Evidence for Gravity Waves in the Thermosphere of Saturn and Implications for Global Circulation

Gravity wave data corresponding to the article, "Evidence for Gravity Waves in the Thermosphere of Saturn and Implications for Global Circulation," Brown et al. (2022). Temperature profiles were derived from Cassini Grand Finale stellar occultation measurements originally reported in "A Pole-to-Pole Pressure-Temperature Map of Saturn's Thermosphere from Cassini Grand Finale Data" from Brown et al. (2020).
Because gravity waves are disturbances superimposed on the mean flow/state, the vertical temperature profiles T(z) have been separated into the mean temperature and wave-induced perturbations, T′=T−, where denotes averaging over temporal and spatial scales much larger than wave phases. The difference between the local and mean temperature (T') gives wave amplitudes, from which energy, momentum fluxes and forcing imposed on the mean flow can be derived. See Brown et al. (2022) for details, including observation latitudes (Supporting Information Table S1).

本数据集对应论文为《Evidence for Gravity Waves in the Thermosphere of Saturn and Implications for Global Circulation》（《土星热层中的重力波（gravity wave）证据及其对全球环流的启示》），作者为Brown等人（2022年）。其温度廓线（temperature profiles）由卡西尼号（Cassini）终场恒星掩星（stellar occultation）测量数据反演得到，该测量数据最初由Brown等人2020年发表的论文《A Pole-to-Pole Pressure-Temperature Map of Saturn's Thermosphere from Cassini Grand Finale Data》（《基于卡西尼号终场任务数据绘制土星热层极间气压-温度分布图》）发布。
由于重力波是叠加于平均流场与平均态之上的扰动，研究团队将垂直温度廓线T(z)分解为平均温度分量与重力波诱发的扰动温度分量，即T′=T−⟨T⟩，其中⟨T⟩代表对远大于重力波相位的时空尺度进行平均。局地温度与平均温度的差值（T'）即为波幅，据此可推导出施加于平均流场的能量通量、动量通量与强迫项。相关细节包括观测纬度范围详见Brown等人2022年的论文（参见辅助信息表S1，Supporting Information Table S1）。