimum momentum per charge a particle must have in order to reach a certain geographical location. Employing Monte Carlo simulations with the PLANETOCOSMICS code we investigate the correlation between the geomagnetic field structure and the cutoff rigidity. We show that the geometry of the magnetic field has a considerable influence on the resulting cutoff rigidity distribution. Furthermore, we will present a simple geometry-based parameter, δB, which is able to reflect the location-dependent cutoff rigidity. We show that this correlation is also visible in the temporal evolution of the Earth's magnetic field, at least over the last 100 yr. Using latitude scans with neutron monitors, changes of the relative counting rates at different positions are calculated, showing small variations for, e.g., Kiel and Moscow, while large ones occur at Mexico City as well as on the British Virgin Islands.

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 Relationship of the characteristics of large Forbush decreases and the heliolongitude of their sources

2021 ◽  
pp. 125-129
Author(s):  
Maria Papailiou ◽  
Maria Abunina ◽  
Anatoly V. Belov ◽  
Eugenia A. Eroshenko ◽  
Victor G. Yanke ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Flares ◽  
Solar Wind Speed ◽  
Cosmic Ray ◽  
Survey Method ◽  
Forbush Decreases ◽  
Solar Source ◽  
Time Profiles ◽  
Time Period ◽  
Relationship Of

In this investigation the different features and characteristics of Forbush decreases, with emphasis on large For- bush decreases (≥4%) and their association to solar sources, are being examined. According to the heliolongitude of the solar source, the events under study were separated into three subcategories: western (21º ≤ heliolongitude ≤ 60º), eastern (-60º ≤ heliolongitude ≤ -21º) and central (-20º ≤ heliolongitude ≤ 20º). The selected events cover the time period 1967 - 2017. The ‘Global Survey Method’ was used for analyzing the Forbush decreases, along with data on solar flares, solar wind speed, geomagnetic indices (Kp and Dst), and interplanetary magnetic field. In ad - dition, the superimposed epoch method was applied in order to plot the time profiles for the aforementioned group of events. This detailed analysis reveals interesting results concerning the features of cosmic ray decreases in re- gard to the heliolongitude of the solar sources. Moreover, it is also shown that large Forbush decreases, regardless of the heliolongitude of the solar source, are accompanied by increased geomagnetic activity and increased aniso- tropy, including anisotropy before the events, which can serve as a typical precursor of Forbush decreases.

scholarly journals Monitoring of geomagnetic disturbances using the global survey method in real time

2019 ◽  
Vol 5 (3) ◽  
pp. 110-115
Author(s):  
Владислав Григорьев ◽  
Vladislav Grigoryev ◽  
Сергей Стародубцев ◽  
Sergei Starodubtsev ◽  
Петр Гололобов ◽  
...  
Keyword(s):  
Real Time ◽  
Geomagnetic Storms ◽  
Interplanetary Medium ◽  
Three Dimensional ◽  
Cosmic Ray ◽  
Temporal Variations ◽  
Survey Method ◽  
Geomagnetic Disturbances ◽  
Global Survey ◽  
Worldwide Network

A method for forecasting geomagnetic storms using the realization of the global survey method in real time is presented. The method is based on data from the worldwide network of neutron monitors NMDB. Using this method, we analyze the behavior of components of three-dimensional angular distribution of cosmic rays in the interplanetary medium, which were due to the first two spherical harmonics, over the period from 2013 to 2018. We have established that the main parameters that respond to the arrival of geoeffective disturbances of the interplanetary medium at Earth are changes in amplitudes of zonal (north-south) components of cosmic ray distribution. In order to select effective criteria for identifying predictors of geomagnetic disturbances and their possible temporal variations, we have made a retrospective analysis of the relationship between behaviors of the above components and geomagnetic disturbances occurring during the period of interest.

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