• collisional damping;
  • collisionless damping;
  • ray tracing;
  • whistler waves

[1] In this letter we consider the dissipation of magnetospherically reflecting whistler waves from both ionospheric sources and from sources outside the plasmasphere such as chorus. We use a simple spatially dependent model of the suprathermal electron population, a standard cold plasma density model based on a diffusive equilibrium, and a range of plasmaspheric temperatures to demonstrate that the often-ignored (electron-ion) collisional damping is usually at least the same order of magnitude and often an order of magnitude larger than the dissipation due to collisionless damping (Landau and transit-time). Furthermore the collisional damping is sensitive to the cold plasmaspheric temperature, which depends on location (night/day-side) and solar conditions. These results indicate that accurate spatially dependent models of plasmaspheric temperatures as well as suprathermal electron fluxes are necessary for modeling the dissipation of magnetospherically reflecting whistler waves.