||Department of Earth System Science and Technology, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Fluid Dynamics for Global Environmental Studies, Springer, 10.1007/978-4-431-56499-7, Chapter 9 "Space Plasma Environment" (pp.287-332) written by T. Hada., 2017.06.
||E. Mjølhus, Tohru Hada, Soliton Theory of Quasi-Parallel MHD Waves, Terra Scientific Publishing Company, 121-169, 1997.08, There has been some attention to soliton theory for MHD waves in the space plasma community; in particular, the DNLS equation, which describes the behavior of quasi parallel weakly nonlinear and weakly dispersive MHD waves, has been emphasized. Some of the virtues of this model are that (i) there is an abundance of known exact solutions, and (ii) it contains the KdV, MKdV and NLS equations as limiting cases. In this text, the properties of the DNLS equation is reviewed: its physical significance, the exact solutions, its IST, and the soliton formation processes. Finally, the process of dispersive steepening as described by the DNLS equation, is discussed; a combined process of modulational instability and nonlinear Landau damping is described, and the oblique two-parameter solitons are for the first time exhibited in detail..
||Tohru Hada, Hiroshi Matsumoto, Nonlinear Waves and Chaos in Space Plasmas, Terra Publication Company, 1997.08.
||Tohru Hada, Nonlinear evolution of waves and shocks in the solar wind, Univ. of California, Los Angeles, 1985.12, The nonlinear evolution of finite amplitude low-frequency waves is studied by means of analytic theory and numerical simulation, with special emphasis on their relation to shock waves. The steepening rate for finite amplitude magnetohydrodynamic (MHD) waves is defined. It is argued analytically and proved numerically that a wave will steepen to form a shock only when the steepening rate is greater than the collisionless damping rate. This simple criterion suggests that, whereas the MHD fast model should ordinarily steepen, steepened slow waves may occur rarely near 1 AU, in agreement with spacecraft observations. Numerical simulations using a hybrid code show that slow mode waves are subject to strong Landau damping. Nonlinearly steepened waves are also detected in the earth's foreshock, in association with beam ions backstreaming from the bowshock, as a possible free energy source for wave growth. However, linear instability analysis shows that, regardless of the beam ion types, the maximum growth occurs for parallel propagation for which the waves are purely electromagnetic and noncompressive, and cannot steepen..
||C. F. Kennel, J. P. Edmiston, Tohru Hada, A quarter century of collisionless shock research, American Geophysical Union, A87-25326, 1-36, 1985.01.