Introducing Scripps Oceanography’s Newest Faculty Members

From new hires to rising stars who have changed their positions, four scientists and educators have recently joined or advanced within the academic ranks at Scripps Institution of Oceanography at UC San Diego. 

These faculty members — professorial faculty Julien Bonnel, Sophia Merrifield and Robert Rhew, along with research faculty Gunnar Voet — have expertise spanning physical oceanography, marine robotics, biogeochemistry, ocean acoustics and teaching. 

They began their new roles ahead of UC San Diego’s fall quarter, which officially started on Sept. 22. This season also marks a time of transition for Scripps, as Director Margaret Leinen concludes her leadership at the end of September and incoming Director Meenakshi Wadhwa begins her tenure on Oct. 1. 

“Scripps Oceanography is honored to welcome these new and rising hires to our academic community,” said Leinen, who also serves as vice chancellor for marine sciences at UC San Diego. “They bring tremendous experience and exciting research and educational initiatives that will further strengthen our work to understand and protect the planet and inspire the next generation of scientific leaders.”

These newest appointments were finalized prior to the temporary hiring pause currently in place across UC San Diego due to funding uncertainties. Leinen noted that the institution remains committed to working with campus leadership to resume suspended searches and initiate new ones in the upcoming academic year. 

Meet the newest members of Scripps Oceanography’s academic community in the profiles below.
 

Julien Bonnel 

Professor, Marine Physical Laboratory and SIO Department

Julien Bonnel is an interdisciplinary scientist whose research spans signal processing, ocean acoustics, oceanography and bioacoustics. He joined Scripps as a full professor in the summer of 2025 and currently leads the Signals, Inference and Ocean Acoustics Lab (SIO-A Lab), which uses sound to better understand the ocean — through computers, lab experiments and fieldwork at sea.

Bonnel describes his work as being “at the playground between signal processing and ocean acoustics,” with a main focus on inverse problems and seabed inversion, using sound to infer what is happening beneath the seafloor. His acoustics research covers time–frequency analysis, source detection and localization, geoacoustic inversion, acoustical tomography, passive acoustic monitoring and the impacts of noise pollution on marine life. 

"I first visited Scripps as a guest student in 2009. Today, I am thrilled to join the faculty,” said Bonnel. “I am particularly excited to build new collaborations and to contribute to the education program, both at Scripps and in the wider UC San Diego community."

Bonnel grew up in Paris and later earned his PhD in signal processing from the Grenoble Institut National Polytechnique. Prior to joining Scripps, he was an associate scientist at Woods Hole Oceanographic Institution (WHOI) and served as an assistant and associate professor at ENSTA Bretagne, a French engineering school. He is a fellow of the Acoustical Society of America and an associate editor for the Journal of the Acoustical Society of America.
 

Sophia Merrifield

Acting Associate Professor, Marine Physical Laboratory and SIO Department

Sophia Merrifield is a seagoing physical oceanographer specializing in marine robotics. Her research focuses on air-sea interactions and upper-ocean turbulence, with an emphasis on developing uncrewed systems for environmental characterization. She uses autonomous vehicles to study ocean dynamics and designs adaptive path-planning algorithms to improve sampling in complex environments.

In addition to her research, Merrifield developed and taught the course “Hacking for the Oceans,” launched in spring 2020 at UC San Diego, in which students collaborated with external sponsors to design rapid prototypes and innovative solutions to ocean-related challenges.

Merrifield joined Scripps in 2016 as a postdoctoral researcher and later advanced to associate researcher in the Marine Physical Laboratory. She co-directs the Coastal Observing Research and Development Center and was appointed acting associate professor in the summer of 2025. 

“Throughout Scripps Oceanography’s history, scientists such as Chip Cox, Fred Spiess and Russ Davis have advanced seagoing science and technology development in ways I have long admired,” said Merrifield. “It’s an honor to join the faculty and to help expand research and education opportunities using marine robotics.”

In 2021, Merrifield received the Office of Naval Research’s Young Investigator Award to advance observational techniques using robotic vehicle teams for sensing the upper ocean and air-sea interface, and in early 2025, she received a Presidential Early Career Award for Scientists and Engineers — the highest honor bestowed by the United States government to scientists and engineers in the early stages of their independent research careers.

She earned her PhD in physical oceanography through the MIT/WHOI Joint Program and holds a bachelor’s degree in physics and mechanical engineering from Yale University.

Robert Rhew 

Professor, Geosciences Research Division and SIO Department

Robert Rhew is an atmospheric scientist and biogeochemist, with a focus on trace gases involved in ozone depletion, air pollution and climate. His research identifies the biological, environmental and anthropogenic factors that modulate the production and consumption of trace gases from the terrestrial biosphere, ranging from arctic to tropical ecosystems. This research informs us about the origin, fate and persistence of these trace gases in the atmosphere. 

At Scripps, Rhew will merge his atmospheric biogeochemistry research with the long-running Advanced Global Atmospheric Gases Experiment (AGAGE) program. AGAGE provides a global-scale assessment of important trace gases and nascent atmospheric contaminants through high precision measurements, painstakingly accurate calibrations, and rigorous data analysis and modeling.

Rhew holds a bachelor’s degree in earth and planetary sciences from Harvard College and a graduate diploma from the Australian National University. A Scripps Oceanography alumnus, he earned his PhD in earth sciences (geochemistry/marine chemistry) at UC San Diego and went on to serve as a NOAA Climate and Global Change Postdoctoral Fellow at UC Irvine’s Department of Earth System Science. He later held faculty positions as assistant, associate and full professor at UC Berkeley before returning to Scripps in the summer of 2025.

“I was attracted to Scripps, both as a graduate student and now as a professor, because of its reputation for rigorous and innovative science to unravel the mysteries of this planet,” said Rhew. “The work done here is vital to assess the impacts of modern society on our earth system. I look forward to immersing myself in the Scripps community, with its wide-ranging research and inspirational teaching and mentorship.”
 

Gunnar Voet

Associate Researcher, Marine Physical Laboratory

Physical oceanographer Gunnar Voet investigates oceanic processes such as dense overflows and hydraulics, internal waves and turbulent mixing, and their impacts on large-scale ocean circulation. A member of the Multiscale Ocean Dynamics group at Scripps, his research focuses on analyzing ocean observations collected during seagoing expeditions and from moorings.

Voet joined Scripps in 2014, serving as assistant, associate and full project scientist before advancing to associate researcher in the Marine Physical Laboratory in 2024. 

“I am looking forward to continuing my work at Scripps — studying how interactions from flow-topography (think: underwater mountains) drive turbulent mixing in the ocean, and in turn, how this affects large-scale ocean circulation,” said Voet.

Before joining Scripps, he conducted postdoctoral research at the University of Washington, held a research position at the German Federal Maritime and Hydrographic Agency, and worked in software development at the German Federal Waterways Engineering and Research Institute. He holds a Diplom Physik (a master’s-level degree in physics) and a PhD in physical oceanography, both from the University of Hamburg in Germany.