This study identifies a poleward shift in the landfall locations of tropical cyclones (TCs) over China during 1970–2019, which can be attributed to TCs formation positions and steering flows related to western Pacific subtropical high (WPSH). The warming western Pacific warm pool (WPWP) may exert substantial influences on TCs landfall behaviors, leading to an intensified convection (conductive to TC genesis) over southeast of Philippines directly and a strengthened northward-shifting WPSH (inducing enhanced TC activity over the East China Sea) via modulating the local Hadley circulation. The results may be beneficial to disaster prevention and reduction for the offshore engineering.
The western North Pacific (WNP) is the region with the most frequent tropical cyclones (TCs) genesis on the globe. Approximately twenty-seven TCs form in this basin and more than seven TCs landfall over mainland China each year, causing great property damage to the offshore engineering (Guan et al., 2018). A good understanding of the TCs landfall behaviors may be helpful to improve the prediction of TCs activity and thus of great importance to the marine engineering. The most favorable positions for TCs formation have been closely associated with the change of the WNP monsoon trough and on average nearly 70% of TCs generation occurs within the monsoon trough circulation (Wu et al., 2012; Feng et al., 2014; Cao et al., 2016; Li et al., 2017). The movement of TC is determined by the shift and intensity of the 500-hPa western Pacific subtropical high (WPSH) due to the change in the steering flows (Saunders et al., 2000; Wu et al., 2004). Previous works have analyzed the interannual and interdecadal variations of TCs landfall behaviors (Chan, 2005; Huang et al., 2018). It has been widely documented that the landfall location of TC is significantly impacted by the TC genesis position and mid-tropospheric steering flows (Choi and Byun, 2010; Zhan et al., 2011; Zhou et al., 2019). Earlier studies have noted the northeastward movement of the landfalling locations of TCs over China, which is in very close relation to the interdecadal variations of the WPSH and monsoon trough (e.g. Wang et al., 2009). However, the underlying mechanism for the interaction between the tropical and extra-tropical large-scale circulation as well as the original cause for the landfall location shifting trends is still open to question until now.