Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-02T21:29:56.541Z Has data issue: false hasContentIssue false
  • English
  • Français

Vertical Advection — Diffusion Rates in the Oceanic Thermocline Determined from 14C Distributions*

Published online by Cambridge University Press:  18 July 2016

P D Quay  and
Minze Stuiver
P D Quay
Affiliation:
Department of Geological Sciences, University of Washington, Seattle, Washington 98195
Minze Stuiver
Affiliation:
Departments of Geological Sciences and Zoology, Quaternary Research Center, University of Washington, Seattle, Washington 98195
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The characteristics of a one-dimensional vertical advection-diffusion ocean mixing model were examined using temperature, salinity, and bomb 14C measurements made during the GEOSECS program. Vertical advection (W) and eddy diffusion (K) rates for the main oceanic thermocline and CO2 gas exchange rates (E) were determined from the depth distributions of salinity and bomb produced 14C measured in the upper 1000m of the Atlantic and Pacific Oceans. In the Atlantic, the results suggest that vertical diffusion rates are lower in the equatorial region (K = 0.6cm2sec—1) than in the temperate region (K = 1.6cm2sec—1). Upwelling rates were calculated for stations located between about 30° N and 30°S and average 10m yr—1, corresponding to an upward transport of about 10 Sverdrups. Model calculations of the gas exchange rate of CO2 indicate a 2 to 3-fold decrease between temperate latitudes and the equatorial latitudes of the Atlantic. For many of the Pacific GEOSECS stations, the Δ14C depth distribution is distinctly different than in the Atlantic, and cannot be used to calculate unique values of K and W that explain both the salinity and 14C depth distributions.

Type
Oceanography
Information
Radiocarbon , Volume 22 , Issue 3: Heidelberg , 1980 , pp. 607 - 625
Copyright
Copyright © The American Journal of Science

Footnotes

*

The support of the National Science Foundation (GX-28166 and IDO71-04200) and Department of Energy (DE79EV10216) is gratefully acknowledged.

References

Broecker, W S, Gerard, R, Ewing, M, and Heezen, B C, 1960, Natural radiocarbon in the Atlantic Ocean: Jour Geophys Research, v 65, p 2903–2931.Google Scholar
Broecker, W S, Peng, T-H, and Stuiver, Minze, 1978, An estimate of the upwelling rate in the equatorial Atlantic based on the distribution of bomb radiocarbon: Jour Geophys Research, v 83, p 6179–6186.Google Scholar
Carslaw, H S, and Jaegar, J C, 1959, Conduction of heat in solids: Oxford, Oxford Univ Press, 510 p.Google Scholar
Craig, Harmon, 1969, Abyssal carbon and radiocarbon in the Pacific: Jour Geophys Research, v 74, p 5491–5506.Google Scholar
Druffel, E M and Linick, T W, 1978, Radiocarbon in annual coral rings of Florida: Geophys Research Letters, v 5, p 913–916.Google Scholar
Iselin, C O'D, 1939, The influence of vertical and lateral turbulence on the characteristics of waters at mid-depth: Am Geophys Union Trans, p 414–417.Google Scholar
Linick, T W, 1978, La Jolla measurements of radiocarbon on the oceans: Radiocarbon, v 20, p 333–359.Google Scholar
Michel, R L and Suess, H E, 1975, Bomb tritium in the Pacific Ocean: Jour Geophys Research, v 80, p 4139–4152.Google Scholar
Nydal, R K, Lövseth, Knut, and Gulliksen, Steinar, 1979, A survey of radiocarbon variation in nature since the Test Ban Treaty, in Berger, Rainer and Suess, H E, eds, Radiocarbon dating, Internatl radiocarbon conf, 9th, Proc: Berkeley/Los Angeles, Univ California Press, p 313–323.Google Scholar
Oeschger, Hans, Siegenthaler, Ulrich, and Gugelmann, A, 1975, A box diffusion model to study the carbon dioxide exchange in nature: Tellus, v 27, p 168–192.Google Scholar
Ostlund, H G, Brescher, R, Oleson, R, and Ferguson, M J, 1978, GEOSECS Pacific radiocarbon and tritium results (Miami): Tritium Laboratory data rept #8, Univ Miami.Google Scholar
Ostlund, H G, Dorsey, H G, and Brescher, R, 1978, GEOSECS Atlantic radiocarbon and tritium results (Miami): Tritium Laboratory data rept #5, Univ Miami.Google Scholar
Ostlund, H G and Stuiver, Minze, 1980, GEOSECS Pacific radiocarbon: Radiocarbon, v 22, no. 1, p 25–53.Google Scholar
Peng, T-H, Broecker, W S, Mathieu, G G, and Li, Y-H, 1979, Radon evasion rates in the Atlantic and Pacific Oceans as determined during the GEOSECS program: Jour Geophys Research, v 84, p 2471–2486.Google Scholar
Rooth, C G, and Ostlund, H G, 1972, Penetration of tritium into the Atlantic thermocline: Deep Sea Research, v 19, p 481–492.Google Scholar
Stommel, H, 1958, The abyssal circulation: Deep Sea Research, v 5, p 80–82.Google Scholar
Stuiver, Minze, 1980, 14C distribution in the Atlantic Ocean: Jour Geophys Research, v 85, p 2711–2718.Google Scholar
Stuiver, Minze and Ostlund, H G, 1980, GEOSECS Atlantic radiocarbon: Radiocarbon, v 22, no. 1, p 1–24.Google Scholar
Sverdrup, H U, Johnson, M W, and Fleming, R H, 1942, The oceans: New York, Prentice-Hall, 1087 p.Google Scholar
Veronis, George, 1969, On theoretical models of the thermocline circulation: Deep Sea Research, v 16 supp, p 301–323.Google Scholar
Worthington, L V, 1976, On the North Atlantic circulation: Johns Hopkins Oceanog Studies, no. 6, 110 p.Google Scholar