Ground-based Observations of Temporal Variation of the Cosmic-Ray Spectrum during Forbush Decreases
Issued Date
2025-06-10
Resource Type
ISSN
20418205
eISSN
20418213
Scopus ID
2-s2.0-105008134686
Journal Title
Astrophysical Journal Letters
Volume
986
Issue
1
Rights Holder(s)
SCOPUS
Bibliographic Citation
Astrophysical Journal Letters Vol.986 No.1 (2025)
Suggested Citation
Mitthumsiri W., Ruffolo D., Munakata K., Kozai M., Hayashi Y., Kato C., Muangha P., Sáiz A., Evenson P., Mangeard P.S., Clem J., Seunarine S., Nuntiyakul W., Miyashita N., Kataoka R., Kadokura A., Miyake S., Iwai K., Menjo H., Echer E., Dal Lago A., Rockenbach M., Schuch N.J., Bageston J.V., Braga C.R., Al Jassar H.K., Sharma M.M., Burahmah N., Zaman F., Duldig M.L., Sabbah I., Kuwabara T. Ground-based Observations of Temporal Variation of the Cosmic-Ray Spectrum during Forbush Decreases. Astrophysical Journal Letters Vol.986 No.1 (2025). doi:10.3847/2041-8213/add7d1 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/110821
Title
Ground-based Observations of Temporal Variation of the Cosmic-Ray Spectrum during Forbush Decreases
Author(s)
Mitthumsiri W.
Ruffolo D.
Munakata K.
Kozai M.
Hayashi Y.
Kato C.
Muangha P.
Sáiz A.
Evenson P.
Mangeard P.S.
Clem J.
Seunarine S.
Nuntiyakul W.
Miyashita N.
Kataoka R.
Kadokura A.
Miyake S.
Iwai K.
Menjo H.
Echer E.
Dal Lago A.
Rockenbach M.
Schuch N.J.
Bageston J.V.
Braga C.R.
Al Jassar H.K.
Sharma M.M.
Burahmah N.
Zaman F.
Duldig M.L.
Sabbah I.
Kuwabara T.
Ruffolo D.
Munakata K.
Kozai M.
Hayashi Y.
Kato C.
Muangha P.
Sáiz A.
Evenson P.
Mangeard P.S.
Clem J.
Seunarine S.
Nuntiyakul W.
Miyashita N.
Kataoka R.
Kadokura A.
Miyake S.
Iwai K.
Menjo H.
Echer E.
Dal Lago A.
Rockenbach M.
Schuch N.J.
Bageston J.V.
Braga C.R.
Al Jassar H.K.
Sharma M.M.
Burahmah N.
Zaman F.
Duldig M.L.
Sabbah I.
Kuwabara T.
Author's Affiliation
Nagoya University
University of Tasmania
Chiang Mai University
Shinshu University
Kuwait University
Johns Hopkins University Applied Physics Laboratory
Instituto Nacional de Pesquisas Espaciais
Faculty of Science, Mahidol University
Okinawa Institute of Science and Technology Graduate University
The Bartol Research Institute
National Institute of Polar Research
University of Wisconsin-River Falls
College of Technological Studies Kuwait
Joint Support-Center for Data Science Research
National Institute of Technology (KOSEN)
University of Tasmania
Chiang Mai University
Shinshu University
Kuwait University
Johns Hopkins University Applied Physics Laboratory
Instituto Nacional de Pesquisas Espaciais
Faculty of Science, Mahidol University
Okinawa Institute of Science and Technology Graduate University
The Bartol Research Institute
National Institute of Polar Research
University of Wisconsin-River Falls
College of Technological Studies Kuwait
Joint Support-Center for Data Science Research
National Institute of Technology (KOSEN)
Corresponding Author(s)
Other Contributor(s)
Abstract
Observations of temporary Forbush decreases (FDs) in the Galactic cosmic-ray (GCR) flux due to the passage of solar storms are useful for space-weather studies and alerts. Here, we introduce techniques that use global networks of ground-based neutron monitors and muon detectors to measure variations of GCR rigidity spectra in space during FDs by (1) fitting count rate decreases for power-law rigidity spectra in space with anisotropy up to second order and (2) using the “leader fraction” derived from a single neutron monitor. We demonstrate that both provide consistent results for hourly spectral index variations for five major FDs, and they agree with daily space-based data when available from the Alpha Magnetic Spectrometer. We have also made the neutron monitor leader fraction publicly available in real time. This work verifies that ground-based observations can be used to precisely monitor GCR spectral variation over a wide range of rigidities during space-weather events, with results in real time or from short-term postanalysis.