Temporal and Spatial Evolutions of a Large Sunspot Group and Great Auroral Storms around the Carrington Event in 1859

TL;DR

This study analyzes the evolution of the 1859 Carrington event's sunspot activity and auroras, comparing it with other extreme space weather events to understand their spatial and temporal characteristics.

Contribution

It reconstructs the spatial and temporal evolution of the Carrington event's active region and auroras, providing a comparative analysis with other major space weather events.

Findings

The Carrington event was one of the most extreme but not unique space weather events.

Auroral visibility extended to low magnetic latitudes during the storm.

The spatial evolution of auroras correlates with magnetic storm phases.

Abstract

The Carrington event is considered to be one of the most extreme space weather events in observational history within a series of magnetic storms caused by extreme interplanetary coronal mass ejections (ICMEs) from a large and complex active region (AR) emerged on the solar disk. In this article, we study the temporal and spatial evolutions of the source sunspot active region and visual aurorae, and compare this storm with other extreme space weather events on the basis of their spatial evolution. Sunspot drawings by Schwabe, Secchi, and Carrington describe the position and morphology of the source AR at that time. Visual auroral reports from the Russian Empire, Iberia, Ireland, Oceania, and Japan fill the spatial gap of auroral visibility and revise the time series of auroral visibility in mid to low magnetic latitudes (MLATs). The reconstructed time series is compared with magnetic measurements and shows the correspondence between low to mid latitude aurorae and the phase of magnetic storms. The spatial evolution of the auroral oval is compared with those of other extreme space weather events in 1872, 1909, 1921, and 1989 as well as their storm intensity, and contextualizes the Carrington event, as one of the most extreme space weather events, but likely not unique.