Temporal variability of quasi-linear pitch-angle diffusion

Kinetic wave-particle interactions in Earth’s outer radiation belt energize and scatter high-energy electrons, playing an important role the dynamic variation of extent intensity belt. It is possible to model effects across long length time scales using quasi-linear theory, leading a Fokker-Planck equation describe waves on high energy electrons. This powerful theory renders efficacy interaction diffusion coefficient that varies with or momentum pitch angle. In this article we determine how responds temporal case pitch-angle due plasmaspheric hiss. Guided by in-situ observations hiss wave activity local number density change time, use stochastic parameterisation evolution coefficients ensemble numerical experiments. These experiments are informed from three different example locations near-Earth space, comparison results indicates differences distribution can result material solutions. We demonstrate solutions depend both upon timescale variability (varied between minutes hours), shape coefficients. Based theoretical construction presented here, argue there useful maximum averaging should be used construct observations, likely less than orbital period most inner magnetospheric missions. discuss relative drift velocity electrons confirm arithmetic drift-averaging appropriate some cases. show locations, rare but large values occur during periods relatively low density. Ensemble sensitive presence these values, supporting need for accurate cold plasma models descriptions.