FG: 3D Ionospheric Electrodynamics and Its Impact on the Magnetosphere-Ionosphere-Thermosphere Coupled System
Contents
Focus Group Chairs
- Hyunju Connor (hyunju.k.connor@nasa.gov)
- Bin Zhang (binzheng@ucar.edu)
- Gang Lu (ganglu@ucar.edu)
- Haje Korth (haje.korth@jhuapl.edu)
Term
- Five years (2017-2021)
Research area
- Magnetosphere – Ionosphere Coupling
- Global System Modeling
Topic
The magnetosphere is one of the major energy sources that drive the Earth's upper atmosphere. During geomagnetic storms, the magnetosphere transmits significant energy and momentum into the upper atmosphere via field-aligned currents, Poynting flux, and auroral precipitation. In response, the ionospheric electric potentials and conductances increase, the thermosphere heats and expands, and the global atmospheric circulation changes. The ionosphere – thermosphere feedback can also influence magnetospheric dynamics. The heated thermosphere can enhance ionospheric outflows and change magnetic reconnection rates. The modified global circulation redistributes plasmas and neutrals, alters the ionospheric conductance and electric field, and thus changes the magnetospheric convection and reconnection. Although strong coupling of the magnetosphere – ionosphere – thermosphere (MIT) system are widely recognized by the space science community, studying this coupling dynamics as a whole global system has yet to be conducted comprehensively. To magnetospheric scientists, the ionosphere is treated as a two- dimensional, low-altitude boundary. The mass and momentum exchanges between the magnetosphere and the IT system are often ignored. More realistic calculation of upper atmospheric dynamics is necessary in the global magnetosphere - ionosphere models. To upper atmospheric scientists, simple statistical convection patterns and empirical auroral precipitation fluxes driven by the Kp and hemispheric power indices are commonly used to infer complicated magnetospheric dynamics. As a consequence, global IT models (e.g. CTIPe, TIEGCM, and GTIM) cannot sufficiently capture the spatiotemporal dynamics of magnetospheric energy sources during strong geomagnetic activities, thus limiting the predictive capability of these models when it is most needed. More realistic calculation of magnetospheric energy input is necessary. In recent years, the coupled magnetosphere – ionosphere – thermosphere (MIT) models (e.g. OpenGGCM- CTIM, LFM-TIEGCM, BATSRUS-GTIM, and AMIE-TIEGCM) have been gradually matured to the point to revisit the extensive ground/space observations and to investigate the complex coupling processes of the MIT system. It is thus the proper time to build on and expand these recent efforts. For the next five years, this new focus group (FG) will address, via modeling and observational approaches, 1) where, when, and how magnetospheric energy contributes to the IT system and 2) how the IT system feeds back to the magnetosphere.
Goals and Deliverables
The ultimate goal of this focus group is to advance our physics-based understanding of global magnetosphere – ionosphere – thermosphere coupling dynamics. We are particularly interested in the following topics:
- Momentum/Energy input from the magnetosphere to the upper atmosphere: The small and large-scale patterns of field-aligned currents, auroral precipitation, and Poynting flux during various geomagnetic events will be carefully examined using observations, theoretical calculations, and numerical simulations.
- Responses of three-dimensional IT system to the magnetospheric input: This FG will investigate the impact of magnetospheric momentum/energy inputs on the three- dimensional IT system using global MIT models and/or global IT models coupled with AMIE. We will address how the spatiotemporal dynamics of magnetospheric input modifies the altitudinal profiles of electron density, ionospheric conductivity, and Joule heating. We will also study how this modification influences global ionospheric electrodynamics.
- IT feedbacks to the magnetosphere: Variations in global ionospheric electrodynamics can influence the magnetospheric convection patterns and modify the magnetic reconnection rates. The coupled magnetosphere – ionosphere – thermosphere models can be a good tool to investigate the IT dynamics and their impact on the magnetospheric phenomena. Additionally, strong Joule heating and enhanced ionospheric temperature can produce ion outflows and modulate the reconnection rates. The outcome from this FG can be a good asset for the ion outflow modelers.
The main deliverables of this focus group will include the development, refinement, and application of more comprehensive and self-consistent, physics-based models that cover from the magnetosphere to the upper atmosphere, those of which fulfill the main objective of the GEM program.
2017 Mini-GEM Workshop
Our MIT coupling session will be held between 15:30 - 17:00pm on Dec 10 (Sunday before the AGU meeting) at the Hilton Garden Inn - New Orleans Convention Center, 1001 S Peters St, New Orleans, LA70130. We hope both GEM and CEDAR scientists to join our session, sharing and discussing their recent results in the MI, IT, or MIT field. This session will create synergy between the two communities and help to advance our physics-based understanding of the global MIT system. If you are interested in giving a talk, please send the title of your talk to Hyunju Connor at hkconnor@alaska.edu. We are looking forward to your participation.
List of presenters
- Alex Chartier: Puzzling Global (N+S) December Maximum of Polar Cap Patches Observed using Swarm
- Qingyu Zou: Impacts of small scale electric field/particle precipitation on Joule heating: GITM simulations
- Olga Verkhoglyadova: Semi-analytical estimation of energy deposition by Alfven waves into the ionosphere during storms
- Ryan McGranaghan: TBD
- Robert Rankin: Suppression of the ionospheric feedback instability
Session Proposal
Download the session proposal here.
