9310753 Huang We propose to carry out a comprehensive investigation of the Uranian and Neptunian magnetospheres. The investigation includes the following aspects: (1) The guiding center motion of charged particles and the plasma bulk properties along a field line in the magnetospheres with large offset and tilted dipole (OTD) magnetic field; (2) The formation and configuration of the plasmaspheres at Uranus and Neptune; (3) The magnetospheric dynamics, especially the current systems and their effects on the mass and energy transports and the stability of the OTD magnetospheres; (4) The sources and transport processes of the plasma in the Uranian and Neptunian magnetospheres, The proposed studies will be developed on the basis of our previous work, the studies on the motion of chareged particles in the magnetospheres with spin axis aligned magnetic dipole field Huang et al., 1988 , the spatial variations of density and temperature along a magnetic field line in an anisotropic rotating magnetospheric plasma Huang and Birmingham, 1992 and the 3D description of magnetosphere in a OTD frame Huang and Sittler, 1993 . They will also be guided by observational data. The results of these studies would increase our understanding of the Uranian and Neptunian magnetospheres as well of the terrestrial magnetosphere. ***
