91 citations · 830 across the 33 of their papers we have counts for
6 papers · 1 filter
A Review for Japanese auroral records on the three extreme space weather events around the International Geophysical Year (1957 -- 1958)
Hisashi Hayakawa, Yusuke Ebihara, Hidetoshi Hata
Solar Cycle 19 was probably the greatest solar cycle over the last four centuries and significantly disrupted the solar-terrestrial environments with a number of solar eruptions an…
The current state and future directions of modeling thermosphere density enhancements during extreme magnetic storms
Denny M. Oliveira, Eftyhia Zesta, Piyush M. Mehta +4
Satellites, crewed spacecraft and stations in low-Earth orbit (LEO) are very sensitive to atmospheric drag. A satellite's lifetime and orbital tracking become increasingly inaccura…
Temporal Variations of the Three Geomagnetic Field Components at Colaba Observatory around the Carrington Storm in 1859
Hisashi Hayakawa, Heikki Nevanlinna, Séan P. Blake +3
The Carrington storm in 1859 September has been arguably identified as the greatest geomagnetic storm ever recorded. However, its exact magnitude and chronology remain controversia…
Analyses of a Datable Solar Eclipse Record in Maya Classic Period Monumental Inscriptions
Hisashi Hayakawa, Misturu Sôma, J. Hutch Kinsman
Historical records of total solar eclipses provide vital information for computing the rotation of the Earth and understanding its long-term variations by providing data from the t…
Stephan Prantner's Sunspot Observations during the Dalton Minimum
Hisashi Hayakawa, Shoma Uneme, Bruno P. Besser +2
In addition to regular Schwabe cycles (~ 11 years), solar activity also shows longer periods of enhanced or reduced activity. Of these, reconstructions of the Dalton Minimum provid…
Daniel Mögling's sunspot observations in 1626 - 1629: A manuscript reference for the solar activity before the Maunder Minimum
Hisashi Hayakawa, Tomoya Iju, Koji Murata +1
The sunspot groups have been observed since 1610 and their numbers have been used for evaluating the amplitude of solar activity. Daniel Mögling recorded his sunspot observations f…