Solitary kinetic Alfven waves in the inertial limit region

Considering the effects of hot ions and Lorentz force, a numerical study on the properties of solitary kinetic Alfven waves (SKAWs) in the inertial li mit region in the magnetosphere is presented. In contrast to the results ob tained by Hasegawa and Mima [Phys. Rev. Lett. 37, 690 (1976)], Shukla et al . [J. Plasma Phys. 28, 125 (1982)], and Wu et al. [Phys. Plasmas 3, 2879 (1 996)], both hump and dip density Alfvenic solitons can exist in the inertia l limit region (beta much less than 2m(e)/m(i), where beta (= 2 mu(0)nT(e)/ B-0(2)) is the ratio of thermal pressure to magnetic pressure). These resul ts provide a more realistic interpretation for the SKAWs phenomena observed by the Freja satellite, in which not only SKAWs accompanied by dip density solitons, but also SKAWs accompanied by hump density solitons were found a t the Earth's ionospheric altitude. (C) 2000 American Institute of Physics. [S1070-664X(00)03701-0].