Abnormal Phase Structure of Thermal Tides During Major Dust Storms on Mars: Implications for the Excitation Source of High-altitude Water Ice Clouds
Abnormal Phase Structure of Thermal Tides During Major Dust Storms on Mars: Implications for the Excitation Source of High-altitude Water Ice Clouds
复制标题
火星重大沙尘暴期间热潮汐的反常相结构：对高空水冰云激发源的启示
DOI：
10.1029/2020je006758
复制
发表时间：
2021
影响因子：
3.9
通讯作者：
Cui Jun
中科院分区：
文献类型：
--
作者：
Wu Zhaopeng;Li Tao;Li Jing;Zhang Xi;Yang Chengyun;Cui Jun
热潮汐、气载尘埃和水冰云之间的相互作用对火星大气层产生了重大影响。由于火星上没有平流层，因此比地球上更容易从观测数据中识别热潮汐，使火星成为研究潮汐激发和传播过程的天然实验室。然而，全球潮汐相位结构及其对火星潮汐激发源的响应还没有从观测中得到研究。在这里，我们提出了一个综合分析的相位结构的迁移日潮（DW1）使用多本地时间观测火星气候探测器。低至中纬度的DW1相位显示出向下的相位进展，这表明全年的潮汐能和动量传播都是向上的，但具有明显的半球不对称性。整个DW1相位结构随着南部中纬度地区的尘埃高度而上升和福尔斯下降，这表明激发源高度上的垂直尘埃范围的调制。在主要的区域性沙尘暴期间，DW1相在南半球从10到1 Pa向上传播。Hough分析表明，尘埃层中的DW1只能向上传播到10 Pa，而10 Pa以上的向下传播模式可能是由高空源激发的。有证据表明，增强的高海拔水冰云可能是这些向下传播的潮汐模式的潜在激发源。这些发现证明了热潮汐如何在局部表现得像惯性重力波，以及水冰云对火星大气动力学的重要性。
Interactions among the thermal tide, airborne dust, and water ice clouds significantly influence the Martian atmosphere. The absence of a stratosphere on Mars allows easier identification of the thermal tides from observational data than that on Earth, making Mars a natural laboratory to study the tidal excitation and propagation processes. However, the global tidal phase structure and its response to the tidal excitation sources on Mars have not been studied from observations. Here, we present a comprehensive analysis of the phase structure of migrating diurnal tide (DW1) using multi‐local‐time observations of the Mars Climate Sounder. The DW1 phase at low‐to‐mid latitudes shows a downward phase progression, which indicates upward tidal energy and momentum propagation throughout the year but with an apparent hemispheric asymmetry. The entire DW1 phase structure rises and falls with the dust height at the southern mid‐latitudes suggesting a modulation of vertical dust extent on the altitude of the excitation source. During major regional dust storms, the DW1 phase propagates anomalously upward from 10 to 1 Pa in the Southern hemisphere. The Hough analysis suggests that the DW1 in the dust layer can only propagate upward to 10 Pa while the downward propagating mode above 10 Pa may be excited from a high‐altitude source. Evidence suggests that the enhanced high‐altitude water ice clouds could be a potential excitation source for these downward propagating tidal modes. These findings demonstrate how thermal tides can locally behave like inertia‐gravity waves and the importance of water ice clouds to Martian atmospheric dynamics.