A special transformation is found to solve the Magnetohydrodynamic equations,by which two classes of exactanalytic time-dependent solutions of magnetic annihilation for incompressible magnetic fluid have been obtained...A special transformation is found to solve the Magnetohydrodynamic equations,by which two classes of exactanalytic time-dependent solutions of magnetic annihilation for incompressible magnetic fluid have been obtained.The solutions derived here possesses scaling property with time t as the scale factor.We find that the currentcan perform the soliton-like behaviour in the case of asymmetric inflow.The relevant evolution characteristics inthe process of magnetic annihilation are also revealed.展开更多
Some observational examples for the possible occurrence of the turbulent magnetic reconnection in the solar wind are found by analysing Helios spacecraft’s high resolution data. The phenomena of turbulent magnetic re...Some observational examples for the possible occurrence of the turbulent magnetic reconnection in the solar wind are found by analysing Helios spacecraft’s high resolution data. The phenomena of turbulent magnetic reconnections in small scale solar wind are simulated by introducing a third order accuracy upwind compact difference scheme to the compressible two-dimensional MHD flow. Numerical results verify that the turbulent magnetic reconnection process could occur in small scale interplanetary solar wind, which is a basic feature characterizing the magnetic reconnection in high-magnetic Replolds number (R(inM) = 2 000-10 000) solar wind. The configurations of the magnetic reconnection could evolve from a single X-line to a multiple X-line reconnection, exhibiting a complex picture of the formation, merging and evolution of magnetic islands, and finally the magnetic reconnection would evolve into a low-energy state. Its life-span of evolution is about one hour order of magnitude. Various magnetic and flow signatures are recorded in the numerical test for different evolution stages and along different crossing paths, which could in principle explain and confirm the observational samples from the Helios spacecraft. These results are helpful for revealing the basic physical processes in the solar wind turbulence.展开更多
基金Supported by the National Natural Science Poundation of China under Grant Nos.49990453 and 49925412,and Chinese Postdoctoral Foundation.
文摘A special transformation is found to solve the Magnetohydrodynamic equations,by which two classes of exactanalytic time-dependent solutions of magnetic annihilation for incompressible magnetic fluid have been obtained.The solutions derived here possesses scaling property with time t as the scale factor.We find that the currentcan perform the soliton-like behaviour in the case of asymmetric inflow.The relevant evolution characteristics inthe process of magnetic annihilation are also revealed.
文摘Some observational examples for the possible occurrence of the turbulent magnetic reconnection in the solar wind are found by analysing Helios spacecraft’s high resolution data. The phenomena of turbulent magnetic reconnections in small scale solar wind are simulated by introducing a third order accuracy upwind compact difference scheme to the compressible two-dimensional MHD flow. Numerical results verify that the turbulent magnetic reconnection process could occur in small scale interplanetary solar wind, which is a basic feature characterizing the magnetic reconnection in high-magnetic Replolds number (R(inM) = 2 000-10 000) solar wind. The configurations of the magnetic reconnection could evolve from a single X-line to a multiple X-line reconnection, exhibiting a complex picture of the formation, merging and evolution of magnetic islands, and finally the magnetic reconnection would evolve into a low-energy state. Its life-span of evolution is about one hour order of magnitude. Various magnetic and flow signatures are recorded in the numerical test for different evolution stages and along different crossing paths, which could in principle explain and confirm the observational samples from the Helios spacecraft. These results are helpful for revealing the basic physical processes in the solar wind turbulence.
