Multiple movement characteristics of the Meiyu rain belt in East Asia: reconstructing historical data on the southern margin from 1861 to 2017

Abstract

The location of the Meiyu belt has an important influence on the summer precipitation pattern in East Asia. In this study, historical diary-recorded data and modern instrument-measured data were used to reconstruct the Meiyu sequence at its southern margin from 1861 to 2017. Combining with the variation of Meiyu intensity in the middle and lower Yangtze River Valley (YRV) and the Huai River Valley (HRV), this study discussed the change characteristics of the Meiyu rain belt. The overall shift of the Meiyu belt is basically the same as the change to the southern margin of the rain belt which has interdecadal and multidecadal north-south shifts. The northward shift of the rain belt after 2000 occurred only as an interdecadal fluctuation. The summer monsoon is the main factor for the shift of the Meiyu belt on a multidecadal-centennial scale, AMO (Atlantic Multidecadal Oscillation) has a certain role in modulation, and PDO (Pacific Decadal Oscillation) is the decisive factor for the interdecadal scale of the Meiyu belt position. When PDO is in a positive (negative) phase, the whole Meiyu belt tends to be strong (weak) and shifts to the South (North). AMO and IOBM (Indian Ocean Basin Mode) play a particular role in modulation. The shift of the Meiyu belt is usually consistent with the north-south variation of the main rain belt of eastern China. Its location may play a role in predicting summer precipitation in North China.