Japan Geoscience Union Meeting 2016

Presentation information

International Session (Poster)

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

[P-EM04] Space Weather, Space Climate, and VarSITI

Sun. May 22, 2016 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall HALL6)

Convener:*Ryuho Kataoka(National Institute of Polar Research), Antti Pulkkinen(NASA GSFC), Yusuke Ebihara(Research Institute for Sustainable Humanosphere, Kyoto University), Yoshizumi Miyoshi(Institute for Space-Earth Environmental Research, Nagoya University), Toshifumi Shimizu(Institute of Space and Astronautical Science, JAXA), Ayumi Asai(Unit for Synergetic Studies of Space, Kyoto University), Hidekatsu Jin(National Institude of Information and Communications Technology), Tatsuhiko Sato(Japan Atomic Energy Agency), Kanya Kusano(Institute for Space-Earth Environmental Research, Nagoya University), Hiroko Miyahara(College of Art and Design, Musashino Art University), Kiminori Itoh(Graduate School of Engineering, Yokohama National University), Kazuo Shiokawa(Institute for Space-Earth Environmental Research, Nagoya University), Takuji Nakamura(National Institute of Polar Research), Shigeo Yoden(Division of Earth and Planetary Sciences, Graduate School of Science, Kyoto University), Kiyoshi Ichimoto(Kwasan and Hida Observatories, Kyoto University), Mamoru Ishii(National Institute of Information and Communications Technology)

5:15 PM - 6:30 PM

[PEM04-P24] Solar energy transport with significantly suppressed velocity

*Shota Arai1, Hideyuki Hotta1 (1.Astorophysics Laboratory , Department of Physics , Faculty of Science , Chiba University)

Keywords:Sun, Thermal convection, Magnetic field

We carry out a series of 2D convection calculations with highly suppressed velocity. Thermal convection in the solar interior is thought to maintain differential rotation and meridional circulation. Although the solar equator is rotating faster than polar region, recent high-resolution calculations with solar parameters accelerate the pole. This problem can be attributed to over-excited thermal convection in numerical calculations. Local helioseismology also supports this finding. Recent MHD simulations suggest that the small-scale Lorentz force is able to suppress the convection velocity, but the suppression is not enough and has not been numerical converged, i.e., higher resolution shows stronger suppression.
In this study, we assume that the Lorentz feedback in extremely high resolution, i.e., the sun, becomes stronger enough to explain equator acceleration and the result of the local helioseismology. In order to investigate this extreme condition, we carry out series of 2D hydrodynamics simulations with high viscosity mimicking the strong Lorentz force. The purpose of our research is to investigate energy flux transported by the thermal convection. Even if the velocity is reduced, convection needs to transport imposed energy flux at the bottom boundary. Generally it is expected that upflow and down flow become hotter and cooler, respectively than those without viscosity. We also find that the correlation becomes better with high viscosity with suppressing the small-scale chaotic motion.