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.

Thunderstorms are severe convective weather systems generating lightning, which can lead to various catastrophic weather when a large amount of lightning is produced. In the past decade, high spatiotemporal resolution lightning detection technology has been developed, which has laid a solid foundation for investigating the propagation and development mechanism of lightning as well as associated physical effects. Based on the Doppler dual polarization weather radar and high-resolution numerical models, thunderstorm dynamics, microphysics, electrical processes, and their interactions have been well investigated, and some new insights into the thunderstorm charge distribution and its relation to the thunderstorm structure have been obtained. All these have promoted the lightning forecasting and lightning data assimilation. This paper reviews the recent research progress in detection, mechanism, and forecasting of thunderstorms and lightning in China in the last decade from four aspects: 1) high-resolution three-dimensional (3D) lightning mapping technology and application, 2) lightning in different thunderstorms and its relationship with cloud dynamics and microphysics, 3) observation and simulation of lightning charge structure in thunderstorms, and 4) lightning prediction and lightning data assimilation for thunderstorm forecasting. Major challenges and the cutting-edge research directions in lightning and thunderstorms studies are also highlighted.

A comparative analysis of the spatiotemporal distribution characteristics of rainfall and lightning in coastal and inland areas of Guangdong Province of China during the pre-summer rainy season (PSRS) from 2008 to 2017 reveals distinct patterns. In the inland target region (ITR), rainfall is concentrated in the central and eastern mountainous areas. It exhibits a bimodal diurnal variation, with peaks in the afternoon and morning. The afternoon peak becomes more pronounced during the post-monsoon-onset period because of the increased rainfall frequency. Similarly, in the coastal target region (CTR), rainfall concentrates around mountainous peripheries. However, CTR’s rainfall is weaker than ITR’s during the pre-monsoon-onset period, primarily associated with the lower-level moisture outflow in CTR, but it strengthens significantly during the post-monsoon-onset period owing to enhanced moisture inflow. CTR’s diurnal rainfall variation transitions from bimodal to a single broad peak during the post-monsoon-onset period, influenced by changes in both rainfall frequency and intensity. In contrast to rainfall, the spatiotemporal distribution of lightning centers remains relatively stable during the PSRS. The strongest center is located over ITR’s plains west of the rainfall center, with a secondary center in the western plains of CTR. Lightning activity significantly increases during the post-monsoon-onset period, particularly in ITR, primarily because of the increased lightning hours. The diurnal lightning flash density and lightning hours show a single afternoon peak in the two target regions, and the timing of the peak in ITR is approximately two hours later than in CTR. Composite circulation analysis indicates that during early morning, the lower atmosphere is nearly neutral in stratification. The advected warm, moist, unstable airflow, combined with topography, favors convection initiation. In the afternoon, solar radiation increases thermal instability, further enhancing the convection frequency and intensity. Improved moisture and thermal conditions contribute to an increase in rainfall and lightning during the post-monsoon-onset period. Moreover, the occurrence of lightning is found to be closely linked to the most unstable convective available potential energy, low-level vertical wind shear, and updraft intensity.