scholarly journals Probabilistic versus deterministic skill in predicting the western North Pacific‐East Asian summer monsoon variability with multimodel ensembles

2016 ◽  
Vol 121 (3) ◽  
pp. 1079-1103 ◽  
Author(s):  
Dejian Yang ◽  
Xiu‐Qun Yang ◽  
Qian Xie ◽  
Yaocun Zhang ◽  
Xuejuan Ren ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
North Pacific ◽  
East Asian Summer Monsoon ◽  
Western North Pacific ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Monsoon Variability ◽  
Asian Summer ◽  
Multimodel Ensembles

Enhanced tropospheric biennial oscillation of the East Asian summer monsoon since the late-1970s

2021 ◽  
pp. 1-54
Author(s):  
Wen Chen ◽  
Kaiming Hu ◽  
Shangfeng Chen
Keyword(s):  
Summer Monsoon ◽  
North Pacific ◽  
East Asian Summer Monsoon ◽  
Western North Pacific ◽  
El Nino ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Tropospheric Biennial Oscillation ◽  
Asian Summer ◽  
Biennial Oscillation

Abstract The tropospheric biennial oscillation (TBO) of East Asian summer monsoon (EASM) has major impacts on East Asian climate. Here it is shown that, since the late-1970s, the TBO signal of EASM has strengthened significantly. The EASM TBO in wind anomalies undergoes a transition from a cyclone over the western North Pacific (WNPC) in preceding summer to an anticyclone over the western North Pacific (WNPAC) in following summer, with the anomalies strengthening remarkably after the late-1970s. Correspondingly, the biennial component of precipitation anomalies in eastern China show different distributions. Both observational and numerical simulation analyses demonstrate that these changes are caused by the westward shift of El Niño warming and enhanced Indo-Pacific and Atlantic-Pacific coupling. The positive sea surface temperature (SST) anomalies associated with the TBO of EASM shift toward the central Pacific after the late-1970s, which favor the strengthening of the WNPC and cause a weakened EASM. In following summer, both the north Indian Ocean and tropical north Atlantic SST warming are closely coupled with El Niño since the late-1970s, which favor the strengthening of WNPAC and cause an intensified EASM. Together, these changes provide more favorable background state for the transition of circulation anomalies over the western North Pacific, giving rise to enhanced biennial variability in EASM in the late-1970s.

scholarly journals Coupling Modes of Climatological Intraseasonal Oscillation in the East Asian Summer Monsoon

2016 ◽  
Vol 29 (17) ◽  
pp. 6363-6382 ◽  
Author(s):  
Zehao Song ◽  
Congwen Zhu ◽  
Jingzhi Su ◽  
Boqi Liu
Keyword(s):  
East Asia ◽  
North Pacific ◽  
East Asian Summer Monsoon ◽  
Western North Pacific ◽  
Diabatic Heating ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Intraseasonal Oscillation ◽  
Rainfall Anomaly ◽  
Asian Summer

Abstract The present study used harmonic and multivariate empirical orthogonal function (MV-EOF) analyses to identify the existence of climatological intraseasonal oscillation (CISO) in the diabatic heating, precipitation, and circulation of the East Asian summer monsoon (EASM). The strongest CISO signals are found in the north of the western North Pacific, possibly because of the horizontal gradient of diabatic heating induced by the seasonal land–sea thermal contrast. Further, the phase relationship between the diabatic heating components maintains the EASM CISO. The first two coupling modes of EASM CISO in the circulation are robust during May through August, with a period of 40–80 days, and exhibit phase locking to the stepwise establishment of the EASM, which reveals the coaction of the Mongolian cyclone (MC) around Lake Baikal at 850 hPa, the western North Pacific subtropical high (WNPSH) at 500 hPa, and the South Asian high (SAH) over the Tibetan Plateau (TP) at 200 hPa. The first mode shows that the jointly enhanced MC, WNPSH, and SAH correspond to a tripole rainfall anomaly with strong mei-yu and baiu fronts over East Asia. The second mode, however, indicates the eastward and northwestward propagation of MC and WNPSH, respectively, with suppressed SAH, as well as a dipole rainfall anomaly over East Asia. Both the observations and numerical simulation verify the importance of daily diabatic heating and SST in maintaining the CISO modes over the WNP, where the condensation heating related to atmospheric forcing determines the local intraseasonal air–sea interaction.

Decadal- to Centennial-Scale East Asian Summer Monsoon Variability Over the Past Millennium: An Oceanic Perspective

2018 ◽  
Vol 45 (15) ◽  
pp. 7711-7718 ◽  
Author(s):  
Richard Ching Wa Cheung ◽  
Moriaki Yasuhara ◽  
Briony Mamo ◽  
Kota Katsuki ◽  
Koji Seto ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
The Past ◽  
Monsoon Variability ◽  
Asian Summer ◽  
Past Millennium

Moisture Source-to-Receptor Network for East Asian Summer Monsoon and the Associated Atmospheric Bridges

2020 ◽  
Author(s):  
Tat Fan Cheng ◽  
Mengqian Lu
Keyword(s):  
Pacific Ocean ◽  
River Basin ◽  
North Pacific ◽  
East Asian Summer Monsoon ◽  
Western North Pacific ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Intraseasonal Variation ◽  
The Pacific ◽  
Asian Summer

<p>There has been growing interest in studying precipitation recycling and identifying relationships between moisture sources and receptors. The network built upon the relationships is crucial for the knowledge of the atmospheric water cycle, weather prediction, and adaptation to hydroclimatic disasters. This study aims to provide an interesting perspective of a Source-to-Receptor (SR) network to study the dynamics of the East Asian Summer Monsoon (EASM). By prescribing 24 sources and 6 EASM subregions, the SR network during the wet season is quantified using the two-dimensional physically-based Dynamical Recycling Model (DRM). Results reveal that in addition to oceanic sources, land sources including the often-overlooked plateau regions play an important role in supplying moisture to most EASM subregions. A seesaw relationship of the Indian Ocean/South Asia sector from April to June and the Pacific Ocean/East Asia sector from July to September is evidenced in the intraseasonal variation of the SR network for EASM subregions including South China coast and Taiwan, Yangtze River basin, South Japan and Korean Peninsula. Conversely, weaker intraseasonal variation is seen in the SR network for the Yellow River basin and North China. During heavy rainfall days, the zonal oscillation of western North Pacific Subtropical High (WNPSH) is deemed crucial to modulate the SR network through enhanced contributions from Bay of Bengal, Indochina, Indian subcontinent and Southwest China (the Philippine Sea and western North Pacific) during the positive (negative) phase. Coupled circulations such as two distinct pressure dipoles and coherent upper-level wave trains from mid-latitudes are responsible for bridging the moisture routes. Lastly, preceding winter/springtime El Niño is likely associated with the enhanced (weakened) moisture supply from the southwesterly (Pacific Ocean) sources. Longer-term variabilities such as the Pacific Decadal Oscillation is also considered influential to the SR network. We believe that the attributable atmospheric bridges and the SR network itself can offer insights to the current understanding of EASM and model simulations of the monsoon systems and the water cycles.</p>

Astronomical and glacial forcing of East Asian summer monsoon variability

2015 ◽  
Vol 115 ◽  
pp. 132-142 ◽  
Author(s):  
Youbin Sun ◽  
John Kutzbach ◽  
Zhisheng An ◽  
Steven Clemens ◽  
Zhengyu Liu ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Monsoon Variability ◽  
Asian Summer
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