  In radiative-convective equilibrium (RCE) simulations, convective
self-aggregation (CSA) is the spontaneous organization into segregated cloudy
and cloud-free regions. Evidence exists for how CSA is stabilized, but how it
arises favorably on large domains is not settled. Using large-eddy simulations
(LES), we link the spatial organization emerging from the interaction of cold
pools (CPs) to CSA. We systematically weaken simulated rain evaporation to
reduce maximal CP radii, $R_{\text{max}}$, and find reducing $R_{\text{max}}$
causes CSA to occur earlier. We further identify a typical rain cell generation
time and a minimum radius, $R_{\text{min}}$, around a given rain cell, within
which the formation of subsequent rain cells is suppressed. Incorporating
$R_{\text{min}}$ and $R_{\text{max}}$, we propose a toy model that captures how
CSA arises earlier on large domains: when two CPs of radii
$r_{i,j}\in[R_{\text{min}},R_{\text{max}}]$ collide, they form a new convective
event. These findings imply that interactions between CPs may explain the
initial stages of CSA.

Atmospheric and Oceanic Physics