GPS Seminars & Events

It's well known that climate simulations depend on the magnitude of ocean mixing, but watermass modification depends on the gradient of the mixing - a much higher bar for measurement. As we move towards understanding mixing near fronts and the ocean's upper and lower boundaries, we require much better accuracy and resolution - and a reexamination of the assumptions we use to compute mixing from microstructure. In this talk I go over the confusing details of how turbulence leads to watermass modification and upwelling in two submarine canyons. I also present our early attempts to make measurements in the reference frame of the evolving turbulence in order to measure tricky quantities such as mixing efficiency and to check some of the assumptions going into turbulence recipes such as Osborn-Cox.

It's well known that climate simulations depend on the magnitude of ocean mixing, but watermass modification depends on the gradient of the mixing - a much higher bar for measurement. As we move towards understanding mixing near fronts and the ocean's upper and lower boundaries, we require much better accuracy and resolution - and a reexamination of the assumptions we use to compute mixing from microstructure. In this talk I go over the confusing details of how turbulence leads to watermass modification and upwelling in two submarine canyons. I also present our early attempts to make measurements in the reference frame of the evolving turbulence in order to measure tricky quantities such as mixing efficiency and to check some of the assumptions going into turbulence recipes such as Osborn-Cox.

▶ Register for Francois Tissot's Watson Lecture

About the Talk

In 1965, Caltech geochemist Clair Patterson published what was, at the time, a highly controversial finding: that leaded gasoline and other products like canned food solder, paints, and insecticide were exposing Americans to dangerously high levels of lead. His work helped galvanize the environmental movement, ultimately leading to the Clean Air Act of 1970. Fifty years later, Caltech researchers, led by Francois Tissot, professor of geochemistry and Heritage Medical Research Institute Investigator, were once again at the center of investigations on environmental lead contamination when the Eaton fire devastated communities surrounding Caltech. A year on from the LA fires of 2025, Tissot will discuss Patterson's legacy and its connections to his own research group's efforts to study the presence of lead and other toxic metals in the aftermath of the fires. He will also share the impact of his findings to date—and how they can help communities prepare as fires at the wildland-urban interface grow increasingly common.

Evening Schedule

6 p.m. — Activities and music. Food, drinks, and books available for purchase.
7 p.m. — Doors open.
7:30 p.m. — Talk and Q&A.
8:30 p.m. — Post-talk concessions and conversation.

The live event is in-person and a recording will be made available on our Youtube channel.

About the Series

For more than 100 years, the Watson Lectures have brought the wonder of Caltech research and discovery to the public.

Free and open to the public, the Watson Lecture Series offers a unique and accessible opportunity to learn more about cutting-edge science directly from Caltech's premier researchers. Come early to mingle with your neighbors over food, drink and music, as well as interactive displays related to the evening's topic. Then head inside to hear a stimulating talk and stay to ask your burning questions.

Many past Watson Lectures are available on Caltech's YouTube channel.