Characterizing effects of monsoons and climate teleconnections on precipitation in China using wavelet coherence and global coherence

Xueyu Chang,Yan Yan,Ming Zhang,Yonghong Hao,Binbin Wang

doi:10.1007/s00382-018-4439-1

Abstract

Weather and climate in a location are generally affected by global climatic phenomena. Monsoons and teleconnections are two climatic phenomena that have been assessed in specific regions for their correlations with regional precipitation. This study characterized the effects of monsoons and climate teleconnections on precipitation in eight climate zones across China. Correlations between monthly precipitation from 1951 to 2013 across the eight zones and each of two important monsoon indices [the Indian Summer Monsoon (ISM) and East Asian Summer Monsoon (EASM)] and two major teleconnection indices [El Niño–Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO)] were analyzed based on wavelet coherence and global coherence. The results demonstrated that on the annual timescale, monsoons have stronger effects than teleconnections on monthly precipitation in each of the eight climate zones. On the intra-annual (0.5–1 year) and inter-annual (2–10 year) scales, the ISM mainly affects precipitation in the East Arid Region, Northeastern China, Northern China, and Qinghai-Tibet Plateau; the EASM mainly affects Northern China, Central China, and Southern China; the ENSO mainly affects Western Arid/Semiarid region and Qinghai-Tibet Plateau; the PDO mainly affects the Western Arid/Semiarid region. On the decadal timescale, the ISM mainly affects the Western arid/Semiarid and Central China; the EASM mainly affects Western arid/Semiarid, Central China, and Qinghai–Tibet Plateau; the ENSO mainly affects Northeastern China and Central China; and the PDO mainly affects East arid and Southern China regions. These findings provide a practical reference for water resources management and/or for the prediction of precipitation in different regions of China.

Highlights

Monsoons and teleconnections are two important large-scale climatic phenomena that affect global precipitation and distribution of the global water resources (Christensen et al 2013)
Previous works have indicated that the Indian Summer Monsoon (ISM) and East Asian Summer Monsoon (EASM) are two major monsoon indices that affect Asian precipitation (Lau and Li 1984; Wang et al 2001)
We focus on the analysis of precipitation data and climate indices, adopt the latter classification (Fig. 1): Zone I (Western arid/Semiarid), Zone II (East arid), Zone III (Northeastern China), Zone IV (Northern China), Zone V (Central China), Zone VI (Southern China), Zone VII (Southwestern China), and Zone VIII (Qinghai–Tibet Plateau)

Summary

Introduction

Monsoons and teleconnections are two important large-scale climatic phenomena that affect global precipitation and distribution of the global water resources (Christensen et al 2013). It is well known that many large-scale climatic factors (represented by different climate indices) have strong heterogeneity at both spatial and temporal scales (Karl et al 1999; Sun et al 2017). Understanding their characteristic scales in both space and time is crucially important to the allocation and management of local water resources. We applied wavelet analysis to quantitatively evaluate the effects of four major indices (ISM, EASM, ENSO, and PDO) on precipitation within China, using precipitation data recorded during 1951–2013 at 756 meteorological stations nationwide

Methods

Results

Conclusion