THREE-DIMENSIONAL STRUCTURES OF EQUATORIAL WAVES AND THE RESULTING SUPER-ROTATION IN THE ATMOSPHERE OF A TIDALLY LOCKED HOT JUPITER
THREE-DIMENSIONAL STRUCTURES OF EQUATORIAL WAVES AND THE RESULTING SUPER-ROTATION IN THE ATMOSPHERE OF A TIDALLY LOCKED HOT JUPITER
复制标题
赤道波的三维结构以及由此产生的潮汐锁定热木星大气层中的超级自转
DOI：
10.1088/0004-637x/793/2/141
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
P. Gu
中科院分区：
文献类型：
--
作者：
Shang;I. Dobbs;P. Gu
研究了在潮汐锁定热木星垂直层结大气中由恒星隔离激发的三维赤道陷波以及由此产生的赤道超旋喷流。以热木星HD189733b为例，我们解析地求解了考虑均匀纬向平均流的定常恒星加热的线性方程组。我们还从我们对HD189733b的辐射流体力学模拟中提取了大气最终平衡态的波动信息。我们的解析波解能够定性地解释三维模拟结果。除了前人对波的研究外，研究波的垂直结构使我们能够探索新的波特征，如与Rossby波共振有关的波前倾斜以及赤道波的频散。我们还尝试用我们的线性波分析来解释Showman和Polvani在大气环流模式中看到的与赤道急流发展有关的一些数值特征。在赤道急流的自旋上升阶段，喷流的加速度原则上可以由Rossby波共振来增强。然而，我们也发现，随着喷流速度的增加，Rossby波结构向东移动，而Kelvin波结构保持不变，导致加速速率下降。我们的喷流演化解析模型表明，大气只存在一个稳定的平衡态，这可能意味着在线性区域内大气的终态与初始条件无关。文中还讨论了我们的线性模型的局限性和未来的改进。
Three-dimensional (3D) equatorial trapped waves excited by stellar isolation and the resulting equatorial super-rotating jet in a vertical stratified atmosphere of a tidally locked hot Jupiter are investigated. Taking the hot Jupiter HD 189733b as a fiducial example, we analytically solve linear equations subject to stationary stellar heating with a uniform zonal-mean flow included. We also extract wave information in the final equilibrium state of the atmosphere from our radiative hydrodynamical simulation for HD 189733b. Our analytic wave solutions are able to qualitatively explain the 3D simulation results. Apart from previous wave studies, investigating the vertical structure of waves allows us to explore new wave features such as the wavefronts tilts related to the Rossby-wave resonance as well as dispersive equatorial waves. We also attempt to apply our linear wave analysis to explain some numerical features associated with the equatorial jet development seen in the general circulation model by Showman and Polvani. During the spin-up phase of the equatorial jet, the acceleration of the jet can be in principle boosted by the Rossby-wave resonance. However, we also find that as the jet speed increases, the Rossby-wave structure shifts eastward, while the Kelvin-wave structure remains approximately stationary, leading to the decline of the acceleration rate. Our analytic model of jet evolution implies that there exists only one stable equilibrium state of the atmosphere, possibly implying that the final state of the atmosphere is independent of initial conditions in the linear regime. Limitations of our linear model and future improvements are also discussed.
初始气流对近地行星大气环流的影响
DOI：
10.1088/0004-637x/716/1/144
发表时间：
2010
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Thrastarson H
通讯作者：
Thrastarson H