A steady state model of particulate organic carbon flux below the mixed layer and application to the Joint Global Ocean Flux Study
Article first published online: 20 SEP 2012
Copyright 2001 by the American Geophysical Union.
Journal of Geophysical Research: Oceans (1978–2012)
Volume 106, Issue C12, pages 31227–31237, 15 December 2001
How to Cite
2001), A steady state model of particulate organic carbon flux below the mixed layer and application to the Joint Global Ocean Flux Study, J. Geophys. Res., 106(C12), 31227–31237, doi:10.1029/2000JC000654., and (
- Issue published online: 20 SEP 2012
- Article first published online: 20 SEP 2012
- Manuscript Accepted: 23 JUL 2001
- Manuscript Received: 22 SEP 2000
The downward flux of particulate organic carbon (POC) through the ocean is controlled by a complex coupling of physical and biological processes. Here we analyze the equation that describes steady state coagulation, fragmentation, sedimentation, and grazing of POC below the mixed layer. The analysis yields a set of conditions under which vertical flux of POC is uncoupled from coagulation and fragmentation. When these conditions are satisfied, the model predicts that the flux of POC decays exponentially with depth down to 200–500 m, below which the flux is constant. From the magnitude of the terminal flux an estimate for the in situ clearance rate (volume swept clear of prey per grazer per unit time) for the grazer community can be obtained. This in situ clearance rate is estimated for five oceanic field sites using data collected during the Joint Global Ocean Flux Study, and the resulting values compare favorably to previously published laboratory estimates. These results suggest that, in some cases, bacterial mineralization may not be needed to explain the decline in POC flux in the mesopelagic zone of the ocean.