摘要
迄今为止,已有五千多颗太阳系外行星和两千多颗褐矮星被确认,它们展现出了丰富的多样性.伴随着愈来愈多系外行星的发现,关于系外行星大气的观测和理论研究均在迅速发展.本文将回顾近几十年来系外行星和褐矮星探测的主要进展,依序介绍系外行星中的热木星、具有大气层的类地行星,以及孤立并快速旋转的褐矮星大气环流的基本特征,这些大气环流特征是未来系外行星探测的基础.然后,将介绍基于观测建立的大气模式对这些系外行星和褐矮星大气演化和动力学特征的模拟结果,包括大气的垂直温度分布、层结的稳定性、辐射传输、大气成分等.热木星受到强烈辐射且被潮汐锁定,环流模式预测其具有大的昼夜温差和赤道地区向东的急流.温木星通常不会被潮汐锁定,展现出广泛的自转率倾角和轨道偏心率,导致环流模式与热木星相比有很大不同.潮汐锁定的类地行星具有类似热木星的大气环流模式,但可能存在的海洋以及各种化学过程会深刻改变类地行星的气候,在这一部分本文还将讨论系外行星研究的最终目标——寻找宜居行星.褐矮星作为行星和恒星之间的过渡状态,通常是缺乏外部辐射并快速旋转的星体,内部具有剧烈的对流,大气表现出云层和温度的不均匀性.最后,我们将对系外行星和褐矮星大气这一前沿科学领域未来所面临的关键问题和挑战给出展望.
To date,more than 5000 exoplanets and more than 2000 brown dwarfs have been confirmed,which shows rich diversities in many aspects.With the rapid growth of the planet family,both observational and theoretical research on exoplanet atmosphere is developing rapidly.This paper aims to review the progress of exoplanet atmospheric circulation research,and these atmospheric circulation characteristics are the basis for exoplanet and brown dwarf exploration in the future.First,this paper will review the main progress on exoplanet and brown dwarf detection in recent decades,and introduce the basic characteristics of the atmospheric circulation of hot Jupiters,terrestrial planets with atmosphere,and isolated and rapidly rotating brown dwarfs.Then,the simulation results of the atmospheric evolution and dynamic characteristics of exoplanets based on the atmospheric observations will be introduced,including the vertical temperature distribution of the atmosphere,the stability of the stratification,the radiation transfer,and the atmospheric composition,etc.Hot Jupiters are strongly irradiated and tidally locked.The general circulation models of hot Jupiters predict large day-night temperature differences and equatorial eastward jets.Warm Jupiters are generally not tidally locked,exhibiting a wide range of inclinations,orbital eccentricities and rotation rates,resulting in very different circulation patterns compared with hot Jupiters.At mospheric circulation patterns of tidally locked terrestrial planets are similar to those of hot Jupiters,however,the existence of oceans and various chemical processes will largely change the climate of terrestrial planets.Besides,in the part of terrestrial planets,we will discuss the ultimate goal of exoplanet research—searching and characterizing habitable planets.As a transition state between planets and stars,brown dwarfs are rapidly rotating without external irradiation.Their interiors are fully convective,and their atmosphere exhibits clouds and temperature inhomogeneities.Finally,an
作者
连雨辰
胡永云
Lian Yuchen;Hu Yongyun(Department of Atmospheric and Oceanic Sciences,School of Physice,Peking University,Beijing 100871,China)
出处
《地球与行星物理论评（中英文）》
2023年第1期56-80,共25页
Reviews of Geophysics and Planetary Physics
基金
国家自然科学基金资助项目(41888101)。
关键词
系外行星
大气环流
宜居行星
热木星
褐矮星
exoplanets
atmospheric circulation
habitable planets
hot Jupiters
brown dwarfs
