武汉上空潮汐波活动的全天时钠激光雷达研究

Investigation of tidal wave activities over Wuhan by daytime sodium lidar

通过武汉物理与数学所的白天钠激光雷达,对武汉(30°30′N,114°E)上空的钠层昼夜变化特性及潮汐波活动进行了观测。在一次持续时间超过两天的观测中,钠层表现出了很强的日周期变化特性,钠层的柱密度、层宽度、质心高度都呈现出24 h的变化周期。各个高度上的钠层密度变化也呈现出清晰的24 h下行波的相位传播现象。这些结果都可以归因于一个显著的日潮汐波扰动。从观测数据中提取出来的潮汐相位与GSWM00模式符合得很好。在其它的三个短时间白天观测中我们也观察到了显著的钠层日周期变化,而平均钠层日变化呈现出了显著的日潮汐波传播结构。这个结果与已有的报道很符合,即日潮汐波是武汉上空主要的潮汐波。

The first daytime sodium lidar observations in China were made in Wuhan （30°30N′,114°E）. In a long observation cycle lasting more than two days, the sodium layer presented strong .diurnal variations. The sodium column density, layer width and centroid height, all presented 24 h periodic variations. The density variation at each height also presents a clear 24 h downward wave phase propagation. All these can be attributed to a prominent diurnal tidal wave perturbation, and the derived phase agrees very well with that obtained from the GSWM00 model. A large sodium diurnal variation was also presented in three other shorter daytime observations, while the mean diurnal variations of ＇the sodium layer present a prominent structure of diurnal tidal wave propagation. These results agree with early reports, namely, that the diurnal tide component is the dominant tide wave over Wuhan.