STATISTICAL STUDY OF EMERGING ACTIVE REGIONS USING DEEP-FOCUS LOCAL HELIOSEISMOLOGY

THE SCIENCE GOALS AND OBJECTIVES TO BE ADDRESSED BY THE PROPOSAL. PREDICTION OF EMERGENCE AND EVOLUTION OF ACTIVE REGIONS IS A KEY TO UNDERSTANDING THE ORIGINS OF THE SUN'S ACTIVITY AND PREDICTING THE VARIATIONS IN THE SPACE ENVIRONMENT. LOCAL HELIOSEISMOLOGY HAS DEMONSTRATED POTENTIAL FOR DETECTION OF LARGE ACTIVE REGIONS PRIOR THEIR EMERGENCE. DEMONSTRATED ABILITY OF ACTIVE REGION DETECTION HAS BEEN OBTAINED BY TWO DIFFERENT TECHNIQUES: DEEP-FOCUS TIME-DISTANCE HELIOSEISMOLOGY AND ACOUSTIC HOLOGRAPHY. HOWEVER THE RELIABILITY AND LIMITATIONS OF SUCH DETECTION HAVE NOT BEEN ESTABLISHED. IN PARTICULAR THE IMPACT OF PRE-EXISTING MAGNETIC FIELD ON THE HELIOSEISMOLOGY MEASUREMENTS HAS BEEN DEBATED. THE OBJECTIVES OF THIS PROPOSAL ARE TO CARRY OUT A COMPREHENSIVE STATISTICAL STUDY OF EMERGING ACTIVE REGIONS OBSERVED DURING THE WHOLE SOLAR DYNAMICS OBSERVATORY (SDO) MISSION SINCE 2011 BY USING BOTH THE TIME-DISTANCE AND ACOUSTIC HOLOGRAPHY METHODS PERFORM A COMPARATIVE STUDY OF THE HELIOSEISMIC SIGNALS IN RELATION TO THE BACKGROUND RANDOM NOISE DUE TO STOCHASTIC NATURE OF SOLAR OSCILLATIONS AND ESTIMATE THE ROLE OF SYSTEMATIC UNCERTAINTIES CAUSED SURFACE MAGNETIC FIELDS. IN ADDITION TO DETECTION OF PRE-EMERGENCE SIGNATURES WE WILL INVESTIGATE A POTENTIAL FOR PREDICTION OF THE FUTURE EVOLUTION OF MAGNETIC FLUX THAT HAS APPEARED ON THE SURFACE. A LISTING OF THE MISSION DATA TO BE USED IN THE INVESTIGATION. THE PRIMARY MISSION DATA WILL BE FULL-DISK DOPPLERGRAMS AND MAGNETOGRAMS WITH 45-SEC CADENCE FROM THE HELIOSEISMIC AND MAGNETIC IMAGER (HMI) ONBOARD SDO. SECONDARY DATA SETS WILL INCLUDE THE HMI CONTINUUM AND SDO/AIA EUV IMAGES FOR CONTENTS STUDIES. THE SDO DATA OBTAINED DURING THE WHOLE MISSION WILL BE USED IN THE PROPOSED ANALYSIS. A LISTING OF THE DATA ANALYSIS METHODOLOGY AND ANY MODELS OR SIMULATIONS TO BE USED. THE DATA ANALYSIS WILL BE PERFORMED BY USING TWO LOCAL HELIOSEISMOLOGY TECHNIQUES: DEEP-FOCUS TIME-DISTANCE HELIOSEISMOLOGY AND ACOUSTIC HOLOGRAPHY AS WELL AS THEIR MODIFICATIONS. BOTH TECHNIQUES HAVE BEEN USED IN THIS TYPE OF STUDIES WELL DESCRIBED AND TESTED. THE DATA ANALYSIS CODES WILL BE OPTIMIZED AND IMPLEMENTED ON THE SDO JSOC AND NASA HEC COMPUTER SYSTEMS. A NECESSARY PARAMETRIC STUDY WILL BE PERFORMED TO OPTIMIZE THE PARAMETERS OF BOTH TECHNIQUES. FOR TESTING THE HELIOSEISMOLOGY CODES WE WILL USE PREVIOUSLY DEVELOPED 3D SIMULATIONS OF SOLAR OSCILLATIONS IN THE PRESENCE OF SUBSURFACE SOUND-SPEED PERTURBATIONS. A BRIEF STATEMENT OF THE RELEVANCE OF THE PROBLEM TO THE GOALS OF THE MISSION. THE PROJECT WILL SUBSTANTIALLY CONTRIBUTE TO ACHIEVING THE PRIMARY SDO MISSION GOAL: 'TO UNDERSTAND DRIVING TOWARDS A PREDICTIVE CAPABILITY THE SOLAR VARIATIONS THAT INFLUENCE LIFE ON EARTH AND HUMANITY'S TECHNOLOGICAL SYSTEMS BY DETERMINING HOW THE SUN'S MAGNETIC FIELD IS GENERATED AND STRUCTURED' AS WELL AS THE HMI INVESTIGATION GOAL: 'TO INVESTIGATE THE ORIGIN AND EVOLUTION OF SUNSPOTS ACTIVE REGIONS AND COMPLEXES OF ACTIVITY'. THE PROPOSAL DIRECTLY ADDRESSES THE FIRST HELIOPHYSICS DECADAL SURVEY SOLAR AND SPACE PHYSICS OBJECTIVE: 'DETERMINE THE ORIGINS OF THE SUN S ACTIVITY AND PREDICT THE VARIATIONS IN THE SPACE ENVIRONMENT'. THE RESULTS OF THIS PROJECT WILL HELP TO BETTER UNDERSTAND PROPERTIES OF EMERGING ACTIVE REGIONS AND POTENTIALLY DEVELOP NEW PREDICTIVE CAPABILITIES.