Inter-decadal variability of the location of maximum intensity of category 4–5 typhoons and its implication on landfall intensity in East Asia

This study investigates the variations of the location of the lifetime-maximum intensity (LMI) of the tropical cyclones (TCs) over the western North Pacific and the possible implications on the TC landfall intensity in different regions of East Asia. While the annual mean LMI latitude of TCs with at least tropical storm intensity shows a significant upwards trend during 1960–2016, that for intense typhoons (category 4–5) has no trend but a significant inter-decadal variation, with distinct periods of higher latitude (1960–1969 and 1991–2011) and lower latitude (1970–1990, 2012–2016). A comparison of the spatial patterns of LMI during the periods 1970–1990 and 1991–2011 shows that the LMI location migrates from the southern to the northern part of East Asia from the first to the second period. This shift results from a higher percentage of recurving and north oriented TCs, a northwards shift of genesis locations and an increase in latitudinal distance between genesis position and LMI location in the second period. The frequency of intense typhoon landfalls and the average landfall intensities of the landfalling TCs therefore increase in Japan, the Korean Peninsula and east China but decrease in southern China. The higher frequency and average landfall intensity lead to higher annual maximum landfall intensity, which is more significant for Japan and the Korean Peninsula. However, the effect on landfall intensity in the southern part of East Asia is not obvious, with only a significant decrease in annual maximum landfall intensities in southern China.