For: Journal of Physical Oceanography

• Main Authors: Thermocline Waters, Alexander Sen Gupta, Matthew H. England
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2006
• Subjects: Indian; Pacific; North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.598.8285; http://web.maths.unsw.edu.au/~alexg/bibliography/offline2.pdf

A high-resolution, off-line, ocean general circulation model, incorporating a realistic parameterisation of mixed layer convection is used to diagnose pathways and timescales of Southern Hemisphere Intermediate, Mode and lower thermocline water ventilation. The use of such an off-line methodology represents the only feasible way of simulating the long timescales required to validate the internal pathways of a high resolution ocean model. Simulated and observed CFC-11 are in reasonably good agreement, demonstrating the model’s skill in representing realistic ventilation. Regional passive-dye and age tracer experiments aid in the identification of pathways originating from different Southern Hemisphere locations. Northern Hemisphere penetration of Intermediate, Mode and thermocline waters is most extensive and rapid into the North Atlantic Ocean- because these waters are involved in closing the Atlantic meridional overturning cell. However, less than 8 % of this ventilation is derived from subduction within the South Atlantic in the simulation. Instead this water enters the Atlantic just to the south of South Africa having originally subducted primarily in the east Indian Ocean, but also in the west Indian Ocean and the west Pacific region where a pathway advects water westward to the south