安第斯山上空平流层山地波统计特征的AIRS观测研究

利用AIRS红外探测仪在2013—2018年的辐射测量数据，对安第斯山20km，27km，35km及41km高度的山地波进行个例研究和统计分析.观测结果表明安第斯山上空山地波主要发生在5—10月，月平均水平波长、垂直波长及动量通量均没有明显的年际变化.水平波长在5月和10月相比6—9月较小，垂直波长和动量通量5—7月逐渐升高，达到峰值后在8—10月逐渐下降.在20～41km范围内，水平波长从43.5～53.9km缓慢升高至89.3～176.8km，垂直波长从7.4～14.7km上升至7.4～29.7km，动量通量由376.0～801.3mPa显著下降至10.4～239.3mPa.总体而言，山地波在向上传播的过程中，水平波长缓慢增加，在逆风传播的情况下，受到背景风场影响垂直波长随高度升高而增大.动量通量随高度升高显著下降，说明安第斯山山地波向上传播的同时伴有强烈耗散，耗散的能量将储存在背景大气中，对高平流层甚至中间层产生重要影响.

Statistical Characteristics of Stratospheric Mountain Waves over Southern Andes Based on AIRS Observations

Using the radiation measurement data of the Atmospheric Infrared Sounder (AIRS) on the Aqua satellite from 2013 to 2018, case studies and statistical analysis of mountain waves at 20 km, 27 km, 35 km, and 41 km in the Andes are carried out. Observation results show that the mountain waves over the Andes from 2013 to 2018 mainly occur from May to October, and the monthly average horizontal wavelength, vertical wavelength, and momentum flux have no obvious interannual changes.The horizontal wavelength decreases slightly in May and October compared to June to September. The vertical wavelength gradually increases from May to June and reaches its peak in July. Then it decreases from August to October. The momentum flux shows a similar seasonal changes pattern as the vertical wavelength. In the range of 20 km to 41 km, the horizontal wavelength slowly increases from 43.5~53.9km to 89.3~176.8km. Affected by the background wind field, the vertical wavelength increases with height, from 7.4~14.7 km at 20 km to 7.4~29.7km at 41 km. The momentum flux ranges from 376.0~801.3mPa at 20 km and drops to 10.4~239.3mPa at 41 km. In general, the horizontal wavelength of the mountain waves increases slowly with height as it propagates upward, and the vertical wavelength increases with height under the influence of the background wind field in the case of upstream propagation. The momentum flux decreases significantly with height, indicating that the Andes mountain waves propagate upward while accompanied by strong dissipation. The dissipated energy will be stored in the background atmosphere, which will have an important impact on the upper stratosphere and even the mesosphere.