Alexander S. Lipatov

Merging for Particle-Mesh Complex Particle Kinetic modeling of the multiple plasma beams

We suggest a merging procedure for the Particle-Mesh Complex Particle Kinetic (PMCPK) method in case of inter-penetrating flow (multiple plasma beams). We examine the standard particle-in-cell (PIC) and the PMCPK methods in the case of particle acceleration by shock surfing for a wide range of the control numerical parameters. The plasma dynamics is described by a hybrid (particle-ion-fluid-electron) model. Note that one may need a mesh if modeling with the computation of an electromagnetic field. Our calculations use specified, time-independent electromagnetic fields for the shock, rather than self-consistently generated fields. While a particle-mesh method is a well-verified approach, the CPK method seems to be a good approach for multiscale modeling that includes multiple regions with various particle/fluid plasma behavior. However, the CPK method is still in need of a verification for studying the basic plasma phenomena: particle heating and acceleration by collisionless shocks, magnetic field reconnection, beam dynamics, etc.

Space weathering investigations enabled by NASA's virtual heliophysical observatories

Space weathering by the plasma and energetic particle radiation environment of the heliosphere contributes to the physical and chemical evolution of exposed surfaces on airless bodies such as the Moon, asteroids, comets, and icy bodies of the outer solar system. The Multi-Source Spectral Plot (MSSP) service of the NASA Virtual Energetic Particle Observatory (VEPO) enables enhanced access and comparative global heliospheric analysis of ion flux spectra from the past and present fleet of interplanetary spacecraft for modeling of space weathering effects. Commonly red colors of low-inclination Classical Kuiper Belt Objects may be the result of specific compositional origin and spectral irradiation effects in the outer heliosphere. VEPO also enables easy comparison of flux spectra to check intercalibration issues.