FIngering convection: enhanced mixing and the emergence of large-scale structures.

University Of California-Santa Cruz, Santa Cruz CA

Investigators

Abstract

This program combines analytical studies with computer modeling to better understand large-scale fluid instabilities that lead to "fingering convection". This process could play an important role in a range of natural systems, from Earth's oceans to the atmospheres of red giant stars. This program will form the basis of a PhD thesis and provide opportunities for UCSC undergraduates and interns (visiting UCSC from the Ecole Normale Superieure in France) to gain valuable research training. In conjunction with this effort, the PI and her students will be involved with the next International Summer-Institute for Modeling in Astrophysics, a 6-week long program to solve topical outstanding problems in astrophysics. The program aims to train graduate students in a particular field through intense research experience, and to catalyze long-lasting collaborations between more senior researchers through shared mentorship of a student. The PI and her students will carry out analytical and computational modeling of the process of "fingering convection" and attempt to produce flux laws to predict how much heat and material is transferred by this process in various scenarios likely to be found in stellar astrophysics. Fingering convection results in radiative regions of stars from instabilities produced by a gradient in composition even when the density gradient is otherwise stable. This can happen, for example, by the accretion of metal rich material is accreted or near the Hydrogen burning layer in red giants. While primarily an analytical and computational study of instabilities and convection, this program could lead to modules that can be incorporated into stellar evolution codes.