130 citations · 227 across the 16 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…
Role of CME clusters and CME-CME interactions in producing sustained -ray emission
Atul Mohan, Pertti Makela, Natchimuthuk Gopalswamy +2
Fast (V>1000) coronal mass ejections (CMEs) capable of accelerating protons beyond 300MeV are thought to trigger hours-long sustained -ray emissi…
Relationship between prominence eruptions and coronal mass ejections during solar cycle 24
Pooja Devi, Nat Gopalswamy, Seiji Yashiro +3
In this article, we present the relationship between prominence eruptions (PEs) and coronal mass ejections (CMEs) from May 2010 to December 2019 covering most of solar cycle 24. We…
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…
Multispacecraft Observations of the 2024 September 9 Backside Solar Eruption that Resulted in a Sustained Gamma Ray Emission Event
Nat Gopalswamy, Pertti Mäkelä, Sachiko Akiyama +6
We report on the 2024 September 9 sustained gamma ray emission (SGRE) event observed by the Large Area Telescope (LAT) onboard the Fermi satellite. The event was associated with a…
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…
The Solar and Geomagnetic Storms in May 2024: A Flash Data Report
Hisashi Hayakawa, Yusuke Ebihara, Alexander Mishev +16
In May 2024, the scientific community observed intense solar eruptions that resulted in a great geomagnetic storm and auroral extension, highlighting the need to document and quant…
Implications of the abundance of halo coronal mass ejections for the strength of solar cycle 25
Nat Gopalswamy, Grzegorz Michalek, Seiji Yashiro +3
We assess the relative strength of solar cycle (SC) 25 with respect to SCs 23 and 24 based on the abundance of halo coronal mass ejections (CMEs). We make use of the halo CME datab…
The SOHO LASCO CME Catalog -- Version 2
Nat Gopalswamy, Grzegorz Michałek, Seiji Yashiro +4
This paper provides an update on the coronal mass ejection (CME) catalog maintained at the CDAW Data Center, NASA Goddard Space Flight Center (https://cdaw.gsfc.nasa.gov/CME_list).…
Rotation of a Stealth CME on 2012 October 5 Observed in the Inner Heliosphere
Sandeep Kumar, Dinesha V. Hegde, Nandita Srivastava +3
Coronal Mass Ejections (CMEs) are subject to changes in their direction of propagation, tilt, and other properties. This is because CMEs interact with the ambient solar wind and ot…
What is Unusual about the Third Largest Geomagnetic Storm of Solar Cycle 24?
N. Gopalswamy, S. Yashiro, S. Akiyama +4
We report on the solar and interplanetary (IP) causes of the third largest geomagnetic storm (2018 August 26) in solar cycle 24. The underlying coronal mass ejection (CME) originat…
The Balloon-borne Investigation of Temperature and Speed of Electrons in the corona (BITSE): Mission Description and Preliminary Results
N. Gopalswamy, J. Newmark, S. Yashiro +16
We report on the Balloonborne Investigation of Temperature and Speed of Electrons in the corona (BITSE) mission launched recently to observe the solar corona from about 3 Rs to 15…
A Catalog of Prominence Eruptions Detected Automatically in the SDO/AIA 304 Å Images
S. Yashiro, N. Gopalswamy, S. Akiyama +1
We report on a statistical study of prominence eruptions (PEs) using a catalog of these events routinely imaged by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamic…
Comparative Study of Microwave Polar Brightening, Coronal Holes, and Solar Wind Over the Solar Poles
Ken'ichi Fujiki, Kiyoto Shibasaki, Seiji Yashiro +3
We comparatively studied the long-term variation (1992-2017) in polar brightening observed with the Nobeyama Radioheliograph, the polar solar wind velocity with interplanetary scin…
Statistical Relation between Solar Flares and Coronal Mass Ejections with Respect to Sigmoidal Structures in Active Regions
Y. Kawabata, Y. Iida, T. Doi +3
Statistical dependencies among features of coronal mass ejections (CMEs), solar flares, and sigmoidal structures in soft-X-ray images were investigated. We applied analysis methods…