Characteristics of Solitary Waves and Weak Double Layers in the Magnetospheric Plasma

The wave experiment of the Viking satellite frequently detected dynamic small-scale (≃ 100 m), large-amplitude, rarefactive ($\left|\frac{\Delta n}{n}\right|\lesssim 50\%$) solitary waves of negative potential ($\left|\phi \right|\lesssim 2$ V) moving upwards along the magnetic field lines ($\upsilon =5\mathrm{} \mathrm{to} >50\mathrm{}$ km/s). The structures, which resemble ion holes, often have an upward-directed net potential drop (≲ 1 V) and are then interpreted as weak double layers.