COMPUTATIONAL MODEL OF DYNAMICS AND MAGNETIC ACTIVITY OF THE SUN AND SOLARTYPE STARS

THE GOAL FOR THIS PROJECT IS TO DEVELOP A NEW COMPUTATIONAL MODEL OF THE INTERNAL DYNAMICS TURBULENT ENERGY AND MOMENTUM TRANSPORT AND MAGNETIC FIELD GENERATION INSIDE THE SUN AND SOLAR-TYPE STARS. THE METHODOLOGY WILL BE BASED ON PERFORMING HIGH-RESOLUTION NUMERICAL MHD SIMULATIONS FOR THE SUN AND VARIOUS SOLAR-TYPE STARS IN ORDER TO BETTER UNDERSTAND THE INTERNAL CONVECTION DIFFERENTIAL ROTATION AND DYNAMO. MOST OF THE PROPOSED EFFORT IS TO DEVELOP A NEW EFFICIENT COMPUTATIONAL FRAMEWORK BASED ON THE VECTOR SPHERICAL HARMONICS REPRESENTATION OF THE FLOW AND MAGNETIC FIELDS. IT IS ANTICIPATED THAT THE NEW MATHEMATICAL FORMULATION THAT EFFECTIVELY SEPARATES TURBULENT AND ACOUSTIC PROCESSES WILL PROVIDE AN ACCURATE DESCRIPTION OF THE MULTISCALE TURBULENT CONVECTION AND DYNAMO. INITIAL STUDIES OF THIS PROBLEM HAVE BEEN PERFORMED AT THE NASA AMES SUPERCOMPUTING DIVISION BY USING THE ANELASTIC MHD CODE EULAG. THE PROPOSED RESEARCH PLAN IS TO DEVELOP A NEW COMPUTATIONAL MODEL AND NUMERICAL CODE TO PERFORM 3D MHD SIMULATIONS OF THE INTERNAL DYNAMICS AND DYNAMO IN THE SPHERICAL CONVECTIVE ENVELOPE IMPLEMENT THE CODE ON THE MASSIVE PARALLEL SUPERCOMPUTER SYSTEM AT THE NAS AND PERFORM A SERIES OF SIMULATIONS TO INVESTIGATE HOW THE MAGNETIC ACTIVITY DEPENDS ON THE ROTATION RATE AND PROPERTIES OF THE CONVECTION ZONE AND COMPARE THE MODELING RESULTS WITH OBSERVATIONAL DATA. THE RESULTS WILL CONTRIBUTE TO ANALYSIS AND INTERPRETATION OF DATA FROM THE NASA'S MISSIONS SOLAR DYNAMICS OBSERVATORY (SDO) AND KEPLER/K2.