Self-consistent closure for large-scale residual convective heating

Determine the residual large-scale heating contribution generated by unresolved moist convective dynamics, thereby closing the thermal forcing term in the homogenized large-scale tropical circulation equations rather than prescribing only its sum with the diagnosed convective buoyancy-flux convergence.

Background

The effective large-scale equations contain a thermal forcing term F(z) composed of two contributions: the horizontally averaged residual heating from the weaker source component S_1 and the convergence of the leading-order convective buoyancy flux. The buoyancy-flux contribution can be diagnosed from the prescribed small-scale convective circulation, but the residual heating associated with cloud microphysics and thermodynamic processes is not determined by the present homogenization theory.

Because only the combined forcing F(z) enters the large-scale equations, the model treats F(z) as prescribed. A more complete moist-convective formulation that derives the residual heating self-consistently would provide a systematic closure for the thermal feedback alongside the momentum-transport closure developed in the paper.

References

Although its buoyancy-flux convergence contribution can be diagnosed from the leading-order convective circulation, the residual heating \langle S_1\rangle is not determined by the present theory, and only their sum enters the large-scale equations.

— A multiscale theory of convective momentum transport in the tropical atmosphere  (2608.31055 - Goldsmith et al., 31 Aug 2026) in Section 2.3, “Effective large-scale equations”