Coherent and large scale structures in the solar wind, their associated driven shocks, and effects on galactic cosmic rays

DASSO, S.

Córdoba

Conferencia; 6th Friend of Friends meeting; 2016

The Sun is a variable star and its magnetic activity has important consequences over the variability of physical properties in the solar wind.In particular, as a consequence of plasma instabilities, large amounts of mass, magnetic flux, and magnetic helicity, are erupted into the interplanetary medium during huge solar explosions.When observed in the solar corona, the structures formed during these impulsive events are called Coronal Mass Ejections (CMEs).When they are in situ observed by spacecraft in the interplanetary medium they are termed Interplanetary CMEs (ICMEs).Interplanetary magnetic clouds (MCs) are a very important subset of ICMEs, showing a particular internal magnetic field configuration, consistent with the presence of a coherent magnetic flux rope. Then, MCs are coherent and large scale structures that travel from the Sun to the outer heliosphere.Furthermore, faster (super-Alfvenic and super-sonic) MCs can drive interplanetary shocks, which can strongly affect the transport of energetic particles (both, solar and galactic origin).From the study of a large number of MCs observed in the past years, we significantly enlarged the knowledge of several of their properties, such as:the identification of their sub-structures, their local properties, their global 3D structure in the heliosphere, the amount of MHD quantities transported in the solar wind by the carried flux ropes, how the plasma and magnetic field are distributed inside these astrophysical objects, their effects on the transport of galactic cosmic rays, etc.In the present talk I will present a general review of these aspects of MCs and also the recent results obtained by our group. I will also present recently developed programs inside two international collaborations (in which Argentina participates): (1) the Pierre Auger Observatory (PAO) and (2) the Latin American Giant Observatory (LAGO).Both of them study effects of these interplanetary structures on the heliospheric transport of galactic cosmic rays.