Fast and Slow Responses of Atmospheric Energy Budgets to Perturbed Cloud and Convection Processes in an Atmospheric Global Climate Model

Cloud and convection strongly modulate atmospheric energy budgets, but the latter's responses often vary across timescales because of complex interactions between fast and slow processes. Here, based on atmospheric model simulations at intermediate state between weather and climate timescales, we investigate how the responses in the global-mean atmospheric energy budgets evolve over time after simultaneously perturbing various cloud-scale processes. We find that the responses in radiative and sensible heat fluxes converge much more rapidly compared to condensation heat associated with precipitation, which is attributed to the compensating feedback effects of precipitation on longwave cooling and shortwave heating. Because of energy conservation, uncertainty in long-term precipitation simulations can be substantially reduced by constraining the fast processes of radiative and sensible heat fluxes. These findings can help economize on computational resources required for model tuning and serve as a crucial link between the convective-scale and equilibrium-state outcomes within the model. Cloud and convection occurring on short timescales can interact with processes that require much longer time to respond to small perturbations in the climate system, making it extremely difficult to understand the sources of uncertainty in climate modeling. Here, with an atmospheric model, we investigate how the simulated global-mean atmospheric energy budgets gradually evolve over time when various cloud-scale processes are simultaneously perturbed. We find that the responses in radiative and sensible heat fluxes converge much more rapidly compared to condensation heat associated with precipitation. As a result, a substantial reduction in uncertainty regarding long-term precipitation simulations can be achieved by constraining the radiative and sensible heat fluxes at shorter timescales, in accordance with energy conservation principles. Our results can help modelers economize on computational resources required for model tuning and serve as a crucial link between the model physics parameterization community and the model application community. The responses in radiative and sensible heat fluxes converge much more rapidly compared to precipitationThe rapid radiative response is attributed to the compensating feedback effects of precipitation on longwave cooling and shortwave heatingConstraining the fast processes of radiative and sensible heat fluxes can alleviate uncertainty in long-term precipitation simulations