Base on observations of three-dimensional lightning location network, dual polarization weather radars, ground automatic stations and wind profile radars as well as FY-4A satellite TBB data, typhoon data, and ERA5 reanalysis data, convective precipitation features and characteristics of lightning activities within the rainbands of typhoon Duksuri that occurred in 2023 are analyzed. The relationship between lightning activities and microphysical characteristics of thunderstorm clouds with different organizational structures in the Mesoscale Convective System (MCS) within the outer rainband are analyzed in detail by using statistical and diagnostic methods. The results show that during Duksuri's landfall, both typhoon eyewall and the inner and outer rainbands produced convective precipitation with high efficiency. The convective precipitation in the outer rainband was more significant in terms of intensity, impact range and duration compared to that in the eyewall and inner rainband. Lightning activities had a lower frequency in the eyewall and inner rainband and the highest frequency was found in the outer rainband. Lightnings were mainly distributed in the MCS in the outer rainband, with negative cloud-to-ground flash being the main type. During the mature stage of MCS in the outer rainband, there were thunderstorm clouds with different convective structures, which produced significant differences in lightning frequency. Lightning frequency was lower in the coastal areas of northeastern Fujian, while it was much higher in the coastal areas of central Fujian. Based on vertical structure inversion results of dual polarization weather radar and multiple parameters, it is found that the strong thunderstorm clouds in the heavy rainfall-inactive lightning area had a low convective center of the main echo, which was composed of high-concentration liquid raindrops. Therefore, the heavy rainfall was caused by a strong warm rain process. In contrast, the main convective center of the strong echo in the heavy rainfall-active lightning area was higher, and the content and size of ice-phase particles on the melting layer were also higher. Below 0℃ layer, there were active high raindrops and ice phase particles, which led to the occurrence of intense lightning activity. Below 0℃ layer, there was deep and strong updraft in the mixed phase zone in the heavy rainfall-active lightning area, while the heavy rainfall-inactive lightning area was dominated by liquid phase particles, and the strong updraft layer was shallow. The above results provide a reference basis for the characteristics of lightning activities in the rain bands outside typhoons and their relationship with the microphysical structure of heavy rainfall.

Using lightning data from the Lightning Imaging Sensor onboard the Tropical Rainfall Measurement Mission satellite, together with cloud and precipitation property data extracted from the Radar Precipitation Feature dataset, this study investigated the statistical characteristics of thunderstorm structure and lightning properties over land (South China) and the South China Sea (SCS) during 1998–2014. The objective was to compare thunderstorm structural differences and explore the impact of thunderstorm structure on lightning properties between land and transitional water areas to the deep ocean. The results indicate that the lightning activity in South China is notably more intense than that over the SCS, with the average frequency and density of lightning in South China approximately doubling the values of those over the SCS. Although the mean flash duration is similar in both regions, lightning over the SCS exhibits larger average values for flash length, footprint, and radiance. Additionally, the horizontal scale and the verti-cal extension of thunderstorms over the SCS are substantially larger than those in South China, i.e., the thunderstorm precipitation area and the 20-dBZ area over the SCS are twice the size of those in South China, and the average 20-dBZ echo top height is 1.25 km higher over the SCS. Nevertheless, thunderstorms in South China develop more intensely, with elevated heights of the intense convective core (40-dBZ echo) compared with those thunderstorms over the SCS. The mean values of the 37-GHz minimum polarization-corrected temperature (PCT) are comparable between the two regions, but the mean value of the 85-GHz PCT is lower over the SCS, suggesting a higher concentration of small ice particles in SCS thunderstorms. Finally, a conceptual diagram that highlights the differences in thunderstorm structure and lightning flash properties between South China and the SCS is proposed. Compared with previous studies, this study has elucidated the distinct characteristics of oceanic lightning over the SCS, and highlighted the gradual transition of thunderstorm scale and lightning properties from land, to the SCS, and finally to the deep ocean area of the Northwest Pacific Ocean.