Long-term changes in wintertime persistent heavy rainfall over southern China contributed by the Madden–Julian Oscillation

Yu Liu,Pang-Chi Hsu

doi:10.1080/16742834.2019.1639471

Abstract

During the boreal winter, abundant persistent heavy rainfall (PHR) amount and significant rainfall variability at subseasonal timescale are generally observed over the southern sector of East China...

Highlights

Persistent heavy rainfall (PHR) with high intensity and long duration can cause flooding and landslides, and is one of the deadliest natural disasters
Abundant persistent heavy rainfall (PHR) amount and significant rainfall variability at subseasonal timescale are generally observed over the southern sector of East China, where the large-scale circulation and moisture transport are tightly connected with the equatorial Madden-Julian Oscillation (MJO)
We found that the anomalies of wintertime PHR amount in southern China (SC) (YR) tend to increase when the MJO convection is over the Indian Ocean (Figure 2(a))

Summary

Introduction

Persistent heavy rainfall (PHR) with high intensity and long duration can cause flooding and landslides, and is one of the deadliest natural disasters. Winter precipitation in the southern parts of East China shows significant variability at the subseasonal time scale (Jia et al 2011; Yao, Lin, and Wu 2015), which is attributable to the activity of the Madden–Julian Oscillation (MJO; Madden and Julian 1971). MJO-related moisture transport towards offequatorial areas leads to the variation in the southeastern China rainfall at the intraseasonal time scale (Jia et al 2011; Yao, Lin, and Wu 2015; Li et al 2016). Whether or not the long-term variation in the MJO affects PHR, and the mechanisms responsible for decadal changes in wintertime PHR in the southern sectors of East China, are discussed in this study. The results of this study may facilitate risk reduction and decision making at a longer lead time

Data and methods

Results

Summary