Day‐to‐Day Variability of Diurnal Tide in the Mesosphere and Lower Thermosphere Driven From Below
Day‐to‐Day Variability of Diurnal Tide in the Mesosphere and Lower Thermosphere Driven From Below
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DOI：
10.1029/2019ja027759
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发表时间：
2021-02
期刊：
影响因子：
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通讯作者：
Jack C. Wang;S. Palo;Han L. Liu;D. Siskind
中科院分区：
文献类型：
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作者：
Jack C. Wang;S. Palo;Han L. Liu;D. Siskind
迁移的潮流（DW1）是中层中的主要波动，它在中性气氛中起着至关重要的作用DW1的长期变化主要归因于源和背景气氛的可变性，在这里，短期DW1变异性的驱动机制仍在此处公开DW1的结构是使用新型的多卫星估计技术从观测中提取的，并与模型模拟（Nogaps-Alpha和WACCM-X）进行了比较。持久性和无处不在的功能结果表明，DW1的日常变异反映了全球尺度的变化，而不是局部振荡的局部兴奋。昼夜模式的日常变异可能是由较低大气中的变异性驱动的，（1,2）模式的日常变异源尚不确定Nogaps-Alpha与多卫星估计技术之间DW1日常变异性的相关性也表明该模型能够每天重现DW1结构。
The migrating diurnal tide (DW1) is one of the dominant wave motions in the mesosphere and lower thermosphere. It plays a crucial role in neutral atmosphere and ionosphere coupling. The DW1 can vary over a range of time scales from days to years. While the long‐term variability of the DW1 is mainly attributed to the source and background atmosphere variability, the driving mechanism of short‐term DW1 variability is still openly debated. Herein the daily structure of the DW1 is extracted from observations using a novel multi‐satellite estimation technique and compared with model simulations (NOGAPS‐ALPHA and WACCM‐X). Both the observations and the models show that the day‐to‐day variability of the DW1 is a persistent and ubiquitous feature. The standard deviation peak of DW1 amplitudes, which is used to measure the maximum variability, is generally aligned with the DW1 amplitude peak. This result indicates that the day‐to‐day variability of the DW1 reflects global‐scale changes rather than local excitation of diurnal oscillation. The spatial lag‐correlation analysis of the diurnal (1,1) and (1,2) Hough modes suggests that the day‐to‐day variability of the diurnal (1,1) Hough mode is likely driven by variability in the lower atmosphere and the source of day‐to‐day variability of the (1,2) mode is uncertain. The significant correlation of the DW1 day‐to‐day variability between the NOGAPS‐ALPHA and the multi‐satellite estimation techniques also indicates that the model is capable of reproducing the DW1 structure on a daily basis.