研究期間：10108~10207;Earth’s space environment above 1000 km from the Earth to the edge of the solar system is permeated nearly with collisionless ionized gas – plasma which consists of primarily electrons and ions (protons etc.). One of the major characteristics associated with collisionless space plasmas is its extremely low number density which could not possibly be produced in the laboratory. In addition space plasma is intrinsically magnetized that the generation and evolution of large scale magnetic field is of great interest to space scientists. Due to the lack of collisions many interesting plasma phenomena with wide range of temporal and spatial scales such as the formation of thin current sheets and nonlinear plasma waves etc. may develop which can only be observed by in-situ measurement of spacecraft. Studies of collisionless space plasmas are not only of fundamental and challenging research but also have important applications. Indeed the topics of how the solar wind particles at the magnetopause current may find ways to enter into the magnetosphere, then be stored in the magnetotail in the form of thin current and transported to the near-Earth space environment are one of the major issues of space plasma physics as well as space weather. Under the support of National Science Council grants we have made several important discoveries and contributions to space plasma physics in the past few years, including nonthermal plasma physics, the structure and dynamics of thin current sheet as well as nonlinear plasma waves and instabilities etc. The proposed three-year research project will focus on two major important problems of space plasma physics by utilizing the magntohydrodynamic (MHD) and kinetic theories along with modeling、 numerical simulations as well as data analyses etc. (1) The physics of large-scale magnetized plasma current sheet with the applications to magnetopause and magnetotail currents、solar plasma and interplanetary space etc. In particular, we will study the propagation of low-frequency plasma wave in thin current sheet and analyze its stability due to the nonthermal effect as well as study the magnetic reconnection based on MHD and particle simulations. The structure and dynamics of magnetopause currents in terms of magnetic reconnection will also be studied systematically by analyzing the satellite data. (2) The physics of nonlinear plasma waves with the applications to the solar wind、interplanetary space and magnetosphere etc. The structure、formation and evolution of solitary waves、magnetic holes、shock waves and magnetic flux tubes/ropes etc. will be studied based on fluid and kinetic theories as well as numerical simulations.
