Presentation #1042 in the session “Open Engagement Session A”.
Planets with high obliquity may widely exist in the universe in absence of a large moon. This type of planets have extremely strong seasonal variation, and receive more radiation in the polar regions than in low latitudes, and therefore, are expected to have drastically different climates from the Earth-like low obliquity planets.Using a model hierarchy, from a 1D Eady-like model to a 3D dry dynamic model and then to a full GCM, we aim to approach the questions: 1) whether high obliquity planets are generally warmer or colder than low obliquity equivalents, 2) how the habitable zone changes with obliquity, 3) whether obliquity affects likelihood of water molecules that are evaporated from the surface ocean being detected through spectroscopy, 4) how atmosphere circulates on high obliquity planets, and 5) whether the atmospheric circulation has some potentially observable aspects that can be used to infer the planet’s climate using future observations. The significance of understanding the climate under different configurations is not merely a curiosity about exoplanets; in fact, these seemingly exotic exoplanet regimes provide an opportunity to test our theories. From this work, we realized that atmospheric motions, even in the tropics, do not necessarily rise (or sink) in warm (or cold) regions/latitude bands. There are deeper reasons besides the vertical density profile leading to the top-amplified structure of mid-latitude eddies on Earth. Also, changes in general circulation can dramatically affect the troposphere-stratosphere tracer exchange.