AI 中文总结
该研究提出受物理驱动的多维大气参数化方法，结合日食归一化与三维温度参数化，应用于WASP-121b的JWST观测，揭示其热结构、化学状态等特征，为从光谱相位曲线推导多维大气结构提供高效路径。
AI 中文摘要
理解强辐射系外行星的多维结构对于解释其大气动力学、化学和能量传输至关重要，但当前分析仍受限于难以提取可靠的相位分辨光谱，以及缺乏可用于反演的物理解释性参数化方法。我们将数据驱动的日食归一化方法与基于辐射、平流和扩散能量平衡推导的分析型三维温度参数化相结合，该参数化由少数特征时间尺度控制。将其应用于WASP-121b的JWST/NIRSpec G395H观测数据，该方法得到的光谱与传统相位曲线拟合结果一致，同时参数化方法再现了通用环流模型（GCM）预测的大尺度热结构。最优反演结果显示存在显著的昼夜温差、延伸至两侧的昼侧热反转、夜侧部分区域的反转，以及两侧温度相差数百开尔文；动力学输运随压力增强，且在G395H探测的压力范围内，热点偏移从约4°增大至约9°；受限的昼侧热区和小的压力相关偏移更接近约3 G GCM的结果，而非其非磁对应模型，尽管无法排除瑞利拖曳的影响。光谱还支持昼侧与夜侧存在不同化学状态，夜侧CH₄含量仅用温度降低无法完全解释，表明存在非平衡化学；反演得到的热结构进一步暗示云分布不均匀，夜侧和较凉的晨侧更易发生凝结。该框架提供了一条计算高效、物理解释性强的路径，可从光谱相位曲线推导出多维大气结构。
英文摘要
Understanding the multidimensional structure of strongly irradiated exoplanets is essential for interpreting their atmospheric dynamics, chemistry and energy transport, yet current analyses remain limited by the difficulty of extracting reliable phase-resolved spectra and by the lack of physically interpretable parameterisations for retrievals. We combine a data-driven eclipse-normalisation method with an analytical three-dimensional temperature parameterisation derived from radiative, advective and diffusive energy balance and controlled by a few characteristic timescales. Applied to JWST/NIRSpec G395H observations of WASP-121b, the method yields spectra consistent with conventional phase-curve fitting, while the parameterisation reproduces the large-scale thermal structures predicted by general circulation models. The preferred retrieval reveals a pronounced day--night contrast, a dayside thermal inversion extending to both limbs, an inversion over part of the nightside, and limb temperatures differing by several hundred kelvin. Dynamical transport strengthens with pressure, and the hotspot offset increases from $\sim4^\circ$ to $\sim9^\circ$ across the pressures probed by G395H. The confined dayside hot region and the small, pressure-dependent offsets lie closer to the $\sim$3~G GCM than to its non-magnetic counterpart, although Rayleigh drag cannot be excluded. The spectra also favour distinct dayside and nightside chemical states, with more nightside CH$_4$ than the cooler temperatures alone can explain, pointing to disequilibrium chemistry. The retrieved thermal structure further implies an inhomogeneous cloud distribution, with condensation favoured on the nightside and cooler morning limb. The framework provides a computationally efficient, physically interpretable path from spectroscopic phase curves to multidimensional atmospheric structure.
Comments31 pages, 20 figures, resubmitted to ApJ after initial referee report
