Variations of landfalling tropical cyclones in China since the 1950s

Based on track data of tropical cyclones in the Northwest Pacific from 1951 to 2017, the characteristics of landfalling tropical cyclones（TCs） in China over the last 67 years, such as number, frequency, intensity, and landfalling location, were statistically analyzed using trend analysis, run-test analysis, and periodic analysis. The results showed that there were slight declines in the number and frequencies of landfalling TCs from 1951 to 2017, the dropping magnitude were 0.003 a–1 and 0.008 a–1 respectively, however, this decreasing trend was not significant in the test of M-K significance. In the future, the number of landfalling TCs is expected to slowly increase. The period in which landfalling TCs frequently occurred was from June to October, and this was especially observed in August. The lowest and mean central pressures showed an increasing trend in previous years, and the lowest central pressure passed the M-K significance test. The landfalling intensity of TCs generally showed a decreasing trend and they would continue to show a decreasing trend in the near future; however, high-intensity landfalling TCs showed a considerably increasing trend. The locations of landfalling TCs were mainly in Guangdong, Taiwan, Fujian, Hainan, and Zhejiang. The landfalling locations of TCs display a trend of eastward and northward shift, and this tendency will continue in the future. In this paper, the number and intensity of landfalling TCs in China from 1951 to 2017 were analyzed using direct track data of tropical cyclones. The purpose was to gain an in-depth understanding of the the characteristics and frequencies of tropical cyclones affecting China and to provide scientific references for the prediction, early warning, disaster prevention, and mitigation of TCs

Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

We present a measurement of the integrated luminosity e+e- of collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm = 3.773 GeV. The integrated luminosities of the datasets taken from December 2021 to June 2022, from November 2022 to June 2023, and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1, 8.157±0.031 fb-1, and 4.191±0.016 fb-1, respectively, by analyzing large angle Bhabha scattering events. The uncertainties are dominated by systematic effects, and the statistical uncertainties are negligible. Our results provide essential input for future analyses and precision measurements