ISSN:
1089-7674
Source:
AIP Digital Archive
Topics:
Physics
Notes:
A new type of density soliton, which we call "dipole density soliton,'' is discovered in data from the Freja satellite. Like the dip or hump density solitons that were recently discovered in the Freja data [D.-J. Wu, G.-L. Huang, and D.-Y. Wang, Phys. Plasmas 3, 2879 (1996)], the dipole density solitons are also associated with strong electric spikes (∼ a few 100 mV/m) and have a spatial scale length of a few 100 m. This indicates that the three types of density solitons (dip, hump, and dipole) probably have the same physical nature. In this paper, a two-dimensional solitary kinetic Alfvén wave (SKAW) model with a dipole vortex structure is proposed to account for the three kinds of density solitons (dip, hump, and dipole), in which the differences in their appearances can naturally be attributed to differences in the positions and directions at which the satellite crosses dipole vortex structures. Some features of this two-dimensional SKAW model are discussed, and the results are compared to the one-dimensional cases. © 1997 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.872181
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