Cosmic ray modulations related to the interplanetary magnetic field intensity

1983 ◽  
Vol 88 (A4) ◽  
pp. 2973 ◽  
Author(s):  
S. P. Duggal ◽  
M. A. Pomerantz ◽  
R. K. Schaefer ◽  
C. H. Tsao
1968 ◽  
Vol 46 (10) ◽  
pp. S962-S965 ◽  
Author(s):  
Leonard F. Burlaga ◽  
Norman F. Ness

A radial gradient of the interplanetary magnetic field between 0.81 and 1.0 AU has been observed in agreement with Parker's model. The average magnitude of the magnetic field component perpendicular to the ecliptic plane was zero during 1966.Discontinuities in the direction of the magnetic field were observed when viewing on a scale of one hour; directional distributions are presented which describe the topology of these discontinuities. It was found that sometimes a large, discontinuous change in the field direction was accompanied by a dip in the field intensity; the measured minimum magnetic field intensity agrees with the value calculated from the hypothesis that the dip was the result of magnetic field annihilation. At least two of these "D-sheets" appear to be transitional regions associated with tangential discontinuities.


2008 ◽  
Vol 8 (3) ◽  
pp. 501-507 ◽  
Author(s):  
G. Prattes ◽  
K. Schwingenschuh ◽  
H. U. Eichelberger ◽  
W. Magnes ◽  
M. Boudjada ◽  
...  

Abstract. We present the results of ground-based Ultra Low Frequency (ULF) magnetic field measurements observed from June to August 2004 during the Bovec earthquake on 12 July 2004. Further we give information about the seismic activity in the local observatory region for an extended time span 2004 and 2005. ULF magnetic field data are provided by the South European Geomagnetic Array (SEGMA) where the experience and heritage from the CHInese MAGnetometer (CHIMAG) fluxgate magnetometer comes to application. The intensities of the horizontal H and vertical Z magnetic field and the polarization ratio R of the vertical and horizontal magnetic field intensity are analyzed taking into consideration three SEGMA observatories located at different close distances and directions from the earthquake epicenter. We observed a significant increase of high polarization ratios during strong seismic activity at the observatory nearest to the Bovec earthquake epicenter. Apart from indirect ionospheric effects electromagnetic noise could be emitted in the lithosphere due to tectonic effects in the earthquake focus region causing anomalies of the vertical magnetic field intensity. Assuming that the measured vertical magnetic field intensities are of lithospheric origin, we roughly estimate the amplitude of electromagnetic noise in the Earths crust considering an average electrical conductivity of <σ>=10−3 S/m and a certain distance of the observatory to the earthquake epicenter.


2018 ◽  
Vol 120 (3) ◽  
Author(s):  
M. Amenomori ◽  
X. J. Bi ◽  
D. Chen ◽  
T. L. Chen ◽  
W. Y. Chen ◽  
...  

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