Last Updated: 12/08/2023


Version: 6.0

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.).

Model is time-dependent.

Change Log

Version 6 supports the TDm Flux Rope definition


  • Solar
  • Heliosphere / Inner Heliosphere


  • Coronal Mass Ejections



Code Languages: Fortran, PHP, BASH, Python, C/C++, Javascript


Publication Policy

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)

In addition to any model-specific policy, please refer to the General Publication Policy.