Ray F Weiss, Scripps Institution of Oceanography, University of California San Diego, USA
Recipient of the 2026 Urey Award
RAY F. WEISS is a Distinguished Professor of Geochemistry Emeritus at the Scripps Institution of Oceanography, University of California San Diego, where he has been for 62 years. For roughly the first half of his academic career his research focused on chemical tracers in oceanography and on applying analytical chemistry methods to this research. Among his earlier contributions were the systematic quantification of gas solubilities in water and seawater that are still used today. His remote sampling of elevated temperature near-bottom waters at the Galapagos spreading center in the Eastern Pacific for measurements of helium isotopes and other geochemical tracers provided the first proof-of-existence of deep-sea hydrothermal vents. In the Weddell Sea, he carried out the first geochemical study of the sub-surface and ice-edge Antarctic mixing processes that play a major role in deep water formation for the world oceans. And in the wider Pacific, Atlantic and Indian Oceans, he and his students and postdocs developed the practical application of measuring dissolved atmospheric chlorofluorocarbons to determine the rates of ventilation, transport and mixing in the deep oceans. These studies included the first applications of time-dependent tracers in deep western boundary currents and deep equatorial countercurrents. This aquatic tracer work was also expanded to studies of mixing rates and biological productivity in deep temperate lakes, and to an improved understanding of how the P-V-T properties of water control deep mixing in these lakes.
Since many of the time-dependent tracers used in oceanography come from the atmosphere, and with the growing awareness of the environmental impacts of anthropogenic emissions to the atmosphere, the second half of Prof. Weiss’s research career shifted toward atmospheric trace gas research. He carried out the first accurate quantification of the global increase and latitudinal distribution of atmospheric nitrous oxide, an important greenhouse gas and stratospheric ozone depleting substance. With the discovery of the dominant role of chlorine- and bromine-bearing anthropogenic gases in the catalytic destruction of stratospheric ozone, and the resulting passage of the Montreal Protocol, it became important to verify by direct atmospheric measurement whether its resulting restrictions were being followed by the signatories. In 1990, Prof Weiss joined with Massachusetts Institute of Technology (MIT) colleague Prof. Ronald Prinn to lead the experimental component of the Advanced Global Atmospheric Gases Experiment (AGAGE), now a 13-nation collaboration to measure and model the distributions and lifetimes of more than 55 chemically and radiatively important trace gases emitted into the global and regional atmosphere. AGAGE has played a major role in the discovery and quantification of unreported or under-reported emissions, especially from East Asia, and in showing that some of these spurious emissions have subsequently been remediated.
Prof. Weiss has mentored graduate students and postdocs who now research and teach atmospheric and oceanic chemistry around the globe. He has authored or co-authored 273 research publications, and he has served on a wide range of advisory and review committees. He is a Fellow of the American Geophysical Union and of the American Association for the Advancement of Science.