61 citations · 113 across the 4 of their papers we have counts for
8 papers
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…
The Extreme Space Weather Event in February/March 1941
Hisashi Hayakawa, Sean P. Blake, Ankush Bhaskar +3
Given the infrequency of extreme geomagnetic storms, it is significant to note the concentration of three extreme geomagnetic storms in 1941, whose intensities ranked fourth, twelf…
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…
A Transit of Venus Possibly Misinterpreted as an Unaided-Eye Sunspot Observation in China on 9 December 1874
Hisashi Hayakawa, Mitsuru Sôma, Kiyotaka Tanikawa +6
Large sunspots can be observed with the unaided eye under suitable atmospheric seeing conditions. Such observations are of particular value because the frequency of their appearanc…
Occurrence of Great Magnetic Storms on 6-8 March 1582
Kentaro Hattori, Hisashi Hayakawa, Yusuke Ebihara
Although knowing the occurrence frequency of severe space weather events is important for a modern society, it is insufficiently known due to the lack of magnetic or sunspot observ…
A Great Space Weather Event in February 1730
Hisashi Hayakawa, Yusuke Ebihara, José M. Vaquero +9
Aims. Historical records provide evidence of extreme magnetic storms with equatorward auroral extensions before the epoch of systematic magnetic observations. One significant magne…