88 citations · 207 across the 17 of their papers we have counts for
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Unusual Circumstances of the 2024 June 8 GLE
Nat Gopalswamy, Pertti Makela, Hong Xie +3
Ground Level Enhancement (GLE) in large solar energetic particle (SEP) events is indicative of protons accelerated to GeV energies. Almost all GLE events are associated with sustai…
Third Harmonic Structure in an Interplanetary Type II Radio Burst and Other Energetic Phenomena During the 2024 September 14 Solar Eruption
Nat Gopalswamy, Pertti Makela, Hong Xie +2
We report on the observation of first, second, and third harmonic components during an interplanetary (IP) type II solar radio burst observed on 2024 September 14 by the radio inst…
The Longest Duration SGRE Event in Solar Cycle 25
Nat Gopalswamy, Pertti Makela, Hong Xie +2
Solar Cycle (SC) 24 was the weakest in the space age, yet it produced many sustained gamma ray emission (SGRE) events from the Sun. Solar cycle (SC) 25, which is a bit stronger tha…
Solar Cycle Variation of Axial Orientations and Favorable Locations of Eruptive MFRs
Hong Xie, Nat Gopalswamy, Sachiko Akiyama +2
Using multi-viewpoint observations from STEREO and SOHO during three solar cycles from 23 to 25, we study the magnetic flux rope (MFR) structures of coronal mass ejections (CMEs) n…
Intense Geomagnetic Storms during Solar Cycles 23-25
N. Gopalswamy, S. Akiyama, S. Yashiro +2
Intense geomagnetic storms are characterized by a minimum value of the Dst index at or below -100 nT. It is well known that these storms are caused by the southward magnetic fields…
What do halo CMEs tell us about solar cycle 25?
Nat Gopalswamy, Grzegorz Michalek, Seiji Yashiro +3
It is known that the weak state of the heliosphere due to diminished solar activity in cycle 24 back-reacted on coronal mass ejections (CMEs) to make them appear wider for a given…