Abstract: How much will Earth warm in response to increasing carbon dioxide emissions? Climate projections are highly uncertain yet have important societal implications. Climate models are the most effective tools for making climate projections, however, their ability to reliably project climate has been hindered primarily by challenges in representing clouds in Earth’s atmosphere. Cold clouds composed of supercooled liquid droplets and ice crystals are particularly challenging to represent in climate models due to the large number of complex micro-scale physical properties and processes associated with these clouds. In this talk, I will demonstrate how satellite observations are indispensable tools for improving our understanding of cloud physical processes and improving the representation of these processes in climate models. I will also identify the key micro-scale physical processes associated with cold clouds that are important for Earth’s changing climate through their interactions with solar and terrestrial radiation. I will then focus on clouds in the Arctic --- a region where Earth is experiencing accelerated warming compared to the rest of the globe -- and show how nonlinear interactions between clouds, the vertical thermal structure of the atmosphere, and sea ice contribute to the amplified warming. I will conclude with a glimpse into exciting new developments underway, including the future launch of satellite instruments and the rise of high-resolution global storm-resolving models, and explain how these advancements will enhance our understanding of Earth’s physical climate system in the coming decade.
The Physics Frontiers Centers (PFC) program supports university-based centers and institutes where the collective efforts of a larger group of individuals can enable transformational advances in the most promising research areas. The program is designed to foster major breakthroughs at the intellectual frontiers of physics by providing needed resources such as combinations of talents, skills, disciplines, and/or specialized infrastructure, not usually available to individual investigators or small groups, in an environment in which the collective efforts of the larger group can be shown to be seminal to promoting significant progress in the science and the education of students. PFCs also include creative, substantive activities aimed at enhancing education, broadening participation of traditionally underrepresented groups, and outreach to the scientific community and general public.