CORHEL/MAS-TDM

This model combination from the CORona-HELiosphere (CORHEL) modeling suite (Predictive Science Inc.) consists of the MAS (Magnetohydrodynamic Algorithm outside a Sphere) model and the TDm flux rope designer.

TDm designer is an interface that allows a user to interactively create a modied Titov-Demoulin (TDm) flux rope for insertion into realistic, observation-based background magnetic fields, then investigate the stability/instability properties with the MAS MHD model.

At present, zero-beta eruptions generated by the TDm designer can be simulated with MAS (in the future full thermodynamic CME simulations will become available).

The zero-beta model is useful for exploring flux-rope stability, and properties such as the initial trajectory of the erupting flux rope.

Model inputs are provided through a GUI. The steps are as follows:

1. Select a date and time
2. Select an observatory source for the magnetic map
3. Select a region on the map
4. Select a polarity inversion line for the flux rope
5. Select the foot points of the flux rope and flux-rope parameters:

Axis apex height, fractional width, fractional field strength relative to background, preserve magnetogram flux (yes/no)

The interface creates a tarball with the file or performing the MHD simulation on a computer where CORHEL-6 is installed. Approximate run times for different processor counts are provided. After the simulation run is performed, a diagnostics tarball is created. After opening the tarball, the user opens an html page that guides the user through the results (movies of the evolution, run histories, etc.).

Version 6 supports the TDm Flux Rope definition

Papers you must cite if you plan to publish the results:

• Titov et al. ApJ 790, 163 (2014)
• Linker et al. AIP conf. 1720, 020002, (2016)
• Torok et al. ApJ 865, 75 (2018)