Monday, 7th February 2005

Speaker: Professor Oleg Saenko
Canadian Centre for Climate Modelling and Analysis
Victoria, CANADA

Tuesday 8th February
11 a.m. - 12 noon
Room RC-4082, Level 4, Red Centre Building

Observations suggest that strong mixing in the ocean is localized. This has important consequences for the ocean general circulation and climate. Model experiments are presented which show that the circulation of bottom water in the ocean cannot be supported with a uniform vertical diffusivity of 0.1 cm^2/s.

This also follows from dynamical constraints, such as conservation of potential vorticity and the buoyancy budget in the abyssal ocean.It is argued that the topography induced mixing of 1.0-10 cm^2/s is required to support the circulation of AABW, whereas the circulation of NADW can still be supported with diffusivity of 0.1 cm^2/s.

that simulated ocean circulation, vertical heat transfer and climate, as well as the climate response to the increase of atmospheric CO2, can be quite sensitive to the assumptions
about the magnitude and distribution of mixing in the ocean.