Comparison of Spatiotemporal Characteristics and Complementarity of ADTD and FY-4A Lightning Observation Data in the Beijing-Tianjin-Hebei Region

To clarify the spatiotemporal characteristics and complementarity of lightning observation data in the Beijing-Tianjin-Hebei region, this study used ADTD ground-based and FY-4A satellite lightning data from April to September 2020–2022 for comparative analysis, focusing on frequency, density, intensity and typical cases. The results show that the interannual and diurnal variations of lightning frequency from both datasets are consistent, with concentration in summer (June-August) and high activity from afternoon to evening, and the peak of lightning "events" is earlier than cloud-to-ground (CG) lightning. There are differences in monthly peaks, related to detection principles and capabilities for different lightning types. Spatially, both show a "south more and north less" pattern: FY-4A has a wider observation range and obvious advantages in cloud-to-cloud (CC) lightning-dominated areas, while ADTD clearly reflects the topographic correlation of CG lightning. The high-value areas of ADTD CG lightning are scattered in the eastern coastal plains, and those of FY-4A are in the northwest and northern topographic uplift areas, showing significant complementarity. For diurnal intensity variation, ADTD CG lightning intensity is uniform throughout the day, while FY-4A optical radiation intensity peaks at 11:00–13:00. In terms of precipitation correlation, lightning frequency of both datasets increases near precipitation peaks: ADTD CG lightning concentrates 0–30 minutes before the peak, while FY-4A total lightning activity is earlier, verifying the classic convective electrical activity model. There are obvious differences in the timing of intensity peaks, reflecting the phased response of optical detection. This study clarifies the characteristics and complementary value of the two datasets, providing support for regional severe convection monitoring and early warning.