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

Abstract

Understanding of underlying mechanisms of drastic variations of the near-Earth space (geospace) is one of the current focuses of the magnetospheric physics. The science target of the geospace research project Exploration of energization and Radiation in Geospace (ERG) is to understand the geospace variations with a focus on the relativistic electron acceleration and loss processes. In order to achieve the goal, the ERG project consists of the three parts: the Arase (ERG) satellite, ground-based observations, and theory/modeling/integrated studies. The role of theory/modeling/integrated studies part is to promote relevant theoretical and simulation studies as well as integrated data analysis to combine different kinds of observations and modeling. Here we provide technical reports on simulation and empirical models related to the ERG project together with their roles in the integrated studies of dynamic geospace variations. The simulation and empirical models covered include the radial diffusion model of the radiation belt electrons, GEMSIS-RB and RBW models, CIMI model with global MHD simulation REPPU, GEMSIS-RC model, plasmasphere thermosphere model, self-consistent wave-particle interaction simulations (electron hybrid code and ion hybrid code), the ionospheric electric potential (GEMSIS-POT) model, and SuperDARN electric field models with data assimilation. ERG (Arase) science center tools to support integrated studies with various kinds of data are also briefly introduced.

Medium-energy particle experiments—electron analyzer (MEP-e) for the exploration of energization and radiation in geospace (ERG) mission

“…It detects electrons with energies of 7-87 keV and obtains velocity distribution functions, which are the key to understanding the formation and decay of the radiation belt. Observations in combination with other instruments onboard the ERG, other magnetospheric explorers (Angelopoulos et al 2008;Burch et al 2016;Escoubet et al 1997;Mauk et al 2013;Nishida et al 1994), as well as ground-based observatories (e.g., Shiokawa et al 2017) and modeling output (Seki et al 2018) are expected to shed new light on radiation belt physics. Fig.…”

Geospace exploration project ERG

“…In order to investigate the physical processes quantitatively and reveal the relative role of each process, integrated data analyses with the numerical simulations are indispensable (Seki et al 2018). The multi-point observations of the ERG satellite and ground-based observations provide a macroscopic view of geospace, which can be compared to the global simulation for the inner magnetosphere, e.g., the evolution of the plasmasphere, ring current, and radiation belts.…”

Deformation of Ionospheric Potential Pattern by Ionospheric Hall Polarization

“…We are also grateful to O. Amm for his suggestion on the latter half of section 4.2. This study utilized the GEMSIS‐POT potential solver (Nakamizo et al, ), which is developed under the GEMSIS project of ISEE, Nagoya University, as a part of model development efforts of the ERG project (Seki et al, ). Works at NICT and Kyushu University were supported in part by JSPS KAKENHI grant 15H05815.…”