Interplanetary magnetic field collimated cosmic ray flow across magnetic shock from inside of Forbush decrease, observed as local-time-dependent precursory decrease on the ground

1994 ◽  
Vol 99 (A11) ◽  
pp. 21419 ◽  
Author(s):  
K. Nagashima ◽  
K. Fujimoto ◽  
I. Morishita
Author(s):  
Dimitra Lingri ◽  
Helen Mavromichalaki ◽  
Anatoly V. Belov ◽  
Eugenia A. Eroshenko

Many previous studies have shown that before the beginning of a Forbush Decrease (FD) of the cosmic ray intensity, a precursor signal can be observed. All these surveys were focused on FDs that are associated with a sudden storm com- mencement (SSC). In this work we demonstrate that precursors could also be observed in events without a SSC that is determined by an abrupt increase of the interplanetary magnetic field. The type of precursory signals and their diversity among the events are the main purpose of this study. We try to figure out similarities and differences on the signals and the associated events from both categories in the last fifty years, from 1969 to 2019, using the same selection criteria of the under investigation FDs. Simultaneously the orientation of the upcoming solar disturbances in comparison to the way they configure the increase of the interplanetary magnetic field and create these signals are discussed.


2021 ◽  
Vol 103 (4) ◽  
Author(s):  
M. G. Aartsen ◽  
R. Abbasi ◽  
M. Ackermann ◽  
J. Adams ◽  
J. A. Aguilar ◽  
...  

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

2019 ◽  
Vol 37 (3) ◽  
pp. 299-314 ◽  
Author(s):  
Christoph Lhotka ◽  
Yasuhito Narita

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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