Space Weather ModelinG Framework (BATSRUS with Rice Convection Model)

Model Developer(s)
Tamas Gombosi et al., R. Wolf et al.
Center for Space Environment Modeling, University of Michigan

Model Description
SWMF contains 9 modules that cover the various regions between the Sun and Earth:

• Solar Corona SC: The solar coronal module extends from the solar surface up to 20 R_S. This module is driven by solar magnetogram data and establishes the coronal base solution for the solar wind. The coordinate system is either Heliographic Intertial (HGI) or Heliographic Rotating (HGR). Gravity and solar wind acceleration terms are added to the magnetohydrodymanic equations (which include intertial terms in a co-rotation coordinate system). Coronal heating can be approximated by alternative models such as large-scale turbulence or a variable adiabatic index (Groth et al, 2000, Usmanov et al., 2000, find references in Tóth et al., 2005).
• Eruptive Event generator EE: The EE module interacts with the SCmodule by describing eruptions such as CMEs as either boundary conditions to SC or by non-linearly perturbing the SC solution. SC is implemented by an implementation of BATS-R-US, the Block-Adaptive-Tree-Solarwind-Roe-Upwind-Scheme.
• Inner Heliosphere IH: The IH module describes the heliosphere from the outer boundary of SC up to several astronomical units. IH is implemented by a version of BATS-R-US.
  IH can surround and drive the GM module in a complete simulation from Sun to Earth. Solar wind parameters needed by GM are taken from IH at the upstream boundary of GM.
• Solar energetic Particles SP: The SP domain consists of one-dimensional magnetic field lines. The transport equations describe the acceleration and spatial diffusion of particle distributions in fields obtained from the SC and IH SWMF modules (Kóta and Jokipii, 1999, Kóta et al., submitted to ApJ, 2005).
• Global Magnetosphere GM: The GM module describes the Earth's magnetosphere and is driven either by upstream satellite data or by being embedded into the IH module of SWMF. GM is also implemented by a version of BATS-R-US and includes the magnetosphere from 33 R_E upstream to some 250 R_E downtail. The GM domain has a near-Earth boundary located between 2.5 and 3.5 R_E distance from the center of the Earth. Near-Earth boundary conditions are determined by the interaction with the IM module.
• Inner Magnetosphere IM: The IM module represents the inner region of the magnetosphere and is modeled by a version of the Rice Convection Model (RCM) (Wolf et al, 1982, Toffoletto, 2003). IM module obtains the information on closed field lines from GM and the electrostatic potential from IE and provides density and pressure corrections back to GM.
• Radiation Belt RB: The RB module is implemented using the serial Rice Radiation Belt Model (RRBM) that solves the adiabatic transformation of phase space density of relativistic electrons on a 2D nonuniform spherical grid. The RB module takes data from GM and IE, similar to the IM module. RB does not return any information to other modules.
• Ionospheric Electrodynamics IE: The IE module is a two-dimensional electrostatic potentail solver that obtains the field-aligned currents (FAC) from GM and employs a statistical auroral ionosphere conductance model driven by the solar irradiation index (F10.7) and by the FAC patterns (Ridley et al, 2004, Ridley and Liemohn, 2002). IE delivers electric potentials back to GM and on to UA and IM.
• Upper Atmosphere UA: The UA module is implemented by the Global ionosphere Thermosphere Model GITM (Ridley et al., 2005) and extends from about 90 to 600 km altitude. UA describes the multi-species chemistry in the upper atmosphere including viscosity, coupling of ions and electric field, ion-neutral friction and ionization source terms. The UA module is implemented in co-rotating Geocentric (Geographic) coordinates. UA obtains electric fields from GM through IE and returns ionospheric conductances and modified FAC back to IE.

BATS-R-US request runs for the magnetosphere are now executed using SWMF/GM (coupled with SWMF/IE).
A SWMF run of the magnetosphere at CCMC can include the Rice Convection Model (RCM) in the inner magnetosphere (SWMF/IM) in addition to the BATS-R-US MHD module of the global magnetosphere (GM) and the ionospheric electrodynamics (IE) potential solver.

If a SWMF/(BATSRUS + RCM) run is requested, the RCM modifies the plasma pressure distribution in the inner magnetosphere and changes the resulting field-aligned currents in the ionosphere (yields more realistic Region-1 currents). The RCM inside SWMF does not generate any outputs.

Model Input

• SC/IH stand alone runs Inputs to the SWMF/SC are solar magnetogram data for a n entire Carrington rotation period of the Sun (approx. 27 days), obtained from ground-based observatories (Kitt Peak or Mount Wilson) or from satellite observations.
• GM/IE stand alone runs Inputs to SWMF/GM are solar wind plasma (density, velocity, V_x, V_y, V_z, temperature) and magnetic field (B_x, B_y, B_z) measurements, transformed into GSM coordinates and propagated from the solar wind monitoring satellite's position propagated to the sunward boundary of the simulation domain. The Earth's magnetic field is approximated by a dipole with updated axis orientation and co-rotating inner magnetospheric plasma or with a fixed orientation during the entire simulation run. The orientation angle is updated according to the time simulated or a fixed axis position can be specified \ independently from the time interval that is simulated.

Model Output

• Outputs of SWMF/SC, SWMF/IH, SWMF/GM modules include plasma parameters (atomic mass unit density N, pressure P, velocity V_x, V_y, V_z), the magnetic field B_x, B_y, B_z, and electric currents, J_x, J_y, J_z.
  
• SWMF/IM returns ionospheric electrodymanics parameters (electric potential PHI, Hall and Pedersen conductances Σ_H, Σ_P).

• SWMF/UA returns densities of upper atmospheric particle species, Hall and Pedersen conductivities σ_H, σ_P, and drift velocities of ions and neutral gas.

Relevant links
Center for Space Environment Modeling (CSEM).
Description of modules rewritten from: Tóth, G., et al. (2005), Space Weather Modeling Framework: A new tool for the space science community, J. Geophys. Res., 110, A12226, doi:10.1029/2005JA011126.

CCMC Contact(s)

301-286-9571

Developer Contact(s)

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