Long-Term Solar Variability (LSV) Section
Solar Convecton and Mean Flows
Any inquiry into the ultimate origins of solar magnetic activity must soon confront turbulent thermal convection. Convection is a means by which the Sun shines. Energy liberated by nuclear fusion deep in the core of the Sun filters outward by the diffusion of photons. In the outer approximately 30% of the Sun by radius, the solar plasma is cooler and more opaque, making radiative diffusion less efficient. Convection takes over as the primary mechanism by which energy is transported from 0.7 R to the solar photosphere, where it is radiated into space.
Convection in a rotating star not only transports energy, it also transports momentum, establishing global circulations and shearing flows. Such mean flows work together with turbulent convection to amplify, organize, and transport magnetic fields, converting kinetic energy to magnetic energy. This is the solar dynamo, where the chain of events that gives rise to space weather begins.
HAO scientists study convection and mean flows in the solar interior. Read More »
Currently, HAO scientists are conducting numerical simulations to underpin dynamical processes in the near-surface shear layer, and explore the theory of meridional circulation at the polar cap based on low-latitude observations. Read More »
See Profiles in Science pages for Mausumi Dikpati, Mark Miesch, and Michael Thompson.