CRCM + BATS‒R‒US two‒way coupling

Abstract

[1] We present the coupling methodology and validation of a fully coupled inner and global magnetosphere code using the infrastructure provided by the Space Weather Modeling Framework (SWMF). In this model, the Comprehensive Ring Current Model (CRCM) represents the inner magnetosphere, while the Block-Adaptive-Tree Solar-Wind Roe-Type Upwind Scheme (BATS-R-US) represents the global magnetosphere. The combined model is a global magnetospheric code with a realistic ring current and consistent electric and magnetic fields. The computational performance of the model was improved to surpass real-time execution by the use of the Message Passing Interface (MPI) to parallelize the CRCM. Initial simulations under steady driving found that the coupled model resulted in a higher pressure in the inner magnetosphere and an inflated closed field-line region as compared to simulations without inner-magnetosphere coupling. Our validation effort was split into two studies. The first study examined the ability of the model to reproduce Dst for a range of events from the Geospace Environment Modeling (GEM) Dst Challenge. It also investigated the possibility of a baseline shift and compared two approaches to calculating Dst from the model. We found that the model did a reasonable job predicting Dst and Sym-H according to our two metrics of prediction efficiency and predicted yield. The second study focused on the specific case of the 22 July 2009 moderate geomagnetic storm. In this study, we directly compare model predictions and observations for Dst, THEMIS energy spectragrams, TWINS ENA images, and GOES 11 and 12 magnetometer data. The model did an adequate job reproducing trends in the data. Moreover, we found that composition can have a large effect on the result.

Magnetosphere dynamics during the 14 November 2012 storm inferred from TWINS, AMPERE, Van Allen Probes, and BATS-R-US–CRCM

“…The coupling algorithm is similar to that described in De Zeeuw et al (2004) for BATS-R-US two-way coupling with the RCM ring current model. More details on the two-way coupling between the CRCM and BATS-R-US are found in Glocer et al (2013). From the previously reported observations, the dropouts have similar structure at Probe A and Probe B; however, there is a time lag of up to 5 min between the same structures appearing in Probe A and B data (Hw15, Di15).…”

“…BATS-R-US is a part of the Space Weather Modeling Framework (SWMF) (Tóth et al, 2005 and interacts with the required physical domains represented by different codes. In the particular configuration used here, BATS-R-US is coupled in two-way mode with the ionospheric electrodynamic (IE) module and also in two-way mode with the Comprehensive Ring Current Model (CRCM) (Fok et al, 1996(Fok et al, , 2001Fok and Moore, 1997;Glocer et al, 2013;Meng et al, 2013). The IE module calculates precipitationinduced conductances from field-aligned currents using the AMIE model formalism described in Ahn et al (1983) and Ridley et al (2004).…”

“…Third, we include new simulation results using the BATS-R-US-CRCM model Glocer et al, 2013) to physically interpret the local and global observations. Recently, significant progress has been made in ring current and global magnetosphere modeling with the development of so-called "twoway coupled models" Pembroke et al, 2012;Glocer et al, 2013;Meng et al, 2013). We demonstrate how this modeling approach helps to infer systemlevel dynamics, connect multipoint observations in different domains, and analyze global magnetosphere dynamics and coupling with the ionosphere.…”

Ion distributions upstream and downstream of the Earth's bow shock: first results from Vlasiator

“…The first approach is based on coupling kinetic and MHD models for respective magnetospheric regions (e.g., Tóth et al, 2012), while the second approach is focused on solving the kinetic equations throughout the entire system. The former approach was successfully applied in modeling the inner magnetosphere and ring current region (Glocer et al, 2013) where collisional processes and multi-ion plasma composition become significant. The latter approach is typically based on hybrid particle-in-cell (PIC) simulations, where electrons are modeled as fluid while ions are modeled as macroparticles for which plasma kinetic equations are solved (Winske et al, 2003).…”

Theory, modeling, and integrated studies in the Arase (ERG) project

“…The CIMI can also be coupled with global magnetohydrodynamics (MHD) models (i.e., Glocer et al 2013). In this subsection, we show an example of the simulation result of CIMI with the electric and magnetic fields provided by the MHD simulation REProduce Plasma Universe (REPPU) (Tanaka 2015).…”