Radiation dose forecast of WASAVIES during ground‐level enhancement

Kataoka, Ryuho; Sato, Tatsuhiko; Kubo, Yûki; Shiota, Daikou; Kuwabara, T.; Yashiro, S.; Yasuda, Hiroshi

doi:10.1002/2014sw001053

Cited by 26 publications

(23 citation statements)

References 31 publications

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“…Our simulations can provide solar wind speed profiles as well as occurrence probabilities for magnetic storms, which are both important for radiation‐belt forecasting [ Miyoshi et al , ; Kataoka and Miyoshi , , ]. The magnetic field lines connecting CME shocks and the Earth will be important information for future predictions of solar energetic particles [ Rouillard et al , ; Kataoka et al , ]. The timing of energetic particles flux enhancement [ Mertens et al , ] are associated with the shock propagations investigated in this study.…”

Section: Summary and Discussionmentioning

confidence: 95%

Magnetohydrodynamic simulation of interplanetary propagation of multiple coronal mass ejections with internal magnetic flux rope (SUSANOO‐CME)

2016

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Coronal mass ejections (CMEs) are the most important drivers of various types of space weather disturbance. Here we report a newly developed magnetohydrodynamic (MHD) simulation of the solar wind, including a series of multiple CMEs with internal spheromak‐type magnetic fields. First, the polarity of the spheromak magnetic field is set as determined automatically according to the Hale‐Nicholson law and the chirality law of Bothmer and Schwenn. The MHD simulation is therefore capable of predicting the time profile of the southward interplanetary magnetic field at the Earth, in relation to the passage of a magnetic cloud within a CME. This profile is the most important parameter for space weather forecasts of magnetic storms. In order to evaluate the current ability of our simulation, we demonstrate a test case: the propagation and interaction process of multiple CMEs associated with the highly complex active region NOAA 10486 in October to November 2003, and present the result of a simulation of the solar wind parameters at the Earth during the 2003 Halloween storms. We succeeded in reproducing the arrival at the Earth's position of a large amount of southward magnetic flux, which is capable of causing an intense magnetic storm. We find that the observed complex time profile of the solar wind parameters at the Earth could be reasonably well understood by the interaction of a few specific CMEs.

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Section: Summary and Discussionmentioning

confidence: 95%

Magnetohydrodynamic simulation of interplanetary propagation of multiple coronal mass ejections with internal magnetic flux rope (SUSANOO‐CME)

2016

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“…In order to estimate the GCR flux at a top of atmosphere, we improved the GCR protons trace model in the geomagnetic field developed for WASAVIES (Warning System of Aviation Exposure to solar energetic particle (SEP)) [ Kataoka et al , ] so that we can obtain the geomagnetic transmission function that indicates the ability of the particle to reach a target position inside the Earth's magnetosphere. In this model, we calculated the gyromotion of GCRs in an empirical geomagnetic field by using the standard technique for the time‐reversed Lorentz trajectory of the negatively charged antiprotons [ Smart et al , ].…”

Section: Modelmentioning

confidence: 99%

Cosmic ray modulation and radiation dose of aircrews during the solar cycle 24/25

2017

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Weak solar activity and high cosmic ray flux during the coming solar cycle are qualitatively anticipated by the recent observations that show the decline in the solar activity levels. We predict the cosmic ray modulation and resultant radiation exposure at flight altitude by using the time‐dependent and three‐dimensional model of the cosmic ray modulation. Our galactic cosmic ray (GCR) model is based on the variations of the solar wind speed, the strength of the heliospheric magnetic field, and the tilt angle of the heliospheric current sheet. We reproduce the 22 year variation of the cosmic ray modulation from 1980 to 2015 taking into account the gradient‐curvature drift motion of GCRs. The energy spectra of GCR protons obtained by our model show good agreement with the observations by the Balloon‐borne Experiment with a Superconducting magnetic rigidity Spectrometer (BESS) and the Payload for Antimatter Matter Exploration and Light‐nuclei Astrophysics (PAMELA) except for a discrepancy at the solar maximum. Five‐year annual radiation dose around the solar minimum at the solar cycle 24/25 will be approximately 19% higher than that in the last cycle. This is caused by the charge sign dependence of the cosmic ray modulation, such as the flattop profiles in a positive polarity.

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“…Warning system of AVIAtion Exposure to Solar Energetic Particle (SEPs) named WASAVIES was developed by a collaboration among several institutes in Japan and the U.S. [ Kataoka et al ., ; Sato et al ., ]. The system is designed to deterministically forecast the SEP fluxes incident on the atmosphere within 6 h after flare onset using the latest space weather research facilities.…”

Section: Present Programsmentioning

confidence: 95%

Japanese space weather research activities

Ishii

2017

Space Weather

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In this paper, we present existing and planned Japanese space weather research activities. The program consists of several core elements, including a space weather prediction system using numerical forecasts, a large‐scale ground‐based observation network, and the cooperative framework “Project for Solar‐Terrestrial Environment Prediction (PSTEP)” based on a Grant‐in Aid for Scientific Research on Innovative Areas.

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Radiation dose forecast of WASAVIES during ground‐level enhancement

Cited by 26 publications

References 31 publications

Magnetohydrodynamic simulation of interplanetary propagation of multiple coronal mass ejections with internal magnetic flux rope (SUSANOO‐CME)

Magnetohydrodynamic simulation of interplanetary propagation of multiple coronal mass ejections with internal magnetic flux rope (SUSANOO‐CME)

Cosmic ray modulation and radiation dose of aircrews during the solar cycle 24/25

Japanese space weather research activities

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