66°

Turbulence and Nonlinear Processes in the Solar Atmosphere

May 26, 2021 3:00pm to 4:00pm
270 Seminar

 

Speaker: Trevor Bowen

Institution: UC Berkeley

Abstract:

Nonlinear and turbulent energy transport in the solar atmosphere is likely responsible for heating of the solar corona and acceleration of the solar wind. In neutral-fluid dynamics, turbulent dissipation is typically mediated through the viscous forces that emerge via inter-particle collisions; however, the uppermost regions of the solar atmosphere have collisional length scales that are much larger than the spatial scales over which heating occurs. The physical processes behind collisionless turbulent dissipation in the solar atmosphere, and other collisionless plasmas, remain poorly understood. These processes are fundamental drivers of the large-scale structure of the solar system and the interaction of planetary bodies with the solar wind.

NASA's Parker Solar Probe (PSP) mission, launched in 2018, provides in situ measurements of the solar atmosphere requisite to understanding collisionless dissipation of plasma turbulence. The mission has already shed light on a number of outstanding problems surrounding energy transport and plasma heating. Here, I will provide an overview of canonical nonlinear turbulent processes thought to occur in magnetized plasmas and their connection to observational signatures observed by PSP. We will discuss both signatures of heating, as well as observations that challenge the canonical understanding of nonlinear Alfvén-wave turbulence.

Please email Caitlyn Ongjoco (congjoco@atmos.ucla.edu) for zoom link.