Antarctic Circumpolar Current NADW AABW

Circulation of Deep Waters in Southern Ocean 50ºS ACC 65ºS Antarctic Circumpolar Current (ACC) flows eastward and extends from surface into the Deep Sea

N-S Cross Sections Atlantic Ocean 3

Zonal (E-W) Cross Sections (at 7ºS) in Atlantic Ocean 4

N-S Cross Sections in the Pacific Ocean 5

Zonal (E-W) Cross Sections (30ºS) in Pacific Ocean 6

North-South Cross Sections in Indian Ocean 7

T and S in Atlantic versus Pacific Oceans

Nitrate Trends in Deep Sea Atlantic Ocean Southern Ocean Pacific Ocean (umol/kg)

Oxygen Trends in Deep Sea Atlantic Ocean Southern Ocean Pacific Ocean (umol/kg)

CFC History in the Atmosphere 11

CFCs in the N. Atlantic Ocean N-S Cross Section (1988) E-W Cross Section at 10ºN (1993) 12

Theoretical Circulation for Deep Waters

CFC Ages of Water Parcels in Deep Atlantic (~3000m) Years

CFCs in Pacific Ocean

Aging Deep Water using Radiocarbon (14C) 12C = 99% 13C= 1% 14C = 10-10 % Radioactive Decay Equation Nt = No * e-λt , where t = time and λ = 0.69/t½ t½ (half-life) = 5700 years for 14C Nt/No = e-λt or ln (Nt/No) = - λt Time (t) = -5700 yrs/0.69 * ln(Nt/No)

14C Distribution in Deep Sea 1000 1000 2000 3000 4000 5000 6000 (per mil)

Interbasin Trends in 14C in Deep Sea

Ocean’s Uptake of Fossil-fuel Combustion CO2 Ocean adsorbs about one-third of the CO2 produced by fossil fuel combustion