Upper hybrid waves in Jupiter's outer magnetosphere are the subject of this paper which proposes a new theoretical model for their generation. Energetic electrons are assumed to be accelerated in the high- latitude auroral zone and stream away from the planet to the outer magnetosphere. The electrons travel along magnetic field lines located at the edges of the plasma sheet through a region which has the properties of a plasma sheet boundary layer similar to the terrestrial entity. The kinematic evolution of the electron beam results in a highly collimated field-aligned distribution which excites quasi-perpendicular upper hybrid waves through a so-called beam-anisotropic heat flux instability. The instability is dominated by anomalous cyclotron harmonic resonances in a parameter regime where the gyroradius of the beam electrons is comparable to the wavelength of the wave. Propagation of the upper hybrid waves across the magnetic field into a plasma density gradient produces a spectrum of Z mode waves which then undergo a linear mode conversion to ordinary mode electromagnetic radiation. The model successfully accounts for the observations of upper hybrid noise, Z mode emissions, and continuum radiation in the Jovian magnetosphere in a self-consistent coherent manner. ¿American Geophysical Union 1990