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Earth’s Geomagnetic Environment—Progress and Gaps in Understanding,

Prediction, and Impacts

ISWAT G1 Cluster Members

Table of Contents

I. Introduction

II. Understanding the Geomagnetic Response to CMEs�Leads: Chigo Ngwira, Hermann Opgenoorth

Solar wind coupling
Extreme events
Gaps/Recommended Actions

III Auroral Precipitation and High Latitude Electrodynamics�Leads: Bob Robinson and Katie Garcia-Sage

Auroral precipitation and conductance
Auroral electrodynamics - Electric fields - Field-aligned currents
Joule heating and Poynting Flux
Auroral Boundaries - Ion outflow
Gaps/Recommended Actions

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IV. Modeling of the Geomagnetic Environment

Leads: Dibyendu, Sur, Dan Welling, Mostafa El Alaoui (to be confirmed)

MHD simulations
Hybrid models
Low- and Mid-latitude effects
Gaps/Recommended Actions

V. GMDs, GICs, and Geoelectric Fields�Leads: James Weygand, Hermann Opgenoorth, David Boteler, Chigo Ngwira

Geomagnetically Induced Currents
Geoelectric fields
Gaps/Recommended Actions

VI. Conclusions

Leads: Hermann Opgenoorth, Bob Robinson

Recommendations
Summary of actions

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II. Understanding the Geomagnetic Response to CMEs�Leads: Chigo Ngwira, Hermann Opgenoorth,..��

Papers collected:

Papers on solar wind coupling

Papers on extreme events

Solar wind coupling

Extreme events

Gaps/Recommended Actions

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II. Understanding the geomagnetic response to CMEs�Science questions/gaps:

Understand and quantify relative role of different magnetized solar wind plasma and field parameters on the generation of electric currents and energization of plasma in various regions of coupled geospace system.
Understand the role of pre-history of driving.
Understand and quantify differences in magnetospheric current systems for low, moderate or extreme solar wind drivers.
Assessment of capabilities to forecast geomagnetic environment variability.
Assessment of capabilities to forecast magnetopause position.
Assessment and improvement of capabilities to model auroral boundaries.
To what extents can extreme events can be predicted?

Time scales:

~10 min: M-I reconfiguration time
~1 hour: Propagation from L1
~2-3 days: Sun-Earth propagation time
~27 days: Solar rotation period

Predictions:

What do we mean by predictions?
To what extent does the solar wind contain information allowing predictions?
Can we apply our knowledge of typical events to extreme events?
Need for global, continuous, and real-time measurements, along with solar and solar wind observations and model simulations

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III. Auroral Precipitation and High Latitude Electrodynamics�Leads: Bob Robinson and Katie Garcia��Papers collected:

Papers on field-aligned currents
Papers on Joule heating and Poynting flux
Papers on auroral boundary specification
Papers on ion outflow
Papers on GMD�

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III. Auroral Precipitation and High Latitude Electrodynamics�Science questions/gaps

Understand and quantify effects of coupling between ionosphere-magnetosphere current systems and processes in upper atmosphere.
Understand and quantify properties of the high latitude region, including particle precipitation, conductivities, electric fields, currents, electromagnetic energy input, and Joule heating
Quantify the effects of neutral winds, Joule heating vs Poynting flux, polar cap Joule heating
Review of geomagnetic activity indices and activity scales (which are best: AE vs SME vs HPO vs PCI)
Understand and quantify substorms initiation and dynamics

Where they occur, where they connect to in the magnetosphere
How related to bursty bulk flows; ionospheric, low altitude proxies
Streamers (optical and magnetic signatures)

Understand the physical mechanisms for the ‘explicit By effect’ on the intensity of auroral electrojets and its influence on the occurrence and strength of substorms
Are the current MHD models able to reproduce the By-dependence of auroral currents?
Quantify the magnitude of Joule heating and the spatial and temporal behavior of Joule heating intensifications
Determine if GIC events correlate with the large-scale distribution of energy flux, electric fields, horizontal and parallel currents, and Joule heating
Understand the current-voltage relationship of the global magnetosphere-ionosphere circuit, and any linkage to GIC occurrence

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IV. Modeling of the Geomagnetic Environment�Leads: Dan Welling, Dibyendu Sur, M. Liemohn��Papers collected:

Papers on MHD Simulations

Papers on Hybrid Simulations

Papers on models focusing on mid- to low-latitude space weather effects (Maybe make a separate section)�

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IV. Modeling of the Geomagnetic Environment�Science questions/gaps:

Advance modeling capability of coupled geospace system

What’s needed: simulating substorm conditions, spikiness, accurate conductance model
Making the connection between modeled parameters and visual aurora

Understand and quantify spatial and temporal features of geomagnetic variability in response to external and internal drivers

Simulating localized and transient phenomena
Capturing the stochastic nature of magnetosphere-ionospheric phenomena

Tentative:

Understanding of mid- to low-latitude space weather effects

Feedback between ionosphere and magnetosphere (loading and unloading)
Conductances in troughs and downward current regions
Enhanced electric fields and FAC closure
STEVE—optical emissions and conjugacy

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V. GMDs, GICs, and Geoelectric Fields�Leads: James Weygand, Hermann Opgenoorth, David Boteler�Papers collected �(differentiate papers for GMD and GIC):

Papers on Geo-Magnetic Disturbances�
Papers on Geomagnetically Induced Currents �
Papers on Geoelectric Fields

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V. GMDs, GICs, and Geoelectric Fields �Science questions/gaps:

Understand and quantify impact of geomagnetic variability on critical infrastructure

Repetitive GMDs; frequency of GMDs; stochastic nature of GMDs
Connection to dynamic aurora: omega bands, Westward Traveling Surge, wedgelets

Understand spatial and temporal development of dB/dt
Understand the origins of non-substorm, non-storm dB/dt events
Is dB/dt associated with temporal changes in large-scale, sheet-like FACs or filamentary FACs?
What is the role of Bursty Bulk Flows in the origin and evolution of dB/dt?
Magnetospheric connections to dB/dt events
What is the relation between BBFs and localized particle injection events?
Understand and quantify role of soil, ocean or crustal conductivities on the enhancement or modification of any electric fields induced by the geomagnetic disturbances;
Need for 3D conductivity models
Effect of infrastructure network characteristics
Quantification of extreme GIC characteristics