Detecting the impact of climate change on tropical cyclones in Southern China

It is well known that tropical cyclones (TCs) making landfall in Southern China (SC) account for more than half of all TCs making landfall in China. Therefore, it is important to have an in-depth understanding of the activities of TCs in SC under climate warming. Our results show that there have been no significant changes in the frequency and duration of these TCs, but their intensities have unexpectedly decreased by ∼20% since 1980, which is inconsistent with the previous understanding that climate change increases TC intensity. The results consistently show a significant decrease in the different TC intensity percentiles, which is related to the intensity distribution that shows a significant decrease in the proportion of tropical storms and a significant increase in the proportion of tropical depressions, as well as a slight decrease in the proportion of category 1–2. Because of the locations of those TCs activity show a clear shoreward migration tendency, indicating that land friction can suppress TC intensification, so that TC intensity has weakened. In addition, results also suggest that TC development is strongly suppressed and is mainly related to the enhancement of atmospheric stability, vertical wind shear and subtropical high under global warming. These results are quite different from the previous understanding of the changes in TC intensity under global warming. Such knowledge can help us better understand the relationship between climate change and the impact of TC activity at the regional scale.