Through long-term Rayleigh lidar observations during 2010-2022, atmospheric gravity wave (AGW) activities in the middle atmosphere (30–65 km) are statistically investigated at Haikou (110.3°E, 19.9°N) in China. In total, 827 quasi-monochromatic AGW events are identified from the lidar dataset, and the vertical wavelength, observed wave period, and vertical propagation direction of dominant waves are extracted for each AGW event by analyzing the power spectra of wave-induced temperature perturbations. It is revealed that 81.7% of all AGW events were associated with upward-propagating waves, and the proportion of upward-propagating AGWs reached a maximum in autumn and a minimum in winter. The most common vertical wavelengths and wave periods were 6–11 km and 4–10 hours, respectively. In particular, 68 AGW events associated with simultaneous upward and downward propagating waves were observed by lidar, corresponding to 8.2% of the events. The occurrence of such special AGW phenomena is qualitatively discussed, and multiple formation mechanisms may exist. Comparisons are made with previously reported lidar observation results, and the statistical features of AGW activity in the low-latitude middle atmosphere may vary over a relatively wide range depending on the location and altitude. However, a majority of AGWs propagate upward in the middle atmosphere.

The characteristics and formation mechanisms of lightning activity during the lifetime of Super Typhoon Doksuri (2023) were investigated using ERA5 reanalysis data and observation data from the World-Wide Lightning Location Network (WWLLN) and Himawari-8/9 satellite. The lightning activity exhibited pronounced intermittent outbreak behavior, and intense lightning flashes mainly occurred in the outer rainband region approximately 200–600 km from the typhoon center. The occurrence of intense lightning was mainly related to the development of deep convections which were characterized by a high CAPE index and low cloud-top brightness temperature. In the landfall stage, intense lightning outbreaks may have been further modulated by the orographic lifting from the underlying surface and island thermal effects. Strong updrafts within the typhoon provided favorable conditions for intracloud microphysical electrification processes. The formation of intense lightning was interpreted via the non-inductive charging mechanism and validated using E-WRF model simulations. During the first rapid-intensification episode, intense inner-core lightning preceded the typhoon intensity peak by 14–41 h; during the re-intensification episode, it occurred ~9 h after the typhoon peak. These insights into the intense lightning activity in Super Typhoon Doksuri (2023) contribute to improving typhoon forecasting and disaster warning in the Western Pacific.