Not listed THE INTERACTION OF THE SOLAR WIND WITH EARTH S MAGNETOSPHERE IS CRUCIAL FOR PREDICTING SPACE WEATHER WHICH CAN IMPACT SATELLITE COMMUNICATION AND THE POWER GRID AMONG OTHER THINGS. THE COUPLING PROCESS OCCURS THROUGH MAGNETIC RECONNECTION AT THE DAYSIDE MAGNETOPAUSE WHERE THE MAGNETIC FIELD IN THE SOLAR WIND EFFECTIVELY BREAKS AND CROSS CONNECTS WITH THE MAGNETOSPHERIC MAGNETIC FIELD. WHILE EARLY STUDIES OF RECONNECTION EMPLOYED TWO-DIMENSIONAL (2D) MODELS WITH A HIGH DEGREE OF SYMMETRY FOR SIMPLICITY RECONNECTION AT THE DAYSIDE MAGNETOPAUSE IS NOT SYMMETRIC AND CONTAINS BULK FLOWS. PREVIOUS WORK HAS REVEALED THAT THESE DIFFERENCES CAN BE VERY IMPORTANT. WHEN THERE IS A PRESSURE GRADIENT ACROSS THE MAGNETOPAUSE AND AN OUT-OF-PLANE (GUIDE) MAGNETIC FIELD THERE ARE DIAMAGNETIC DRIFTS IN THE DIRECTION OF THE RECONNECTION OUTFLOW. THIS EFFECTIVELY WEAKENS THE TENSION FORCE OF THE RECONNECTED MAGNETIC FIELD WHICH CAN SLOW OR EVEN COMPLETELY SUPPRESS RECONNECTION. A SIMILAR EFFECT HAS BEEN IDENTIFIED FOR RECONNECTION WITH A BULK FLOW PARALLEL TO THE RECONNECTING MAGNETIC FIELDS. THESE EFFECTS HAVE LARGELY BEEN STUDIED INDEPENDENTLY UNTIL NOW THERE IS NO QUANTITATIVE UNDERSTANDING OF ASYMMETRIC RECONNECTION INCLUDING BOTH DIAMAGNETIC EFFECTS AND FLOW SHEAR EVEN IN 2D. IN 3D A HOST OF INSTABILITIES CAN ARISE AND THEIR EFFECT ON THE RECONNECTION PROCESS IS NOT WELL UNDERSTOOD. THE OBJECTIVES OF THE PROPOSED WORK ARE: (1) TO DEVELOP A SCALING LAW FOR THE RECONNECTION RATE OF 2D ASYMMETRIC RECONNECTION WITH DIAMAGNETIC DRIFTS AND ARBITRARY FLOW SPEEDS PARALLEL TO THE RECONNECTING MAGNETIC FIELD (2) TO DETERMINE THE 3D PROPERTIES OF SYSTEMS WITH ALL THREE EFFECTS WHICH ARE EXPECTED TO INCLUDE DRIFT WAVES AND SHEAR FLOW DRIVEN KELVIN-HELMHOLTZ MODES AND (3) TO OBSERVATIONALLY DETERMINE THE VALIDITY OF 2D THEORETICAL MODELS AND THE IMPORTANCE OF 3D MODES AT THE DAYSIDE MAGNETOPAUSE WHERE ALL THREE EFFECTS ARE IMPORTANT. IN ORDER TO DEVELOP A QUANTITATIVE AND PREDICTIVE UNDERSTANDING OF RECONNECTION EFFICIENCY INCLUDING A CONDITION FOR SUPPRESSION OF RECONNECTION DUE TO DIAMAGNETIC EFFECTS AND FLOW SHEAR WE WILL EMPLOY THE FOLLOWING METHODOLOGY: (1) PERFORM A LARGE NUMBER OF PIC SIMULATIONS IN 2D WITH DIFFERENT PLASMA CONDITIONS TO MAP THE DESIRED PARAMETER SPACE (2) BUILD OFF PREVIOUS WORK TO DEVELOP AN EXPRESSION FOR THE RECONNECTION RATE IN 2D SYSTEMS WITH DIAMAGNETIC EFFECTS ASYMMETRIES AND FLOW SHEAR AND VALIDATE IT WITH THE SIMULATIONS (3) PERFORM 3D PIC SIMULATIONS TO DETERMINE IF 3D EFFECTS ALTER THE 2D PREDICTIONS AND INVESTIGATE THE ROLE OF RECONNECTION AT OBLIQUE ORIENTATIONS DRIFT WAVES AND THE KELVIN-HELMHOLTZ INSTABILITY AT BOTH ELECTRON AND ION LENGTH SCALES AND (4) COMPARE THE RESULTS WITH OBSERVATIONS OF RECONNECTION AT EARTH S DAYSIDE MAGNETOPAUSE. THE PROPOSED WORK IS RELEVANT TO NASA HELIOPHYSICS OBJECTIVES AS IS EMBODIED BY ITS REPRESENTATION IN THE KEY SCIENCE GOALS FROM THE 2013 HELIOPHYSICS DECADAL SURVEY SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY . THE MOST DIRECT CONNECTION IS THROUGH KEY SCIENCE GOAL 2 WHICH IS TO DETERMINE THE DYNAMICS AND COUPLING OF EARTH S MAGNETOSPHERE IONOSPHERE AND ATMOSPHERE AND THEIR RESPONSE TO SOLAR AND TERRESTRIAL INPUTS. THIS PROJECT IS AN INTEGRAL AND CRUCIAL COMPONENT OF UNDERSTANDING HOW THE MAGNETOSPHERE RESPONDS TO INPUT FROM THE SUN. THE PROPOSED WORK ALSO ADDRESSES KEY SCIENCE GOAL 4 TO DISCOVER AND CHARACTERIZE FUNDAMENTAL PROCESSES THAT OCCUR BOTH WITHIN THE HELIOSPHERE AND THROUGHOUT THE UNIVERSE. THE LIST OF UNIVERSAL PROCESSES OF FUNDAMENTAL IMPORTANCE TO SOLAR AND SPACE PHYSICS INCLUDE MAGNETIC RECONNECTION. THE PROPOSED WORK IS RELEVANT NOT JUST TO THE DAYSIDE MAGNETOPAUSE BUT ALSO OTHER SETTINGS WHERE DIAMAGNETIC EFFECTS HAVE PROVEN IMPORTANT INCLUDING THE SOLAR WIND PLANETARY MAGNETOSPHERES SUCH AS MERCURY JUPITER AND SATURN FUSION DEVICES AND THE HELIOPAUSE. $0 3/8/19 3 THE INTERACTION OF THE SOLAR WIND WITH EARTH S MAGNETOSPHERE IS CRUCIAL FOR PREDICTING SPACE WEATHER, WHICH CAN IMPACT SATELLITE COMMUNICATION AND THE POWER GRID, AMONG OTHER THINGS. THE COUPLING PROCESS OCCURS THROUGH MAGNETIC RECONNECTION AT THE DAYSIDE MAGNETOPAUSE, WHERE THE MAGNETIC FIELD IN THE SOLAR WIND EFFECTIVELY BREAKS AND CROSS CONNECTS WITH THE MAGNETOSPHERIC MAGNETIC FIELD. WHILE EARLY STUDIES OF RECONNECTION EMPLOYED TWO-DIMENSIONAL (2D) MODELS WITH A HIGH DEGREE OF SYMMETRY FOR SIMPLICITY, RECONNECTION AT THE DAYSIDE MAGNETOPAUSE IS NOT SYMMETRIC AND CONTAINS BULK FLOWS. PREVIOUS WORK HAS REVEALED THAT THESE DIFFERENCES CAN BE VERY IMPORTANT. WHEN THERE IS A PRESSURE GRADIENT ACROSS THE MAGNETOPAUSE AND AN OUT-OF-PLANE (GUIDE) MAGNETIC FIELD, THERE ARE DIAMAGNETIC DRIFTS IN THE DIRECTION OF THE RECONNECTION OUTFLOW. THIS EFFECTIVELY WEAKENS THE TENSION FORCE OF THE RECONNECTED MAGNETIC FIELD, WHICH CAN SLOW OR EVEN COMPLETELY SUPPRESS RECONNECTION. A SIMILAR EFFECT HAS BEEN IDENTIFIED FOR RECONNECTION WITH A BULK FLOW PARALLEL TO THE RECONNECTING MAGNETIC FIELDS. THESE EFFECTS HAVE LARGELY BEEN STUDIED INDEPENDENTLY UNTIL NOW THERE IS NO QUANTITATIVE UNDERSTANDING OF ASYMMETRIC RECONNECTION INCLUDING BOTH DIAMAGNETIC EFFECTS AND FLOW SHEAR, EVEN IN 2D. IN 3D, A HOST OF INSTABILITIES CAN ARISE, AND THEIR EFFECT ON THE RECONNECTION PROCESS IS NOT WELL UNDERSTOOD. THE OBJECTIVES OF THE PROPOSED WORK ARE: (1) TO DEVELOP A SCALING LAW FOR THE RECONNECTION RATE OF 2D ASYMMETRIC RECONNECTION WITH DIAMAGNETIC DRIFTS AND ARBITRARY FLOW SPEEDS PARALLEL TO THE RECONNECTING MAGNETIC FIELD (2) TO DETERMINE THE 3D PROPERTIES OF SYSTEMS WITH ALL THREE EFFECTS, WHICH ARE EXPECTED TO INCLUDE DRIFT WAVES AND SHEAR FLOW DRIVEN KELVIN-HELMHOLTZ MODES AND (3) TO OBSERVATIONALLY DETERMINE THE VALIDITY OF 2D THEORETICAL MODELS AND THE IMPORTANCE OF 3D MODES AT THE DAYSIDE MAGNETOPAUSE WHERE ALL THREE EFFECTS ARE IMPORTANT. IN ORDER TO DEVELOP A QUANTITATIVE AND PREDICTIVE UNDERSTANDING OF RECONNECTION EFFICIENCY INCLUDING A CONDITION FOR SUPPRESSION OF RECONNECTION DUE TO DIAMAGNETIC EFFECTS AND FLOW SHEAR, WE WILL EMPLOY THE FOLLOWING METHODOLOGY: (1) PERFORM A LARGE NUMBER OF PIC SIMULATIONS IN 2D WITH DIFFERENT PLASMA CONDITIONS TO MAP THE DESIRED PARAMETER SPACE (2) BUILD OFF PREVIOUS WORK TO DEVELOP AN EXPRESSION FOR THE RECONNECTION RATE IN 2D SYSTEMS WITH DIAMAGNETIC EFFECTS, ASYMMETRIES, AND FLOW SHEAR, AND VALIDATE IT WITH THE SIMULATIONS (3) PERFORM 3D PIC SIMULATIONS TO DETERMINE IF 3D EFFECTS ALTER THE 2D PREDICTIONS AND INVESTIGATE THE ROLE OF RECONNECTION AT OBLIQUE ORIENTATIONS, DRIFT WAVES AND THE KELVIN-HELMHOLTZ INSTABILITY AT BOTH ELECTRON AND ION LENGTH SCALES, AND (4) COMPARE THE RESULTS WITH OBSERVATIONS OF RECONNECTION AT EARTH S DAYSIDE MAGNETOPAUSE. THE PROPOSED WORK IS RELEVANT TO NASA HELIOPHYSICS OBJECTIVES AS IS EMBODIED BY ITS REPRESENTATION IN THE KEY SCIENCE GOALS FROM THE 2013 HELIOPHYSICS DECADAL SURVEY SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY . THE MOST DIRECT CONNECTION IS THROUGH KEY SCIENCE GOAL 2, WHICH IS TO DETERMINE THE DYNAMICS AND COUPLING OF EARTH S MAGNETOSPHERE, IONOSPHERE, AND ATMOSPHERE AND THEIR RESPONSE TO SOLAR AND TERRESTRIAL INPUTS. THIS PROJECT IS AN INTEGRAL AND CRUCIAL COMPONENT OF UNDERSTANDING HOW THE MAGNETOSPHERE RESPONDS TO INPUT FROM THE SUN. THE PROPOSED WORK ALSO ADDRESSES KEY SCIENCE GOAL 4, TO DISCOVER AND CHARACTERIZE FUNDAMENTAL PROCESSES THAT OCCUR BOTH WITHIN THE HELIOSPHERE AND THROUGHOUT THE UNIVERSE. THE LIST OF UNIVERSAL PROCESSES OF FUNDAMENTAL IMPORTANCE TO SOLAR AND SPACE PHYSICS INCLUDE MAGNETIC RECONNECTION. THE PROPOSED WORK IS RELEVANT NOT JUST TO THE DAYSIDE MAGNETOPAUSE, BUT ALSO OTHER SETTINGS WHERE DIAMAGNETIC EFFECTS HAVE PROVEN IMPORTANT INCLUDING THE SOLAR WIND, PLANETARY MAGNETOSPHERES SUCH AS MERCURY, JUPITER AND SATURN, FUSION DEVICES, AND THE HELIOPAUSE. Other Administrative Action $0 3/8/19 Not listed THE INTERACTION OF THE SOLAR WIND WITH EARTH S MAGNETOSPHERE IS CRUCIAL FOR PREDICTING SPACE WEATHER WHICH CAN IMPACT SATELLITE COMMUNICATION AND THE POWER GRID AMONG OTHER THINGS. THE COUPLING PROCESS OCCURS THROUGH MAGNETIC RECONNECTION AT THE DAYSIDE MAGNETOPAUSE WHERE THE MAGNETIC FIELD IN THE SOLAR WIND EFFECTIVELY BREAKS AND CROSS CONNECTS WITH THE MAGNETOSPHERIC MAGNETIC FIELD. WHILE EARLY STUDIES OF RECONNECTION EMPLOYED TWO-DIMENSIONAL (2D) MODELS WITH A HIGH DEGREE OF SYMMETRY FOR SIMPLICITY RECONNECTION AT THE DAYSIDE MAGNETOPAUSE IS NOT SYMMETRIC AND CONTAINS BULK FLOWS. PREVIOUS WORK HAS REVEALED THAT THESE DIFFERENCES CAN BE VERY IMPORTANT. WHEN THERE IS A PRESSURE GRADIENT ACROSS THE MAGNETOPAUSE AND AN OUT-OF-PLANE (GUIDE) MAGNETIC FIELD THERE ARE DIAMAGNETIC DRIFTS IN THE DIRECTION OF THE RECONNECTION OUTFLOW. THIS EFFECTIVELY WEAKENS THE TENSION FORCE OF THE RECONNECTED MAGNETIC FIELD WHICH CAN SLOW OR EVEN COMPLETELY SUPPRESS RECONNECTION. A SIMILAR EFFECT HAS BEEN IDENTIFIED FOR RECONNECTION WITH A BULK FLOW PARALLEL TO THE RECONNECTING MAGNETIC FIELDS. THESE EFFECTS HAVE LARGELY BEEN STUDIED INDEPENDENTLY; UNTIL NOW THERE IS NO QUANTITATIVE UNDERSTANDING OF ASYMMETRIC RECONNECTION INCLUDING BOTH DIAMAGNETIC EFFECTS AND FLOW SHEAR EVEN IN 2D. IN 3D A HOST OF INSTABILITIES CAN ARISE AND THEIR EFFECT ON THE RECONNECTION PROCESS IS NOT WELL UNDERSTOOD. THE OBJECTIVES OF THE PROPOSED WORK ARE: (1) TO DEVELOP A SCALING LAW FOR THE RECONNECTION RATE OF 2D ASYMMETRIC RECONNECTION WITH DIAMAGNETIC DRIFTS AND ARBITRARY FLOW SPEEDS PARALLEL TO THE RECONNECTING MAGNETIC FIELD; (2) TO DETERMINE THE 3D PROPERTIES OF SYSTEMS WITH ALL THREE EFFECTS WHICH ARE EXPECTED TO INCLUDE DRIFT WAVES AND SHEAR FLOW DRIVEN KELVIN-HELMHOLTZ MODES; AND (3) TO OBSERVATIONALLY DETERMINE THE VALIDITY OF 2D THEORETICAL MODELS AND THE IMPORTANCE OF 3D MODES AT THE DAYSIDE MAGNETOPAUSE WHERE ALL THREE EFFECTS ARE IMPORTANT. IN ORDER TO DEVELOP A QUANTITATIVE AND PREDICTIVE UNDERSTANDING OF RECONNECTION EFFICIENCY INCLUDING A CONDITION FOR SUPPRESSION OF RECONNECTION DUE TO DIAMAGNETIC EFFECTS AND FLOW SHEAR WE WILL EMPLOY THE FOLLOWING METHODOLOGY: (1) PERFORM A LARGE NUMBER OF PIC SIMULATIONS IN 2D WITH DIFFERENT PLASMA CONDITIONS TO MAP THE DESIRED PARAMETER SPACE; (2) BUILD OFF PREVIOUS WORK TO DEVELOP AN EXPRESSION FOR THE RECONNECTION RATE IN 2D SYSTEMS WITH DIAMAGNETIC EFFECTS ASYMMETRIES AND FLOW SHEAR AND VALIDATE IT WITH THE SIMULATIONS; (3) PERFORM 3D PIC SIMULATIONS TO DETERMINE IF 3D EFFECTS ALTER THE 2D PREDICTIONS AND INVESTIGATE THE ROLE OF RECONNECTION AT OBLIQUE ORIENTATIONS DRIFT WAVES AND THE KELVIN-HELMHOLTZ INSTABILITY AT BOTH ELECTRON AND ION LENGTH SCALES AND (4) COMPARE THE RESULTS WITH OBSERVATIONS OF RECONNECTION AT EARTH S DAYSIDE MAGNETOPAUSE. THE PROPOSED WORK IS RELEVANT TO NASA HELIOPHYSICS OBJECTIVES AS IS EMBODIED BY ITS REPRESENTATION IN THE KEY SCIENCE GOALS FROM THE 2013 HELIOPHYSICS DECADAL SURVEY SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY . THE MOST DIRECT CONNECTION IS THROUGH KEY SCIENCE GOAL 2 WHICH IS TO DETERMINE THE DYNAMICS AND COUPLING OF EARTH S MAGNETOSPHERE IONOSPHERE AND ATMOSPHERE AND THEIR RESPONSE TO SOLAR AND TERRESTRIAL INPUTS. THIS PROJECT IS AN INTEGRAL AND CRUCIAL COMPONENT OF UNDERSTANDING HOW THE MAGNETOSPHERE RESPONDS TO INPUT FROM THE SUN. THE PROPOSED WORK ALSO ADDRESSES KEY SCIENCE GOAL 4 TO DISCOVER AND CHARACTERIZE FUNDAMENTAL PROCESSES THAT OCCUR BOTH WITHIN THE HELIOSPHERE AND THROUGHOUT THE UNIVERSE. THE LIST OF UNIVERSAL PROCESSES OF FUNDAMENTAL IMPORTANCE TO SOLAR AND SPACE PHYSICS INCLUDE MAGNETIC RECONNECTION. THE PROPOSED WORK IS RELEVANT NOT JUST TO THE DAYSIDE MAGNETOPAUSE BUT ALSO OTHER SETTINGS WHERE DIAMAGNETIC EFFECTS HAVE PROVEN IMPORTANT INCLUDING THE SOLAR WIND PLANETARY MAGNETOSPHERES SUCH AS MERCURY JUPITER AND SATURN FUSION DEVICES AND THE HELIOPAUSE. $150.0k 2/8/18 2 THE INTERACTION OF THE SOLAR WIND WITH EARTH S MAGNETOSPHERE IS CRUCIAL FOR PREDICTING SPACE WEATHER, WHICH CAN IMPACT SATELLITE COMMUNICATION AND THE POWER GRID, AMONG OTHER THINGS. THE COUPLING PROCESS OCCURS THROUGH MAGNETIC RECONNECTION AT THE DAYSIDE MAGNETOPAUSE, WHERE THE MAGNETIC FIELD IN THE SOLAR WIND EFFECTIVELY BREAKS AND CROSS CONNECTS WITH THE MAGNETOSPHERIC MAGNETIC FIELD. WHILE EARLY STUDIES OF RECONNECTION EMPLOYED TWO-DIMENSIONAL (2D) MODELS WITH A HIGH DEGREE OF SYMMETRY FOR SIMPLICITY, RECONNECTION AT THE DAYSIDE MAGNETOPAUSE IS NOT SYMMETRIC AND CONTAINS BULK FLOWS. PREVIOUS WORK HAS REVEALED THAT THESE DIFFERENCES CAN BE VERY IMPORTANT. WHEN THERE IS A PRESSURE GRADIENT ACROSS THE MAGNETOPAUSE AND AN OUT-OF-PLANE (GUIDE) MAGNETIC FIELD, THERE ARE DIAMAGNETIC DRIFTS IN THE DIRECTION OF THE RECONNECTION OUTFLOW. THIS EFFECTIVELY WEAKENS THE TENSION FORCE OF THE RECONNECTED MAGNETIC FIELD, WHICH CAN SLOW OR EVEN COMPLETELY SUPPRESS RECONNECTION. A SIMILAR EFFECT HAS BEEN IDENTIFIED FOR RECONNECTION WITH A BULK FLOW PARALLEL TO THE RECONNECTING MAGNETIC FIELDS. THESE EFFECTS HAVE LARGELY BEEN STUDIED INDEPENDENTLY; UNTIL NOW THERE IS NO QUANTITATIVE UNDERSTANDING OF ASYMMETRIC RECONNECTION INCLUDING BOTH DIAMAGNETIC EFFECTS AND FLOW SHEAR, EVEN IN 2D. IN 3D, A HOST OF INSTABILITIES CAN ARISE, AND THEIR EFFECT ON THE RECONNECTION PROCESS IS NOT WELL UNDERSTOOD. THE OBJECTIVES OF THE PROPOSED WORK ARE: (1) TO DEVELOP A SCALING LAW FOR THE RECONNECTION RATE OF 2D ASYMMETRIC RECONNECTION WITH DIAMAGNETIC DRIFTS AND ARBITRARY FLOW SPEEDS PARALLEL TO THE RECONNECTING MAGNETIC FIELD; (2) TO DETERMINE THE 3D PROPERTIES OF SYSTEMS WITH ALL THREE EFFECTS, WHICH ARE EXPECTED TO INCLUDE DRIFT WAVES AND SHEAR FLOW DRIVEN KELVIN-HELMHOLTZ MODES; AND (3) TO OBSERVATIONALLY DETERMINE THE VALIDITY OF 2D THEORETICAL MODELS AND THE IMPORTANCE OF 3D MODES AT THE DAYSIDE MAGNETOPAUSE WHERE ALL THREE EFFECTS ARE IMPORTANT. IN ORDER TO DEVELOP A QUANTITATIVE AND PREDICTIVE UNDERSTANDING OF RECONNECTION EFFICIENCY INCLUDING A CONDITION FOR SUPPRESSION OF RECONNECTION DUE TO DIAMAGNETIC EFFECTS AND FLOW SHEAR, WE WILL EMPLOY THE FOLLOWING METHODOLOGY: (1) PERFORM A LARGE NUMBER OF PIC SIMULATIONS IN 2D WITH DIFFERENT PLASMA CONDITIONS TO MAP THE DESIRED PARAMETER SPACE; (2) BUILD OFF PREVIOUS WORK TO DEVELOP AN EXPRESSION FOR THE RECONNECTION RATE IN 2D SYSTEMS WITH DIAMAGNETIC EFFECTS, ASYMMETRIES, AND FLOW SHEAR, AND VALIDATE IT WITH THE SIMULATIONS; (3) PERFORM 3D PIC SIMULATIONS TO DETERMINE IF 3D EFFECTS ALTER THE 2D PREDICTIONS AND INVESTIGATE THE ROLE OF RECONNECTION AT OBLIQUE ORIENTATIONS, DRIFT WAVES AND THE KELVIN-HELMHOLTZ INSTABILITY AT BOTH ELECTRON AND ION LENGTH SCALES, AND (4) COMPARE THE RESULTS WITH OBSERVATIONS OF RECONNECTION AT EARTH S DAYSIDE MAGNETOPAUSE. THE PROPOSED WORK IS RELEVANT TO NASA HELIOPHYSICS OBJECTIVES AS IS EMBODIED BY ITS REPRESENTATION IN THE KEY SCIENCE GOALS FROM THE 2013 HELIOPHYSICS DECADAL SURVEY SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY . THE MOST DIRECT CONNECTION IS THROUGH KEY SCIENCE GOAL 2, WHICH IS TO DETERMINE THE DYNAMICS AND COUPLING OF EARTH S MAGNETOSPHERE, IONOSPHERE, AND ATMOSPHERE AND THEIR RESPONSE TO SOLAR AND TERRESTRIAL INPUTS. THIS PROJECT IS AN INTEGRAL AND CRUCIAL COMPONENT OF UNDERSTANDING HOW THE MAGNETOSPHERE RESPONDS TO INPUT FROM THE SUN. THE PROPOSED WORK ALSO ADDRESSES KEY SCIENCE GOAL 4, TO DISCOVER AND CHARACTERIZE FUNDAMENTAL PROCESSES THAT OCCUR BOTH WITHIN THE HELIOSPHERE AND THROUGHOUT THE UNIVERSE. THE LIST OF UNIVERSAL PROCESSES OF FUNDAMENTAL IMPORTANCE TO SOLAR AND SPACE PHYSICS INCLUDE MAGNETIC RECONNECTION. THE PROPOSED WORK IS RELEVANT NOT JUST TO THE DAYSIDE MAGNETOPAUSE, BUT ALSO OTHER SETTINGS WHERE DIAMAGNETIC EFFECTS HAVE PROVEN IMPORTANT INCLUDING THE SOLAR WIND, PLANETARY MAGNETOSPHERES SUCH AS MERCURY, JUPITER AND SATURN, FUSION DEVICES, AND THE HELIOPAUSE. Funding Only Action $150.0k 2/8/18 Not listed THE INTERACTION OF THE SOLAR WIND WITH EARTH S MAGNETOSPHERE IS CRUCIAL FOR PREDICTING SPACE WEATHER WHICH CAN IMPACT SATELLITE COMMUNICATION AND THE POWER GRID AMONG OTHER THINGS. THE COUPLING PROCESS OCCURS THROUGH MAGNETIC RECONNECTION AT THE DAYSIDE MAGNETOPAUSE WHERE THE MAGNETIC FIELD IN THE SOLAR WIND EFFECTIVELY BREAKS AND CROSS CONNECTS WITH THE MAGNETOSPHERIC MAGNETIC FIELD. WHILE EARLY STUDIES OF RECONNECTION EMPLOYED TWO-DIMENSIONAL (2D) MODELS WITH A HIGH DEGREE OF SYMMETRY FOR SIMPLICITY RECONNECTION AT THE DAYSIDE MAGNETOPAUSE IS NOT SYMMETRIC AND CONTAINS BULK FLOWS. PREVIOUS WORK HAS REVEALED THAT THESE DIFFERENCES CAN BE VERY IMPORTANT. WHEN THERE IS A PRESSURE GRADIENT ACROSS THE MAGNETOPAUSE AND AN OUT-OF-PLANE (GUIDE) MAGNETIC FIELD THERE ARE DIAMAGNETIC DRIFTS IN THE DIRECTION OF THE RECONNECTION OUTFLOW. THIS EFFECTIVELY WEAKENS THE TENSION FORCE OF THE RECONNECTED MAGNETIC FIELD WHICH CAN SLOW OR EVEN COMPLETELY SUPPRESS RECONNECTION. A SIMILAR EFFECT HAS BEEN IDENTIFIED FOR RECONNECTION WITH A BULK FLOW PARALLEL TO THE RECONNECTING MAGNETIC FIELDS. THESE EFFECTS HAVE LARGELY BEEN STUDIED INDEPENDENTLY; UNTIL NOW THERE IS NO QUANTITATIVE UNDERSTANDING OF ASYMMETRIC RECONNECTION INCLUDING BOTH DIAMAGNETIC EFFECTS AND FLOW SHEAR EVEN IN 2D. IN 3D A HOST OF INSTABILITIES CAN ARISE AND THEIR EFFECT ON THE RECONNECTION PROCESS IS NOT WELL UNDERSTOOD. THE OBJECTIVES OF THE PROPOSED WORK ARE: (1) TO DEVELOP A SCALING LAW FOR THE RECONNECTION RATE OF 2D ASYMMETRIC RECONNECTION WITH DIAMAGNETIC DRIFTS AND ARBITRARY FLOW SPEEDS PARALLEL TO THE RECONNECTING MAGNETIC FIELD; (2) TO DETERMINE THE 3D PROPERTIES OF SYSTEMS WITH ALL THREE EFFECTS WHICH ARE EXPECTED TO INCLUDE DRIFT WAVES AND SHEAR FLOW DRIVEN KELVIN-HELMHOLTZ MODES; AND (3) TO OBSERVATIONALLY DETERMINE THE VALIDITY OF 2D THEORETICAL MODELS AND THE IMPORTANCE OF 3D MODES AT THE DAYSIDE MAGNETOPAUSE WHERE ALL THREE EFFECTS ARE IMPORTANT. IN ORDER TO DEVELOP A QUANTITATIVE AND PREDICTIVE UNDERSTANDING OF RECONNECTION EFFICIENCY INCLUDING A CONDITION FOR SUPPRESSION OF RECONNECTION DUE TO DIAMAGNETIC EFFECTS AND FLOW SHEAR WE WILL EMPLOY THE FOLLOWING METHODOLOGY: (1) PERFORM A LARGE NUMBER OF PIC SIMULATIONS IN 2D WITH DIFFERENT PLASMA CONDITIONS TO MAP THE DESIRED PARAMETER SPACE; (2) BUILD OFF PREVIOUS WORK TO DEVELOP AN EXPRESSION FOR THE RECONNECTION RATE IN 2D SYSTEMS WITH DIAMAGNETIC EFFECTS ASYMMETRIES AND FLOW SHEAR AND VALIDATE IT WITH THE SIMULATIONS; (3) PERFORM 3D PIC SIMULATIONS TO DETERMINE IF 3D EFFECTS ALTER THE 2D PREDICTIONS AND INVESTIGATE THE ROLE OF RECONNECTION AT OBLIQUE ORIENTATIONS DRIFT WAVES AND THE KELVIN-HELMHOLTZ INSTABILITY AT BOTH ELECTRON AND ION LENGTH SCALES AND (4) COMPARE THE RESULTS WITH OBSERVATIONS OF RECONNECTION AT EARTH S DAYSIDE MAGNETOPAUSE. THE PROPOSED WORK IS RELEVANT TO NASA HELIOPHYSICS OBJECTIVES AS IS EMBODIED BY ITS REPRESENTATION IN THE KEY SCIENCE GOALS FROM THE 2013 HELIOPHYSICS DECADAL SURVEY SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY . THE MOST DIRECT CONNECTION IS THROUGH KEY SCIENCE GOAL 2 WHICH IS TO DETERMINE THE DYNAMICS AND COUPLING OF EARTH S MAGNETOSPHERE IONOSPHERE AND ATMOSPHERE AND THEIR RESPONSE TO SOLAR AND TERRESTRIAL INPUTS. THIS PROJECT IS AN INTEGRAL AND CRUCIAL COMPONENT OF UNDERSTANDING HOW THE MAGNETOSPHERE RESPONDS TO INPUT FROM THE SUN. THE PROPOSED WORK ALSO ADDRESSES KEY SCIENCE GOAL 4 TO DISCOVER AND CHARACTERIZE FUNDAMENTAL PROCESSES THAT OCCUR BOTH WITHIN THE HELIOSPHERE AND THROUGHOUT THE UNIVERSE. THE LIST OF UNIVERSAL PROCESSES OF FUNDAMENTAL IMPORTANCE TO SOLAR AND SPACE PHYSICS INCLUDE MAGNETIC RECONNECTION. THE PROPOSED WORK IS RELEVANT NOT JUST TO THE DAYSIDE MAGNETOPAUSE BUT ALSO OTHER SETTINGS WHERE DIAMAGNETIC EFFECTS HAVE PROVEN IMPORTANT INCLUDING THE SOLAR WIND PLANETARY MAGNETOSPHERES SUCH AS MERCURY JUPITER AND SATURN FUSION DEVICES AND THE HELIOPAUSE. $150.0k 2/9/17