Baroclinic instability as an essential regulator of the Sun’s differential rotation

Speaker: Yuto Bekki

Jul 9, 2024 11:00 PDT

COFFIES is supporting the Heliophysics Big Year! NASA’s Heliophysics Big Year (HBY) is a global celebration of solar science and the Sun’s influence on Earth and the entire solar system. The HBY began in October 2023 with the annular eclipse and lasts until December 2024 with the PSP Perihelion! Each month of the big year has a particular outreach theme, which you can find listed in this article.

The theme for July is “Physical and Mental Health”!

We recommend that everyone read and consider the implications of Nikoukar, R. et al. (2023) Raising awareness on mental health in the heliophysics community. Front. Phys. 11:1237166. DOI:10.3389/fphy.2023.1237166.

We will preceed our science seminar with a brief mindfulness exercise, led by Dra. Nicole Cabrera Salazar!

Mindfulness Exercise 11:00-11:10 am PDT

  • Nicole Cabrera Salazar, Movement Consulting

Seminar Abstract: Spiralling flow patterns are known to exist around the Sun’s poles. Conventionally, they are thought to be giant convection cells from the deep interior (Hathaway et al. 2013, Science). Recently, however, we have demonstrated that they are global modes of inertial oscillation of the whole convection zone (Gizon et al. 2021, A&A). Furthermore, we find that they are baroclinically-unstable with the presence of latitudinal entropy gradient (Bekki et al. 2022, A&A). In this talk, we will show that these baroclinically-unstable inertial modes play a significant dynamical role in the Sun’s convection zone by transporting heat equatorward to regulate the baroclinicity. This negative feedback process has a controlling impact on the Sun’s latitudinal differential rotation (Bekki et al. 2024, Sci. Adv.).


Watch the recording.