Speaker: Michael Byrne (St Andrews)
Title: Dynamical constraints on tropical climate change over land
Abstract: Understanding the responses of temperature and humidity to anthropogenic forcing is a fundamental science question with widespread impacts. In this talk, I will discuss work led by my group over the last decade to understand the physical mechanisms controlling tropical climate over land. Atmospheric convection and weak free-tropospheric gradients (associated with a weak Coriolis force) place a strong, dynamical constraint on how tropical temperature and humidity respond to forcing. This dynamical constraint, coupled to a conceptual model for boundary-layer land humidity, forms the basis of a variety of simple theories we have developed to explain the land-ocean warming contrast, the decreasing trend in land relative humidity, and the amplified warming of hot days over tropical land. These advances will be presented along with ongoing work focused on extreme temperatures, including the development of potential emergent constraints on future changes.