Indo-Pacific climate during the decaying phase of the 2015/16 El Niño: role of southeast tropical Indian Ocean warming

2017 ◽  
Vol 50 (11-12) ◽  
pp. 4707-4719 ◽  
Author(s):  
Zesheng Chen ◽  
Yan Du ◽  
Zhiping Wen ◽  
Renguang Wu ◽  
Chunzai Wang
2020 ◽  
Vol 33 (13) ◽  
pp. 5427-5443
Author(s):  
Jiepeng Chen ◽  
Jin-Yi Yu ◽  
Xin Wang ◽  
Tao Lian

ABSTRACTPrevious studies linked the increase of the middle and low reaches of the Yangtze River (MLRYR) rainfall to tropical Indian Ocean warming during extreme El Niños’ (e.g., 1982/83 and 1997/98 extreme El Niños) decaying summer. This study finds the linkage to be different for the recent 2015/16 extreme El Niño’s decaying summer, during which the above-normal rainfalls over MLRYR and northern China are respectively linked to southeastern Indian Ocean warming and western tropical Indian Ocean cooling in sea surface temperatures (SSTs). The southeastern Indian Ocean warming helps to maintain the El Niño–induced anomalous lower-level anticyclone over the western North Pacific Ocean and southern China, which enhances moisture transport to increase rainfall over MLRYR. The western tropical Indian Ocean cooling first enhances the rainfall over central-northern India through a regional atmospheric circulation, the latent heating of which further excites a midlatitude Asian teleconnection pattern (part of circumglobal teleconnection) that results in an above-normal rainfall over northern China. The western tropical Indian Ocean cooling during the 2015/16 extreme El Niño is contributed by the increased upward latent heat flux anomalies associated with enhanced surface wind speeds, opposite to the earlier two extreme El Niños.


2014 ◽  
Vol 119 (8) ◽  
pp. 5105-5122 ◽  
Author(s):  
Soumi Chakravorty ◽  
C. Gnanaseelan ◽  
J. S. Chowdary ◽  
Jing-Jia Luo

2017 ◽  
Vol 51 (5-6) ◽  
pp. 2097-2112 ◽  
Author(s):  
N. Herold ◽  
A. Santoso

2012 ◽  
Vol 40 (5-6) ◽  
pp. 1467-1481 ◽  
Author(s):  
Soumi Chakravorty ◽  
J. S. Chowdary ◽  
C. Gnanaseelan

2013 ◽  
Vol 31 (6) ◽  
pp. 1375-1383 ◽  
Author(s):  
Haibo Hu ◽  
Xiaoyuan Hong ◽  
Yuan Zhang ◽  
Xiuqun Yang ◽  
Wei Liu ◽  
...  

2021 ◽  
Vol 118 (12) ◽  
pp. e2022255118
Author(s):  
Zhen-Qiang Zhou ◽  
Shang-Ping Xie ◽  
Renhe Zhang

Heavy monsoon rainfall ravaged a large swath of East Asia in summer 2020. Severe flooding of the Yangtze River displaced millions of residents in the midst of a historic public health crisis. This extreme rainy season was not anticipated from El Niño conditions. Using observations and model experiments, we show that the record strong Indian Ocean Dipole event in 2019 is an important contributor to the extreme Yangtze flooding of 2020. This Indian Ocean mode and a weak El Niño in the Pacific excite downwelling oceanic Rossby waves that propagate slowly westward south of the equator. At a mooring in the Southwest Indian Ocean, the thermocline deepens by a record 70 m in late 2019. The deepened thermocline helps sustain the Indian Ocean warming through the 2020 summer. The Indian Ocean warming forces an anomalous anticyclone in the lower troposphere over the Indo-Northwest Pacific region and intensifies the upper-level westerly jet over East Asia, leading to heavy summer rainfall in the Yangtze Basin. These coupled ocean-atmosphere processes beyond the equatorial Pacific provide predictability. Indeed, dynamic models initialized with observed ocean state predicted the heavy summer rainfall in the Yangtze Basin as early as April 2020.


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