Dipole density solitons and solitary dipole vortices in an inhomogeneous space plasma

A new type of density soliton, a dipole density soliton, as well as single dip and hump density solitons, were discovered in recent satellite observations of space plasmas. Moreover, these three kinds of density solitons are all associated with similar local electromagnetic fluctuations with Alfven characteristics. This indicates that they originate from the same physical mechanism. We propose that the solitary plasma dipole vortex moder can consistently account for these three kinds of density solitons, with the differences in their appearances attributed to the differences in the positions and directions at which the satellite crosses the solitary dipole vortex.