The heliospheric structure during the recent solar minimum: shocks in the lower corona and the magnetic field structure in the heliosheath

In this talk we review the recent heliospheric structure as affected by the recent solar minimum. We will focus especially on two frontiers areas: a) evolution of shocks in the lower corona and b) the heliosheath. In particular, we will focus on how the recent extended minimum allowed us to separate spatial and temporal effects in the outer heliosphere. We will describe new phenomena that we were able to explore, the reconnection of the sectored magnetic field in the heliosheath. Very little is known on how shocks thought to be driven by CMEs, form and evolve in the lower corona. This is a crucial area since its has been shown by observations that they form low in the corona (1-4Rs) and coincide with the acceleration to GeV energies. We will describe our recent attempts (e.g., Evans et al. 2011; Das et al.; 2011) to uncover the evolution of CMEs at these locations. All the current global models of the heliosphere are based on the assumption that the magnetic field in the heliosheath, in the region close to the heliopause is laminar and connect back to the Sun. We argue recently, based on Voyager observations that in that region the heliospheric magnetic field is not laminar but instead consists of magnetic bubbles, or magnetic structures disconnected from the Sun (Opher et al. 2011). The consequence is that the heliopause might be a porous membrane instead of a shield. As the sun increased its activity, it will be more complicated to disentangle temporal from spatial and global structure. We will comment on how the increased solar activity might affect the sector structure in the heliosheath as well as the implication for our understanding of how galactic cosmic rays enter the heliosphere. Due to the slow flows in the heliosheath, the heliosheath has a long time memory of solar activity. Moreover, Corotating Interaction Regions and Global Merged Interacting Regions are known to disturb the termination shock and heliopause as well as the heliosheath flows and fields. For example it is still poorly understood how temporal effects propagate in the heliosheath and affect the level of turbulence. We will present some of our recent work trying to understand how temporal effects, such as CIRs propagates from the sun into the outer heliosphere.