Simulating Convective Self-Aggregation in a Shallow Water Model

Organized convective storms and their associated overturning circulations can self-emerge over an ocean surface with uniform temperature in cloud-resolving simulations. This phenomenon is referred to as convective self-aggregation. Here we will present a 1D (x) shallow water model for convective self-aggregation. This model simulates dynamics of the planetary boundary layer using parameterized convection and radiation. Organized large-scale circulations self-emerged with uniform boundary conditions and random initial conditions. Figure 1 shows the simulation results from our shallow water model (right panel), which captures the essential features of the 2D (x, z) cloud-resolving simulation results (left panel). There are only three independent parameters in the shallow water model. We will show scaling analysis of the parameters to understand what sets the timescale for the development of convective self-aggregation and what determines its spatial scale at steady state.