第67回「非線形・統計力学とその周辺」セミナーのご案内
日時:平成17年9月13日(火)午後1時半〜午後2時半
場所:京都大学工学部総合校舎102室
講演者: Prof. Abraham C.-L. Chian
(Solar-Terrestrial Environment Laboratory (STEL), Nagoya Univ.
& National Institute for Space Research (INPE), Brazil)
講演題目:
On the Complex Nature of Space Environment
講演要旨:
Sun-Earth system is a complex, electrodynamically coupled, system dominated by nonlinear interactions. The complex behaviors of space environment are an indication that it is in a state far from equilibrium whereby instabilities, nonlinear waves and turbulence play key roles in the system dynamics. One of the ubiquitous features of the complex space environment is the occurrence of intermittency and chaos in solar dynamo, solar corona, solar wind, and terrestrial magnetosphere-ionosphere-atmosphere. First we will discuss the observational evidence of intermittency and chaos in the solar-terrestrial environment. Next we will discuss a chaotic model of interplanetary Alfven intermittency and its relevance for the understanding of solar-wind driving of intense geomagnetic activities. We show that the origin of temporal intermittency and spatiotemporal intermittency is the unstable structures, namely, chaotic saddles and unstable periodic orbits, embedded in the chaotic attractors. The characteristics intermittency time obeys a scaling law which can be useful for space weather forecasting and economic forecasting. We will complete this talk by reviewing the ongoing research and training activities of the international network WISER - World Institute for Space Environment Research (http://www.cea.inpe.br/wiser), which focuses on the application of complex systems science for monitoring and forecasting natural disasters in the Earth-Oceans-Space (EOS) systems. Chian ACL et al., Phys. Rev. E 65, 035203 (R), 2002. Rempel EL, Chian ALC, Phys. Lett. A 319, 104, 2003. Rempel EL et al., Physica D 199, 407, 2004. Rempel EL, Chian ACL, Int. J. Bifurcation & Chaos 14, 4009, 2004. Rempel EL et al., Chaos 14, 545, 2004. Rempel EL, Chian ACL, Phys. Rev. E 71, 016203, 2005.