2000 WILLIAM JENKINS
Dr. Jenkins, the twenty-third recipient of the A. G. Huntsman Award, is honoured in recognition of his development of the tritium-helium dating technique and its application to studies of ocean circulation, mixing and productivity. The analytical methods developed by Dr. Jenkins use the large scale addition of tritium to the oceans as a result of atmospheric testing of nuclear weapons in the 1950s and 1960s, and provide unique tools for studying mixing processes in the upper ocean. As the tritium has decayed and undergone dilution by mixing, it has been essential for Dr. Jenkins to continually improve the sensitivity of his methods. He has developed state-of-the-art advection-diffusion models and three-dimensional graphic simulations which allow estimation of water mass velocities and mixing rates over time scales that were previously inaccessible. He was also one of the first to point out that simple vertical mixing processes could not explain the observed distribution of tracers, and developed quantitative models which demonstrate the importance of isopycnal mixing and advection. He also showed that tritium-helium ages could be used to calculate oxygen utilization rates finding values higher than expected. These results led to the conclusion that earlier measurements of new production were too low. He has also made fundamental contributions to solid earth geochemistry through studies of seafloor hydrothermal systems. He is one of those rare people who can make superb measurements and formulate sound, quantitative models for the insightful interpretation of these data. Throughout his career, his research has illuminated key oceanographic processes and advanced our understanding of global climate mechanisms.