Yuchen Lian1, Adam P. Showman1,2, Xianyu Tan3, and Yongyun Hu1*
1Laboratory for Climate and Ocean-Atmosphere Studies, Department of Atmospheric and Oceanic Sciences, Peking University, Beijing 100871, China
2Lunar and Planetary Laboratory, University of Arizona, 1629 University Boulevard, Tucson AZ 85721, USA
3Atmospheric Oceanic and Planetary Physics, Department of Physics, University of Oxford OX1 3PU, UK
*Correspondence to: Yongyun Hu (E-mail: yyhu@pku.edu.cn)
Abstract
Close-in giant planets with strong stellar irradiation show atmospheric circulation patterns with strong equatorial jets and global-scale stationary waves. So far, almost all modeling works on atmospheric circulations of such giant planets have mainly considered external radiation alone, without taking into account the role of internal heat fluxes or just treating it in very simplified ways. Here, we study atmospheric circulations of strongly irradiated giant planets by considering the effect of internal forcing, which is characterized by small-scale stochastic interior thermal perturbations, using a threedimensional atmospheric general circulation model. We show that the perturbation-excited waves can largely modify atmospheric circulation patterns in the presence of relatively strong internal forcing. Specifically, our simulations demonstrate three circulation regimes: superrotation regime, midlatitudejet regime, and quasi-periodic oscillation regime, depending on the relative importance of external and internal forcings. It is also found that strong internal forcing can cause noticeable modifications of the thermal phase curves.
Keywords: exoplanet atmosphere, atmospheric circulation, brown dwarfs, hot Jupiters
Full Paper: accepted by the Astrophysical Journal, https://arxiv.org/pdf/2202.11974
Figure 1. Zonal-mean zonal wind for various external and internal forcings. The abbreviates are like: InmedExweak means medium internal forcing with weak external forcing, etc.
