3-D MHD simulation of plasmoid formation during coalescence of two current loops     

Toshiaki Fushiki  Jun-Ichi Sakai 《Solar physics》1995,156(2):265-280

We consider two force-free current loops, as proposed by Gold and Hoyle (1960), as the initial current loops, to investigate two types of the magnetic reconnection process, the partial and complete reconnections during coalescence of these loops, by using a 3-D resistive MHD code. It is shown that two plasmoids can be produced on both sides of the coalescence area by both types of the magnetic reconnection process during coalescence of two current loops. It is also shown that strong fast magnetosonic waves can be induced in the partial reconnection case of two-current-loop collision. When two current loops collide locally at two points, four plasmoids can be produced and two of these plasmoids merge into one.  相似文献   

3-D MHD simulation of the generation of a shell current loop with closure current     

Jun-Ichi Sakai  Toshiaki Fushiki 《Solar physics》1995,156(2):281-292

We present results for the generation process of a shell current loop by using a three-dimensional ideal MHD code. It is shown that a shell current loop with a diffuse closure current can be generated due to the twisting motions of the loop footpoints. It is also shown that during the generation of a shell current loop, plasma density enhancement propagates along a shell current loop. It is suggested that the generation process of a shell current loop may be related to the movement of soft X-ray enhancement from the footpoints along a loop before onset of a solar flare.  相似文献   

Microstructural development of fine-grained quartz aggregates by syntectonic recrystallization     

Toshiaki Masuda  Akio Fujimura   《Tectonophysics》1981,72(1-2)

Experimental study of syntectonic recrystallization of fine-grained quartz aggregates was carried out in order to simulate the development of some natural microstructures of quartz tectonites and to understand their formation condition. Agate was axially compressed with a constant-strain-rate apparatus. Experiments were conducted at 4 kbar solid confining pressure, 700–1000°C and 10⁻⁴-10⁻⁶ sec⁻¹ to 10%–45% strain. In all runs, deformation has proceeded under wet condition caused by dehydration of pyrophyllite used as pressure medium.Two different types of microstructure were distinguished in the deformed specimens. One is P-type which is characterized by equant, equidimensional, and polygonal grains. The other is S-type which is characterized by the highly oblate grains with the largest dimension perpendicular to the compression axis. The P-type microstructure is developed at higher temperatures and slower strain rates, while the S-type developed at lower temperatures and faster strain rates. The transition between the S- and P-types is found to be very sharp.  相似文献   

Three different downstream fates of the boreal-summer MJOs on their passages over the Maritime Continent     

Fu  Joshua-Xiouhua  Wang  Wanqiu  Ren  Hong-Li  Jia  Xiaolong  Shinoda  Toshiaki 《Climate Dynamics》2018,51(5-6):1841-1862

Climate Dynamics - The boreal-summer MJOs exhibit three distinctive downstream evolutions on their passages over the Maritime Continent (MC): (i) smoothly transitioning from Indian Ocean (IO) to...  相似文献