Impacts of Different Types of El Niño on the East Asian Climate: Focus on ENSO Cycles

Abstract

Using multiple datasets and a partial correlation method, the authors analyze the different impacts of eastern Pacific (EP) and central Pacific (CP) El Niño on East Asian climate, focusing on the features from El Niño developing summer to El Niño decaying summer. Unlike the positive–negative–positive (+/−/+) anomalous precipitation pattern over East Asia and the equatorial Pacific during EP El Niño, an anomalous −/+/− rainfall pattern appears during CP El Niño. The anomalous dry conditions over southeastern China and the northwestern Pacific during CP El Niño seem to result from the anomalous low-level anticyclone over southern China and the South China Sea, which is located more westward than the Philippine Sea anticyclone during EP El Niño. The continuous anomalous sinking motion over southeastern China, as part of the anomalous Walker circulation associated with CP El Niño, also contributes to these dry conditions. During the developing summer, the impact of CP El Niño on East Asian climate is more significant than the influence of EP El Niño. During the decaying summer, however, EP El Niño exerts a stronger influence on East Asia, probably due to the long-lasting anomalous warming over the tropical Indian Ocean accompanying EP El Niño. Temperatures over portions of East Asia and the northwestern Pacific tend to be above normal during EP El Niño but below normal from the developing autumn to the next spring during CP El Niño. A possible reason is the weakened (enhanced) East Asian winter monsoon related to EP (CP) El Niño.

Indo-western Pacific ocean capacitor and coherent climate anomalies in post-ENSO summer: A review

“…Subsequent studies (Shen and Lau, 1995;Chang et al, 2000;Wang et al, 2000;Wu et al, 2003) showed that in post-El Niño summer the TNW Pacific AAC causes above-normal rainfall in the Yangtze River valley. The relationship between East Asian summer rainfall and ENSO is unstable over time (Wu and Wang, 2002;Ye and Lu, 2011), possibly due to the slow modulations by variations in ENSO amplitude and/or type Feng et al, 2011;Yuan and Yang, 2012;. Further complications include apparent asymmetry between polarities in the leading mode of East Asian summer rainfall variability (Hsu and Lin, 2007).…”

Seasonal predictability of winter ENSO types in operational dynamical model predictions

“…Many previous studies revealed that the CP type of El Niño has significantly different global climate impacts from the EP El Niño through tropical-extratropical teleconnections (e.g., Weng et al 2007Weng et al , 2009; Kim et al 2009;Feng et al 2010;Feng and Li 2011;Zhang et al 2011Zhang et al , 2012Yuan and Yang 2012) as these two types of El Niño are accompanied with distinct tropical atmospheric circulations. La Niña events, the negative phase of ENSO events, are usually less distinguishable in terms of the two types (Kug and Ham 2011).…”

Different types of La Niña events and different responses of the tropical atmosphere

“…One is the South American coastal warming and westward propagation of the sea surface temperature anomaly (SSTA) and the other is the central Pacific warming and eastward propagation of the SSTA [1][2][3][4][5][6]. In recent years, it is found that the SSTA distribution during the mature phase of most El Niño events after 1990s shifts more westward to the central Pacific as compared to those before the 1990s, which also leads to significant changes in the convection, vertical motion and precipitation in the tropics [7][8][9]. This "new" type of El Niño is named as dateline El Niño [10], El Niño Modoki [7], warm-pool El Niño [11], or central Pacific (CP) El Niño [12].…”