The relationship between vertical eddy diffusion and buoyancy gradient in the deep sea

Jorge Louis Sarmiento, H. W. Feely, W. S. Moore, A. E. Bainbridge, W. S. Broecker

Research output: Contribution to journalArticlepeer-review

100 Scopus citations


Vertical eddy diffusivities (Kv's) have been estimated at fourteen widely separated locations from fourteen 222Rn profiles and two 228Ra profiles measured near the ocean floor as part of the Atlantic and Pacific GEOSECS programs. They show an inverse proportionality to the local buoyancy gradient [(g/ρ{variant})(∂ρ{variant}pot/∂z)] calculated from hydrographic measurements. The negative of the constant of proportionality is the buoyancy flux [-Kv(g/ρ{variant})(∂ρ{variant}pot/∂z)] which has a mean of -4 × 10-6 cm2/sec3. Our results suggest that the buoyancy flux varies very little near the ocean floor. Kv's for the interior of the deep Pacific calculated from the relationship Kv = (4 × 10-6 cm2/sec3)/[(g/ρ{variant})(∂ρ{variant}pot/∂z)] agree well with published estimates. Kv's calculated for the pycnocline are one to two orders of magnitude smaller than upper limits estimated from tritium and 7Be distributions. Heat fluxes calculated with the model Kv's obtained from the 222Rn profiles average 31 μcal cm-2 sec-1 in the Atlantic Ocean and 8 μcal cm-2 sec-1 in the Pacific Ocean.

Original languageEnglish (US)
Pages (from-to)357-370
Number of pages14
JournalEarth and Planetary Science Letters
Issue number2
StatePublished - Oct 1976

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Geochemistry and Petrology
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science


Dive into the research topics of 'The relationship between vertical eddy diffusion and buoyancy gradient in the deep sea'. Together they form a unique fingerprint.

Cite this