Tropical Convection, Clouds, and Climate: Lessons from Idealized Models of Radiative-Convective Equilibrium

Abstract

The Tropics are home to a wide variety of atmospheric phenomena that play major roles in global weather and climate. Tropical convection and its associated clouds are notoriously difficult to represent in global climate models, and as a result many cloud- and convection-related processes remain sources of great uncertainty in our understanding of climate and projections of future change. In this dissertation, I explore four distinct but interrelated research projects, each using a variety of tools to address critical questions related to tropical anvil clouds, convection, circulation, and climate. The overarching theme of this work is the extraction of robust insights from idealized models of radiative-convective equilibrium (RCE), a conceptual framework of great historical importance in the study of tropical climate and one that remains instrumental to our understanding of complex phenomena. Chapter 1 provides background and motivation for my key research questions. In Chapter 2, I use an energy balance framework to study how surface warming affects the amount of cloud ice the tropical troposphere. In Chapter 3, I examine anvil cloud radiative feedbacks in high-resolution models and consider the implications for climate change. In Chapter 4, I investigate the congestus mode of tropical convection and explains its variability across cloud-resolving models. Finally, in Chapter 5, I examine the coupled variability of deep convection, atmospheric circulation, and sea surface temperature in an idealized simulation.