Long-term variation of galactic cosmic ray intensity observed with the Nagoya multidirectional muon detector

Kazuoki Munakata; Rafael Mendonca; Chihiro Kato; Munetoshi Tokumaru

Presentation information

[E] Oral

P (Space and Planetary Sciences ) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM12] Space Weather and Space Climate

Tue. May 28, 2019 9:00 AM - 10:30 AM A04 (TOKYO BAY MAKUHARI HALL)

convener:Ryuho Kataoka(National Institute of Polar Research), Antti A Pulkkinen(NASA Goddard Space Flight Center), Kanya Kusano(Institute for Space-Earth Environmental Research, Nagoya University), Kaori Sakaguchi(National Institute of Information and Communications Technology), Chairperson:Ryuho Kataoka(National Institute of Polar Research)

9:45 AM - 10:00 AM

[PEM12-28] Long-term variation of galactic cosmic ray intensity observed with the Nagoya multidirectional muon detector

*Kazuoki Munakata¹, Rafael Mendonca², Chihiro Kato¹, Munetoshi Tokumaru³ (1.Department of Physics, Faculty of Science, Shinshu University, 2.INPE, Brazil, 3.ISEE, Nagoya University)

Keywords:long-term variation of galactic cosmic ray intensity, energy spectrum of galactic cosmic rays, solar modulation

We have recently developed a correction method of the atmospheric temperature effect on muon count rate by using the GMDN (Global Muon Detector Network) data (R. R. S. Mendonca et al., Astrophys. J., 830:88, 2016). This is a significant step, because it makes possible for the first time to analyze the long-term variation of ~50 GeV cosmic ray density (i.e. isotropic intensity) which has been nalyed only for cosmic ray below ~10 GeV using the neutron monitor data nearly free from the temperature effect. In this paper, we report the 11-year and 22-year variations of cosmic ray density observed with Nagoya muon detector in 1970-2016 and discuss the energy dependence of variations by comparing the observation with neutron monitors.