基于新型往返式探空观测的下平流层重力波特征分析

Analysis of gravity wave characteristics in the lower stratosphere based on new round-trip radiosonde

中文关键词:  下平流层  重力波  往返式探空资料  下投探空

英文关键词:Lower stratosphere  Gravity wave  Round-trip sounding data  Drop sounding

中文摘要:

      利用2018年6月9日—7月10日安庆、长沙、赣州、南昌、宜昌、武汉6个探空站的往返式探空观测试验数据，研究分析了重力波参数（能量密度、固有频率、波长及传播方向），统计了试验地区6—7月的重力波特征，比较了各站之间以及上升与下降段之间重力波的差异。主要结果如下：（1）该区域重力波动能分布在0.2—1.2 J/m³，平均约为0.8 J/m³，势能分布在0.03—0.5 J/m³，平均约为0.2 J/m³。（2）垂直波长中90%样本分布在1—2.5 km，超过50%的样本分布在2—2.5 km，平均波长为1.8 km左右；水平波长分布范围40—1500 km，主要集中在200—800 km，平均600 km，重力波垂直波长与水平波长的比值很小，在平流层重力波以水平传播为主。（3）大部分站点的上升和下降段结果均存在比较明显的主要传播方向，但主要传播方向特征并不一致，以西北方向传播最多，其次是北向传播。这种往返式探空数据适用于下平流层重力波的观测与分析，下降段资料起到对重力波事件的加密观测作用。上升与下降段所获得的结果存在一定差异，但除水平传播方向外，其余参数差别较小，除能量外，其余参数在下降段结果偏大。

英文摘要:

      The observational data of the round-trip sounder collected at Anqing, Changsha, Ganzhou, Nanchang, Wuhan and Yichang stations during an observation experiment from 9 June to 10 July 2018 are used to extract the parameters of gravity wave, including the energy density, natural frequency, wavelength and propagation direction. By studying and analyzing the parameters of gravity wave at these stations, the gravity wave from June to July in the experimental area is counted. Characteristics and horizontal differences as well as the differences between the up and down sections are compared between various sites. The main results are as follows: (1) The gravitational wave energy in this region is generally distributed in the range of 0.2 to 1.2 J/m³, with an average value of about 0.8 J/m³, and the potential energy is generally distributed in the range of 0.03 to 0.5 J/m³, with an average value of about 0.2 J/m³. (2) For the vertical wavelength, 90% of the samples are within the range of 1 to 2.5 km, and more than 50% of the samples are within the range of 2 to 2.5 km. The average wavelength is about 1.8 km. The horizontal wavelength is mainly distributed in the range of 200 to 800 km, with an average of about 600 km. The ratio of vertical wavelength to horizontal wavelength of gravity wave is very small, and the gravity wave propagates horizontally in the stratosphere. (3) There are obvious main propagation directions in the ascending and descending sections of most stations, but the characteristics of the main propagation directions are not the same. The northwest ward propagation prevails, followed by the northward propagation. This new type of data are suitable for the observation and analysis of gravity wave in the lower stratosphere. The data in the descending section can play an important role in the intense observations of gravity wave events. There are some differences between the results obtained in the ascending section and the descending section, but the differences in other parameters are small except for the horizontal propagation direction, and the results in the descending section are generally large except for the energy.