Geomagnetic storm-time variations in the South Atlantic Anomaly Region

Abstract. This research intends to characterize the South Atlantic Anomaly (SAA) by applying power spectrum analysis approach. From the approach, the Hurst exponent can be determined. The motivation to study the SAA region is due to its nature. A comparison was made between the stations in the SAA region and outside the SAA region during the geomagnetic storm occurrence (active period) and normal period where no geomagnetic storm occurred. The data for the occurrence of the active period was taken on 11 March 2011 while for normal period on 3 February 2011. The outcomes of the research revealed that the SAA region had a tendency to be persistent during active period and normal periods. It can be said, it experiences this characteristic because of the Earth’s magnetic field strength. Through the research, it is found that as the Earth magnetic field increases, it is likely to show an antipersistent value. This is found in the high latitude region. The lower the Earth magnetic field, the more it shows the persistent value as in the middle latitude region. In the region where the Earth magnetic field is very low like the SAA region it shows a tendency to be persistent.

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Characterization of the South Atlantic Anomaly

Nonlinear Processes in Geophysics ◽

10.5194/npg-26-25-2019 ◽

2019 ◽

Vol 26 (1) ◽

pp. 25-35

Author(s):

Khairul Afifi Nasuddin ◽

Mardina Abdullah ◽

Nurul Shazana Abdul Hamid

Keyword(s):

Magnetic Field ◽

Geomagnetic Storm ◽

South Atlantic ◽

Active Period ◽

The South ◽

Earth’S Magnetic Field ◽

South Atlantic Anomaly ◽

Normal Period ◽

Earth's Magnetic Field ◽

Latitude Region

Abstract. This research intends to characterize the South Atlantic Anomaly (SAA) by applying the power spectrum analysis approach. The motivation to study the SAA region is due to its nature. A comparison was made between the stations in the SAA region and outside the SAA region during the geomagnetic storm occurrence (active period) and the normal period where no geomagnetic storm occurred. The horizontal component of the data of the Earth's magnetic field for the occurrence of the active period was taken on 11 March 2011 while for the normal period it was taken on 3 February 2011. The data sample rate used is 1 min. The outcome of the research revealed that the SAA region had a tendency to be persistent during both periods. It can be said that the region experiences these characteristics because of the Earth's magnetic field strength. Through the research, it is found that as the Earth's magnetic field increases, it is likely to show an antipersistent value. This is found in the high-latitude region. The lower the Earth's magnetic field, the more it shows the persistent value as in the middle latitude region. In the region where the Earth's magnetic field is very low like the SAA region it shows a tendency to be persistent.

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Geomagnetic phenomena in the South Atlantic anomaly region in Brazil

Advances in Space Research ◽

10.1016/j.asr.2004.09.020 ◽

2005 ◽

Vol 36 (10) ◽

pp. 2021-2024 ◽

Cited By ~ 11

Author(s):

N.B. Trivedi ◽

B.M. Pathan ◽

Nelson J. Schuch ◽

M. Barreto ◽

L.G. Dutra

Keyword(s):

South Atlantic ◽

The South ◽

South Atlantic Anomaly ◽

Anomaly Region

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Space Weather Effects on Proton Flux Variations in the South Atlantic Anomaly: A Numerical Study performed by Test Particle Simulations

10.5194/egusphere-egu2020-1551 ◽

2020 ◽

Author(s):

Kirolosse Girgis ◽

Tohru Hada ◽

Shuichi Matsukiyo

Keyword(s):

Geomagnetic Storm ◽

Space Weather ◽

Test Particle ◽

Three Dimensional ◽

South Atlantic ◽

Proton Flux ◽

Storm Event ◽

Time Varying ◽

The South ◽

South Atlantic Anomaly

<p>In this study, we assess the hourly variations of the three-dimensional proton flux distribution inside the South Atlantic Anomaly (SAA) during a geomagnetic storm. We have developed a relativistic three-dimensional guiding center test particle simulation code in order to compute the proton trajectories in a time-varying magnetic field background provided by Tsyganenko model TS05 and the corresponding time-varying inductive electric field. The Dst index is the main input parameter to the simulation model, while the maximum proton flux, the area of the SAA calculated below a selected threshold, and the penetration depth of the protons are the main output variables investigated in this study were. Since the LEO spacecraft and human-related activities are already affected by space weather conditions, the South Atlantic Anomaly (SAA) is also believed to create an additional source of risk. As the radiation environment depends essentially on the particle flux, the objective of this study is to estimate quantitatively the proton flux variations inside the South Atlantic Anomaly (SAA) in quiet and in storm conditions. So far, it was found that after several drift periods, the protons in the South Atlantic Anomaly (SAA) could penetrate to lower altitudes during geomagnetic storm event, and that, the SAA maximum flux value and the corresponding area, varied differently with respect to altitudes. Numerical results were compared with observations by NOAA 17 and RD3R2 instrument mounted on International Space Station (ISS).</p>

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