Russ E. Davis: 1941-2022

Russ Davis, a scientist at Scripps Institution of Oceanography at UC San Diego who invented some of the most transformational ocean-observing instrumentation in history, died June 9, 2022 at the age of 81.

A physical oceanographer and engineer, Davis’ development of the sounding oceanographic Lagrangian observer (SOLO) float freed ocean exploration from the limits of shipborne measurements that are inherently constrained by costs and the oceans’ own vastness, as well as the observational limits of satellites.

The float he developed in the 1990s became the backbone of an international network known as Argo, which the New York Times described in 2014 as “one of the scientific triumphs of the age.” The network now has roughly 4,000 floats distributed around the world, supported by contributions from 30 countries.

The floats measure temperature and salinity in the top 2,000 meters (6,560 feet) of the ocean. Being freely drifting, they also provide information on currents. These variables are often called the “vital signs'' of the ocean. Newer Argo generations include floats capable of sinking three times as deep as the originals and others that can measure a suite of biogeochemical conditions. A full complement of Argo floats could thus observe conditions in more than 90 percent of the volume of the oceans.

“Russ was the world leader in instrument development, observational networks, and analytical tools that are the bedrock of today’s global ocean observing system,” said Scripps oceanographer Dean Roemmich. “He was a giant in revealing and understanding the roles of the ocean in Earth’s climate system.”

Davis’ instrument, a precursor of which was developed during the World Ocean Circulation Experiment (WOCE) conducted in the 1990s, has provided data used in more than 5,300 research papers to date. Those studies have assessed ocean warming among other phenomena linked to climate change and Argo provides a vital foundation of reports on the state of the ocean created by the Intergovernmental Panel on Climate Change.

“Without Russ Davis, humankind would know only a fraction of what we know today about the earth’s oceans,” said UC San Diego Chancellor Pradeep K. Khosla. “His innovations in design and implementation of ocean instrumentation, together with creative application of advanced analytical techniques, paved the way for today's global ocean observational programs, providing comprehensive datasets for studies of oceans and climate. Researchers across the globe will continue to use these data to better understand the critical role oceans play in regulating global temperatures.”

Born March 8, 1941, in San Francisco, Davis received his bachelor’s degree from the University of California, Berkeley, and his PhD from Stanford University, both in chemical engineering. He became an assistant research geophysicist at the Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics at Scripps Oceanography in 1967. He joined the faculty the following year and founded the Instrument Development Group (IDG) in 1972.

Prior to the 1980s, acoustically tracked floats mapped out currents over small ocean regions. For WOCE, launched in 1990, Davis conceived and co-designed Autonomous Lagrangian Circulation Explorer (ALACE) floats that used satellites for tracking and communication to provide a cost-effective global array. This success led to Argo. Now multiple research centers around the world manufacture floats to augment the network and replace expired floats.

Subsequently, Davis developed robotic gliders known as Spray that can be piloted across strong currents and shallow continental shelves, effectively connecting the coast with the open ocean.

“Under his leadership, IDG created a long line of oceanographic instruments,” said Jeff Sherman, a development engineer who worked with Davis for three decades. These instruments have measured oceanic phenomena with the most innovative technology of their days. 

The instruments developed by Davis included surface drifting devices tracked via radio transponders and aircraft piloted by Davis, acoustic Doppler methods to measure current velocity, and eventually satellite technology to track floating profilers for many years.

“The latter proved to be the pilot experiment for the Argo program, a cornerstone of modern oceanography,” Sherman said. “Russ most liked to follow interesting ideas, collaborating with others to produce unique measurement platforms across disciplines, including numerous types of sensors on profiling floats and gliders.”

Davis’ family members said that he showed engineering tendencies even as a child.

“When he was a kid, he built radios and model planes,” said Erik Davis, Russ Davis’ son from his first wife Sandi Zarcades. Later, Russ Davis became a pilot and built and sailed his own boat. “He definitely had that maker-engineer-hands-on attitude throughout his life.”

“He was at ease discussing science, engineering, or software,” said Sherman. “It was this mastery that allowed him to create innovative instruments and then produce great science, a very rare combination.”

Daniel Rudnick, a Scripps observational physical oceanographer, credits Davis for making him a better scientist.

“Russ had a fierce intellect and a gift for identifying the heart of a problem,” said Rudnick, who was mentored by Davis as a Scripps Oceanography PhD candidate. “Some of my most lasting memories of Russ involved long, often-intense discussions where we would hold up ideas for analysis and criticism. His probing strengthened my scientific conclusions.”

Davis’s son, an author, award-winning journalist, podcaster, and public speaker, also felt his father’s influence. Most of Erik Davis’s work deals with the humanities, history, and cultural studies, but often veers into technology and scientific culture.

“He treated me very much like an intellectual peer. Even when I was a kid, we had very wide-ranging conversations,” Erik Davis said.

Davis’s honors include the Maurice Ewing Medal from the American Geophysical Union (AGU), the Prince Albert I Gold Medal from the International Association for the Physical Sciences of the Oceans, the Henry Stommel Medal from the Woods Hole Oceanographic Institution, and the A.G. Huntsman Award from the Bedford Institute of Oceanography in Canada. He also was a member of the National Academy of Sciences and a fellow of the American Academy of Arts and Sciences, the American Geophysical Union, and the American Meteorological Society.

Davis is survived by his wife, Geri Davis of Del Mar, Calif.; his son, Erik Davis of San Francisco; his sister, Kathy McFarland, of Menlo Park, Calif.; and his step grandson, Alexander Amo of Colorado Springs, Colo. Davis was previously married to Linda Davis of San Diego and Sandi Zarcades of Rancho Santa Fe, Calif.

Details are pending for a memorial service at Scripps. The family also is planning a private event.

Members of the research and Scripps Oceanography communities are invited to add tributes to Russ Davis. Please submit them to scrippsnews@ucsd.edu. 

TRIBUTES
 

“At the time I came to Scripps Oceanography I had, of course, heard of Russ Davis and his role in Argo. But Argo was still relatively new and there were only about 6 years of data that were comprehensive enough to start to draw conclusions about how deeply and how extensively the ocean was warming. But it was already utterly clear that Russ’s technology was going to completely transform not only our knowledge of ocean warming, but of physical oceanography in general.

As I talked to Russ over the years I’ve been here at Scripps and the picture of ocean change became clearer each year, Russ seemed to marvel at how Argo had outstripped even his vision of what it could do and how much of physical oceanography it would touch. At the time he began work on the early ALACE floats the primary time series of basic physical observations of the ocean came from expensive, geographically and temporally sparse measurements made from ships and moorings. His work resulted in persistent synoptic observations. Russ once described Argo to me, tongue firmly in cheek, as ‘our little experiment on whether we could define a level of no motion in the ocean’. The ‘little experiment’ has changed what we consider to be adequate sampling of the ocean and has resulted in a global alliance of nations contributing Argo floats to ensure that the sampling continues. It is the backbone of the global ocean observing system. Now oceanographers are racing to add measurements to Argo network floats (biogeochemical Argo), and build equivalent networks for the deep ocean (DeepArgo) and for biology and chemistry.

Few oceanographers have completely altered the field. But Russ did.”

    – Margaret Leinen, Director, Scripps Institution of Oceanography and Vice Chancellor for Marine Science

“I'm saddened by the passing of Dr. Russ Davis, a giant in our field whose contributions to ocean observing were revolutionary and seminal. I was lucky to get to know Russ and witness his intellect and influence during my time at the Office of Naval Research.”

    – Rick Spinrad, NOAA Administrator

“I worked with Russ during the North Atlantic WOCE float deployments, on the refinement of the profiling floats and the development of the Spray Glider. Russ was amazing at recognizing the science that these instruments could address and was fanatical in his focus and insistence on making these instruments simple and reliable. There are many people tinkering with new instrumentation, but Russ’ work on developing instrumentation, analytical tools and large field experiments always focused on the underlying scientific problem.

It was a joy to work with Russ and push forward to new capabilities. He also provided that same focus on the science priorities in his many leadership roles in WOCE and other programs. He will be missed.”

     – Breck Owens, physical oceanographer, Woods Hole Oceanographic Institution