Videos

Nicholas Featherstone - Perspectives on the Rotating Solar Convection Zone - IPAM at UCLA

January 29, 2025
Abstract
Recorded 29 January 2025. Nicholas Featherstone of the Southwest Research Institute presents "Perspectives on the Rotating Solar Convection Zone" at IPAM's Rotating Turbulence: Interplay and Separability of Bulk and Boundary Dynamics Workshop. Abstract: Stellar magnetism continues to pose a number of theoretical challenges for modern astronomy. This is particularly true of the Sun, where any description of its dynamo must address both the remarkable degree of spatio-temporal ordering observed in its magnetic field and also the structure of the plasma motions that underpin it. The Sun is unique among the dynamos of our solar system in that we are able to partially observe its inductive motions directly. Convection in the photosphere is observed to occur on timescales of minutes to days, considerably shorter than the Sun's rotation period of roughly one month. Helioseismology provides some additional insight into the subsurface motions, but only in a thin outer layer of the convection zone. Below the outer 15% of the Sun's convection zone, plasma flows remain poorly-constrained and consensus concerning their structure and amplitude remains elusive. One notable exception to this is the solar differential rotation, which is well-measured helioseismically throughout the Sun. The rapid rotation of the solar equator, and the comparatively slower rotation of the poles, is consistent with deep convection that is sufficiently slow enough to be influenced by the Coriolis force. The Sun and, presumably, many other low-mass stars are thus characterized by a high-Rossby-number boundary layer overlying a bulk convection-zone that evinces low-Rossby-number behavior. In this talk, I will discuss the challenges associated with observing and modeling such a system. I will then summarize some recent success and surprises in this regard and discuss potentially fruitful avenues for future investigations of solar convection. Learn more online at: https://www.ipam.ucla.edu/programs/workshops/rotating-turbulence-interplay-and-separability-of-bulk-and-boundary-dynamics/