Shifts in Typhoon Tracks over the western North Pacific during the 20th century based on the recovery of historical data

Since the early 20th century the globally averaged surface temperature has risen. Annual typhoon number has been predicted to decrease; however, the annual number of intense typhoon is expected to increase in a globally-warmed climate. For the western North Pacific (WNP), typhoon datasets were limited to the recent 60 years compared to longer datasets for other basins. The limited record length caused many inconsistencies and controversies in typhoon variability studies of the region. We recovered historical typhoon track data back to 1884 from archived paper records, combined it with the available best track data of 1945-2009 and created a 100-year typhoon track dataset from 1910 to 2009 for the WNP, with some missing data during the war period from 1941 to 1944. Here we report our findings based on the 100-year record. The annual typhoon number was decreasing along the Philippines, Taiwan, and Japan since the early 20th century. We detected a shift in typhoon tracks: the tracks had shifted northward from lower latitude to north of 10°N; they had also shifted eastward from coastal regions along the Philippines Sea to the eastern region east of 145°E during the past 80 years. On the other hand, the total annual typhoon number in our analyzed area did not change during the 20th century. Our results support the eastward shift of typhoon locations that has been predicted in a globally-warmed world.