THE ORIGIN AND EVOLUTION OF SOLAR WIND TURBULENCE AND THE ORIGIN OF THE NON-THERMAL ELECTRONS IN THE SOLAR WIND ARE STILL POORLY UNDERSTOOD. IN-SITU OBSERVATIONS OF SOLAR WIND SHOW 1) THE WAVELENGTHS OF TURBULENCE SPAN FROM MHD TO KINETIC SCALES WITH A BREAK OF MAGNETIC POWER SPECTRA AROUND INERTIAL LENGTH OR GYRO-RADIUS DEPENDING PLASMA BETA. 2) THE ELECTRON VELOCITY DISTRIBUTION FUNCTIONS (EVDFS) ARE NON-MAXWELLIAN. THE EVDFS HAVE A NEARLY ISOTROPIC SUPRATHERMAL COMPONENT CALLED HALO WHILE IN THE FAST WIND WITH SPEED>400 KM/S A LONG NARROW TAIL OR STRAHL IS SUPERPOSED ON THE ELECTRON HALO. WHETHER THE TURBULENCE AND NON-THERMAL ELECTRONS ARE PRODUCED LOCALLY OR IN THE SOLAR CORONA IS DIRECTLY LINKED TO THE ACCELERATION OF SOLAR WIND. HIGH SPATIAL AND SPECTRAL RESOLUTION OBSERVATIONS OF THE SUN HAVE FOUND THAT THE SOLAR WIND CLOSELY ASSOCIATES WITH IMPULSIVE EVENTS CLOSE TO THE SURFACE OF THE SUN WHICH SUGGESTS THAT THE SOLAR WIND ORIGINATES FROM NANOFLARE-LIKE EVENTS. THE REMOTE SENSING OBSERVATIONS FROM HI-C IRIS SDO AND NUSTAR HAVE PROVIDED EVIDENCE FOR THE EXISTENCE OF NANOFLARES IN THE SOLAR CORONA AND RELEVANT PARTICLE ACCELERATION AND HEATING. THE RADIO OBSERVATIONS OF NANOFLARE-TYPE TYPE III BURSTS IMPLY THAT NANOFLARES CAN PRODUCE A SIGNIFICANT NUMBER OF ENERGETIC ELECTRONS AROUND KEV. WE USE PIC SIMULATIONS TO INVESTIGATE THE IMPACT OF THESE NANOFLAREACCELERATED KEV ELECTRON BEAMS ON THE CORONA AND SOLAR WIND. WE HAVE FOUND THAT THE KINETIC ENERGY OF THESE ELECTRON BEAMS CAN BE RELEASED QUICKLY VIA ELECTRON TWO-STREAM INSTABILITY. THE NONLINEAR WAVE-WAVE AND WAVE-PARTICLE INTERACTIONS PRODUCE BOTH THE ISOTROPIC ELECTRON HALO AND ALFV'ENIC WAVE (KAW) AND WHISTLER WAVE TURBULENCE THROUGH FORWARD AND INVERSE ENERGY CASCADES IN THE INNER CORONA (CHE ET AL PRL 2014). THE ENERGY EXCHANGE BETWEEN THE KINETIC TURBULENCE AND THE ELECTRON HALO REACHES A TURBULENT EQUILIBRIUM. THE PREDICTED POWER SPECTRA OF KAW AND THE STRUCTURE OF THE CORE-HALO ARE IN CONSISTENT WITH THE PUBLISHED OBSERVATIONAL RESULTS (CHE AND GOLDSTEIN APJL 2014). THE ELECTRONS DIFFUSED INTO THE CORONA AND THE ASSOCIATED KINETIC TURBULENCE CAN ESCAPE ALONG OPEN MAGNETIC FIELD LINES AND THE ACCELERATION OF SOLAR WIND MAY THUS ORIGINATE FROM THE ELECTRON HEATING IN MAGNETIC LOOPS. THE SOLAR WIND ESCAPED FROM THE CORONA CARRIES THE RELIC TURBULENCE INTO INTERPLANETARY MEDIUM ALONG OPEN FIELD LINES AND SUBSEQUENTLY TO 1AU. IN THIS PROPOSAL WE PROPOSE TO CONTINUE THIS STUDY WITH A FOCUS ON HOW LOCAL PLASMA ENVIRONMENT IN THE CORONA AND SOLAR WIND AFFECTS THE EVOLUTION OF KINETIC PROPERTIES OF THE SOLAR WIND AS IT TRAVELS OUT OF THE CORONA AND IN THE INTERPLANETARY SPACE TO 1AU. THE PROPOSED STUDIES WILL FOCUS ON: 1) HOW DOES PLASMA $BETA$ AFFECT THE PROPERTIES OF ELECTRON HALO AND POWER SPECTRA OF KINETIC TURBULENCE? 2) THE EVOLUTION OF THE EVDF AND THE KINETIC SCALE TURBULENCE IN THE SOLAR WIND. IN PARTICULAR HOW DOES THE ``STRAHL" AFFECT THE ELECTRON HALO AND THE KINETIC WAVES IN THE SOLAR WIND? 3)COMPARISON BETWEEN THE MODEL AND THE OBSERVATIONAL DATA. THE PROPOSED STUDY WILL BE VERY IMPORTANT FOR THE COMPLETE UNDERSTANDING OF THE ROLE NANOFLARES AND LOCAL PROCESSES PLAY IN THE FORMATION AND EVOLUTION OF ELECTRON HALO IN THE EVDF AND THE GENERATION OF KINETIC ALFV'EN WAVE AND WHISTLER WAVE TURBULENCE IN THE SOLAR WIND. THE PROPOSED RESEARCH WILL MAKE DIRECT CONTRIBUTIONS TO THE UNDERSTANDING OF THE ORIGIN AND ACCELERATION OF SOLAR WIND---THE CORE SCIENCE OF THE NEAR FUTURE NASA SPACECRAFTS SPP AND SO AND A TOP PRIORITY IN THE NASA HELIOPHYSICS ROADMAP AND HELIOPHYSICS DECADAL SURVEY.
$179,308FY2017National Aeronautics and Space AdministrationNASA
University Of Maryland, College Park, College Park MD