GEM: Diffuse and Discrete Auroral Electron Precipitation Effects On Magnetosphere-Ionosphere Coupling

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The aurora, also commonly known as the Northern lights, display dynamic, brilliant lights in the Earth’s sky during magnetic disturbances that emanate from the sun. The aurora is an important space weather phenomenon that links what is happening much farther away from the Earth in space to our atmosphere. During magnetically disturbed conditions, electrons that precipitate or rain down into the sky cause these brilliant lights. The precipitating electrons are a source of energy to the atmosphere and can cause space weather effects that are of concern to society and national space security. For example, the redistribution of energy from the precipitating electrons can affect predictions of orbits of satellites in the atmosphere and/or predictions of the location of re-entry of spacecraft back to Earth. The proposed research activities will lead to improved scientific understanding and modeling of the very complex auroral electron precipitation effects. The research outcomes will contribute to a broader NSF-supported community effort of Geospace Environment Modeling (GEM) for advancing space weather models. It enables two underrepresented female scientists to engage in fundamental research that will positively impact national space security concerns. The project will involve career mentoring of an early career female scientist and research training of diverse undergraduate student interns at The Aerospace Corporation that are vital for supporting diversity, equity, and inclusion in the next generation of space scientists and engineers. The objective of this proposal is to understand better the role of diffuse and discrete auroral electron precipitation on magnetosphere-ionosphere (MI) electrodynamic coupling. The science questions are (SQ1) How does diffuse auroral electron precipitation affect the auroral ionospheric conductivity, height-integrated conductance, field-aligned currents, and the ionospheric and inner magnetospheric electric field through the electrodynamic MI coupling during magnetic storms? Can a magnetically and electrically self-consistent treatment of the particle transport and loss, including diffuse auroral precipitation, account for observed conductance (PFISR), field-aligned currents (AMPERE), and electric fields (PFISR, DMSP, Van Allen Probes) during storms? (SQ2) What are the ionospheric conductivity and height-integrated conductance associated with representative discrete auroral electron precipitation in localized regions during magnetic disturbances? What are the effects of the superimposed diffuse and localized discrete auroral electron precipitation on the inner magnetospheric electric field and particle transport? To address SQ1, a coupling of three models will be used: (1) the magnetically and electrically self-consistent Rice Convection Model-Equilibrium (RCM-E) that calculates inner magnetospheric particle transport and precipitation due to the effect of wave-particle interactions, (2) the Superthermal Electron Transport (STET) model that will modify the RCM-E precipitating electron fluxes to include the effects of backscatter and multiple reflections between conjugate hemispheres, and (3) results from the B3C auroral transport model that computes altitudinal profiles of conductivity. To address SQ2, parameterized representative Gaussian auroral electron distributions will be used with STET and the B3C model to compute ionospheric conductivity. Observations such as ground-based photometers and All Sky Imaging data will be used to constrain the integrated electron energy flux, and the average energy of the discrete auroral precipitation will be parameterized. Simulations will be performed to include the conductance and potential drops associated with the discrete aurora in a localized region overlapping the broader diffuse aurora to investigate the effects on the inner magnetospheric particle transport.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.