Publication Date:
2022-05-25
Description:
Author Posting. © American Geophysical Union, 2018. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 123 (2018): 2615-2634, doi:10.1002/2017JC013536.
Description:
In this work, we use realistic isopycnal velocities with a 3-D eddy diffusivity to advect and diffuse
a tracer in the Antarctic Circumpolar Current, beginning in the Southeast Pacific and progressing
through Drake Passage. We prescribe a diapycnal diffusivity which takes one value in the SE Pacific west of
678W and another value in Drake Passage east of that longitude, and optimize the diffusivities using a cost
function to give a best fit to experimental data from the DIMES (Diapycnal and Isopycnal Mixing Experiment
in the Southern Ocean) tracer, released near the boundary between the Upper and Lower Circumpolar
Deep Water. We find that diapycnal diffusivity is enhanced 20-fold in Drake Passage compared with the SE
Pacific, consistent with previous estimates obtained using a simpler advection-diffusion model with constant,
but different, zonal velocities east and west of 678W. Our result shows that diapycnal mixing in the
ACC plays a significant role in transferring buoyancy within the Meridional Overturning Circulation.
Description:
UK Natural Environment Research Council Grant Numbers: NE/F020252/1 , NE/N018028/1 , NE/J007757/1;
US National Science Foundation Grant Numbers: OCE 0622825 , OCE 1232962
Description:
2018-09-26
Keywords:
Diapycnal mixing
;
Ocean circulation
;
Tracer experiment
;
Ocean model
Repository Name:
Woods Hole Open Access Server
Type:
Article
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