Carrington Class Coronal Mass Ejection - ENLIL Simulation of A Series of CMEs

Coronal Mass Ejections (CMEs) are explosive bursts of plasma from the sun's corona. They begin usually with areas in the sun's corona under extreme magnetic tension. These field lines are twisted and hold a lot of potential energy. These events differ from solar flares, where solar flares are an increase in electromagnetic activity on the sun's surface, coronal mass ejections carry dense coronal material across the heliosphere. When these field lines release, they undergo a process called magnetic reconnection. These ejections range in speed between 200 km/s to up to 3000 km/s. At the highest speeds, these CMEs can travel faster than the background solar wind, which creates a shock front. At the shock front, there is an increased particle density, and can accelerate charged particles.

The Carrington Event was the strongest recorded geomagnetic storm in history, caused by an unusually strong solar flare. Geomagnetic storm typically result in increased auroral activity, but particularly strong geomagnetic storms have the potential to disrupt power grids, satellite networks, and cause damage to navigation systems. We refer to solar activity with the potential to cause these effects a "Carrington Class" event.

We were aware of a series of 5 coronal mass ejections between July 12th, 2012 and August 1st, 2012, including a carrington class coronal mass ejection that hit the satellite STEREO-A. 4 smaller CMEs were seen preceeding the largest CME. The largest CME benefitted from the interplanetary material cleared by the other CMEs, allowing it to reach STEREO-A with a less impeded speed.

ENLIL is a time-dependent 3D MHD model of the heliosphere, hosted and maintained by the Community Coordinated Modeling Center (CCMC). The model is able to solve for momentum, energy density, plasma mass, and magnetic field parameters using the Flux-Corrected-Transport algorithm. The model is available as run-on-request.
This is a visualization of the simulation of the simulation of the solar wind density, velocity, and magnetic field during these series of coronal mass ejections.
The computational grid does not extend to the Sun's polar regions, which creates two empty cone shaped artifacts.