Top-Down Approaches to the Study of Cloud Systems

We approach the problem of convection and clouds using a “top-down view” that focuses on system-wide behavior and emergent phenomena.We distinguish this from the traditional “bottom-up,” or reductionist approach, in which the focus is on individual interacting processes, from which one attempts to advance understanding of the system as a whole. With its focus on the overall system behavior, the top-down methodology applies a different conceptual paradigm to the problem of complex systems and can be viewed as complementary to bottom-up reductionist thinking.We discuss the advantages of merging bottom-up and top-down approaches for maximum benefit: reductionism elucidates detailed physical processes and tests ideas about their interplay, while the broader view of atmospheric system behavior uncovers the outcome of interactions between local processes, revealing preferred states and bifurcation behaviors of the system, and responses to perturbations that might change the preferred states.