Powered by Indico
v3.2.3
Since the discoveries of the first exoplanet and brown dwarf in 1995, the field of exoplanets and brown dwarfs have grown substantially from discovery to characterisation. We are able to measure the global distribution of temperature, winds, clouds, and chemical species in their atmospheres, providing clues into their formation and evolution history as well as fundamental physical processes governing their climate. In this colloquium, I will describe our current understanding on the climate dynamics of two class of objects that remain the best-characterised groups of extrasolar substellar objects. The first class contains giant planets that are extremely close to their host stars, a.k.a, hot Jupiters, which are expected to be tidally locked with a permanent dayside receiving enormous stellar irradiation and a permanent nightside. This configuration gives rise to an exotic climate regime that is distinctive to atmospheres in the solar system and has imprinted its features in a variety of observations. The second class includes brown dwarfs, often quoted as failed stars, which are often isolated, receiving negligible stellar irradiation but powering their atmospheres by internal heat. These atmospheres are "cool" enough to be dominated by molecules, clouds, and features due to weather. I will review key observations, important theoretical and modeling developments, and then dive into a few atmospheric dynamical mechanisms shaping the climate dynamics of these objects.
Xianyu Tan is currently a postdoctoral researcher at the Department of Physics, University of Oxford. He is interested in understanding the atmospheres and climate of extrasolar planets and brown dwarfs using theories and numerical simulations. He obtained his B.S. in 2010 from the University of Science and Technology of China, his Master in 2013 from the University of Hong Kong, and his Ph.D. in 2018 from the University of Arizona.