Multi‐Scale Spatiotemporal Community Structure of Organised Convective Clouds Over the Tropics

ABSTRACT The tropics comprise several multiscale convective systems that result in organised deep cloudiness and extreme precipitation. Analysing the dynamics of deep convective clouds that occur at different spatiotemporal scales, spanning from mesoscale to planetary scale events, is critical to improving our understanding of monsoon systems, atmospheric processes, and the Earth's radiation balance. Studying the convective cloud system at a single timescale tends to be inefficient in capturing the dynamics occurring at multiple timescales. We provide a framework that combines the wavelet transform, functional climate networks, and community detection to study the spatiotemporal dynamics of outgoing longwave radiation (OLR), a good proxy for convective cloudiness in the tropics. We discover that the OLR dynamics is coherently organised at a wide range of scales and exhibits a hierarchical nature. The organisation of OLR dynamics at different scales is unravelled using communities in OLR networks constructed at temporal scales ranging from 0.25 to 1024 days. Communities are interpreted as regions where the OLR dynamics is highly coherent since connections are established based on statistical similarity. The smaller size of communities at small scales reflects the coherence established in meso‐ and synoptic scales, where the dynamics are governed by local orography and land‐atmosphere interactions. In contrast, when smaller scales are suppressed, particularly for scales larger than 26 days, larger communities emerge, representing convective cloudiness that is organised at the planetary scale. At the temporal scales of 128 days, the average spatial size of the communities is largest, while their number is lowest. Furthermore, communities reflect the structure of convective cloudiness associated with the intertropical convergence zone in different seasons.