July 2020
Vol 6, Issue 30

About The Cover

Cover image expansion

ONLINE COVER The processes that drive heat transfer on the Sun remain a perplexing problem for solar physicists. While it is thought that these processes in the Sun's outer envelope are key to large-scale phenomena such as differential rotation, meridional circulation, and the global magnetic cycle, they cannot be duplicated in a laboratory environment—scientists can only begin to understand them by comparing observations with the most advanced simulations of convection on the solar surface. In order to better understand how convection produces turbulence on the Sun (as well as on distant yet similar stars), Hanasoge et al. used helioseismology methods to "listen" to waves pulsating through the star like a heartbeat. These waves were recorded in 8 years of observations gathered by the Helioseismic and Magnetic Imager onboard NASA's flagship heliophysics satellite, the Solar Dynamics Observatory. Their findings suggest that turbulence in the Sun is limited to equatorial regions rather than occurring on large scales. Hanasoge et al. also identified differences between observations and simulations that reveal gaps in solar physicists' current understanding of solar convection. [CREDIT: NASA/SDO]