Stability constraining the radiation-driven convective anvil outflow

Abstract. Anvil clouds outflowing from the convection top interact strongly with radiation. The anvil formation is driven by radiation and simultaneously modulates radiation. Since the convective anvil outflow process has not been well resolved from observations, the hypothesized anvil-radiation feedback processes are lack of adequate evidence to be further refined. In this work, by combining the advantages of geostationary satellites for identifying convection producing anvil clouds and the A-Train polar-orbit satellites for the cross section of the radiation heating the anvil, the real-world convective anvil outflow is resolved to further refine the previously hypothesized process of the radiation driving the anvil outflow. The results show that the destabilization of the longwave radiative cooling at the cloud top only partially explains the anvil outflow dynamics at relatively lower levels, and that the shortwave radiative heating and its destabilization can strongly enhance the outflow at higher levels. Nevertheless, notably, the role of the radiation driving the anvil outflow is strongly constrained by its environmental stability and its vertical gradient. In the vertical, the primary radiation-driven anvil outflow is constrained between the levels of the minimum stability and the maximum stability gradient approximately 12–14 km. Less stable environment or upward-shifting of the minimum stability makes the anvil produced at a higher level. Overall, this work clarifies the process of the anvil outflow driven by radiation but constrained by environmental stability and provides a novel stability constraint on the anvil-radiation feedback.