WE SEEK TO DETERMINE THE NATURE OF THE SOLAR DYNAMO: IS THERE ONE SOLAR DYNAMO OR TWO? IS THE DYNAMO A SINGLE FUNDAMENTALLY COMPLEX MECHANISM? OR DO TWO SEPARATE MECHANISMS GIVE RISE TO THE OBSERVED SOLAR CYCLE AND THE SMALL SCALE SALT AND PEPPER FIELD? RECENT THEORETICAL ADVANCES HAVE CALLED INTO QUESTION THE LONG-HELD SEPARATION OF THE SOLAR DYNAMO INTO A GLOBAL-SCALE MECHANISM THAT GENERATES SUNSPOTS AND ASSOCIATED PHENOMENA OF THE SOLAR CYCLE AND A SMALL-SCALE MECHANISM THAT GENERATES MAGNETIC FIELD AT ALL PHASES OF THE SOLAR CYCLE. ACCORDING TO THIS NEW THINKING THE GLOBAL-SCALE AND SMALL-SCALE COMPONENTS OF THE DYNAMO ARE INEXTRICABLY LINKED INTO A SINGLE FUNDAMENTALLY COMPLEX MECHANISM ENCOMPASSING BOTH LARGE AND SMALL SCALES. HOWEVER OBSERVATIONAL TESTS OF THIS HAVE NOT KEPT UP WITH THE THEORETICAL ADVANCES DUE IN PART TO THE LACK OF A LONG-TERM BASELINE OF FULL-DISK HIGH RESOLUTION OBSERVATIONS AND VALIDATED MULTI-SCALE DATA ANALYSIS TOOLS CAPABLE OF MEANINGFULLY EXPLOITING SUCH DATA. OUR INVESTIGATION IS ORGANIZED AROUND THREE SPECIFIC WELL-FORMED QUESTIONS: 1) DO MAGNETIC FEATURES NATURALLY DIVIDE INTO DISTINCT CLASSES THAT ARE ATTRIBUTABLE TO SEPARATE DYNAMOS? 2) WHAT IS THE SCALE AND NATURE OF THE TRANSITION BETWEEN SMALL- AND LARGE-SCALE FLUX EVOLUTION? 3) HOW DO THE INTERACTIONS BETWEEN LARGE- AND SMALL-SCALE MAGNETISM CHANGE OVER THE COURSE OF THE SOLAR CYCLE? WE WILL USE SDO/HMI LINE-OF-SIGHT MAGNETOGRAMS FROM THE 720 S DATA SERIES. THESE MAGNETOGRAMS PROVIDE FULL-DISK HIGH RESOLUTION CONTINUOUS OBSERVATIONS OF THE PHOTOSPHERIC MAGNETIC FIELD AND NOW HAVE A LONG ENOUGH BASELINE TO MEANINGFULLY PROBE THE SOLAR DYNAMO ACROSS A LARGE PORTION OF A SOLAR CYCLE. WE WILL ANALYZE THE MAGNETOGRAMS USING THE FEATURE TRACKING CODE SWAMIS (SOUTHWEST AUTOMATIC MAGNETIC IDENTIFICATION SUITE) AND CONDUCT STATISTICAL ANALYSES ON THE RESULTING CATALOG. IN PARTICULAR WE WILL 1) SEARCH FOR DISTINCT CLASSES OF FEATURES ACROSS SCALE IN EACH OF SEVERAL ALTERNATE INDICATORS OF MAGNETIC ACTIVITY; 2) USE THE STATISTICAL DISTRIBUTIONS OF THOSE CLASSES OF FEATURES TO BETTER UNDERSTAND THEIR FORMATION MECHANISMS; 3) ASSESS THE LENGTH- AND TIME-SCALES AND MECHANISMS OF BIRTH AND DEATH OF MAGNETIC FEATURES TO BETTER UNDERSTAND HOW MAGNETIC FLUX CASCADES UP AND DOWN IN SPATIAL SCALES; AND 4) EXAMINE HOW THESE PROPERTIES CHANGE OVER THE COURSE OF THE SOLAR CYCLE. THIS PROPOSAL IS RELEVANT TO THE SDO MISSION QUESTIONS WHAT MECHANISMS DRIVE THE QUASI-PERIODIC 11-YEAR CYCLE OF SOLAR ACTIVITY? AND HOW IS ACTIVE REGION MAGNETIC FLUX DISPERSED ACROSS THE SOLAR SURFACE? AND TO THE DECADAL SURVEY GOAL DETERMINE THE ORIGINS OF THE SUN S ACTIVITY AND PREDICT THE VARIATIONS IN THE SPACE ENVIRONMENT. THE ANALYSIS OF THE DYNAMOS AND THE COUPLING OF MAGNETIC FIELDS ACROSS A WIDE RANGE OF SPATIAL SCALES IS IMPORTANT FOR UNDERSTANDING AND PREDICTING THE BEHAVIOR OF THE SUN S MAGNETIC FIELD ON SHORT AND LONG TIME SCALES.
$492,084FY2020National Aeronautics and Space AdministrationNASA
Southwest Research Institute, San Antonio TX