Global Structure and Seasonal Variations of the Tidal Amplitude in Sporadic‐E Layer
Global Structure and Seasonal Variations of the Tidal Amplitude in Sporadic‐E Layer
复制标题
零星E层潮汐振幅的全球结构和季节变化
DOI：
10.1029/2022ja030711
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Feng Xueshang
中科院分区：
文献类型：
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作者：
Tang Qiong;Zhou Chen;Liu Huixin;Du Zhitao;Liu Yi;Zhao Jiaqi;Yu Zhibin;Zhao Zhengyu;Feng Xueshang
气象、电离层和气候射电掩星星座观测系统 S4 指数测量用于研究零星 E (Es) 层潮汐成分的全球结构和季节变化。 Es层的日潮汐幅度强度和发生率呈现波-4纵向结构，这是由于纬向波数s=−3（向东，DE3）的日潮分量所致。在春季和冬季的半日潮中也可以观察到第 4 波纵向模式，这主要是由纬向波数 s=−2（东向，SE2）、s=2（西向，SW2）的半日分量组合而成。此外，Es层半日潮汐振幅呈现明显的季节变化，春夏季以北半球为主，秋冬季以南半球为主。此外，北半球Es层的半日潮汐总振幅大于南半球。另一个重要发现是，低海拔（102公里以下）Es层的日潮汐模式与高海拔（102公里以上）Es层的日潮汐模式不同，也与风的不同，这支持了许多研究人员提出的风切变理论不适用于低空Es层的形成。
The Constellation Observing System for Meteorology, Ionosphere, and Climate radio occultation S4 indices measurements are used to investigate the global structure and seasonal variations of tidal components in the sporadic‐E (Es) layer. The diurnal tidal amplitude in the Es layer intensity and occurrence rate shows a wave‐4 longitudinal structure, which is due to the diurnal tidal components of zonal wave numberss= −3 (eastward, DE3). The wave‐4 longitudinal pattern is also observed in the semidiurnal tide during spring and winter, which mostly results from the combination of semidiurnal components of zonal wave numberss= −2 (eastward, SE2),s= 2 (westward, SW2). In addition, the semidiurnal tidal amplitude in Es layers presents obvious seasonal variability, and it dominates in the northern hemisphere during spring and summer and in the southern hemisphere during autumn and winter. Furthermore, the total semidiurnal tidal amplitude in Es layers in the northern hemisphere is greater than that in the southern hemisphere. Another important finding is that the diurnal tidal pattern at the lower altitude (below 102 km) Es layer is different from that of the higher altitude (above 102 km) Es layer and is also different from that of wind, which supports that the wind shear theory is inapplicable for the Es layer formation at low altitude proposed by many researchers.