We relate the spatial and temporal distribution of lightning flash rates and cloud top brightness temperature (CTBT) to concentric atmospheric gravity wave (CGW) events observed at the Southern Space Observatory (SSO) in São Martinho da Serra (29.44°S, 53.82°W, 488.7 m) in southern Brazil. The selected identified cases from 2017 to 2018 were observed by a hydroxyl (OH) all-sky imager. Backward ray tracing shows that the time of gravity wave excitation agrees with the highest values of lightning flash rates (indicating lightning jump) as well as the coldest brightness temperatures that indicate the time of convective overshoot. Radiosonde measurements show high convective available potential energy (CAPE), associated with a maximum updraft velocity just prior to the wave events. We find that these possible source locations correspond to the positions and times that convective plumes overshot the tropopause (seen in GOES-16 CTBT images). We also show that higher spatial lightning density (i.e., number of lightning flashes at a given longitude and latitude) agree with the overshoot locations from the GOES satellite. We also find that the overshoot times from the GOES-16 satellite agree with the times lightning jumps were observed in the lightning flash rate. Finally, we find that the periodicities in the lightning flash rate agree with the periods of the observed CGWs, which further strengthens the result that the CGWs were excited by the deep convective systems determined from backward ray tracing.

中文翻译：

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在圣马丁尼奥·达·塞拉（29.44°S，53.82°W）使用雷电闪速，亮度温度和向后光线追踪的同心重力波源案例研究

我们将雷闪率和云顶亮度温度（CTBT）的时空分布与在圣马丁尼奥·达塞拉（29.44°S，53.82°W ，巴西南部488.7 m）。通过羟基（OH）全天候成像仪观察了2017年至2018年选定的确定病例。向后的射线追踪显示，重力波激发的时间与最高的闪电闪烁速率（指示闪电跳跃）值以及表示对流超调时间的最冷亮度温度一致。探空仪的测量结果显示出高对流可用势能（CAPE），与波事件之前的最大上升气流速度有关。我们发现这些可能的源位置对应于对流羽流超过对流层顶的位置和时间（见GOES-16 CTBT图像）。我们还表明，较高的空间雷电密度（即给定经度和纬度处的闪电数量）与GOES卫星的超调位置一致。我们还发现，GOES-16卫星的超调时间与闪电闪速中观察到的闪电跳跃时间一致。最后，我们发现雷击频率的周期与观测到的CGW的周期一致，这进一步增强了CGW被后向射线追踪确定的深对流系统激发的结果。我们还表明，较高的空间雷电密度（即给定经度和纬度处的闪电数量）与GOES卫星的超调位置一致。我们还发现，GOES-16卫星的超调时间与闪电闪速中观察到的闪电跳跃时间一致。最后，我们发现闪电的闪烁周期与观测到的CGW的周期一致，这进一步增强了CGW被后向射线追踪确定的深对流系统激发的结果。我们还表明，较高的空间雷电密度（即给定经度和纬度处的闪电数量）与GOES卫星的超调位置一致。我们还发现，GOES-16卫星的超调时间与闪电闪速中观察到的闪电跳跃时间一致。最后，我们发现雷击频率的周期与观测到的CGW的周期一致，这进一步增强了CGW被后向射线追踪确定的深对流系统激发的结果。