Conversations After the Fires
You're invited to this special online series for the Caltech community and the public.
When the 2025 Los Angeles fires broke out, Caltech researchers on campus and at JPL, which Caltech manages for NASA, jumped into action, collecting and analyzing data as soon as flames erupted. In the webinar series Conversations After the Fires, you will hear about fire-related research as it is happening and have the chance to ask your own questions.
Upcoming Webinars
Studying Lead in the Environment
APRIL 10, 2025, 11 a.m. PT
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In the first conversation in this series, learn more about what ash, soil, and water samples tell us about the amount of lead released in the environment during the fires. Join Caltech geochemist Francois Tissot, graduate students Merritt McDowell and Isaac Aguilar, and guest speaker Christine O'Connell, assistant professor of Biological Sciences at Chapman University, in a discussion about their ongoing research to address the environmental impact of urban fires, moderated by Caltech science writer Lori Dajose.
Isaac Aguilar, Graduate Student, Geobiology
Isaac (he/him/they/them) is a first-year PhD student in Geobiology at the California Institute of Technology. Their undergraduate research experience in the Middleton Lab at UC Berkeley included investigating museum collections, remote sensing, and environmental DNA techniques as part of his honors biodiversity research in the Sierra de Manantlán of Western México. Before starting graduate school, Isaac worked as a field technician for the UC San Diego Holway Lab invasive ant eradication project on San Clemente Island and as a project coordinator for the UC Los Angeles Ordway Lab to scope a potential NASA airborne and field research campaign in the tropics. Additionally, Isaac enjoys outdoor excursions, live sporting and music events, and exploring new cafes.
Merritt McDowell, Graduate Student, Planetary Science
Merritt McDowell (she/her/hers) is a first-year PhD student in planetary science at Caltech. She completed her undergraduate degree in chemistry with a minor in astronomy at New York University, where her research focused on photoactive molecular crystals. At Caltech, she works with Professor Francois Tissot investigating heavy metal contaminants in dust deposited from the 2025 Eaton fire in Los Angeles, as well as with Professor Mike Brown exploring surface sputtering on Europa, a Galilean moon of Jupiter. Outside of the lab, Merritt enjoys playing volleyball on campus, reading outdoors, and attending sports events.
Christine O'Connell, Assistant Professor, Biological Sciences at Chapman University
Christine Sierra O'Connell, Ph.D. (she/her/ella) is an Assistant Professor of Biological Sciences in the Schmid College of Science and Technology at Chapman University and a Pasadena resident. O'Connell is an ecosystem ecologist and global change scientist whose research focuses on how climate change and global change disturbances are altering terrestrial biogeochemical processes and patterns, particularly in soils. Her current projects include work in tropical forests in Puerto Rico and Costa Rica and, now, work studying the Eaton Fire in Altadena, California.
Francois Tissot, Professor of Geochemistry; Investigator, Heritage Medical Research Institute
Francois Tissot is a professor of geochemistry at Caltech. He and his research group carry out elemental and isotopic investigations by combining wet chemistry sample preparation in a clean laboratory environment, precise isotopic analyses using advanced instruments, and interpretation of the data using physically based models. His research ranges from cosmochemistry (i.e., the formation and evolution of the solar system), to geochemistry (e.g., reconstructing redox conditions throughout Earth's history), and in recent years has focused on isotope metallomics, a nascent field using stable isotopes to study human health. Tissot holds a PhD from the University of Chicago.
in conversation with
Lori Dajose, Content and Media Strategist, Office of Communications and External Relations
Lori Dajose is a content strategist and science writer in Caltech's Office of Strategic Communications covering biology, bioengineering, and neuroscience. Lori received her undergraduate degree in planetary science from Caltech in 2015 and began working in OSC shortly afterward.
This series is presented by the Caltech Science Exchange, which brings expert insight to the scientific questions that define our time. The Caltech Science Exchange offers trustworthy answers, clear explanations, and fact-driven conversation on critical topics in science and technology.