We investigate spatial and temporal scales at which wave-particle interaction of Alfvén waves occurs in Jupiter's magnetosphere. We consider electrons, protons, and oxygen ions and study the regions along magnetic flux tubes where the plasma is the densest, that is, the equatorial plasma sheet, and where the plasma is the most dilute, that is, above the ionosphere, where auroral particle acceleration is expected to occur. We find that within a dipole L-shell of roughly 30, the electron inertial length scale in the auroral region is the dominating scale, suggesting that electron Landau damping of kinetic Alfvén waves can play an important role in converting field energy into auroral particle acceleration. This mechanism is consistent with the broadband bidirectional electron distributions frequently observed by Juno. Due to interchange-driven mass transport in Jupiter's magnetosphere, its magnetosphere-ionosphere coupling is expected to be mostly not in local force balance. This might be a key reason for the dominant role of Alfvénically driven stochastic acceleration compared to the less frequently occurring, locally forced-balanced, and thus static mono-energetic unidirectional acceleration. Outside of approximately L = 30, the ion gyroperiod is the dominating scale suggesting that ion cyclotron damping of heavy ions plays a major role in heating magnetospheric plasma. We also present properties of the dispersion relationship and the polarization relationships of kinetic Alfvén waves including the important effects from the relativistic correction due to the displacement current in Ampère's law.

In hydrodynamic turbulence, it is well established that the length of the dissipation scale depends on the energy cascade rate, i.e., the larger the energy input rate per unit mass, the more the turbulent fluctuations need to be driven to increasingly smaller scales to dissipate the larger energy flux. Observations of magnetic spectral energy densities indicate that this intuitive picture is not valid in solar wind turbulence. Dissipation seems to set in at the same length scale for different solar wind conditions independently of the energy flux. To investigate this difference in more detail, we present an analytic dissipation model for solar wind turbulence at electron scales, which we compare with observed spectral densities. Our model combines the energy transport from large to small scales and collisionless damping, which removes energy from the magnetic fluctuations in the kinetic regime. We assume wave-particle interactions of kinetic Alfvén waves (KAW) to be the main damping process. Wave frequencies and damping rates of KAW are obtained from the hot plasma dispersion relation. Our model assumes a critically balanced turbulence, where larger energy cascade rates excite larger parallel wavenumbers for a certain perpendicular wavenumber. If the dissipation is additionally wave driven such that the dissipation rate is proportional to the parallel wavenumber -as with KAW -then an increase of the energy cascade rate is counter-balanced by an increased dissipation rate for the same perpendicular wavenumber leading to a dissipation length independent of the energy cascade rate.

AFRICOM conducts hundreds of senior leader engagements (SLEs) each year throughout the African continent in order to create strategic partnerships and military relationships that preserve American interests abroad. While AFRICOM has been planning and executing these engagements since the inception of the organization in 2008, it lacks a well-defined method to systemize its SLE process. As a result, SLE development is largely ad hoc, potentially decreasing the strategic effectiveness of the engagements and increasing their cost. This paper delineates a decision-making framework to redesign and enhance AFRICOM’s SLE program. In particular, it posits a multiple objective decision analysis model that quantifies key stakeholder values and develops several alternatives for future evaluation. Of note, potential solutions imagine a more expansive system where subsets of Senior Leaders (SLs) are assigned to clusters of African countries based on the SLs’ similarity to countries within each cluster, providing a basis for relationship ownership and mutual trust.