Prediction of daily average solar wind velocity from solar magnetic field observations using hybrid intelligent systems

1997 ◽  
Vol 22 (7-8) ◽  
pp. 617-622 ◽  
Author(s):  
P. Wintoft ◽  
H. Lundstedt
2020 ◽  
Vol 2 (4) ◽  
Author(s):  
Amaechi Onele Azi ◽  
Godwin Amaechi Agbo ◽  
Uche Daniel Aluge ◽  
Tamunoimi Michael Abbey ◽  
Chijioke A Egbo

The influence of distant parameters on the horizontal component of magnetic field was investigated for two years within two locations in Africa. The measure of storm occurrence (Dst-index) was used to select successful storm days. The effect of distant parameters on residual field was investigated using filter analysis. This study was considered on both time domain and frequency domain. The results showed very close correspondence of rapid changes in amplitudes between residual H–component and the selected IMF parameters especially the solar wind velocity, proton density and Bz. The correlation analysis between the distant parameters and residual H–component completely revealed effective dependence of the depression of residual field on the selected parameters. The value of the correlation coefficient (r) with solar wind velocity, proton density and Bz showed significant values of the range of 0.5 and above. This is direct evidence that Solar wind velocity, proton density and Bz are more effective in causing geomagnetic fluctuations at equatorial low latitude stations.


2012 ◽  
Vol 49 (7) ◽  
pp. 1198-1202 ◽  
Author(s):  
M. Youssef ◽  
A. Mahrous ◽  
R. Mawad ◽  
E. Ghamry ◽  
M. Shaltout ◽  
...  

2019 ◽  
Vol 5 (3) ◽  
pp. 50-63
Author(s):  
Дмитрий Ерофеев ◽  
Dmitry Erofeev

Using data with hourly resolution obtained in near-Earth heliosphere in 1965–2014, we have calculated statistical characteristics of the angles describing the direction of the interplanetary magnetic field (IMF): root-mean-square deviations of azimuthal and elevation angles, asymmetries of their distributions, and coefficient of correlation of the angles. It has been shown that the above characteristics varied in the course of solar cycle, and some of them changed their signs when solar polar magnetic field reversed. The results obtained from the experimental data analysis were compared with a model describing transport of large-scale disturbances of IMF lines by the inhomogeneous solar wind. The comparison has shown that the variations in the angular distribution of IMF in the course of solar cycle probably occur due to the appearance of the large-scale latitudinal gradient of solar wind velocity during solar minima. In addition, the angular distribution of IMF has been found to be substantially affected by the longitudinal velocity gradient in trailing parts of high-speed streams and short-term local-scale variations in velocity gradients.


Author(s):  
Pandey A.C. ◽  
◽  
Sham Singh ◽  
Dinesh Kumar Pathak ◽  
Archana Shukla ◽  
...  

Yearly averages of geomagnetic activity indices Kp and Ap for the years 1984 to 2018 be compared to the relevant averages of VxBs, where V is the solar wind velocity and Bs is the southward interplanetary magnetic field (IMF) component. The correlation of both quantities is known to be rather good. Comparing the averages of Ap and Kp with V and Bs separately. We found that, during the declining phase of solar cycle, V and during the ascending phase Bs have more influence on Ap and Kp indices. According to this observation the 27 days and semiannual, Ap and Kp variations be analysed discretely for years after and before sunspot minima. The time intervals prior to sunspot minima with a significant 27-day recurrent period of the IMF structure and those intervals after sunspot minima with a significant 28 to28.5 day recurrent phase of the structure be used. The averaged spectra of the two Ap and Kp data sets obviously show a period of 27 days before and a period of 28 to 29 days after sunspot minimum.


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