Study of heliospheric disturbances on the basis of cosmic ray muon flux anisotropy

Abstract

IntroductionThe influence of the solar activity on heliospheric and magnetospheric processes is studied with the use of various equipments placed on satellites as well as on the surface of the Earth. As a result of these studies, a vast experimental material has been accumulated and some of relationships between the processes occurring on the Sun and in the heliosphere and the magnetosphere of the Earth have been established. Application of cosmic rays for such studies is of a great importance since cosmic ray particles propagate with the speed close to the speed of light that far exceeds the rate of propagation of any heliospheric disturbances. The usage of the muon component generated by primary cosmic-ray particles for this purpose is of a special interest since muons maintain the direction of the primary particles. Muon hodoscope URAGAN [1] registers the flux of cosmic-ray muons on the surface of the Earth simultaneously from various directions that allows to carry out the spatial and angular measurements of cosmic ray modulation in near-Earth space and study the muon flux variation dynamics in a wide range of zenith and azimuth angles with a single device. This, in its turn, allows studying the anisotropy of the muon flux caused by various disturbances of the heliospheric origin, and anisotropy observations may provide additional information about the nature of these disturbances much earlier than these disturbances reach the space vehicles operating near the Earth.This work is a continuation of the research initiated in 2007 [2], but the technique of the analysis has been significantly modified. Variations of the anisotropy of the muon flux during 2011 which is characterized by a considerable increase of the solar activity have been analyzed.

Experimental Data of Muon Hodoscope URAGAN for Investigations of Geoffective Processes in the Heliosphere

“…Therefore, variations of primary CR caused by various phenomena associated with solar activity may be studied on the basis of the analysis of variations of the angular distribution of the muon flux measured in a real-time mode. This approach is the basis of the method of muon diagnostics developed in the Moscow Engineering Physics Institute using a specially designed muon hodoscope URAGAN (Shutenko et al 2009;Astapov et al 2013). Objects of the muon diagnostics are processes in the heliosphere of solar origin, which may cause negative influence on the vital activity of people (transpolar flights, orbital and interplanetary missions, and others).…”