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INTENSE SCIENTIFIC RESEARCH IS SUPPORTING THE HIGHLY SUCCESSFUL VAN ALLEN PROBES (HEREAFTER RBSP) WHICH IS NOW BEGINNING ITS EXTENDED MISSION PHASE. THE RBSP SPACECRAFT CONTINUE TO OBTAIN DETAILED MEASUREMENTS OF THE INNER-MAGNETOSPHERE THAT CAN BE USED TO PROBE COUPLING BETWEEN DIFFERENT PLASMA POPULATIONS AN IMPORTANT GOAL IN UNDERSTANDING THE PHYSICS OF SPACE WEATHER. EARTH S PLASMASPHERE IN PARTICULAR PARTICIPATES IN A SYSTEM OF SOURCE AND LOSS PROCESSES. THE PLASMASPHERE EVOLVES FROM A FULL DENSITY STATE TO THE PERIODIC EROSION OF ITS OUTER LAYERS DUE TO MAGNETOSPHERIC ELECTRIC FIELDS AND THE SUBSEQUENT IONOSPHERIC FILLING ALONG THOSE EVACUATED MAGNETIC FLUX TUBES. IN VIEW OF RECENT DISCREPANCIES BETWEEN OBSERVATIONS AND SIMULATIONS I PROPOSE TO ADDRESS THE SCIENCE QUESTION OF HOW DOES THE PLASMASPHERE REACH A FULL STATE? SEVERAL SCIENCE OBJECTIVES ARE NECESSARY TO ACCOMPLISH THIS GOAL WITHIN THE FRAMEWORK OF CURRENT COMPUTATIONAL RESOURCES. USING RBSP ELECTRON DENSITY MEASUREMENTS I WILL PRODUCE AN EMPIRICAL REPRESENTATION FOR THE FULL SATURATION DENSITY LEVEL OF THE PLASMASPHERE AS A FUNCTION OF L-SHELL MAGNETIC LOCAL TIME AND SOLAR CONDITIONS. THE DEVELOPED PROFILE WILL ENABLE BETTER ESTIMATES OF REFILLING RATES USED IN SEVERAL DYNAMIC PLASMASPHERIC DENSITY MODELS. THESE RELATIONS WILL THEN BE TESTED AGAINST RBSP OBSERVATIONS IN EQUATORIAL SIMULATIONS OF THE PLASMASPHERE GOVERNED BY SELF-CONSISTENT ELECTRIC FIELDS. WITH AN UNDERSTANDING OF MODEL PERFORMANCE THE TIMESCALE FOR REFILLING CAN BE REVISITED BY TRACKING THE PASSAGE OF A MAGNETIC FLUX TUBE AFTER A PERIOD OF EROSION THROUGH THE DAYSIDE OF THE EARTH WHERE IONOSPHERIC OUTFLOW OCCURS. SATELLITE MEASUREMENTS COMBINED WITH MODEL PREDICTIONS WILL HELP TO CONSTRAIN MISSING PHYSICS IF ANY DISCREPANCIES REMAIN. THIS PROPOSAL SEEKS TO UTILIZE THE UNPRECEDENTED RESOLUTION OF RBSP TO ADVANCE EMPIRICAL ASSUMPTIONS IN THE CONTEMPORARY TREATMENT OF PLASMASPHERE EVOLUTION THEREBY CONTRIBUTING TO NASA'S STRATEGIC GOAL TO UNDERSTAND THE COUPLING OF EARTH'S MAGNETOSPHERE AND IONOSPHERE.

$43,652FY2017National Aeronautics and Space AdministrationNASA

The University Of Iowa

Investigators

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INTENSE SCIENTIFIC RESEARCH IS SUPPORTING THE HIGHLY SUCCESSFUL VAN ALLEN PROBES (HEREAFTER RBSP) WHICH IS NOW BEGINNING ITS EXTENDED MISSION PHASE. THE RBSP SPACECRAFT CONTINUE TO OBTAIN DETAILED MEASUREMENTS OF THE INNER-MAGNETOSPHERE THAT CAN BE USED TO PROBE COUPLING BETWEEN DIFFERENT PLASMA POPULATIONS AN IMPORTANT GOAL IN UNDERSTANDING THE PHYSICS OF SPACE WEATHER. EARTH S PLASMASPHERE IN PARTICULAR PARTICIPATES IN A SYSTEM OF SOURCE AND LOSS PROCESSES. THE PLASMASPHERE EVOLVES FROM A FULL DENSITY STATE TO THE PERIODIC EROSION OF ITS OUTER LAYERS DUE TO MAGNETOSPHERIC ELECTRIC FIELDS AND THE SUBSEQUENT IONOSPHERIC FILLING ALONG THOSE EVACUATED MAGNETIC FLUX TUBES. IN VIEW OF RECENT DISCREPANCIES BETWEEN OBSERVATIONS AND SIMULATIONS I PROPOSE TO ADDRESS THE SCIENCE QUESTION OF HOW DOES THE PLASMASPHERE REACH A FULL STATE? SEVERAL SCIENCE OBJECTIVES ARE NECESSARY TO ACCOMPLISH THIS GOAL WITHIN THE FRAMEWORK OF CURRENT COMPUTATIONAL RESOURCES. USING RBSP ELECTRON DENSITY MEASUREMENTS I WILL PRODUCE AN EMPIRICAL REPRESENTATION FOR THE FULL SATURATION DENSITY LEVEL OF THE PLASMASPHERE AS A FUNCTION OF L-SHELL MAGNETIC LOCAL TIME AND SOLAR CONDITIONS. THE DEVELOPED PROFILE WILL ENABLE BETTER ESTIMATES OF REFILLING RATES USED IN SEVERAL DYNAMIC PLASMASPHERIC DENSITY MODELS. THESE RELATIONS WILL THEN BE TESTED AGAINST RBSP OBSERVATIONS IN EQUATORIAL SIMULATIONS OF THE PLASMASPHERE GOVERNED BY SELF-CONSISTENT ELECTRIC FIELDS. WITH AN UNDERSTANDING OF MODEL PERFORMANCE THE TIMESCALE FOR REFILLING CAN BE REVISITED BY TRACKING THE PASSAGE OF A MAGNETIC FLUX TUBE AFTER A PERIOD OF EROSION THROUGH THE DAYSIDE OF THE EARTH WHERE IONOSPHERIC OUTFLOW OCCURS. SATELLITE MEASUREMENTS COMBINED WITH MODEL PREDICTIONS WILL HELP TO CONSTRAIN MISSING PHYSICS IF ANY DISCREPANCIES REMAIN. THIS PROPOSAL SEEKS TO UTILIZE THE UNPRECEDENTED RESOLUTION OF RBSP TO ADVANCE EMPIRICAL ASSUMPTIONS IN THE CONTEMPORARY TREATMENT OF PLASMASPHERE EVOLUTION THEREBY CONTRIBUTING TO NASA'S STRATEGIC GOAL TO UNDERSTAND THE COUPLING OF EARTH'S MAGNETOSPHERE AND IONOSPHERE. · GrantIndex