雷暴激发的环状重力波在中高层大气中的传播特征

本文使用中国科学院国家空间科学中心——子午工程朔州观测站的全天空气辉成像数据，以及FY-2气象卫星云顶亮温数据（Black Body Temperature，TBB），气象再分析数据和地闪数据，研究了2013年8月10日（LT）发生在内蒙古地区的雷暴活动激发的中高层环状重力波（Concentric Gravity Waves，CGWs）事件.根据最小二乘法的拟合结果和色散关系理论曲线，确定了激发中高层环状重力波的强对流系统，该对流中心位于内蒙古自治区中部（108.9°E，40.47°N），重力波激发于雷暴初期，此时TBB低于220 K的深对流面积较小，随着时间的推移，该次雷暴活动越来越强，深对流面积在23：00达到最大，在23：30-24：00 LT时闪电频数最高，达到120.7 fl/min，随后深对流逐渐消散.在中高层87 km处OH（羟基）气辉层观测到的一次CGWs事件的两组波纹，分别沿水平方向传播了149.64 km和174.25 km，相应位置处的水平波长分别为12.67 km和16.75 km，周期分别为8.56 min和10.72 min，激发时间分别为19：34 LT和19：40 LT；随着水平传播距离的增加，CGWs水平波长增大.

Propagation characteristics of mesospheric concentric gravity waves excited by a thunderstorm

This work used the all-sky airglow data of the Shuozhou station from Meridian Space Weather Monitoring Project, National Space Science Center, Chinese Academy of Sciences, Black Body Temperature (TBB) data from FY-2 meteorological satellites, CG (cloud-ground) flash data, reanalysis data of NCEP (National Centers for Environmental Prediction) and ECWMF (European Centre for Medium-Range Weather Forecasts). We analyzed a concentric gravity waves (CGWs) event observed in the middle and upper atmosphere over North China on 10 August 2013 (local time), caused by a thunderstorm in the troposphere. The ray tracing simulation suggests that the concentric rings observed by all-sky airglow imager in 87 km were motivated by this convective system, of which the convective center was located in the middle of Inner Mongolia autonomous region (108.9°E,40.47°N). At the initial stage, the small area of deep convection with TBB below 220 K excited the CGWs. The stronger convection occurred along with the system development, and deep convection area reached its maximum at 23:00 LT. During 23:30 LT to 24:00 LT, the CG lightning flash frequency reached the maximum 120.7 fl/min, and then deep convection eventually disappeared. At the middle and upper atmosphere, the excitation source was 149.64 km and 174.25 km away from the CGWs ripples in 87 km by all-sky imager, and the horizontal wavelengths were 12.67 km and 16.75 km, periods of waves were 8.56 min and 10.72 min, and the excited times are 19:34 and 19:40 LT, respectively. With the increase of horizontal propagation distance, the horizontal wave length of CGWs increased.