Iris effects, radiator fins, and the tropopause

Abstract

The ways in which clouds, circulation, and climate sensitivity interact are grand challenges of climate science. All of these phenomena depend on water vapor's condensable nature and strong radiative absorption. In this thesis, we take up the premise that a closer study of water vapor may provide a master key for unlocking how clouds, circulation, and climate sensitivity interact. We begin with simple models of tropical climate, water vapor's thermospectric properties, and the water vapor feedback (Chapter 1), then pursue an understanding of how thermospectric properties interact with the general circulation and climate stability in the form of subtropical radiator fins (Chapter 2) and how these properties can constrain the general circulation in the form of the radiative tropopause (Chapter 4). We use this understanding to constrain the anvil cloud area feedback (Chapter 3), a longstanding source of uncertainty in estimating climate sensitivity.