Imagen de Portada

Ground-based Observations of Temporal Variation of Cosmic Ray Spectrum during Forbush Decreases

Fuente: arXiv

Guardado en:

Detalles Bibliográficos
Autores principales:	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., Lago, A. Dal, Rockenbach, M., Schuch, N. J., Bageston, J. V., Braga, C. R., Jassar, H. K. Al, Sharma, M. M., Burahmah, N., Zaman, F., Duldig, M. L., Sabbah, I., Kuwabara, T.
Formato:	Preprint
Publicado:	2025
Materias:	High Energy Astrophysical Phenomena
Acceso en línea:	Acceder al recurso
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

_version_	1866918018650472448
author	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. Lago, A. Dal Rockenbach, M. Schuch, N. J. Bageston, J. V. Braga, C. R. Jassar, H. K. Al Sharma, M. M. Burahmah, N. Zaman, F. Duldig, M. L. Sabbah, I. Kuwabara, T.
author_facet	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. Lago, A. Dal Rockenbach, M. Schuch, N. J. Bageston, J. V. Braga, C. R. Jassar, H. K. Al Sharma, M. M. Burahmah, N. Zaman, F. Duldig, M. L. Sabbah, I. Kuwabara, T.
contents	Observations of temporary Forbush decreases (FDs) in the Galactic cosmic ray (GCR) flux due to 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: A) fitting count rate decreases for power-law rigidity spectra in space with anisotropy up to second order, and B) 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 AMS-02. 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 post-analysis.
format	Preprint
id	arxiv_https___arxiv_org_abs_2505_08248
institution	arXiv
publishDate	2025
record_format	arxiv
spellingShingle	Ground-based Observations of Temporal Variation of Cosmic Ray Spectrum during Forbush Decreases 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. Lago, A. Dal Rockenbach, M. Schuch, N. J. Bageston, J. V. Braga, C. R. Jassar, H. K. Al Sharma, M. M. Burahmah, N. Zaman, F. Duldig, M. L. Sabbah, I. Kuwabara, T. High Energy Astrophysical Phenomena Observations of temporary Forbush decreases (FDs) in the Galactic cosmic ray (GCR) flux due to 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: A) fitting count rate decreases for power-law rigidity spectra in space with anisotropy up to second order, and B) 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 AMS-02. 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 post-analysis.
title	Ground-based Observations of Temporal Variation of Cosmic Ray Spectrum during Forbush Decreases
topic	High Energy Astrophysical Phenomena
url	https://arxiv.org/abs/2505.08248