AUTHOREA
Log in
Sign Up
Browse Preprints
LOG IN
SIGN UP
Essential Site Maintenance
: Authorea-powered sites will be updated circa 15:00-17:00 Eastern on Tuesday 5 November.
There should be no interruption to normal services, but please contact us at
[email protected]
in case you face any issues.
Marcos Fontela
Public Documents
1
Isopycnal eddy stirring dominates thermohaline mixing in the upper subpolar North Atl...
Bieito Fernández Castro
and 9 more
December 07, 2023
The Atlantic Meridional Overturning Circulation entails vigorous thermohaline transformations in the subpolar North Atlantic Ocean (SPNA). There, warm and saline waters originating in the (sub)tropics are converted into cooler and fresher waters by a combination of surface fluxes and sub-surface mixing. Using microstructure measurements and a small-scale variance conservation framework, we quantify the diapycnal and isopycnal contributions --by microscale turbulence and mesoscale eddies, respectively-- to thermohaline mixing within the eastern SPNA. Isopycnal stirring is found to account for the majority of thermal (65%) and haline (84%) variance dissipation in the upper 400~m of the eastern SPNA. A simple dimensional analysis suggests that isopycnal stirring could account for O(5-10) Sv of diahaline volume flux, suggesting an important role of such stirring in regional water-mass transformations. Our mixing measurements are thus consistent with recent indirect estimates in highlighting the importance of isopycnal stirring for North Atlantic overturning.Abstract content goes here