Not listed THE STRUCTURE AND EVOLUTION OF MAGNETIC FIELDS ARE CRUCIAL FOR TRIGGERING SOLAR ERUPTIONS WHICH MAY HAVE ADVERSE SPACE WEATHER EFFECTS ON THE NEAR-EARTH ENVIRONMENT. AMONG VARIOUS MAGNETIC STRUCTURES MAGNETIC FLUX ROPES ARE OF EXTRA IMPORTANCE. THEY ARE HIGHLY TWISTED MAGNETIC FLUX SYSTEMS CARRYING ELECTRIC CURRENTS AND PLAY A KEY ROLE FOR THE INSTABILITY OF PLASMA INVOLVED IN ERUPTIONS. THE FORMATION AND ERUPTION OF MAGNETIC FLUX ROPES HAVE RECEIVED SUBSTANTIAL ATTENTION IN SOLAR AND HELIOSPHERIC RESEARCH.PRIOR OBSERVATIONAL STUDIES OF SOLAR FLUX ROPES PREDOMINANTLY USE IMAGES OF THE OUTER SOLAR CORONA. HOWEVER THE INSUFFICIENT SPATIAL RESOLUTION OF CORONAL IMAGES SERIOUSLY HAMPERS AN UNAMBIGUOUS AND DETAILED IDENTIFICATION AND UNDERSTANDING OF FLUX ROPES AND THEIR RELATION TO ERUPTIONS. IT IS NOW POSSIBLE TO OBTAIN HIGH-QUALITY VECTOR MAGNETOGRAMS FROM HINODE AND THE HELIOSEISMIC AND MAGNETICIMAGER (HMI) ON BOARD THE SOLAR DYNAMIC OBSERVATORY SIMULTANEOUSLY WITH THE UNPRECEDENTED HIGH-RESOLUTION (0.1") IMAGING SPECTROSCOPIC DATA FROM THE 1.6 M NEW SOLAR TELESCOPE (NST) AT BIG BEAR SOLAR OBSERVATORY (BBSO) EQUIPPED WITH HIGH-ORDER ADAPTIVE OPTICS. THIS MAKES IT AN OPPORTUNE MOMENT TO QUANTITATIVELY STUDY THE FINE STRUCTURE AND EVOLUTIONARY DYNAMICS OF FLUX ROPES IN THE LOW SOLAR ATMOSPHERE IN RELATION TO SOLAR ERUPTIONS. NOTABLY WE HAVE DEVOTED GREAT EFFORT TO CARRY OUT CAMPAIGN OBSERVATIONS AND ACHIEVED SIGNIFICANT INITIAL RESULTS.THE SCIENCE OBJECTIVES OF THIS STUDY ARE PLANNED AS FOLLOWS:1. USING 0.1" RESOLUTION H-ALPHA IMAGING SPECTROSCOPY WE WILL STUDY THE STRUCTURE AND EVOLUTION OF ACTIVE FLUX ROPES. AS WE DEMONSTRATED IN RECENT STUDIES USING NST DATA THE TOPOLOGICAL PROPERTIES (E.G. TWIST) OF ERUPTING FLUX ROPES CAN BE IDENTIFIED IN SUCH A HIGH RESOLUTION. IMPORTANT EVIDENCE REGARDING THE FLUX ROPE FORMATION (I.E. WHETHER A FLUX ROPE PRE-EXISTS OR IS FORMED VIA RECONNECTION) CAN ALSO BE OBTAINED.2. USING PRE-ERUPTION HMI AND HINODE VECTOR MAGNETOGRAMS AS BOUNDARY CONDITION WE WILL CARRY OUT NONLINEAR FORCE-FREE FIELD (NLFFF) EXTRAPOLATIONS TO QUANTITATIVELY TRACE MAGNETIC FLUX ROPES AND STUDY THE SURROUNDING MAGNETIC FIELD CONFIGURATION BEFORE ERUPTIONS. THE RESULTS WILL BE COMPARATIVELY STUDIED WITH THE LOW ATMOSPHERE STRUCTURE VISUALIZED BY THE HIGH-RESOLUTION NST OBSERVATION. PHYSICAL PARAMETERS SUCH AS ELECTRIC CURRENT AND MAGNETIC TWIST WILL BE QUANTIFIED. THE PHOTOSPHERIC FLOW FIELDS WHICH CAN BE RELATED TO THE FORMATION AND INSTABILITY OF FLUX ROPES WILL ALSO BE ANALYZED USING ADVANCED FLOW TRACKING METHODS. MOREOVER RAPID CHANGES OF MAGNETIC FIELD STRUCTURE ASSOCIATED WITH ERUPTIONS WILL BE EXAMINED USING NST IMAGES AND MAGNETOGRAMS.3. USING HIGH-RESOLUTION MAGNETOGRAMS FROM HINODE AND NST'S VECTOR MAGNETOGRAPH SYSTEM AS WELL AS VISIBLE-CONTINUUM IMAGES WE WILL CHARACTERIZE THE FORMATION AND EVOLUTION OF THE MAGNETIC CHANNEL STRUCTURE WHICH IS PROMINENTLY OBSERVED IN SOME FLAREPRODUCTIVE ACTIVE REGIONS. MAGNETIC CHANNELS DEFINED AS A SERIES OF OPPOSITELY DIRECTED VERTICAL-FIELD INVERSIONS SEPARATED BY EXTREMELYNARROW ELONGATED TRANSVERSE FIELDS MAY REPRESENT A SIGNIFICANT SIGNATURE OF EMERGING FINE-SCALE TWISTED FLUX TUBES THUS PROVIDING A POSSIBLE CONNECTION BETWEEN THE FLUX ROPE IN THE CHROMOSPHERE AND THE MAGNETIC TWIST IN THE PHOTOSPHERE.THE PROPOSED INVESTIGATION WILL EXTENSIVELY ANALYZE DATA FROM NASA'S CURRENT HELIOPHYSICS MISSIONS (E.G. SDO AND HINODE). TO MAKE ADVANCES IN UNDERSTANDING THE FINE DYNAMIC STRUCTURE OF FLUX ROPES THE USE OF HIGH-RESOLUTION BBSO/NST OBSERVATION IS NECESSARY AND CONSTITUTES A UNIQUE CONTRIBUTION. AS MAGNETIC FLUX ROPES ARE OFTEN FOUND PRONE TO ERUPTIONS STUDIES OF THEM ARE POTENTIALLY IMPORTANT FOR UNDERSTANDING THE ATURE OF SOLAR ERUPTIVE EVENTS. THE STUDY IS CLOSELY RELEVANT TO ONE OF THE HELIOPHYSICS DECADAL SURVEY GOALS:DETERMINE THE ORIGINS OF THE SUN'S ACTIVITY AND PREDICT THE VARIATIONS IN THE SPACE ENVIRONMENT. $0 2/7/19 3 THE STRUCTURE AND EVOLUTION OF MAGNETIC FIELDS ARE CRUCIAL FOR TRIGGERING SOLAR ERUPTIONS, WHICH MAY HAVE ADVERSE SPACE WEATHER EFFECTS ON THE NEAR-EARTH ENVIRONMENT. AMONG VARIOUS MAGNETIC STRUCTURES, MAGNETIC FLUX ROPES ARE OF EXTRA IMPORTANCE. THEY ARE HIGHLY TWISTED MAGNETIC FLUX SYSTEMS CARRYING ELECTRIC CURRENTS, AND PLAY A KEY ROLE FOR THE INSTABILITY OF PLASMA INVOLVED IN ERUPTIONS. THE FORMATION AND ERUPTION OF MAGNETIC FLUX ROPES HAVE RECEIVED SUBSTANTIAL ATTENTION IN SOLAR AND HELIOSPHERIC RESEARCH. PRIOR OBSERVATIONAL STUDIES OF SOLAR FLUX ROPES PREDOMINANTLY USE IMAGES OF THE OUTER SOLAR CORONA. HOWEVER, THE INSUFFICIENT SPATIAL RESOLUTION OF CORONAL IMAGES SERIOUSLY HAMPERS AN UNAMBIGUOUS AND DETAILED IDENTIFICATION AND UNDERSTANDING OF FLUX ROPES AND THEIR RELATION TO ERUPTIONS. IT IS NOW POSSIBLE TO OBTAIN HIGH-QUALITY VECTOR MAGNETOGRAMS FROM HINODE AND THE HELIOSEISMIC AND MAGNETIC IMAGER (HMI) ON BOARD THE SOLAR DYNAMIC OBSERVATORY SIMULTANEOUSLY WITH THE UNPRECEDENTED HIGH-RESOLUTION (0.1") IMAGING SPECTROSCOPIC DATA FROM THE 1.6 M NEW SOLAR TELESCOPE (NST) AT BIG BEAR SOLAR OBSERVATORY (BBSO) EQUIPPED WITH HIGH-ORDER ADAPTIVE OPTICS. THIS MAKES IT AN OPPORTUNE MOMENT TO QUANTITATIVELY STUDY THE FINE STRUCTURE AND EVOLUTIONARY DYNAMICS OF FLUX ROPES IN THE LOW SOLAR ATMOSPHERE IN RELATION TO SOLAR ERUPTIONS. NOTABLY, WE HAVE DEVOTED GREAT EFFORT TO CARRY OUT CAMPAIGN OBSERVATIONS AND ACHIEVED SIGNIFICANT INITIAL RESULTS. THE SCIENCE OBJECTIVES OF THIS STUDY ARE PLANNED AS FOLLOWS: 1. USING 0.1" RESOLUTION H-ALPHA IMAGING SPECTROSCOPY, WE WILL STUDY THE STRUCTURE AND EVOLUTION OF ACTIVE FLUX ROPES. AS WE DEMONSTRATED IN RECENT STUDIES USING NST DATA, THE TOPOLOGICAL PROPERTIES (E.G., TWIST) OF ERUPTING FLUX ROPES CAN BE IDENTIFIED IN SUCH A HIGH RESOLUTION. IMPORTANT EVIDENCE REGARDING THE FLUX ROPE FORMATION (I.E. WHETHER A FLUX ROPE PRE-EXISTS OR IS FORMED VIA RECONNECTION) CAN ALSO BE OBTAINED. 2. USING PRE-ERUPTION HMI AND HINODE VECTOR MAGNETOGRAMS AS BOUNDARY CONDITION, WE WILL CARRY OUT NONLINEAR FORCE-FREE FIELD (NLFFF) EXTRAPOLATIONS TO QUANTITATIVELY TRACE MAGNETIC FLUX ROPES AND STUDY THE SURROUNDING MAGNETIC FIELD CONFIGURATION BEFORE ERUPTIONS. THE RESULTS WILL BE COMPARATIVELY STUDIED WITH THE LOW ATMOSPHERE STRUCTURE VISUALIZED BY THE HIGH-RESOLUTION NST OBSERVATION. PHYSICAL PARAMETERS SUCH AS ELECTRIC CURRENT AND MAGNETIC TWIST WILL BE QUANTIFIED. THE PHOTOSPHERIC FLOW FIELDS, WHICH CAN BE RELATED TO THE FORMATION AND INSTABILITY OF FLUX ROPES, WILL ALSO BE ANALYZED USING ADVANCED FLOW TRACKING METHODS. MOREOVER, RAPID CHANGES OF MAGNETIC FIELD STRUCTURE ASSOCIATED WITH ERUPTIONS WILL BE EXAMINED USING NST IMAGES AND MAGNETOGRAMS. 3. USING HIGH-RESOLUTION MAGNETOGRAMS FROM HINODE AND NST'S VECTOR MAGNETOGRAPH SYSTEM AS WELL AS VISIBLE-CONTINUUM IMAGES, WE WILL CHARACTERIZE THE FORMATION AND EVOLUTION OF THE MAGNETIC CHANNEL STRUCTURE, WHICH IS PROMINENTLY OBSERVED IN SOME FLAREPRODUCTIVE ACTIVE REGIONS. MAGNETIC CHANNELS, DEFINED AS A SERIES OF OPPOSITELY DIRECTED VERTICAL-FIELD INVERSIONS SEPARATED BY EXTREMELY NARROW ELONGATED TRANSVERSE FIELDS, MAY REPRESENT A SIGNIFICANT SIGNATURE OF EMERGING FINE-SCALE TWISTED FLUX TUBES, THUS PROVIDING A POSSIBLE CONNECTION BETWEEN THE FLUX ROPE IN THE CHROMOSPHERE AND THE MAGNETIC TWIST IN THE PHOTOSPHERE. THE PROPOSED INVESTIGATION WILL EXTENSIVELY ANALYZE DATA FROM NASA'S CURRENT HELIOPHYSICS MISSIONS (E.G., SDO AND HINODE). TO MAKE ADVANCES IN UNDERSTANDING THE FINE DYNAMIC STRUCTURE OF FLUX ROPES, THE USE OF HIGH-RESOLUTION BBSO/NST OBSERVATION IS NECESSARY AND CONSTITUTES A UNIQUE CONTRIBUTION. AS MAGNETIC FLUX ROPES ARE OFTEN FOUND PRONE TO ERUPTIONS, STUDIES OF THEM ARE POTENTIALLY IMPORTANT FOR UNDERSTANDING THE ATURE OF SOLAR ERUPTIVE EVENTS. THE STUDY IS CLOSELY RELEVANT TO ONE OF THE HELIOPHYSICS DECADAL SURVEY GOALS: DETERMINE THE ORIGINS OF THE SUN'S ACTIVITY AND PREDICT THE VARIATIONS IN THE SPACE ENVIRONMENT. Other Administrative Action $0 2/7/19 Not listed THE STRUCTURE AND EVOLUTION OF MAGNETIC FIELDS ARE CRUCIAL FOR TRIGGERING SOLAR ERUPTIONS WHICH MAY HAVE ADVERSE SPACE WEATHER EFFECTS ON THE NEAR-EARTH ENVIRONMENT. AMONG VARIOUS MAGNETIC STRUCTURES MAGNETIC FLUX ROPES ARE OF EXTRA IMPORTANCE. THEY ARE HIGHLY TWISTED MAGNETIC FLUX SYSTEMS CARRYING ELECTRIC CURRENTS AND PLAY A KEY ROLE FOR THE INSTABILITY OF PLASMA INVOLVED IN ERUPTIONS. THE FORMATION AND ERUPTION OF MAGNETIC FLUX ROPES HAVE RECEIVED SUBSTANTIAL ATTENTION IN SOLAR AND HELIOSPHERIC RESEARCH.PRIOR OBSERVATIONAL STUDIES OF SOLAR FLUX ROPES PREDOMINANTLY USE IMAGES OF THE OUTER SOLAR CORONA. HOWEVER THE INSUFFICIENT SPATIAL RESOLUTION OF CORONAL IMAGES SERIOUSLY HAMPERS AN UNAMBIGUOUS AND DETAILED IDENTIFICATION AND UNDERSTANDING OF FLUX ROPES AND THEIR RELATION TO ERUPTIONS. IT IS NOW POSSIBLE TO OBTAIN HIGH-QUALITY VECTOR MAGNETOGRAMS FROM HINODE AND THE HELIOSEISMIC AND MAGNETICIMAGER (HMI) ON BOARD THE SOLAR DYNAMIC OBSERVATORY SIMULTANEOUSLY WITH THE UNPRECEDENTED HIGH-RESOLUTION (0.1") IMAGING SPECTROSCOPIC DATA FROM THE 1.6 M NEW SOLAR TELESCOPE (NST) AT BIG BEAR SOLAR OBSERVATORY (BBSO) EQUIPPED WITH HIGH-ORDER ADAPTIVE OPTICS. THIS MAKES IT AN OPPORTUNE MOMENT TO QUANTITATIVELY STUDY THE FINE STRUCTURE AND EVOLUTIONARY DYNAMICS OF FLUX ROPES IN THE LOW SOLAR ATMOSPHERE IN RELATION TO SOLAR ERUPTIONS. NOTABLY WE HAVE DEVOTED GREAT EFFORT TO CARRY OUT CAMPAIGN OBSERVATIONS AND ACHIEVED SIGNIFICANT INITIAL RESULTS.THE SCIENCE OBJECTIVES OF THIS STUDY ARE PLANNED AS FOLLOWS:1. USING 0.1" RESOLUTION H-ALPHA IMAGING SPECTROSCOPY WE WILL STUDY THE STRUCTURE AND EVOLUTION OF ACTIVE FLUX ROPES. AS WE DEMONSTRATED IN RECENT STUDIES USING NST DATA THE TOPOLOGICAL PROPERTIES (E.G. TWIST) OF ERUPTING FLUX ROPES CAN BE IDENTIFIED IN SUCH A HIGH RESOLUTION. IMPORTANT EVIDENCE REGARDING THE FLUX ROPE FORMATION (I.E. WHETHER A FLUX ROPE PRE-EXISTS OR IS FORMED VIA RECONNECTION) CAN ALSO BE OBTAINED.2. USING PRE-ERUPTION HMI AND HINODE VECTOR MAGNETOGRAMS AS BOUNDARY CONDITION WE WILL CARRY OUT NONLINEAR FORCE-FREE FIELD (NLFFF) EXTRAPOLATIONS TO QUANTITATIVELY TRACE MAGNETIC FLUX ROPES AND STUDY THE SURROUNDING MAGNETIC FIELD CONFIGURATION BEFORE ERUPTIONS. THE RESULTS WILL BE COMPARATIVELY STUDIED WITH THE LOW ATMOSPHERE STRUCTURE VISUALIZED BY THE HIGH-RESOLUTION NST OBSERVATION. PHYSICAL PARAMETERS SUCH AS ELECTRIC CURRENT AND MAGNETIC TWIST WILL BE QUANTIFIED. THE PHOTOSPHERIC FLOW FIELDS WHICH CAN BE RELATED TO THE FORMATION AND INSTABILITY OF FLUX ROPES WILL ALSO BE ANALYZED USING ADVANCED FLOW TRACKING METHODS. MOREOVER RAPID CHANGES OF MAGNETIC FIELD STRUCTURE ASSOCIATED WITH ERUPTIONS WILL BE EXAMINED USING NST IMAGES AND MAGNETOGRAMS.3. USING HIGH-RESOLUTION MAGNETOGRAMS FROM HINODE AND NST'S VECTOR MAGNETOGRAPH SYSTEM AS WELL AS VISIBLE-CONTINUUM IMAGES WE WILL CHARACTERIZE THE FORMATION AND EVOLUTION OF THE MAGNETIC CHANNEL STRUCTURE WHICH IS PROMINENTLY OBSERVED IN SOME FLAREPRODUCTIVE ACTIVE REGIONS. MAGNETIC CHANNELS DEFINED AS A SERIES OF OPPOSITELY DIRECTED VERTICAL-FIELD INVERSIONS SEPARATED BY EXTREMELYNARROW ELONGATED TRANSVERSE FIELDS MAY REPRESENT A SIGNIFICANT SIGNATURE OF EMERGING FINE-SCALE TWISTED FLUX TUBES THUS PROVIDING A POSSIBLE CONNECTION BETWEEN THE FLUX ROPE IN THE CHROMOSPHERE AND THE MAGNETIC TWIST IN THE PHOTOSPHERE.THE PROPOSED INVESTIGATION WILL EXTENSIVELY ANALYZE DATA FROM NASA'S CURRENT HELIOPHYSICS MISSIONS (E.G. SDO AND HINODE). TO MAKE ADVANCES IN UNDERSTANDING THE FINE DYNAMIC STRUCTURE OF FLUX ROPES THE USE OF HIGH-RESOLUTION BBSO/NST OBSERVATION IS NECESSARY AND CONSTITUTES A UNIQUE CONTRIBUTION. AS MAGNETIC FLUX ROPES ARE OFTEN FOUND PRONE TO ERUPTIONS STUDIES OF THEM ARE POTENTIALLY IMPORTANT FOR UNDERSTANDING THE ATURE OF SOLAR ERUPTIVE EVENTS. THE STUDY IS CLOSELY RELEVANT TO ONE OF THE HELIOPHYSICS DECADAL SURVEY GOALS:DETERMINE THE ORIGINS OF THE SUN'S ACTIVITY AND PREDICT THE VARIATIONS IN THE SPACE ENVIRONMENT. $134.5k 1/19/18 2 THE STRUCTURE AND EVOLUTION OF MAGNETIC FIELDS ARE CRUCIAL FOR TRIGGERING SOLAR ERUPTIONS, WHICH MAY HAVE ADVERSE SPACE WEATHER EFFECTS ON THE NEAR-EARTH ENVIRONMENT. AMONG VARIOUS MAGNETIC STRUCTURES, MAGNETIC FLUX ROPES ARE OF EXTRA IMPORTANCE. THEY ARE HIGHLY TWISTED MAGNETIC FLUX SYSTEMS CARRYING ELECTRIC CURRENTS, AND PLAY A KEY ROLE FOR THE INSTABILITY OF PLASMA INVOLVED IN ERUPTIONS. THE FORMATION AND ERUPTION OF MAGNETIC FLUX ROPES HAVE RECEIVED SUBSTANTIAL ATTENTION IN SOLAR AND HELIOSPHERIC RESEARCH. PRIOR OBSERVATIONAL STUDIES OF SOLAR FLUX ROPES PREDOMINANTLY USE IMAGES OF THE OUTER SOLAR CORONA. HOWEVER, THE INSUFFICIENT SPATIAL RESOLUTION OF CORONAL IMAGES SERIOUSLY HAMPERS AN UNAMBIGUOUS AND DETAILED IDENTIFICATION AND UNDERSTANDING OF FLUX ROPES AND THEIR RELATION TO ERUPTIONS. IT IS NOW POSSIBLE TO OBTAIN HIGH-QUALITY VECTOR MAGNETOGRAMS FROM HINODE AND THE HELIOSEISMIC AND MAGNETIC IMAGER (HMI) ON BOARD THE SOLAR DYNAMIC OBSERVATORY SIMULTANEOUSLY WITH THE UNPRECEDENTED HIGH-RESOLUTION (0.1") IMAGING SPECTROSCOPIC DATA FROM THE 1.6 M NEW SOLAR TELESCOPE (NST) AT BIG BEAR SOLAR OBSERVATORY (BBSO) EQUIPPED WITH HIGH-ORDER ADAPTIVE OPTICS. THIS MAKES IT AN OPPORTUNE MOMENT TO QUANTITATIVELY STUDY THE FINE STRUCTURE AND EVOLUTIONARY DYNAMICS OF FLUX ROPES IN THE LOW SOLAR ATMOSPHERE IN RELATION TO SOLAR ERUPTIONS. NOTABLY, WE HAVE DEVOTED GREAT EFFORT TO CARRY OUT CAMPAIGN OBSERVATIONS AND ACHIEVED SIGNIFICANT INITIAL RESULTS. THE SCIENCE OBJECTIVES OF THIS STUDY ARE PLANNED AS FOLLOWS: 1. USING 0.1" RESOLUTION H-ALPHA IMAGING SPECTROSCOPY, WE WILL STUDY THE STRUCTURE AND EVOLUTION OF ACTIVE FLUX ROPES. AS WE DEMONSTRATED IN RECENT STUDIES USING NST DATA, THE TOPOLOGICAL PROPERTIES (E.G., TWIST) OF ERUPTING FLUX ROPES CAN BE IDENTIFIED IN SUCH A HIGH RESOLUTION. IMPORTANT EVIDENCE REGARDING THE FLUX ROPE FORMATION (I.E. WHETHER A FLUX ROPE PRE-EXISTS OR IS FORMED VIA RECONNECTION) CAN ALSO BE OBTAINED. 2. USING PRE-ERUPTION HMI AND HINODE VECTOR MAGNETOGRAMS AS BOUNDARY CONDITION, WE WILL CARRY OUT NONLINEAR FORCE-FREE FIELD (NLFFF) EXTRAPOLATIONS TO QUANTITATIVELY TRACE MAGNETIC FLUX ROPES AND STUDY THE SURROUNDING MAGNETIC FIELD CONFIGURATION BEFORE ERUPTIONS. THE RESULTS WILL BE COMPARATIVELY STUDIED WITH THE LOW ATMOSPHERE STRUCTURE VISUALIZED BY THE HIGH-RESOLUTION NST OBSERVATION. PHYSICAL PARAMETERS SUCH AS ELECTRIC CURRENT AND MAGNETIC TWIST WILL BE QUANTIFIED. THE PHOTOSPHERIC FLOW FIELDS, WHICH CAN BE RELATED TO THE FORMATION AND INSTABILITY OF FLUX ROPES, WILL ALSO BE ANALYZED USING ADVANCED FLOW TRACKING METHODS. MOREOVER, RAPID CHANGES OF MAGNETIC FIELD STRUCTURE ASSOCIATED WITH ERUPTIONS WILL BE EXAMINED USING NST IMAGES AND MAGNETOGRAMS. 3. USING HIGH-RESOLUTION MAGNETOGRAMS FROM HINODE AND NST'S VECTOR MAGNETOGRAPH SYSTEM AS WELL AS VISIBLE-CONTINUUM IMAGES, WE WILL CHARACTERIZE THE FORMATION AND EVOLUTION OF THE MAGNETIC CHANNEL STRUCTURE, WHICH IS PROMINENTLY OBSERVED IN SOME FLAREPRODUCTIVE ACTIVE REGIONS. MAGNETIC CHANNELS, DEFINED AS A SERIES OF OPPOSITELY DIRECTED VERTICAL-FIELD INVERSIONS SEPARATED BY EXTREMELY NARROW ELONGATED TRANSVERSE FIELDS, MAY REPRESENT A SIGNIFICANT SIGNATURE OF EMERGING FINE-SCALE TWISTED FLUX TUBES, THUS PROVIDING A POSSIBLE CONNECTION BETWEEN THE FLUX ROPE IN THE CHROMOSPHERE AND THE MAGNETIC TWIST IN THE PHOTOSPHERE. THE PROPOSED INVESTIGATION WILL EXTENSIVELY ANALYZE DATA FROM NASA'S CURRENT HELIOPHYSICS MISSIONS (E.G., SDO AND HINODE). TO MAKE ADVANCES IN UNDERSTANDING THE FINE DYNAMIC STRUCTURE OF FLUX ROPES, THE USE OF HIGH-RESOLUTION BBSO/NST OBSERVATION IS NECESSARY AND CONSTITUTES A UNIQUE CONTRIBUTION. AS MAGNETIC FLUX ROPES ARE OFTEN FOUND PRONE TO ERUPTIONS, STUDIES OF THEM ARE POTENTIALLY IMPORTANT FOR UNDERSTANDING THE ATURE OF SOLAR ERUPTIVE EVENTS. THE STUDY IS CLOSELY RELEVANT TO ONE OF THE HELIOPHYSICS DECADAL SURVEY GOALS: DETERMINE THE ORIGINS OF THE SUN'S ACTIVITY AND PREDICT THE VARIATIONS IN THE SPACE ENVIRONMENT. Funding Only Action $134.5k 1/19/18 1 THE STRUCTURE AND EVOLUTION OF MAGNETIC FIELDS ARE CRUCIAL FOR TRIGGERING SOLAR ERUPTIONS, WHICH MAY HAVE ADVERSE SPACE WEATHER EFFECTS ON THE NEAR-EARTH ENVIRONMENT. AMONG VARIOUS MAGNETIC STRUCTURES, MAGNETIC FLUX ROPES ARE OF EXTRA IMPORTANCE. THEY ARE HIGHLY TWISTED MAGNETIC FLUX SYSTEMS CARRYING ELECTRIC CURRENTS, AND PLAY A KEY ROLE FOR THE INSTABILITY OF PLASMA INVOLVED IN ERUPTIONS. THE FORMATION AND ERUPTION OF MAGNETIC FLUX ROPES HAVE RECEIVED SUBSTANTIAL ATTENTION IN SOLAR AND HELIOSPHERIC RESEARCH. PRIOR OBSERVATIONAL STUDIES OF SOLAR FLUX ROPES PREDOMINANTLY USE IMAGES OF THE OUTER SOLAR CORONA. HOWEVER, THE INSUFFICIENT SPATIAL RESOLUTION OF CORONAL IMAGES SERIOUSLY HAMPERS AN UNAMBIGUOUS AND DETAILED IDENTIFICATION AND UNDERSTANDING OF FLUX ROPES AND THEIR RELATION TO ERUPTIONS. IT IS NOW POSSIBLE TO OBTAIN HIGH-QUALITY VECTOR MAGNETOGRAMS FROM HINODE AND THE HELIOSEISMIC AND MAGNETIC IMAGER (HMI) ON BOARD THE SOLAR DYNAMIC OBSERVATORY SIMULTANEOUSLY WITH THE UNPRECEDENTED HIGH-RESOLUTION (0.1") IMAGING SPECTROSCOPIC DATA FROM THE 1.6 M NEW SOLAR TELESCOPE (NST) AT BIG BEAR SOLAR OBSERVATORY (BBSO) EQUIPPED WITH HIGH-ORDER ADAPTIVE OPTICS. THIS MAKES IT AN OPPORTUNE MOMENT TO QUANTITATIVELY STUDY THE FINE STRUCTURE AND EVOLUTIONARY DYNAMICS OF FLUX ROPES IN THE LOW SOLAR ATMOSPHERE IN RELATION TO SOLAR ERUPTIONS. NOTABLY, WE HAVE DEVOTED GREAT EFFORT TO CARRY OUT CAMPAIGN OBSERVATIONS AND ACHIEVED SIGNIFICANT INITIAL RESULTS. THE SCIENCE OBJECTIVES OF THIS STUDY ARE PLANNED AS FOLLOWS: 1. USING 0.1" RESOLUTION H-ALPHA IMAGING SPECTROSCOPY, WE WILL STUDY THE STRUCTURE AND EVOLUTION OF ACTIVE FLUX ROPES. AS WE DEMONSTRATED IN RECENT STUDIES USING NST DATA, THE TOPOLOGICAL PROPERTIES (E.G., TWIST) OF ERUPTING FLUX ROPES CAN BE IDENTIFIED IN SUCH A HIGH RESOLUTION. IMPORTANT EVIDENCE REGARDING THE FLUX ROPE FORMATION (I.E. WHETHER A FLUX ROPE PRE-EXISTS OR IS FORMED VIA RECONNECTION) CAN ALSO BE OBTAINED. 2. USING PRE-ERUPTION HMI AND HINODE VECTOR MAGNETOGRAMS AS BOUNDARY CONDITION, WE WILL CARRY OUT NONLINEAR FORCE-FREE FIELD (NLFFF) EXTRAPOLATIONS TO QUANTITATIVELY TRACE MAGNETIC FLUX ROPES AND STUDY THE SURROUNDING MAGNETIC FIELD CONFIGURATION BEFORE ERUPTIONS. THE RESULTS WILL BE COMPARATIVELY STUDIED WITH THE LOW ATMOSPHERE STRUCTURE VISUALIZED BY THE HIGH-RESOLUTION NST OBSERVATION. PHYSICAL PARAMETERS SUCH AS ELECTRIC CURRENT AND MAGNETIC TWIST WILL BE QUANTIFIED. THE PHOTOSPHERIC FLOW FIELDS, WHICH CAN BE RELATED TO THE FORMATION AND INSTABILITY OF FLUX ROPES, WILL ALSO BE ANALYZED USING ADVANCED FLOW TRACKING METHODS. MOREOVER, RAPID CHANGES OF MAGNETIC FIELD STRUCTURE ASSOCIATED WITH ERUPTIONS WILL BE EXAMINED USING NST IMAGES AND MAGNETOGRAMS. 3. USING HIGH-RESOLUTION MAGNETOGRAMS FROM HINODE AND NST'S VECTOR MAGNETOGRAPH SYSTEM AS WELL AS VISIBLE-CONTINUUM IMAGES, WE WILL CHARACTERIZE THE FORMATION AND EVOLUTION OF THE MAGNETIC CHANNEL STRUCTURE, WHICH IS PROMINENTLY OBSERVED IN SOME FLAREPRODUCTIVE ACTIVE REGIONS. MAGNETIC CHANNELS, DEFINED AS A SERIES OF OPPOSITELY DIRECTED VERTICAL-FIELD INVERSIONS SEPARATED BY EXTREMELY NARROW ELONGATED TRANSVERSE FIELDS, MAY REPRESENT A SIGNIFICANT SIGNATURE OF EMERGING FINE-SCALE TWISTED FLUX TUBES, THUS PROVIDING A POSSIBLE CONNECTION BETWEEN THE FLUX ROPE IN THE CHROMOSPHERE AND THE MAGNETIC TWIST IN THE PHOTOSPHERE. THE PROPOSED INVESTIGATION WILL EXTENSIVELY ANALYZE DATA FROM NASA'S CURRENT HELIOPHYSICS MISSIONS (E.G., SDO AND HINODE). TO MAKE ADVANCES IN UNDERSTANDING THE FINE DYNAMIC STRUCTURE OF FLUX ROPES, THE USE OF HIGH-RESOLUTION BBSO/NST OBSERVATION IS NECESSARY AND CONSTITUTES A UNIQUE CONTRIBUTION. AS MAGNETIC FLUX ROPES ARE OFTEN FOUND PRONE TO ERUPTIONS, STUDIES OF THEM ARE POTENTIALLY IMPORTANT FOR UNDERSTANDING THE ATURE OF SOLAR ERUPTIVE EVENTS. THE STUDY IS CLOSELY RELEVANT TO ONE OF THE HELIOPHYSICS DECADAL SURVEY GOALS: DETERMINE THE ORIGINS OF THE SUN'S ACTIVITY AND PREDICT THE VARIATIONS IN THE SPACE ENVIRONMENT. Funding Only Action $130.4k 1/5/17