The Structure of the Heliosphere with Solar Cycle and Its Effect on the Conditions in the Local ISM
Abstract
We argued (Opher et al. 2015, Drake et al. 2015) that the magnetic tension of the solar magnetic field plays a crucial role in organizing the solar wind in the heliosheath into two jet-like structures. The heliosphere then has a "croissant"-like shape where the distance to the heliopause downtail is almost the same as towards the nose. Regardless of whether the heliospheric tail is split in two or has a long comet shape there is consensus that the magnetic field in the heliosheath behaves differently than previously expected - it has a "slinky" structure and is turbulent. In this presentation, we will discuss several aspects related with this new model. We will show that this structure persists when the solar magnetic field is treated as a dipole. We show how the heliosphere, with its "Croissant" shape, evolves when the solar wind with solar cycle conditions are included and when the neutrals are treated kinetically (with our new MHD-Kinetic code). Due to reconnection (and turbulence of the jets) there is a substantial amount of heliosheath material sitting on open field lines. We will discuss the impact of artificial dissipation of the magnetic field in driving mixing and how it evolves with the solar cycle. We will discuss as well the development of turbulence in the jets and its role in mixing the plasma in the heliosheath and LISM and controlling the global structure of the heliosphere. We will discuss how the conditions upstream of the heliosphere, in the local interstellar medium are affected by reconnection in the tail and how it evolves with solar cycle. Recently we established (Opher et al. 2017) that reconnection in the eastern flank of the heliosphere is responsible for the twist of the interstellar magnetic field (BISM) acquiring a strong east-west component as it approaches the Heliopause. Reconnection drives a rotational discontinuity (RD) that twists the BISM into the -T direction and propagates upstream in the interstellar medium toward the nose. The consequence is that the N component of BISM is reduced in a band upstream of the HP. We show how the location of the RD upstream of the heliopause is affected by the solar cycle.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFMSH54B..04O
- Keywords:
-
- 2104 Cosmic rays;
- INTERPLANETARY PHYSICS;
- 2124 Heliopause and solar wind termination;
- INTERPLANETARY PHYSICS;
- 2126 Heliosphere/interstellar medium interactions;
- INTERPLANETARY PHYSICS;
- 2144 Interstellar gas;
- INTERPLANETARY PHYSICS