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Constraints placed by silicon cycling on vertical exchange in general circulation models
Author(s) -
Gnanadesikan Anand,
Toggweiler J. R.
Publication year - 1999
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/1999gl900379
Subject(s) - pycnocline , flux (metallurgy) , advection , mesoscale meteorology , environmental science , geology , atmospheric sciences , mixed layer , thermohaline circulation , eddy , potential temperature , climatology , oceanography , turbulence , meteorology , materials science , physics , metallurgy , thermodynamics
The flux of biogenic silica out of the oceanic mixed layer (the export flux) must balance the import of high‐silicate deep waters associated with mass exchange between the surface and deep ocean. Recent regional estimates of the export flux limit it to 50–80 Tmol yr −1 . In order to reproduce such low export fluxes, coarse‐resolution general circulation models must have low pycnocline diffusivity and a lateral exchange scheme which involves advection of tracers by unresolved mesoscale eddies. Failure to capture low rates of vertical exchange will result in climate models which overpredict the uptake of anthropogenic carbon dioxide and fail to capture the proper locations and rates of density transformation.