Analysis of the decay trend of tropical cyclones landing in China's mainland
In the context of global warming,it is controversial whether the decay of landfalling tropical cyclone(TC)slows down,and it is unclear whether the trend of decay of landfalling TCs with different landing intensity is consistent.In this paper,two physical quantities describing landfall TC decay,decay time scale r and decay duration D,are used to study the trend of landfall TC decay for TCs landing in China's mainland from 1980 to 2021,and the influence of different landing intensity on the trend is discussed.For all the TCs landing in China's mainland,the trend over time for r or D has no significant change.In this paper,the landfalling TCs are further divided into groups of tropical storm(TS),severe tropical storm(STS)and typhoon(TY)according to their landing intensities.It is found that the landing sites and post-landing paths of the different TC groups show different characteristics,resulting in different decay trends.From TS group to STS group and then to TY group,the trend of r over time changes continuously from increasing to decreasing to obviously decreasing,while the trend of D changes from increasing to decreasing to increasing,and does not change continuously,indicating that the decay trend is inconsistent for TCs with different landing intensity.From the significance point of view,only the trend of r of TY group meets the significant decline trend of 90%confidence interval,indicating that the decay trend is uncertain for TCs with different landing intensity.
tropical cyclonedecay trendlanding intensitydecay time scaledecay duration