Da Yang

Convective self-aggregation is proposed to be fundamental to the development of tropical cyclones and the Madden-Julian Oscillation, both of which are long-term mysteries in tropical meteorology. Therefore, understanding self-aggregation is key to deciphering how convection works in the tropical atmosphere. Here we present a 1D shallow water model that simulates the dynamics of the planetary boundary layer. We parameterize convection as a small-scale, short-lived mass sink that is triggered when the layer thickness exceeds a certain threshold. Once triggered, convection lasts for finite time and occupies finite length. We show that the model can successfully simulate self-aggregation, and that the results are robust to a wide range of parameter values. By analyzing the available potential energy budget (APE), we show convection generates APE, providing energy for self-aggregation. This paper provides a simple modeling framework to study self-aggregation, which can be used to understand the temporal and spatial scales of self-aggregation.