scholarly journals Atmospheric moisture channels and pre-existing weather regimes for rain belt events during East Asian summer monsoon season

2020 ◽  
Author(s):  
Tat Fan Cheng ◽  
Lun Dai ◽  
Mengqian Lu
Keyword(s):  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Monsoon Season ◽  
East Asian ◽  
Atmospheric Moisture ◽  
Summer Monsoon Season ◽  
Rain Belt ◽  
Weather Regimes ◽  
Asian Summer

scholarly journals Contributions of GCM/RCM Uncertainty in Ensemble Dynamical Downscaling for Precipitation in East Asian Summer Monsoon Season

SOLA ◽  
2018 ◽  
Vol 14 (0) ◽  
pp. 97-104 ◽  
Author(s):  
Asuka Suzuki-Parker ◽  
Hiroyuki Kusaka ◽  
Izuru Takayabu ◽  
Koji Dairaku ◽  
Noriko N. Ishizaki ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Dynamical Downscaling ◽  
Asian Summer Monsoon ◽  
Monsoon Season ◽  
East Asian ◽  
Summer Monsoon Season ◽  
Asian Summer

Seasonal variations in the lake-water oxygen isotope composition of four lakes in the East Asian summer monsoon region: Implications for the interpretation of paleo-isotope records

2019 ◽  
Vol 44 (4) ◽  
pp. 572-588 ◽  
Author(s):  
Zhiping Zhang ◽  
Jianbao Liu ◽  
Xiaokang Liu ◽  
Shengqian Chen ◽  
Ailing Yu ◽  
...  
Keyword(s):  
Oxygen Isotope ◽  
Summer Monsoon ◽  
Lake Water ◽  
Seasonal Variations ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Monsoon Season ◽  
East Asian ◽  
Water Oxygen ◽  
Asian Summer

The scarcity of modern process studies of the relationship between climatic variables and lake-water oxygen isotope (δ18OLW) composition has restricted our understanding of the climatic significance of oxygen isotope (δ18O) records from lake sediments. We measured changes in δ18OLW at four lakes (Nanyihu, Gonghai, Mayinghai and Xihaizi) at various locations across the East Asian summer monsoon (EASM) region, from December 2016 to January 2018. The variations in δ18OLW at Lake Nanyihu, located in the lower reach of the Yangtze River, are controlled by precipitation oxygen isotope (δ18OP) composition, temperature and evaporation during the non-monsoon season. However, the variations in δ18OLW at the lakes close to the northern limit of the EASM (Gonghai, Mayinghai and Xihaizi) are affected not only by δ18OP, temperature and evaporation, but also by the replenishment of groundwater during the non-monsoon season. In general, during the non-monsoon season, the variation of δ18OLW exhibits a variety of patterns and the controlling factors across the EASM region are complex. During the monsoon season, although the effect of evaporation-induced isotopic enrichment still affects δ18OLW, the variations in δ18OLW are more influenced by the supply of abundant precipitation with lower δ18OP to the lakes, which caused a substantial decrease in δ18OLW across the EASM region in this season. Therefore, the variations in δ18OLW mainly reflect the δ18OP of the EASM during the monsoon season. However, the timing of the peak in monsoon precipitation does not correspond well to minima in δ18OLW, and correlation analysis reveals that there is only a weak relationship between δ18OLW and precipitation/humidity at all four lakes during the monsoon season. These findings demonstrate that although δ18OLW can represent the δ18OP of the EASM, it does not reflect precipitation/humidity during the monsoon season. Overall, our findings indicate that the seasonal variations of δ18OLW across the EASM region are controlled by different climatic variables, which implies that the interpretation of lacustrine δ18O records across the EASM region as an indicator of regional effective precipitation/humidity needs to be reassessed.

Effects of the Tibetan Plateau on East Asian Summer Monsoon via Weakened Transient Eddies

2020 ◽  
Author(s):  
Qiaoling Ren ◽  
Song Yang ◽  
Xinwen Jiang ◽  
Yang Zhang ◽  
Zhenning Li
Keyword(s):  
East Asia ◽  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Early Summer ◽  
The Tibetan Plateau ◽  
Rain Belt ◽  
Westerly Jet ◽  
Asian Summer

<p>Previous studies have revealed that the Tibetan Plateau (TP) can weaken the high-frequency and low-frequency transient eddies (TE) transported along the westerly jet. Here the effects of TP on East Asian summer monsoon via weakened TE are investigated based on the simulations by the NCAR Community Earth System Model, in which a nudging method is used to amplify the TP’s inhibition of TE without changing the steady dynamic and thermodynamic effects of TP. Results reveal that the weakened TE by TP weaken the East Asian westerly jet (EAWJ) and shift the jet southward via transient vorticity flux. The southward EAWJ accompanied with reduced poleward transport of moisture by TE results in less rainfall in northern East Asia but more rainfall in southern East Asia, particularly in early summer when the EAWJ is stably located over the TP and the meridional gradient of water vapor is large. Furthermore, the anomalous precipitation can move the EAWJ further southward through the anomalous diabatic heating in early summer, forming a positive feedback. Therefore, the TP’s inhibition of TE can shift the East Asian rain belt southward, different from the TP’s steady forcing which favors a poleward shift of the rain belt. It is also demonstrated that the atmospheric internal variability can lead to the south-flood-north-drought pattern of summer rainfall change over East Asia, indicating the important role of TE in East Asian summer monsoon.</p>

scholarly journals Efficient transport of atmospheric microplastics onto the continent via the East Asian summer monsoon

2021 ◽  
Vol 414 ◽  
pp. 125477
Author(s):  
Xiaohui Wang ◽  
Kai Liu ◽  
Lixin Zhu ◽  
Changjun Li ◽  
Zhangyu Song ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Asian Summer ◽  
Efficient Transport

scholarly journals Holocene variability of East Asian summer monsoon as viewed from the speleothem δ18O records in central China

2021 ◽  
Vol 558 ◽  
pp. 116758
Author(s):  
Yanjun Cai ◽  
Xing Cheng ◽  
Le Ma ◽  
Ruixue Mao ◽  
Sebastian F.M. Breitenbach ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Central China ◽  
Asian Summer

Nonlinear, Intraseasonal Phases of the East Asian Summer Monsoon: Extraction and Analysis Using Self-Organizing Maps

2012 ◽  
Vol 25 (20) ◽  
pp. 6975-6988 ◽  
Author(s):  
Jung-Eun Chu ◽  
Saji N. Hameed ◽  
Kyung-Ja Ha
Keyword(s):  
Time Scales ◽  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Self Organizing Maps ◽  
Dry Spell ◽  
Asian Summer ◽  
Upper Level ◽  
Self Organizing

Abstract The hypothesis that regional characteristics of the East Asian summer monsoon (EASM) result from the presence of nonlinear coupled features that modulate the seasonal circulation and rainfall at the intraseasonal time scale is advanced in this study. To examine this hypothesis, the authors undertake the analysis of daily EASM variability using a nonlinear multivariate data classifying algorithm known as self-organizing mapping (SOM). On the basis of various SOM node analyses, four major intraseasonal phases of the EASM are identified. The first node describes a circulation state corresponding to weak tropical and subtropical pressure systems, strong upper-level jets, weakened monsoonal winds, and cyclonic upper-level vorticity. This mode, related to large rainfall anomalies in southeast China and southern Japan, is identified as the mei-yu–baiu phase. The second node represents a distinct circulation state corresponding to a strengthened subtropical high, monsoonal winds, and anticyclonic upper-level vorticity in southeast Korea, which is identified as the changma phase. The third node is related to copious rain over Korea following changma, which we name the postchangma phase. The fourth node is situated diagonally opposite the changma mode. Because Korea experiences a dry spell associated with this SOM node, it is referred to as the dry-spell phase. The authors also demonstrate that a strong modulation of the changma and dry-spell phases on interannual time scales occurs during El Niño and La Niña years. Results imply that the key to predictability of the EASM on interannual time scales may lie with analysis and exploitation of its nonlinear characteristics.

scholarly journals The Variability of the Indian–East Asian Summer Monsoon Interface in Relation to the Spring Seesaw Mode between the Indian Ocean and the Central-Western Pacific

2016 ◽  
Vol 29 (13) ◽  
pp. 5027-5040 ◽  
Author(s):  
Jie Cao ◽  
Shu Gui ◽  
Qin Su ◽  
Yali Yang
Keyword(s):  
Indian Ocean ◽  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
General Circulation ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Western Pacific ◽  
Observational Analysis ◽  
Westerly Winds ◽  
Asian Summer

Abstract The interannual zonal movement of the interface between the Indian summer monsoon and the East Asian summer monsoon (IIE), associated with the spring sea surface temperature (SST) seesaw mode (SSTSM) over the tropical Indian Ocean (TIO) and the tropical central-western Pacific (TCWP), is studied for the period 1979–2008. The observational analysis is based on Twentieth Century Reanalysis data (version 2) of atmospheric circulations, Extended Reconstructed SST data (version 3), and the Climate Prediction Center Merged Analysis of Precipitation. The results indicate that the IIE’s zonal movement is significantly and persistently correlated with the TIO–TCWP SSTSM, from spring to summer. The results of two case studies resemble those obtained by regression analysis. Experiments using an atmospheric general circulation model (ECHAM6) substantiate the key physical processes revealed in the observational analysis. When warmer (colder) SSTs appear in the TIO and colder (warmer) SSTs occur in the TCWP, the positive (negative) SSTSM forces anomalous easterly (westerly) winds over the Bay of Bengal (BOB), South China Sea (SCS), and western North Pacific (WNP). The anomalous easterly (westerly) winds further result in a weakened (strengthened) southwest summer monsoon over the BOB and a strengthened (weakened) southeast summer monsoon over the SCS and WNP. This causes the IIE to shift farther eastward (westward) than normal.

scholarly journals Two major modes of variability of the East Asian summer monsoon

2010 ◽  
Vol 136 (649) ◽  
pp. 829-841 ◽  
Author(s):  
Xuguang Sun ◽  
Richard J. Greatbatch ◽  
Wonsun Park ◽  
Mojib Latif
Keyword(s):  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Modes Of Variability ◽  
Asian Summer
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