CORHEL-CME

CORHEL-CME, developed by Predictive Science Inc., is a novel MHD modeling framework specifically designed to be used by non-experts. It consists of a collection of tools and simulation codes that are seamlessly integrated and accessible through a web interface. The web interface empowers users to simulate multiple coronal mass ejections (CMEs) in a realistic coronal and solar wind environment.

The CORHEL-CME web interface simplifies the process of conducting full physics-based CME simulations by guiding users through the following three steps.

I. Flux ropes and their eruptive/non-eruptive behavior

Users begin by creating one or more flux ropes using simplified (zero-beta) MHD simulations and evaluating their eruptive or non-eruptive behavior. A key innovation of CORHEL-CME is its incorporation of the Regularized Biot Savart Laws (RBSL; Titov et al., 2018) model. The RBSL model allows users to create pre-eruptive flux rope configurations above elongated and curved polarity inversion lines. This feature enables realistic simulations of CME eruptions from complex active regions (Török et al., 2018).

II. Thermodynamic MHD solution of the corona and solar wind background

Users can choose from two heating models (soon to be three) to simulate the thermodynamic state of the corona and solar wind background, in which the eruptions from step 1 will be embedded later. As part of the CORHEL-CME framework, the MAS model incorporates a realistic energy equation that takes into account anisotropic thermal conduction, radiative losses, and coronal heating. This allows MAS to compute plasma density and temperature, enabling the simulation of EUV and X-ray emissions as observed from space.

III. Full physics-based CME simulations

In the final step, users can request full physics-based thermodynamic CME simulation runs. These simulations involve launching individually designed CME eruptions (step 1) into the corona and solar wind background (step 2).

At each step of the CME design and simulation, the CORHEL-CME user interface provides guidance to the user through a "Take a Tour" button. It assists with design choices by generating diagnostic plots and generates web-based visualization reports upon completion of each step.

To ensure quick turnaround in these research-focused CME simulations, all CORHEL-CME runs are performed on high-performance GPU servers on Amazon Web Services (AWS).

The current interface allows up to a maximum of two flux ropes in a single run.

Model inputs are provided through a web interface. 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 design your own flux rope by modifying a variety of parameters
6. Select a heating model and create a background solution for the CME simulation
7. Start the thermodynamic CME simulation run

After completing each main step, a run report is generated. The user can download or open the report through the CCMC simulation results page. An HTML page guides users through the results, including movies of the CME eruption and evolution.

CORHEL-CME Version 1.0 is a substantial upgrade over its predecessor, CORHEL-TDm, also available on CCMC's ROR system.