# Ray F. Weiss
Ray F. Weiss (also published as R. F. Weiss) is a chemical oceanographer and atmospheric scientist at the [Scripps Institution of Oceanography](https://www.edgepedia.org/scripps-institution-of-oceanography), University of California San Diego, where he is Distinguished Professor Emeritus, Distinguished Research Professor, and Associate Dean of Academic Affairs Emeritus.[1](https://rfweiss.scrippsprofiles.ucsd.edu/biography/) His research concerns the distributions of trace gases in the atmosphere and the sea, especially halocarbons, nitrous oxide, and methane; geochemical tracers of ocean circulation and mixing; and chemical limnology.[2](https://oceanexpert.org/expert/7028) He is known for providing the first experimental proof of deep-sea hydrothermal vents, for discovering the global atmospheric increase of nitrous oxide, and for developing chlorofluorocarbon measurements as clocks for deep-ocean circulation.[1](https://rfweiss.scrippsprofiles.ucsd.edu/biography/)
| Key facts | |
|---|---|
| Field | Chemical oceanography and atmospheric trace-gas science[2](https://oceanexpert.org/expert/7028) |
| Position | Distinguished Professor Emeritus, Scripps Institution of Oceanography, UC San Diego (Scripps appointment since June 1970)[1](https://rfweiss.scrippsprofiles.ucsd.edu/biography/) • [3](https://orcid.org/0000-0001-9551-7739) |
| Training | BS in chemistry, Caltech, 1964; MS and PhD in Earth sciences, Scripps, 1964–1970, under Harmon Craig[1](https://rfweiss.scrippsprofiles.ucsd.edu/biography/) • [4](https://heritageproject.caltech.edu/interviews/ray-weiss) |
| Signature work | "Hydrothermal plumes in the Galápagos Rift", *Nature*, 1977, the first experimental proof of deep-sea hydrothermal vents[1](https://rfweiss.scrippsprofiles.ucsd.edu/biography/) • [5](https://www.whoi.edu/feature/history-hydrothermal-vents/pdf/naturev267.pdf) |
| AGAGE role | Lead principal investigator for the measurement component of the Advanced Global Atmospheric Gases Experiment[1](https://rfweiss.scrippsprofiles.ucsd.edu/biography/) |
| Honors | Elected Fellow of the American Association for the Advancement of Science and of the American Geophysical Union[1](https://rfweiss.scrippsprofiles.ucsd.edu/biography/) |
## Career and training
Weiss received a BS in chemistry from the [California Institute of Technology](https://www.edgepedia.org/california-institute-of-technology) in 1964 and a PhD in Earth sciences from the Scripps Institution in 1970.[1](https://rfweiss.scrippsprofiles.ucsd.edu/biography/) According to a Caltech Heritage Project interview, his graduate work at Scripps was under the geochemist [Harmon Craig](https://www.edgepedia.org/harmon-craig), and as a student he joined the GEOSECS program (Geochemical Ocean Section Studies), the global survey of ocean chemistry.[4](https://heritageproject.caltech.edu/interviews/ray-weiss) His graduate research also addressed the rate of deep-ocean circulation using tracers such as helium isotopes; according to a Caltech Heritage Project interview, this work showed average deep-water ages of thousands of years in the north Pacific against a few hundreds of years in the Atlantic.[4](https://heritageproject.caltech.edu/interviews/ray-weiss) As a graduate student he measured gas solubilities; his equations for calculating oxygen and CO2 solubilities in the ocean remain his most highly cited papers.[4](https://heritageproject.caltech.edu/interviews/ray-weiss)
His ORCID record lists a Geosciences Research appointment at Scripps from 1 June 1970 to the present.[3](https://orcid.org/0000-0001-9551-7739) In an oral history interview he recalled being offered a faculty position at MIT at the full professor level but accepting a similar offer from Scripps and staying.[4](https://heritageproject.caltech.edu/interviews/ray-weiss)
## Representative work
According to Ray Weiss's biography, the 1977 Galápagos Rift plume measurements gave the first experimental proof of the existence of deep-sea hydrothermal vents.[1](https://rfweiss.scrippsprofiles.ucsd.edu/biography/) The paper, "Hydrothermal plumes in the Galápagos Rift", appeared in *Nature* volume 267, pages 600–603, on 16 June 1977, and reported the water-column signature of hydrothermal discharge at the rift.[5](https://www.whoi.edu/feature/history-hydrothermal-vents/pdf/naturev267.pdf)
His 1981 analysis of air samples collected between 1976 and 1980 showed that tropospheric nitrous oxide was increasing at about 0.2% per year, with a northern-hemisphere excess of about 0.8 ppb against a January 1, 1978 northern-hemisphere mole fraction of 300.2 ppb.[6](https://doi.org/10.1029/jc086ic08p07185) This established the global rise of a greenhouse gas regulated under the [Kyoto Protocol](https://www.edgepedia.org/kyoto-protocol).[12](https://pmc.ncbi.nlm.nih.gov/articles/PMC3607011/) • [1](https://rfweiss.scrippsprofiles.ucsd.edu/biography/)
## Transient tracers and ocean ventilation
He applied dissolved atmospheric chlorofluorocarbons to determine rates of ventilation, transport, and mixing in the deep ocean and deep lakes.[1](https://rfweiss.scrippsprofiles.ucsd.edu/biography/) Significant applications include the deep limb of the [Atlantic meridional overturning circulation](https://www.edgepedia.org/atlantic-meridional-overturning-circulation), upper-ocean ventilation, apparent oxygen utilization rates, and anthropogenic CO2 inventories.[7](https://www.annualreviews.org/content/journals/10.1146/annurev.marine.010908.163933) Because atmospheric CFC concentrations have started to decrease while SF6 continues to increase, measuring both expands the range of water-mass ages that can be estimated and enhances anthropogenic CO2 inventory calculations.[7](https://www.annualreviews.org/content/journals/10.1146/annurev.marine.010908.163933)
## AGAGE and the Scripps measurement program
Weiss is the lead principal investigator responsible for the measurement component of the Advanced Global Atmospheric Gases Experiment (AGAGE).[1](https://rfweiss.scrippsprofiles.ucsd.edu/biography/) Scripps is the central calibration and development laboratory of AGAGE.[8](https://scripps.ucsd.edu/news/research-signals-milestone-cutting-gases-deplete-ozone-layer) The network and its predecessors have measured atmospheric trace gases since 1978, as the Atmospheric Lifetime Experiment (1978–1981), the Global Atmospheric Gases Experiment (1982–1992) and AGAGE (since 1993).[9](https://essd.copernicus.org/articles/17/6557/2025/) Stations include Ragged Point (Barbados), Cape Matatula ([American Samoa](https://www.edgepedia.org/american-samoa)), Kennaook/Cape Grim (Tasmania), Mace Head (Ireland, from 1987), Trinidad Head (California, from 1995), [Jungfraujoch](https://www.edgepedia.org/jungfraujoch) (Switzerland, from 2000), and Zeppelin (Svalbard, from 2001).[9](https://essd.copernicus.org/articles/17/6557/2025/)
AGAGE measures, at high frequency and multiple sites, all the important [Montreal Protocol](https://www.edgepedia.org/montreal-protocol) species, and all the important non-CO2 gases assessed by the IPCC, including chlorocarbons, CFCs, bromocarbons, HCFCs, HFCs, PFCs, NF3, SO2F2, SF6, CH4, N2O, CO, H2, CH3Cl, and CH3Br.[10](https://essd.copernicus.org/articles/10/985/2018/) It also determines tropospheric hydroxyl-radical concentrations and trends from the rates of destruction of trichloroethane, HFCs, and HCFCs.[10](https://essd.copernicus.org/articles/10/985/2018/)
## Recent developments
A 2025 paper in *Earth System Science Data*, with Weiss among its authors, presents annually updated global emissions and mole-fraction trends for 42 compounds through 2023, derived with a 12-box atmospheric model and an inverse method.[9](https://essd.copernicus.org/articles/17/6557/2025/) A 2024 study using AGAGE and NOAA measurements found that global direct radiative forcing from HCFCs peaked in 2021 at 61.75 ± 0.056 mW m−2 and equivalent effective chlorine peaked at 321.69 ± 0.27 ppt, five years before the most recent projected decrease, with both declining between 2021 and 2023; Scripps scientists including Ray Weiss contributed.[11](https://www.nature.com/articles/s41558-024-02038-7) • [8](https://scripps.ucsd.edu/news/research-signals-milestone-cutting-gases-deplete-ozone-layer)
## Honors, roles and service
Weiss is an elected Fellow of the [American Association for the Advancement of Science](https://www.edgepedia.org/american-association-for-the-advancement-of-science) and of the [American Geophysical Union](https://www.edgepedia.org/american-geophysical-union).[1](https://rfweiss.scrippsprofiles.ucsd.edu/biography/) He has served on IPCC assessment processes and on the UNEP/WMO Scientific Assessment of Ozone Depletion reports, and on national and international planning and steering committees and editorial boards.[1](https://rfweiss.scrippsprofiles.ucsd.edu/biography/)
## References
1. Biography | RAY WEISS. https://rfweiss.scrippsprofiles.ucsd.edu/biography/
2. OceanExpert – Prof. Ray F. WEISS. https://oceanexpert.org/expert/7028
3. Ray Weiss (0000-0001-9551-7739) – ORCID. https://orcid.org/0000-0001-9551-7739
4. Ray Weiss – Caltech Heritage Project. https://heritageproject.caltech.edu/interviews/ray-weiss
5. Hydrothermal Plumes in the Galápagos Rift (Nature 267:600–603, 1977). https://www.whoi.edu/feature/history-hydrothermal-vents/pdf/naturev267.pdf
6. The temporal and spatial distribution of tropospheric nitrous oxide (JGR, 1981). https://doi.org/10.1029/jc086ic08p07185
7. Observations of CFCs and SF6 as Ocean Tracers (Annual Review of Marine Science). https://www.annualreviews.org/content/journals/10.1146/annurev.marine.010908.163933
8. Research Signals Milestone in Cutting Gases that Deplete Ozone Layer (Scripps news). https://scripps.ucsd.edu/news/research-signals-milestone-cutting-gases-deplete-ozone-layer
9. Global emissions and abundances of trace gases from the AGAGE network (ESSD, 2025). https://essd.copernicus.org/articles/17/6557/2025/
10. History of chemically and radiatively important atmospheric gases from the AGAGE (ESSD, 2018). https://essd.copernicus.org/articles/10/985/2018/
11. A decrease in radiative forcing and equivalent effective chlorine from HCFCs (Nature Climate Change, 2024). https://www.nature.com/articles/s41558-024-02038-7
12. PMC3607011 (pmc.ncbi.nlm.nih.gov). https://pmc.ncbi.nlm.nih.gov/articles/PMC3607011/
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*Topic: Encyclopedia › Physical world and mathematics › Physical and mathematical scientists › Earth and climate scientists › Researchers in climate, atmospheric, and ocean science › Carbon cycle and biogeochemistry*
*Initially written Sep 21, 2026 · Reviewed: Sep 25, 2026; Sep 30, 2026 · Edited: Sep 25, 2026; Sep 30, 2026; Oct 11, 2026; Oct 15, 2026 · Last review: Sep 30, 2026*
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