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arXiv · 1811.02786

Low-Latitude Aurorae during the Extreme Space Weather Events in 1859

Hisashi Hayakawa·Yusuke Ebihara·David P. Hand·Satoshi Hayakawa·Sandeep Kumar·Shyamoli Mukherjee·B. Veenadhari
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Abstract

The Carrington storm (September 1/2, 1859) is one of the largest magnetic storms ever observed and it has caused global auroral displays in low-latitude areas, together with a series of multiple magnetic storms during August 28 and September 4, 1859. In this study, we revisit contemporary auroral observation records to extract information on their elevation angle, color, and direction to investigate this stormy interval in detail. We first examine their equatorward boundary of "auroral emission with multiple colors" based on descriptions of elevation angle and color. We find that their locations were 36.5 deg ILAT on August 28/29 and 32.7 deg ILAT on September 1/2, suggesting that trapped electrons moved to, at least, L~1.55 and L~1.41, respectively. The equatorward boundary of "purely red emission" was likely located at 30.8 deg ILAT on September 1/2. If "purely red emission" was a stable auroral red arc, it would suggest that trapped protons moved to, at least, L~1.36. This reconstruction with observed auroral emission regions provides conservative estimations of magnetic storm intensities. We compare the auroral records with magnetic observations. We confirm that multiple magnetic storms occurred during this stormy interval, and that the equatorward expansion of the auroral oval is consistent with the timing of magnetic disturbances. It is possible that the August 28/29 interplanetary coronal mass ejections (ICMEs) cleared out the interplanetary medium, making the ICMEs for the Carrington storm on September 1/2 more geoeffective.

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Hisashi Hayakawa, Yusuke Ebihara, David P. Hand, Satoshi Hayakawa, Sandeep Kumar, Shyamoli Mukherjee, B. Veenadhari. 2018-11-07. Low-Latitude Aurorae during the Extreme Space Weather Events in 1859. https://doi.org/10.3847/1538-4357/aae47c

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