A traceable physical calibration of the vertical advection-diffusion equation for modelling ocean heat uptake
Huber, M., Tailleux, R., Ferreira, D., Kuhlbrodt, T. and Gregory, J. (2015) A traceable physical calibration of the vertical advection-diffusion equation for modelling ocean heat uptake. Geophysical Research Letters, 42 (7). pp. 2333-2341. ISSN 0094-8276
To link to this article DOI: 10.1002/2015GL063383
The classic vertical advection-diffusion (VAD) balance is a central concept in studying the ocean heat budget, in particular in simple climate models (SCMs). Here we present a new framework to calibrate the parameters of the VAD equation to the vertical ocean heat balance of two fully-coupled climate models that is traceable to the models’ circulation as well as to vertical mixing and diffusion processes. Based on temperature diagnostics, we derive an effective vertical velocity w∗ and turbulent diffusivity k∗ for each individual physical process. In steady-state, we find that the residual vertical velocity and diffusivity change sign in mid-depth, highlighting the different regional contributions of isopycnal and diapycnal diffusion in balancing the models’ residual advection and vertical mixing. We quantify the impacts of the time-evolution of the effective quantities under a transient 1%CO2 simulation and make the link to the parameters of currently employed SCMs.