The slab mixed-layer ocean model assumes a mixed-layer depth of 50 meters. The SST is determined by the energy balance between radiative flux at surface, latent and sensible heat fluxes and Q-flux, which crudely simulates the ocean transport. Q-flux is typically taken from a control QTCM1 run when SST is specified as observations or climatology. Or estimates of observed net flux may be used. In either case, the implied ocean heat transport is calculated by the balance between net surface fluxes and rate of change of SST. It can be annually averaged or monthly averaged. The air-sea coupling interval is 1 day, i.e., SST is updated every 24 hours.