Dynamical evolution of coherent structures in intermittent two-dimensional MHD turbulence

Recent satellite observations indicate that the Earth's magnetotail is generally in a state of intermittent turbulence. A model of sporadic localized merging of coherent structures has recently been proposed by Chang to describe the dynamics of the Earth's magnetotail. The authors report the results of MHD simulations regarding the development and merging of two dimensional coherent structures. With a magnetic shear, such coherent structures are generated in alignment with the imposed current sheet. The calculated fluctuation spectra suggest long-ranged correlations with power-law characteristics.