Using an effective ocean diffusivity of 0.65 cm ^ 2 / s (which is the central estimate derived in the Forest 06 study), the surface temperature response to a step forcing increase reaches about 90 % of its ultimate level within 25 years, if I've got everythng right. (judithcurry.com)
Ocean parameters: horizontal and vertical ocean diffusivity k H = 200 — 5,000 -LCB- 2000 -RCB- m2 / s, k V = 0.1 — 1.0 × 10 − 4 -LCB- 0.3 × 10 − 4 -RCB- m2 / s at top, 1.1 — 2.0 × 10 − 4 -LCB- 1.3 × 10 − 4 -RCB- m2 / s at ocean bottom (vertical profile after Bryan Lewis). (link.springer.com)
Tan, Z., C. M. Kaul, K. G. Pressel, Y. Cohen, T. Schneider, and J. Teixeira, 2018: An extended eddy - diffusivity mass - flux scheme for unified representation of subgrid - scale turbulence and convection. (climate-dynamics.org)