WIDELY EMPLOYED TO MODEL COLLISIONLESS PLASMA PHENOMENA OCCURRING NATURALLY IN EARTH S MAGNETIC ENVIRONMENT THROUGHOUT THE HELIOSPHERE AND IN LABORATORY FUSION DEVICES THE VLASOV EQUATION SELF-CONSISTENTLY DESCRIBES THE FUNDAMENTAL KINETIC DYNAMICS OF PLASMA PARTICLES AS THEY ARE ACCELERATED THROUGH PHASE SPACE VIA ELECTRIC AND MAGNETIC FORCES. FOR THE FIRST TIME IN THE HISTORY OF PLASMA PHYSICS RESEARCH INSTRUMENTATION COMPRISING THE FAST PLASMA INVESTIGATION (FPI) ONBOARD NASA S MAGNETOSPHERIC MULTISCALE (MMS) FOUR-SPACECRAFT MISSION SUFFICIENTLY RESOLVES THE SEVEN SPATIAL TEMPORAL AND VELOCITY-SPACE DIMENSIONS OF PHASE SPACE NEEDED TO DIRECTLY MEASURE TERMS OF THE ELECTRON VLASOV EQUATION. THIS TECHNIQUE MOTIVATES UNPRECEDENTED EXPLORATION OF THE KINETIC MECHANISMS SUSTAINING ELECTRON-SCALE PLASMA PHENOMENA IN EARTH S MAGNETOSPHERE SUCH AS THE ELECTRON DIFFUSION REGION OF MAGNETIC RECONNECTION THIN CURRENT SHEET FORMATION AND THE ONSET OF ELECTRON-SCALE TURBULENCE. WE PROPOSE TO EXTEND THIS METHODOLOGY IN ORDER TO COMPUTE AND COMPARE ALL THREE TERMS OF THE VLASOV EQUATION IN THE CONTEXT OF MAGNETOPAUSE RECONNECTION: THE TIME DERIVATIVE DF/DT SPATIAL DERIVATIVE V*GRAD(F) AND VELOCITY-SPACE DERIVATIVE (F/M)*GRAD_V(F). USING ESTABLISHED RECONNECTION EVENT LISTS AND OUR DATABASE OF ROUGHLY 2 000 DAYSIDE BURST DATA INTERVALS CONTAINING STRONG (J > 1 UA/ M^2) ELECTRON-SCALE CURRENT STRUCTURES WITH SUFFICIENT DENSITY (N > 2 CM^-3) TO ENSURE REASONABLE COUNTING STATISTICS WE WILL QUANTIFY THE RELATIVE CONTRIBUTION OF EACH TERM OF THE VLASOV EQUATION USING MMS OBSERVATIONS IN VARIOUS RECONNECTION REGIONS INCLUDING THE INFLOW EXHAUST SEPARATRICES AND ION AND ELECTRON DIFFUSION REGIONS. USING BOTH CASE-STUDIES AND STATISTICAL ANALYSIS WE WILL PURSUE THE FOLLOWING SCIENCE QUESTIONS: #1. WHICH TERMS IN THE ION AND ELECTRON VLASOV EQUATIONS PROVIDE THE DOMINANT CONTRIBUTION FOR SUSTAINING ION AND ELECTRON PHASE SPACE DENSITY GRADIENTS THAT DRIVE THE EVOLUTION OF THE DISTRIBUTION FUNCTION DURING ASYMMETRIC MAGNETIC RECONNECTION? #2. WHAT ARE THE VELOCITY-SPACE SIGNATURES OF TERMS OF THE VLASOV EQUATION THAT CHARACTERIZE THE INFLOW EXHAUST SEPARATRICES AND ION AND ELECTRON DIFFUSION REGIONS OF ASYMMETRIC MAGNETIC RECONNECTION? #3. DO MMS OBSERVATIONS OF THE VLASOV EQUATION TEMPORAL SPATIAL AND VELOCITY-SPACE GRADIENT TERMS AGREE WITH PREDICTIONS FROM FULLY KINETIC PARTICLE-IN-CELL SIMULATIONS? OUR UNPRECEDENTED INVESTIGATION TO BOTH EXPLORE AND QUANTIFY TERMS IN THE VLASOV EQUATION DURING MAGNETIC RECONNECTION USING MMS DATA OFFERS A NOVEL OBSERVATIONAL PERSPECTIVE NECESSARY TO DEEPEN OUR KNOWLEDGE OF THE FUNDAMENTAL KINETIC MECHANISMS OCCURRING UBIQUITOUSLY IN ASTROPHYSICAL PLASMA ENVIRONMENTS WHICH BOTH ADVANCES MMS MISSION SCIENCE GOALS AND DIRECTLY ADDRESSES SCIENCE OBJECTIVE 4 OF THE HELIOPHYSICS DECADAL SURVEY TO DISCOVER AND CHARACTERIZE FUNDAMENTAL PROCESSES THAT OCCUR BOTH WITHIN THE HELIOSPHERE AND THROUGHOUT THE UNIVERSE.

University Of Maryland, College Park, College Park MD

Investigators