scholarly journals Weakening of the East Asian summer monsoon at 1000-1100 A.D. within the Medieval Climate Anomaly: Possible linkage to changes in the Indian Ocean-western Pacific

2014 ◽  
Vol 119 (5) ◽  
pp. 2209-2219 ◽  
Author(s):  
Jianbao Liu ◽  
Fahu Chen ◽  
Jianhui Chen ◽  
Xiaojian Zhang ◽  
Jian Liu ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Western Pacific ◽  
Medieval Climate Anomaly ◽  
Climate Anomaly ◽  
The Indian Ocean ◽  
Asian Summer

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.

Tropical Indian Ocean Basin Warming and East Asian Summer Monsoon: A Multiple AGCM Study

2008 ◽  
Vol 21 (22) ◽  
pp. 6080-6088 ◽  
Author(s):  
Shuanglin Li ◽  
Jian Lu ◽  
Gang Huang ◽  
Kaiming Hu
Keyword(s):  
Indian Ocean ◽  
Time Scales ◽  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Tropical Indian Ocean ◽  
Ocean Warming ◽  
Indian Ocean Warming ◽  
Asian Summer

Abstract A basin-scale warming is the leading mode of tropical Indian Ocean sea surface temperature (SST) variability on interannual time scales, and it is also the prominent feature of the interdecadal SST trend in recent decades. The influence of the warming on the East Asian summer monsoon (EASM) is investigated through ensemble experiments of several atmospheric general circulation models (AGCMs). The results from five AGCMs consistently suggest that near the surface, the Indian Ocean warming forces an anticyclonic anomaly over the subtropical western Pacific, intensifying the southwesterly winds to East China; and in the upper troposphere, it forces a Gill-type response with the intensified South Asian high, both favoring the enhancement of the EASM. These processes are argued to contribute to the stronger EASM during the summer following the peak of El Niño than monsoons in other years. These model results also suggest that tropical Indian Ocean warming may not have a causal relationship to the synchronous weakening of EASM on interdecadal time scales.

Interdecadal Strengthening in the Independent Relationship Between the East Asian Summer Monsoon and the Indian Ocean Basin Mode around the Early 1990s

2021 ◽  
pp. 1-42
Author(s):  
KUI LIU ◽  
LIAN-TONG ZHOU ◽  
ZHIBIAO WANG ◽  
YONG LIU ◽  
XIAOXUE YIN
Keyword(s):  
Indian Ocean ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Ocean Basin ◽  
Indian Ocean Basin Mode ◽  
Basin Mode ◽  
The Indian Ocean ◽  
Asian Summer ◽  
The Relationship

AbstractThis study conducts correlation and regression analyses of the JRA-55 reanalysis data and observational rainfall datasets from China’s National Climate Center. The analyses reveal that interdecadal enhancement in the relationship between the East Asian summer monsoon (EASM) and the Indian Ocean Basin mode (IOBM) after the early 1990s, and the diminished correlation between the EASM and the Niño-3 index. The analyses also reveal that the relationship between EASM-related rainfall/circulation with IOBM also experienced an interdecadal shift at the same time. During the first epoch (1977–1989), EASM-related rainfall was correlated significantly with the Niño-3 index, and accompanied by a Pacific–Japan-like anomaly pattern of horizontal winds. In a subsequent epoch (1994–2014), EASM-related rainfall was correlated significantly with IOBM, and accompanied by a meridional dipole pattern in the horizontal winds. After the 1990s, IOBM exerted influence on EASM through land–sea thermal contrast, and the critical land area was the region 33°–47°N, 110°–140°E. The interdecadal strengthening in the EASM–IOBM linkage around the early 1990s may be attributable to a faster rate of decay of El Niño after the 1990s.

scholarly journals Recent Intensification of the Western Pacific Subtropical High Associated with the East Asian Summer Monsoon

2015 ◽  
Vol 28 (7) ◽  
pp. 2873-2883 ◽  
Author(s):  
Shinji Matsumura ◽  
Shiori Sugimoto ◽  
Tomonori Sato
Keyword(s):  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Western Pacific Subtropical High ◽  
Western Pacific ◽  
Subtropical High ◽  
The Past ◽  
The North ◽  
Asian Summer

Abstract The summer western Pacific subtropical high (WPSH) has intensified during the past three decades. However, the underlying mechanism is not yet well understood. Here, it is shown that baiu rainband activity in midsummer, which is part of the East Asian summer monsoon, plays an important role in recent intensification in the WPSH along the baiu rainband. In contrast with the WPSH, the summer Okhotsk high, which is located to the north of the baiu rainband, has weakened during the past three decades. The north–south contrasting changes between the two highs reflect a response to northward-moved and enhanced baiu heating, which intensifies the upper-tropospheric ridge, resulting in the baroclinic intensification of the WPSH. Regional climate model experiments also support the observational analysis. Therefore, baiu convective activity in midsummer can act as a major driver for the WPSH intensification. The results here suggest that the mechanism intensifying the summer North Pacific subtropical high clearly differs between the western and eastern Pacific.

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