Progress Towards Developing a Self-Consistent Model for the Production and Transport of SEPs by CME-Driven Shocks. Ilia Roussev, Igor Sokolov, Valeriy Tenishev and Tamas Gombosi University of Michigan Marty Lee, Chee Ng, Allan Tylka, and Jozsef Kóta Collaborators. Objectives. Background:
Ilia Roussev, Igor Sokolov, Valeriy Tenishev and Tamas Gombosi
University of Michigan
Marty Lee, Chee Ng, Allan Tylka, and Jozsef Kóta
Wisdom says:Vision without action is only day dreaming, while action without vision is merely passing time BUT vision with action can change the world!
Wisdom says: Life is too short to skip dessert!
This is why numerical simulations are important!
Wisdom says: By believing passionately in something that still does not exist, we create it. The nonexistent is whatever we have not sufficiently desired…
Wisdom says: Geocentric system is long dead (not egocentrism though!). Revise your stand point, broaden your scope of view, and new horizons discover you will!
Map of Production and Transport of SEPs by CME-Driven ShocksB0 (radial component) at the Sun on 2003 Oct 28 (n=90)
Computed coronal magnetic field, B0+B1, at steady-state with solar windReal Magnetic Data Drive MHD Simulations
Sheared-Arcade Production and Transport of SEPs by CME-Driven Shocks
ModelsVariety of CME Models
(Amari et al. 2000, 2003; Antiochos et al. 1999; Forbes & Isenberg 1991; Gibson & Low 1998; Kliem et al. 2004; Lin et al. 2001; Linker et al. 2001; Lynch et al. 2005; Manchester et al. 2003, 2004; Moore et al. 2001;Sturrock et al. 2001; Titov & Démoulin 1999; Tokman & Bellan 2002; Roussev et al. 2003, 2004)
Summary on existing models:
Presently, we do not have a realistic CME model at work!
BUT, there are some CME models that are inspired by real events….
Wisdom says: You have not failed yet. You have found 10,000 ways that do not apply to real world (Sun).
CME-Shock Dynamics Production and Transport of SEPs by CME-Driven Shocks
Key features of CME model
Color code represents the flow speed in a meridional plane. Black lines visualize magnetic field lines. Grid structure is shown as the yellow mesh.
Number density distribution along the same field line at the same 13 instantsFrom coupled CME-SEP Simulation of Sokolov et al. (2004)
“Realistic” Evolution of Shock Wave
Wisdom says: As far as the laws of mathematics refer to reality, they are not certain. And, as far as they are certain, they do not refer to reality.
where is the plasma density.
Note: Transformed equation depends on A SINGLE SPATIAL COORDINATE (quasi-1D). At the same time, the full 3D geometry of the IMF is preserved!
Next step is: Compute the scalar diffusion coefficient, D, in a self-consistent manner by taking into account the enhanced level of Alfvén wave turbulence near the shock wave front due to the pitch-angle anisotropy of accelerated particles.
where the resonant wave number kr is the inverse of the Larmor radius (=1/rB).
Summary: For the first time, realistic evolution of turbulence is coupled with the particle acceleration process!
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(here f is the isotropic distribution function of particles)
4RSShock Evolution Cont.
Shock compression ratio and fast-wave Mach number against time.
Plasma beta (log-scale) and cosine of angle of upstream field to shock normal against time.
dark cavity region (flux rope)Density Structure and Field Geometry at t=1.1 hours.
SEP Event (FLAMPA)
(3-4)RS!SEP Data for 1998 May 2 Event
Compression ratio of shock and proton cut-off energy predicted by diffusive-shock-acceleration theory. Interior labels along left axis indicate spectral index for non-relativistic particle flux used in theory: =0.5(X+2)/(X-1). Lower values of indicate harder spectrum
At R=12RS (before and after the shock wave passes)
Time interval between two adjacent curves is 10 min. Dark red curve corresponds to t = 1.6 hrs (shock at R=12.2RS), whereas low-lying dark green curve refers to t = 0.27 hrs.