Merging of coronal and heliospheric numerical two‐dimensional MHD models

Abstract

[1] Space weather research requires investigation of a complex chain of coupled dynamic phenomena occurring simultaneously on various spatial and temporal scales between the Sun and Earth. Specialized physically based numerical models have been developed to address particular aspects of the entire system. However, an integrated modeling approach is necessary to provide a complete picture suitable for interpretation of various remote and in situ observations and for development of forecasting capabilities. In this paper we demonstrate merging of coronal and heliospheric MHD models for a two-dimensional hypothetical case involving a magnetic cloud, shock, streamer belt, and current sheet. The disruption of a sheared helmet streamer launches a coronal mass ejection (CME) (simulated by the coronal model), which evolves during its propagation through interplanetary space (simulated by the heliospheric model). These models employ different physical approximations and numerical grids to simulate physical phenomena over their respective spatial and temporal domains. The merging of the models enables accurate tracking of a CME from its origin in the solar atmosphere to its arrival at Earth.

STEREO IMPACT Investigation Goals, Measurements, and Data Products Overview

“…These structures and others from different initiation schemes can be realistically transported to 1 AU using solar wind simulation codes (e.g. Odstrcil et al 2002;Riley et al 1997Riley et al , 2003Roussev et al 2003), and then compared with the in situ measurements from IMPACT and PLASTIC. Only comprehensive, sophisticated analyses of this kind can definitively test how ICMEs from various CME generation mechanisms differ, and which, if any, have been confirmed by STEREO observations.…”

“…Correlative data analysis by itself generally cannot provide the complex and coupled 3D descriptions available from state-of-the-art realistic simulations of the global corona, solar wind, CMEs, ICMEs and SEPs. The SAIC 3D MHD corona model coupled with the University of Colorado/SEC solar wind model (Riley et al 2003;Odstrcil et al 2002), and the University of Michigan 3D MHD adaptive grid solar wind and ICME transport model (Manchester et al 2005;Roussev et al 2003), will be brought to bear on the interpretation of IMPACT observations. Overlap between the IMPACT and other STEREO modeling efforts enables the treatment of the CME problem in its entirety.…”

THREE-DIMENSIONAL SOLARWINDMODELING FROM THE SUN TO EARTH BY A SIP-CESE MHD MODEL WITH A SIX-COMPONENT GRID

“…The most convenient grid system for solar wind modeling is the latitude-longitude grid under spherical shell geometry, which is especially welcomed for numerical schemes for governing equations in the spherical polar coordinates (Usmanov & Dryer 1995;Usmanov 1996;Wu et al 1999;Usmanov & Goldstein 2003;Linker et al 1999;Odstrcil et al 2002;Feng et al 2005;Hayashi 2005;Shen et al 2007) since its orthogonality is expected from numerical reasons. The grid mesh of the latitude-longitude grid is uniform when it is seen in the computational space of the spherical surface S = {(θ, φ), 0 θ π , 0 φ 2π } but it is in fact nonuniform when observed in real space.…”

“…The spherical shell is a key computational domain in both computational geophysics and solar-terrestrial physics (Kageyama & Sato 2004;Kageyama 2005;Yoshida & Kageyama 2004;Usmanov & Dryer 1995;Usmanov 1996;Wu et al 1999;Usmanov & Goldstein 2003;Linker et al 1999;Odstrcil et al 2002;Feng et al 2005;Hayashi 2005;Shen et al 2007). Simulations in these fields such as geodynamo, mantle convection, global circulation of the atmosphere, and space weather modeling from the Sun to Earth are all performed in spherical shell geometry, such as (r, θ, φ) with radius r between some intervals (for example, r 0 r r 1 , 0 θ π , and 0 φ 2π ), if defined in the spherical coordinates.…”

Theoretical modeling for the stereo mission

“…The NOAA/SEC heliospheric model (ENLIL) solves the time-dependent MHD equations in a spherical geometry using either the Flux-Corrected-Transport or Total-VariationDiminishing schemes (e.g., Odstrcil, 1994;Toth andOdstrcil, 1996, 2003;Odstrcil et al, 2002). These high-resolution schemes produce second-order accuracy away from discontinuities, while simultaneously providing the stability that ensures non-oscillatory solutions.…”