Kinetic energy‐conserving hyperdiffusion can improve low resolution atmospheric models

Abstract Motivated by findings that energetically consistent subgrid dissipation schemes can improve eddy‐permitting ocean simulations, this work investigates the impact of the subgrid dissipation scheme on low‐resolution atmospheric dynamical cores. A kinetic energy‐conserving dissipation scheme is implemented in the model adding a negative viscosity term that injects back into the eddy field the kinetic energy dissipated by horizontal hyperdiffusion. The kinetic energy‐conserving scheme enhances numerical convergence when horizontal resolution is changed with fixed vertical resolution and gives superior low‐resolution results. Improvements are most obvious for eddy kinetic energy but also found in other fields, particularly with strong or little scale‐selective horizontal hyperdiffusion. One advantage of the kinetic energy‐conserving scheme is that it reduces the sensitivity of the model to changes in the subgrid dissipation rate, providing more robust results.