This is one of five profiles spotlighting an outstanding postdoc as part of Baskin Engineering’s celebration of National Postdoc Appreciation Week, September 20–24. Visit Baskin Engineering News and Voices of Baskin of Engineering for additional profiles of outstanding postdocs.
Adrian Fraser, a postdoctoral scholar mentored by Applied Mathematics Professor Pascale Garaud, joined UC Santa Cruz in the midst of the pandemic. Although defending a Ph.D. dissertation and moving from Wisconsin to California during a global health crisis proved challenging, Fraser’s research momentum never slowed. According to Garaud, Fraser has played a significant role in her research group, contributing to impactful research at the intersection of math and physics, teaching undergraduate students applicable technical skills, and mentoring graduate students.
As a Ph.D. student at the University of Wisconsin–Madison, Fraser studied the theoretical aspects of turbulence in astrophysical systems and nuclear fusion devices. Working under Garaud, he’s been able to expand upon his doctoral work in mathematics and astrophysics in novel ways.
Fraser’s postdoctoral research focuses on what are known as the missing mixing problems in red giant branch (RGB) stars. When RGB stars are formed, they contain a certain amount of lithium. But these lithium levels can change over time. Based on a theoretical understanding of these stars, scientists thought that lithium would be lost from layers deep within these stars as they age, but that lithium levels on the star’s surface would remain fairly constant. However, the data shows that lithium is lost from the surface of these stars, a finding that continues to puzzle researchers.
Fraser believes that tackling this problem from the perspective of fluid dynamics and turbulence may help explain what’s happening to the lithium on the surface of these stars. Using supercomputers to perform high-resolution simulations of small sections of RGB stars and study the movement of lithium in these regions, Fraser believes his efforts may lead to a better understanding of the missing mixing problems in RGB stars. These simulations may also help scientists study related problems in astrophysics and beyond.
“We are probing unique kinds of turbulence that haven’t been simulated before. This is the kind of research that is the breeding ground for new kinds of models that have high impact wherever turbulence is found,” stated Fraser.