A single column model with parameterized large-scale dynamics is used to better understand the response of steady-state tropical precipitation to relative sea surface temperature under various representations of radiation, convection, and circulation. The large-scale dynamics are parametrized via the weak temperature gradient (WTG), damped gravity wave (DGW), and spectral weak temperature gradient (Spectral WTG) method in NCAR’s Single Column Atmosphere Model (SCAM6). Radiative cooling is either specified or interactive, and the convective parameterization is run using two different values of a parameter that controls the degree of convective inhibition. Results are interpreted in the context of the Global Atmospheric System Studies (GASS) Intercomparison (Daleu et al. 2016). Using the settings given in Daleu et al. (2016), SCAM6 under the WTG and DGW methods produces erratic results, suggestive of numerical instability. However, when key parameters are changed to weaken the strength with which the circulation acts to eliminate tropospheric temperature variations, SCAM6 performs comparably to single column models in the GASS Intercomparison. The Spectral WTG method is less sensitive to changes in convection and radiation than are the other two methods, performing at least qualitatively similarly across all configurations considered. Under all three methods, circulation strength, represented in 1D by grid-scale vertical velocity, is decreased when barriers to convection are reduced. This effect is most extreme under specified radiative cooling, and is shown to come from increased static stability in the column’s reference radiative-convective equilibrium profile. This argument can be extended to interactive radiation cases as well, though perhaps less conclusively.

Tropical cyclones (TCs) are powered by heat fluxes across the air-sea interface, which are in turn influenced by subsurface physical processes that can modulate storm intensity. Here, we use data from 6 profiling floats to recreate 3D fields of temperature (T), salinity (S), and velocity around Super Typhoon Mangkhut (western North Pacific, September 2018). Observational estimates of vorticity (ζ) and divergence (Γ) agree with output from a 3D coupled model, while their relation to vertical velocities is explained by a linear theoretical statement of inertial pumping. Under this framework, inertial pumping is described as a linear coupling between ζ and Γ, whose cycles cause periodic displacements in the ocean thermocline and generate near-inertial waves (NIWs). Vertical profiles of T and S show gradual mixing of the upper ocean with diffusivities as high as κ~10^-1 m^2 s^-1, which caused an asymmetric cold wake of sea surface temperature (SST). We estimate that rain layer destruction used ~ 10% of energy used for mixing near the TC track, therefore inhibiting SST cooling. Lastly, watermass transformation analyses suggest that κ > 3x10^-3 m^2 s^-1 above ~110 m depth and up to 600 km behind the TC. These analyses provide an observational summary of the ocean response to TCs, demonstrate some advantages of ζ and Γ for the study of internal wave fields, and provide conceptual clarity on the mechanisms that lead to NIW generation behind TCs.