Geomagnetic storms: historical perspective to modern view

Gurbax S Lakhina,Bruce T Tsurutani

doi:10.1186/s40562-016-0037-4

Abstract

The history of geomagnetism is more than 400 years old. Geomagnetic storms as we know them were discovered about 210 years ago. There has been keen interest in understanding Sun–Earth connection events, such as solar flares, CMEs, and concomitant magnetic storms in recent times. Magnetic storms are the most important component of space weather effects on Earth. We give an overview of the historical aspects of geomagnetic storms and the progress made during the past two centuries. Super magnetic storms can cause life-threatening power outages and satellite damage, communication failures and navigational problems. The data for such super magnetic storms that occurred in the last 50 years during the space era is sparce. Research on historical geomagnetic storms can help to create a database for intense and super magnetic storms. New knowledge of interplanetary and solar causes of magnetic storms gained from spaceage observations will be used to review the super magnetic storm of September 1–2, 1859. We discuss the occurrence probability of such super magnetic storms, and the maximum possible intensity for the effects of a perfect ICME: extreme super magnetic storm, extreme magnetospheric compression, and extreme magnetospheric electric fields.

Highlights

The history of geomagnetism is more than 400 years old
According to the modern definition, a geomagnetic storm is characterized by a main phase during which the horizontal component of the Earth’s lowlatitude magnetic fields are significantly depressed over a time span of one to a few hours followed by its recovery, which may extend over several days (Rostoker et al 1997)
The intensity of a geomagnetic storm is measured by the disturbance storm time (Dst) index or by the SYM-H index which is a measure of the symmetric ring current intensity (Iyemori 1990)

Summary

Introduction

The history of geomagnetism is more than 400 years old. Geomagnetic storms as we know them were discovered about 210 years ago. If such an interplanetary CME (ICME) with intense southward interplanetary magnetic fields collide with the Earth’s magnetosphere, it will cause an SMS (Tsurutani et al 1992; Echer and Gonzalez 2008a).

Results

Conclusion