论文标题

使用非灰色通用循环模型探索HD 209458B和WASP-43B的深层气氛

Exploring the deep atmospheres of HD 209458b and WASP-43b using a non-gray general circulation model

论文作者

Schneider, Aaron David, Carone, Ludmila, Decin, Leen, Jørgensen, Uffe Gråe, Mollière, Paul, Baeyens, Robin, Kiefer, Sven, Helling, Christiane

论文摘要

具有3D通用循环模型(GCM)的模拟表明,在热木星中观察到的半径膨胀背后的一个潜在驱动器可能是从高度辐照的光球到更深层的能量向下对流。在这里,我们比较了非膨胀的热木星黄蜂43B和规范膨胀的热木星HD 209458B中的动力传输,具有相似的有效温度。我们研究了光球中辐射驱动的加热和冷却的程度(在小于1 bar的压力下)会影响更深的温度曲线(在1至700 bar之间的压力下)。我们对新的非灰3D辐射流动力学模型专家/MITGCM的模拟表明,黄蜂43B的深度温度曲线与相对冷的绝热有关。然而,HD 209458B的深层不会收敛,并且无论使用冷或炎热的初始状态如何,并且几乎保持不变。此外,我们表明深大气层中的不同流量结构发生。在那里,我们发现与HD 209458B(3.47天)相比,WASP-43B表现出深赤道射流,这是由该行星(0.81天)的相对快速潮汐锁定旋转驱动的。但是,通过比较不同旋转周期的模拟,我们发现所产生的流量结构仅略微影响深度大气中的温度演化,这几乎完全由辐射加热和冷却所控制。此外,我们发现较深层的演变会影响WASP-43B光球中的3D温度结构。因此,WASP-43B的日期发射光谱可能会在更大的深度发生的动力学过程中散发出更多的光线。

Simulations with a 3D general circulation model (GCM) suggest that one potential driver behind the observed radius inflation in hot Jupiters may be the downward advection of energy from the highly irradiated photosphere into the deeper layers. Here, we compare dynamical heat transport within the non-inflated hot Jupiter WASP-43b and the canonical inflated hot Jupiter HD 209458b, with similar effective temperatures. We investigate to what extent the radiatively driven heating and cooling in the photosphere (at pressures smaller than 1 bar) influence the deeper temperature profile (at pressures between 1 to 700 bar). Our simulations with the new non-gray 3D radiation-hydrodynamical model expeRT/MITgcm show that the deep temperature profile of WASP-43b is associated with a relatively cold adiabat. The deep layers of HD 209458b, however, do not converge and remain nearly unchanged regardless of whether a cold or a hot initial state is used. Furthermore, we show that different flow structures in the deep atmospheric layers arise. There, we find that WASP-43b exhibits a deep equatorial jet, driven by the relatively fast tidally locked rotation of this planet (0.81 days), as compared to HD 209458b (3.47 days). However, by comparing simulations with different rotation periods, we find that the resulting flow structures only marginally influence the temperature evolution in the deep atmosphere, which is almost completely dominated by radiative heating and cooling. Furthermore, we find that the evolution of deeper layers can influence the 3D temperature structure in the photosphere of WASP-43b. Thus, dayside emission spectra of WASP-43b may shed more light onto the dynamical processes occurring at greater depths.

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