Scripps Student Spotlight: Tricia Light

PhD student researches how ocean life affects global climate

Tricia Light is beginning her fifth year as a PhD student at Scripps Institution of Oceanography at the University of California San Diego. Light was raised in Redondo Beach, Calif., and she earned her bachelor’s degree in chemistry from Scripps College in Claremont, Calif. She currently studies marine chemistry and geochemistry and works with Scripps paleobiologist Richard Norris, her advisor. 


explorations now: Why did you choose to attend Scripps?

Tricia Light: I chose to attend Scripps because it offered me the opportunity to get a great education, but also stay close to my family and prioritize my work-life balance. 


en: What are you researching at Scripps?

TL: I study how the mineral barite in marine sediments can be used as a tool to help understand how life in the ocean affects the global climate and how the climate affects marine life as well. Scientists have been using barite in ocean sediments as a proxy for, or indirect way of studying, ocean life for decades, but there is still a lot that we don't know about marine barite. For example, we still don't know exactly how marine barite and ocean productivity are related, or how much of the barite that forms in the water column ends up in ocean sediments. 

Here Light is on a research cruise on the RV Sally Ride as part of a UC Ship Funds student cruise exploring the geology of the Eastern Pacific.

My thesis is trying to improve our confidence in the barite proxy by answering some of these questions through a combination of fieldwork and lab work. In the field, I go on research cruises to collect barite crystals from different depths and locations in the ocean. By comparing the number, size, and shape of barite crystals between these different depths and locations, I can get a better idea of what processes influence barite formation and dissolution. In the lab, I conduct experiments that try to replicate marine barite formation and dissolution, so I can study these processes while controlling the variables I think might be important. For both my field and lab work, I analyze my barite crystals using a scanning electron microscope, or SEM. The SEM is a fantastic instrument that lets me see and take pictures of my tiny barite crystals, which are each about 1/70th the width of a human hair.  


en: How did you become interested in science and your field of study?

TL:  I was inspired to become a scientist by my grandmother, who was a high school chemistry teacher turned environmental activist. She filled my childhood with nature walks and at-home experiments that made me fall in love with science, and she convinced me that climate change was the biggest issue my generation would face. I settled on marine chemistry in particular because I enjoyed my chemistry classes in college and wanted an excuse to live by the ocean!


en: What’s life like as a Scripps student? Describe a typical day.

TL: I usually start my day off by responding to emails—I’m involved in a few different

student groups and projects on campus. I spend quite a bit of time coordinating these efforts with my colleagues. I'm really interested in science policy and climate activism, so I try to find different ways to be involved with those efforts. I'm a part of UC San Diego's Graduate and Professional Student Association's Climate Action and Policy Committee (CAP), and through that group, I have helped organize events, written op-eds, and met with various leaders on campus. I was also a part of the American Geophysical Union's Voices for Science Program, in which I co-authored a science policy memo and met with staff from the offices of our local, state, and federal government representatives. I'm also helping to lead a class on oceanographic knowledge production and a student research cruise to go along with it, and I'm a teaching assistant for a class on solutions to climate change. I also try to be involved with efforts on campus to make Scripps more equitable and inclusive—I'm a mentor for the Scripps Applicant Support & Knowledgebase (SIO-ASK), and I used to be involved in leadership for Scripps's Women and Minorities in Science

After responding to emails, I might run a barite synthesis experiment and use the SEM to analyze my results, which produces images using electrons to receive information about the composition. In the afternoon, I might read a scientific publication or two and spend some time writing part of one of the chapters of my thesis. I have a (probably excessive) love for and reliance on sticky note to-do lists, so I always try to end my day by reviewing my to-do list from that day and creating my list for the next day. Then, I begin my journey up the Scripps hill back to my apartment. When I'm feeling ambitious I bike up the hill and admire all of the gorgeous ocean views, and when I'm feeling lazy I put my bike on one of our great UCSD shuttles up to main campus and then bike home from there!


en: What’s the most exciting thing about your work (in the field or in the lab)?

TL: The most exciting part of my work is when I plot the results of a project for the first time. I might spend weeks or even months working on something without knowing if it’s going to work or not, so when I find out that I do have interesting findings it is the best feeling in the world!

Light is filtering seawater in the shipboard lab on the same student cruise. She used the filter samples from this cruise as the basis for the first chapter of her dissertation.  

en: Are there any role models or mentors who have helped you along the way?

TL:  My grandmother has been a huge role model in my life, and I always aspire to have a positive impact on the world like she did. I also would have never made it to Scripps Oceanography without the mentorship of my college research advisor, Dr. Branwen Williams, from Scripps College, who really taught me how to be a scientist.


en: What are some of the challenges you face as a student?

TL: It’s always a challenge to prioritize the research that I know I need to do to graduate. I sometimes feel like I could fill my entire workweek with work completely unrelated to my thesis, from side projects to meeting with other students, to pursuing climate activism on campus. I’m continuously trying to improve my time-management skills and figure out how to juggle all the things I care about. 



en: What are your plans post-Scripps?

TL: I hope to pursue a career at the intersection of oceanography, climate change, and public policy. I would love to use my research background to help translate existing research into science-based federal or state policy.

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