A5004802194- Solar and Space Plasma Dynamics
- Geomagnetism and Paleomagnetism Studies
- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Fluid Dynamics and Turbulent Flows
- Astronomy and Astrophysical Research
- American Constitutional Law and Politics
- Laser-Plasma Interactions and Diagnostics
- Legal Systems and Judicial Processes
- Experimental and Theoretical Physics Studies
- Sports Dynamics and Biomechanics
- Legal Cases and Commentary
- Particle Dynamics in Fluid Flows
- Astrophysics and Star Formation Studies
- Computational Fluid Dynamics and Aerodynamics
- Advanced Thermodynamics and Statistical Mechanics
- Information Systems Education and Curriculum Development
- Ionosphere and magnetosphere dynamics
- Combustion and flame dynamics
- Plant Water Relations and Carbon Dynamics
- Sports Analytics and Performance
- Meteorological Phenomena and Simulations
- Magnetic confinement fusion research
- Textile materials and evaluations
- Geophysics and Gravity Measurements
California State University, Chico
2016-2023
Bates College
2023
Los Alamos National Laboratory
2014-2015
Joint Institute for Laboratory Astrophysics
2007-2014
University of Colorado Boulder
2007-2013
Cornell University
2009
Notre Dame High School
2008
University of Notre Dame
2008
Solar-type stars exhibit a rich variety of magnetic activity. Seeking to explore the convective origins this activity, we have carried out series global 3D magnetohydrodynamic (MHD) simulations with anelastic spherical harmonic (ASH) code. Here report on dynamo mechanisms achieved as effects artificial diffusion are systematically decreased. The at nominal rotation rate three times solar value (3$Ω_\odot$), but similar dynamics may also apply Sun. Our previous demonstrated that dynamos can...
Our global 3D simulations of convection and dynamo action in a Sun-like star reveal that persistent wreaths strong magnetism can be built within the bulk convention zone. Here we examine characteristics buoyant magnetic structures are self-consistently created by turbulent convective motions simulation with solar stratification but rotating at three times current rate. These loops originate sections which flows amplify fields to much larger values than is possible through laminar processes....
The current dynamo paradigm for the Sun and sun-like stars places generation site strong toroidal magnetic structures deep in solar interior. Sunspots star-spots on are believed to arise when sections of these become buoyantly unstable rise from interior photosphere. Here we present first 3-D global magnetohydrodynamic (MHD) simulation which turbulent convection, stratification, rotation combine yield a that self-consistently generates buoyant loops. We simulate stellar convection action...
Abstract Global 3D simulations of solar giant-cell convection have provided significant insight into the processes which yield Sun’s observed differential rotation and cyclic dynamo action. However, as we move to higher-resolution a variety codes encountered what has been termed conundrum. As these increase in resolution hence level turbulence achieved, they tend produce weak or even anti-solar patterns associated with rotational influence (high Rossby number) due large convective...
The mixing of materials due to the Richtmyer-Meshkov instability and ensuing turbulent behavior is intense interest in a variety physical systems including inertial confinement fusion, combustion, final stages stellar evolution. Extensive numerical laboratory studies shock-driven have demonstrated rich associated with onset turbulence shocks. Here we report on progress understanding at interfaces between fluids differing densities through three-dimensional (3D) simulations using rage code...
Our Sun exhibits strong convective dynamo action which results in magnetic flux bundles emerging through the stellar surface as spots. Global-scale is believed to generate large-scale structures deep solar interior interplay of convection, rotation and shear. Portions these are then rise layer, forming loops pierce photosphere sunspot pairs. Previous global simulations three-dimensional magnetohydrodynamic convection rotating spherical shells have demonstrated mechanisms whereby wreaths can...
Stellar dynamos are driven by complex couplings between rotation and turbulent convection, which drive global‐scale flows build rebuild stellar magnetic fields. When stars like our sun young, they rotate much more rapidly than the current solar rate. Observations generally indicate that rapid is correlated with stronger activity perhaps effective dynamo action. Here we examine effects of on action in a star sun. We find vigorous realized, field generated throughout bulk convection zone....
Whitepaper #105 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: basic research; infrastructure/workforce/other programmatic. Additional solar physics; research tools infrastructure.
Abstract Low mass, main sequence stars like our Sun exhibit a wide variety of rotational and magnetic states. Observational theoretical advances have led to renewed emphasis on understanding the evolution sun-like has become pressing problem in stellar physics. We use global 3D convection convective dynamo simulations rotating spherical shells with realistic stratification explore behavior “middle-aged” stars. show that for slightly less influence than transition occurs from solar-like (fast...
Observations of sun-like stars rotating faster than our current sun tend to exhibit increased magnetic activity as well cycles spanning multiple years. Using global simulations in spherical shells study the coupling large-scale convection, rotation, and magnetism a younger sun, we have probed effects rotation on stellar dynamos nature cycles. Major 3-D MHD carried out at three times solar rate reveal hydromagnetic dynamo action that yields wreaths strong toroidal field low latitudes, often...
We present multidimensional modeling of convection and oscillations in main-sequence stars somewhat more massive than the Sun, using three separate approaches: 1) Using 3-D planar StellarBox radiation hydrodynamics code to model envelope zone part radiative zone. Our goals are examine interaction stellar pulsations with turbulent envelope, excitation acoustic modes, role convective overshooting; 2) Applying spherical MHD ASH (Anelastic Spherical Harmonics) simulate core goal is determine...
Abstract We present multidimensional modeling of convection and oscillations in main-sequence stars somewhat more massive than the Sun, using three separate approaches: 1) Using 3-D planar StellarBox radiation hydrodynamics code to model envelope zone part radiative zone. Our goals are examine interaction stellar pulsations with turbulent envelope, excitation acoustic modes, role convective overshooting; 2) Applying spherical MHD ASH (Anelastic Spherical Harmonics) simulate core goal is...
The mixing of materials due to the Richtmyer-Meshkov instability and ensuing turbulent behavior is intense interest in a variety physical systems including inertial confinement fusion, combustion, final stages stellar evolution. Extensive numerical laboratory studies shock-driven have demonstrated rich associated with onset turbulence shocks. Here we report on progress understanding at interfaces between fluids differing densities through 3D simulations using RAGE code implicit large eddy...