Interannual variability of summer rainfall over the northern part of China and the related circulation features

Cholaw Bueh,Dawei Lin,Yan Li,Yi Lian

doi:10.1007/s13351-016-5111-5

Abstract

In this study, interannual variability of summer rainfall over the northern part of China (NPC) and associated circulation patterns were investigated by using long-term (1961–2013) observational and reanalysis data. Two important NPC rainfall modes were identified by empirical orthogonal function analysis: the first is characterized by an almost uniformly distributed rainfall anomaly over most parts of the NPC, while the second shows rainfall variability in Northeast China (NEC) and its out-of-phase relationship with that in North China (NC) and the northern part of Northwest China. The results also suggest that the NPC summer rainfall anomalies are also closely associated with those in some other parts of China.

Highlights

The northern part of China (NPC) is an interlaced zone of agriculture, animal husbandry, and forestry, covering Northeast China (NEC), North China (NC), and Northwest China (NWC)
It is revealed that the circumglobal teleconnection (CGT) pattern associated with a strong Indian summer monsoon (ISM) and the PEA− (PEA+) pattern work in concert to constitute the typical circulation pattern of the first NPC rainfall mode in its positive phase
In the second NPC rainfall mode, the typical circulation pattern is characterized by an anomalous Okhotsk high (OKSH) and the accompanying surface pressure anomaly over NEC and Japan

Summary

Introduction

The northern part of China (NPC) is an interlaced zone of agriculture, animal husbandry, and forestry, covering Northeast China (NEC), North China (NC), and Northwest China (NWC). VOL. annual variability of summer rainfall over the eastern part of China is closely associated with a meridionally elongated circulation pattern, i.e., the East Asia/Pacific (EAP) teleconnection pattern (Huang and Li, 1987; Nitta, 1987; Huang and Sun, 1992; Lu, 2004; Bueh et al, 2008) This pattern primarily reflects variations of three key circulation systems: the western Pacific subtropical high (WPSH), the Okhotsk/Yakutsk high over Northeast Asia, and the trough between them (the Meiyu trough). Yang and Zhang (2007) studied the variation of western NWC (Xinjiang Region) rainfall and its associated circulation features They revealed that increased (decreased) rainfall in western NWC is locally caused by an anomalous cyclonic (anticyclonic) circulation over central Asia that corresponds to an active (inactive) central Asian cut-off vortex circulation, which is consistent with the results of Chen and Dai (2009).

Data and methods

Rainfall modes

First NPC rainfall mode

Summary

Findings

Discussion