Space Science Institute

Waves Generated by Accelerated Particles Are Important Throughout Our Heliosphere. These Particles Often Gain Their Energy at Shocks via Fermi Acceleration. at the Earth's Bow Shock This Mechanism Accelerates Ion Beams Back Into the Solar Wind the Beams Can Then Generate Ultra-low Frequency (ULF) Waves When They Interact With the Background Solar Wind Plasma. These Waves Can Influence Space Weather All the Way Down to the Ground and Represent a Natural Laboratory for Future Turbulence-relevant Non-linear Studies. Despite a Clear Connection Between the Beam and the Waves the Mechanisms Responsible for the Properties and Dynamics of the Observed Ulf Waves Are Still a Matter of Debate. for Example Evolution of the Observed Frequencies in Time and Space May Be Due to a) Fast Changes in the Beam Properties or B) a Non-linear Parametric Instability of the Ulf Waves. We Propose to Elucidate This and Other Key Physics Using a Novel Combination of Artemis in Conjunction With Other Spacecraft the Vlasiator Global Hybrid-vlasov Simulation Code and a New Arbitrary Distribution Function Dispersion Solver. the Results Will Be Applicable to Shocks Elsewhere in the Heliosphere and Thus May Inform Present and Future Nasa Missions. the Proposed Study Is Relevant to All Four Decadal Survey Goals: Goal 1) Results of This Study Will Help Predict Variations in the Space Environment in the Ion Foreshock and Coupled Regions of the Magnetosphere of Both Earth and Other Planets. Goal 2) the Ion Beam and Associated Ulf Waves Represent a Response of the Earth's Magnetosphere to Solar Input. a More Complete Understanding of This Response Will Be Obtained by Carrying Out the Proposed Study. Goal 3) the Proposed Research Will Help Us Understand Similar Shocks That Determine the Interaction of the Solar Wind With the Solar System and the Interstellar Medium. Goal 4) Ion Beam-wave Interactions and Parametric Instabilities Are Fundamental Processes That Occur Both Within the Heliosphere and Throughout the Universe. We Aim to Characterize These Processes Using the Earth's Ion Foreshock Region as Our Laboratory.