William Kuperman: 1943-2024

William Kuperman, emeritus professor of oceanography and former Director of the Marine Physical Laboratory (MPL) at UC San Diego’s Scripps Institution of Oceanography, died June 30. He was 81.

Kuperman was widely recognized for his contributions to the fields of underwater acoustics and acoustical oceanography. Though he is known as one of the founding fathers of the discipline of computational ocean acoustics, he also spent several years conducting research at sea. His work at Scripps concentrated on understanding the propagation, analysis and localization of sounds underwater in the natural environment.

Scripps physical oceanographer Bruce Cornuelle credited Kuperman with work that served as the basis of modern ocean acoustics research, including the co-authoring of the textbook "Computational Ocean Acoustics." 

“Bill was the dominant figure in ocean acoustics, and he had a long relationship with the Navy, which relied on him for advice on scientific directions as well as practical choices,” Cornuelle said. “He was generous, kind, loyal and supportive, motivated by curiosity, not glory, and had a great sense of humor. His passing impacts people around the country, and around the world.”

Born in New York City in 1943, Kuperman received a bachelor’s degree from the Polytechnic Institute of Brooklyn in 1965, a master of science from the University of Chicago in 1966, and a PhD from the University of Maryland in 1972, all in physics. He had previously held research positions with the Naval Research Laboratory in Washington, D.C., the SACLANT Undersea Research Center in La Spezia, Italy, and the Naval Ocean and Atmosphere Research Laboratory at NASA’s Stennis Space Center in Mississippi.  He joined Scripps Oceanography in 1992 and served as director of the Marine Physical Laboratory from then until 2020.

Kuperman was a member of the National Academy of Engineering and the American Geophysical Union, and a fellow and former president of the Acoustical Society of America, which awarded him its Pioneers of Underwater Acoustics Medal and its Gold Medal in recognition of his leadership, mentorship, and service. He also received the Walter Munk Award, named for his Scripps colleague, in 2011 from The Oceanography Society, and served as Secretary of the Navy/Chief of Naval Operations Chair for Ocean Science.

“Bill was instrumental in advancing our understanding of ocean sound propagation, shallow water acoustics, and the integration of signal processing in environmental applications,” said Scripps oceanographer and current MPL Director Eric Terrill. “His work encompassed both theoretical and experimental aspects, often involving extensive at-sea experiments.  He was also a wonderful mentor and generous with his time.” 

Kuperman’s mentorship of generations of scientists earned him a reputation for benevolence in the eyes of many.

“Bill made sure that everyone in his group was actively participating in numerous seagoing experiments, including several in conjunction with the NATO laboratory in Italy that was known as SACLANT back then,” said Michael Collins, a mathematician at the Naval Research Laboratory. “Bill was an inspiration to everyone in the group, somewhat along the lines of a football coach whose players would run through a brick wall for him.”

Kuperman himself expressed the value of character as scientists pursued their research careers.

"I was told when I was a young scientist at the U.S. Naval Research Laboratory that in a research environment, 51% of the product is the scientist, and the research results will follow," he said in a 2012 interview. "I've lived by that."

Kuperman is survived by wife Gaby of La Jolla, Calif., daughter Rachel Kuperman of Berkeley, Calif., son Mark Kuperman of Tampa, Fla., and three grandchildren. 

The Kuperman family suggests donations may be made in his name to the Pulmonary Fibrosis Foundation. 

TRIBUTES

“Bill was a masterful genius who helped to revolutionize our understanding of how sound is transported in the sea. His patriotic involvement with the Navy was a strong aspect of his career. He was also a dedicated mentor who was always interested in recruiting and nurturing graduate study of sound. He once told my student, who was taking his departmental exam again because he failed it, "What we do is 90% perspiration and 10% inspiration, so don't worry about passing it the second time!" As MPL director he "steered the ship" for many of us, who were unaware of the crises that he faced and how he successfully navigated our labs' continuance into the 21st century!  We owe him a great debt.”  – Jules Jaffe, Scripps Oceanography

“For so many of us, Bill was a supportive friend, mentor, and colleague. I owe my understanding of ocean acoustics to him. Over time, we had numerous discussions on how to analyze ocean acoustic signals and noise and often these led to plans for at-sea experiments. We carried out a series of experiments in the late-1990s through the mid-2000s time frame with what now is called the Center for Maritime Research and Experimentation (CMRE), a NATO laboratory in La Spezia, Italy. Initially, these explored the physics of time reversal acoustics in the ocean and then later to applications in active acoustics and acoustic communications. A great mix of basic ocean physics, at-sea engineering, and potential applications (as well as a beautiful place to visit!). Bill had a unique ability to pull together a diverse group of people to work on challenging problems. I am grateful to have been able to work with him.” – William Hodgkiss, Scripps Oceanography

"Bill was highly regarded and beloved by scientists worldwide who knew him through his textbook on computational ocean acoustics, through visits to SIO, or from various acoustics conferences. I still recall the day he became my mentor during my postdoc. His infectious enthusiasm and endless creativity transformed every obstacle into an exciting journey. Beyond being a mentor, he was a close friend who offered wise counsel and steadfast support whenever needed. I often think about the ideas he inspired in me, the valuable lessons he imparted, and the memorable moments we shared during sea experiments. His influence on my life and many others will endure long into the future. Although we deeply mourn his loss, we take comfort in knowing that his legacy thrives within all who were fortunate to know him. We will continue to uphold his passion for learning, his innovative spirit, and his unwavering kindness." – Heechun Song, Scripps Oceanography

“His full impact on my and younger generations of scientists and engineers in the acoustics community is well beyond my ability to measure or quantify. My first interaction with Bill occurred in the late 1990s when I visited him and his impressive research group at Scripps Institution of Oceanography. I was a new assistant professor at the University of Michigan and had just been awarded my first Office of Naval Research grant on acoustic time reversal, a topic that also intrigued Bill. At this meeting, Bill suggested several topics to me that were complementary to his pursuits, and these topics became the basis for subsequent research and publications. 

About a half dozen years later in 2002, I invited Bill to the University of Michigan. He gave a very nice seminar on his landmark experiments on underwater acoustic time reversal, and shared many insights with me. One of these has become a daily aspiration for me. When I asked him how he could be so successful as a researcher and an administrator at the same time, his response was impressive for its simplicity and ethical clarity. The following is not a perfect quotation but it is what I remember him saying: ‘Tell everyone the truth. That way you only have one story and all the people you work with will trust you and listen to you, even when you have to tell them things they do not want to hear.’ Clearly, these words have application far beyond underwater acoustics. They have influenced and guided my career since, and I have repeated them when addressing student groups, conference audiences, and engineering classes. For decades to come, anyone who studies underwater acoustics will appreciate and benefit from Bill's impressive intellectual accomplishments. Nevertheless, I believe that his most lasting impact on the acoustics community lies in his perpetual efforts to promote and support all those who he came in contact with, even those who were fully disconnected from his immediate pursuits, like me.” – David Dowling, University of Michigan

“Everybody knew that Bill was incredibly bright and creative, but he could also put his insights into some very incisive wit when he wanted. You knew you were around a sharp (former) New Yorker!” – James Lynch, Woods Hole Oceanographic Institution

“Bill is the best boss we’ve ever had!… words I’ve heard from so many of the people who have come through our lab, and evidenced by how many of them would come back to visit, just to say hi, and ask for his advice (or just to hear another joke). Bill had a knack for seeing your character – what made a person tick – with ease. With me, he quickly realized that I did my best in supporting others in their endeavors, and he gave me every opportunity to work with everyone I could: teaching interns, helping grad students, working with engineers, and collaborating with other scientists across the campus, the country, and abroad. A breadth of experience I can't imagine being given (and it is a gift) with anyone else. I will forever be grateful to Bill for everything he has done for me… he's the best boss I've ever had” – Jit Sarkar, Scripps Institution of Oceanography

"Two things that Bill always used to say stick in my mind: One was 'Nobody starts in underwater acoustics, they end up there.' The other was 'Everything works in simulation.' I think the second observation shows the value he placed on the validation of the efficacy of proposed algorithms, whether for time reversal, imaging or MFP, against data collected at sea." – Kevin LePage, NATO
 

"It is important to emphasize the intellectual excellence which he brought to his endeavors at NRL, Scripps and the Navy. Few have been honored with the accolades of the Gold Medal from ASA, the Munk Medal, a SECNAV/CNO Chair from the Navy and membership in the National Academy of Engineering. There is, however, a lighter side associated with traveling with Bill. Often joined by our spouses we spent times in the Greek Islands, national acoustical academies in Britain and France and his favorite destination, Italy. We were hosted in the former Soviet Union and the People's Republic of China and that typically required a lot of toasting at dinners with many courses which Bill dutiful joined with his abstinence. Surely, a two-week stay a five-star hotel in the Maderia among many of the leaders for ocean acoustics and signal processing was the peak experience for our travels. At all of these we made international friendships which demonstrated that a career in ocean acoustics can be both intellectually stimulating as well as entertaining." – Arthur Baggeroer, MIT

"Bill wanted to experience the ocean the way whales and fish do, through the sounds in it. Good engineer that he was, he developed the tools of modern technology to hear the ocean’s poetry. His gruff exterior disguised a lot, but I could tell. He loved the oceans, the Navy, his work at Scripps, his colleagues and students. What more could a director ask for?" – Charles Kennel, former director, Scripps Oceanography

"Bill single-handedly saved the study of phase-conjugation in ocean acoustics (also known as time-reversal acoustics) from near death. Frustrated by bureaucratic inertia, he called in IOUs and began a successful program of at-sea demonstrations of the concept, marshaling the considerable resources of the Marine Physical Laboratory and the NATO Lab in LaSpezia, Italy." – Darrell Jackson, University of Washington

"I was one of the first PhD students Bill advised when he moved to Scripps in the early 1990s, and he was instrumental in helping my career several times since then. In my mind, he is a blended mix of the physicist Niels Bohr, Yogi Berra, and Yoda. Like Niels Bohr, he has been a keystone scientist in his field, as well as a beloved role model and mentor for generations of students and colleagues. Like his fellow New Yorker Yogi Berra, whom he loved to quote (and misquote), Bill had an uncanny ability to distill complex situations, both physical and political, into little Zen-like zingers that are handy to keep in your pocket. ('You can observe a lot by just looking,' 'never follow an animal act,' and 'first with the worst' are among my favorites). Like Yoda, Bill had a deep insight into the universe (or at least the wet parts that wobble) that bordered on mystical intuition. While he could be mathematically rigorous, I always had the impression that he used math just to formally clothe what he already had imagined. I was fond of him beyond words, so I never said much, but because of him I continue to distrust efforts that involve large complex computations without insight ('big computer, small mind'), to have appreciation bordering on reverence for the Pekeris waveguide model ('almost every relevant principle of shallow water acoustics can be found in the Pekeris waveguide'), and to try to uphold his firm belief in intellectual generosity and honesty in advancing science ('It’s best to be honest, because my father once told me it gets hard to keep track of all your lies'). We’ll miss him terribly." – Aaron Thode, Scripps Oceanography