activity
20172024
most citedTemporal and Spatial Evolutions of a Large Sunspot Group and Great Auroral Storms around the Carrington Event in 1859

98 citations · 255 across the 6 of their papers we have counts for

collaborators

6 papers

astro-ph.SR2024★ 18 cited

The Extreme Space Weather Event of 1872 February: Sunspots, Magnetic Disturbance, and Auroral Displays

Hisashi Hayakawa, Edward W. Cliver, Frédéric Clette +19

We review observations of solar activity, geomagnetic variation, and auroral visibility for the extreme geomagnetic storm on 1872 February 4. The extreme storm (referred to here as…

astro-ph.SR2020★ 14 cited

The intensity and evolution of the extreme storms in January 1938

Hisashi Hayakawa, Kentaro Hattori, Alexei A. Pevtsov +7

Major solar eruptions occasionally direct interplanetary coronal mass ejections (ICMEs) to Earth and cause significant geomagnetic storms and low-latitude aurorae. While single ext…

astro-ph.SR2020★ 49 cited

The Extreme Space Weather Event in 1903 October/November: An Outburst from the Quiet Sun

Hisashi Hayakawa, Paulo Ribeiro, José M. Vaquero +11

While the Sun is generally more eruptive during its maximum and declining phases, observational evidence shows certain cases of powerful solar eruptions during the quiet phase of t…

astro-ph.SR2019★ 15 cited

Sunspot Observations by Hisako Koyama: 1945-1996

Hisashi Hayakawa, Frédéric Clette, Toshihiro Horaguchi +4

The sunspot record is the only observational tracer of solar activity that provides a fundamental, multi-century reference. Its homogeneity has been largely maintained with a succe…

astro-ph.SR2019★ 98 cited

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

Hisashi Hayakawa, Yusuke Ebihara, David M. Willis +10

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 c…

astro-ph.SR2017★ 61 cited

Long-Lasting Extreme Magnetic Storm Activities in 1770 Found in Historical Documents

Hisashi Hayakawa, Kiyomi Iwahashi, Yusuke Ebihara +8

Dim red aurora at low magnetic latitudes is a visual and recognized manifestation of geomagnetic storms. The great low-latitude auroral displays seen throughout East Asia on 16-18…