Heliophysics Modeling & Simulation Project (HMS)
HMS Tools and Codes
The Heliophysics Modeling and Simulation (HMS) team develops high-fidelity modeling and simulation tools for research on, and modeling of, the solar interior and emerging magnetic flux at the solar surface.
The project team is developing operational as well as scientific tools. HMS scientists are supporting substantial enhancements to the Air Force Data Assimilation Photospheric Flux Transport (ADAPT) tool in order to assimilate the high-resolution data provided by NASA’s Solar Dynamics Observatory (SDO).
In addition, tools are being added to the Space Weather Model Framework (SWMF) that enables simulations of the magnetic flux from the deep interior to the corona. The goal is to extend space weather forecasts by up to three days from the current capability.
Stellarbox
Stellarbox is a 3D magnetohydrodynamics code used to simulate the upper part of the convection zone and the lower part of the atmosphere of the Sun and other stars. Equations for the conservation of mass, momentum, energy, and magnetic flux are advanced in time using a tabular equation of state and optical opacity specific to the chosen stellar composition.
The simulation domain is a rectangular volume typically encompassing a horizontal span of tens to hundreds of megameters and a vertical span of a few to tens of megameters. Spatial resolutions typically range from 100 kilometers (km) down to 5 km. The simulations incorporate subgrid-scale turbulence models for the transport of heat and momentum and for electrical resistivity. Radiative heat transfer is simulated with a ray-tracing algorithm suited to parallel computation. Parallelization is achieved using either a planes-based or pencil-based data structure for given mesh dimensions and number of processors. The Stellarbox application was developed by HMS research scientist Alan Wray.
aSHBury
aSHBury is a numerical framework for solving linear and non-linear partial differential equations on massively parallel computers in spherical geometry using a Spherical Harmonic/B-spline discretization scheme.
Currently, there are two applications implemented using aSHBury:
- aSHBury waves: for simulating the linearized magneto-hydrodynamic equations in full 3D. It is used for simulation and analyses of wave propagation in the solar interior. Synthetic data from these simulations are used in fine-tuning helioseismology methods.
- aSHBury static: for non-linear force-free field extrapolation (NLFFF) of solar magnetic fields. It is used to generate 3D force-free magnetic fields in full 3D spherical geometry as applied to the Sun.
aSHBury is fully parallelized using MPI and OpenMP, and runs efficiently on hundreds to thousands of processor cores. The framework was developed and maintained by HMS research scientist Thomas Hartlep.