scholarly journals Stalagmite-inferred variability of the Asian summer monsoon during the penultimate glacial–interglacial period

2014 ◽  
Vol 10 (3) ◽  
pp. 1211-1219 ◽  
Author(s):  
T.-Y. Li ◽  
C.-C. Shen ◽  
L.-J. Huang ◽  
X.-Y. Jiang ◽  
X.-L. Yang ◽  
...  
Keyword(s):  
Oxygen Isotope ◽  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Mainland China ◽  
Warm Pool ◽  
Trade Wind ◽  
Interglacial Period ◽  
Solar Insolation ◽  
The North ◽  
Asian Summer

Abstract. The orbital-timescale dynamics of the Quaternary Asian summer monsoons (ASM) are frequently attributed to precession-dominated northern hemispheric summer insolation. However, this long-term continuous ASM variability is inferred primarily from oxygen isotope records of stalagmites, mainly from Sanbao cave in mainland China, and may not provide a comprehensive picture of ASM evolution. A new spliced stalagmite oxygen isotope record from Yangkou cave tracks summer monsoon precipitation variation from 124 to 206 thousand years ago in Chongqing, southwest China. Our Yangkou record supports that the evolution of ASM was dominated by the North Hemisphere solar insolation on orbital timescales. When superimposed on the Sanbao record, the precipitation time series referred from Yangkou cave stalagmites supports the strong ASM periods at marine isotope stages (MIS) 6.3, 6.5, and 7.1 and weak ASM intervals at MIS 6.2, 6.4, and 7.0. This consistency confirms that ASM events affected most of mainland China. Except for the solar insolation forcing, the large amplitude of minimum δ18O values in Yangkou record during glacial period, such as MIS 6.5, could stem from the enhanced prevailing Pacific trade wind and/or continental shelf exposure in the Indo–Pacific warm pool.

scholarly journals Variability of the Asian summer monsoon during the penultimate glacial/interglacial period inferred from stalagmite oxygen isotope records from Yangkou cave, Chongqing, Southwestern China

2013 ◽  
Vol 9 (6) ◽  
pp. 6287-6309
Author(s):  
T.-Y. Li ◽  
C.-C. Shen ◽  
L.-J. Huang ◽  
X.-Y. Jiang ◽  
X.-L. Yang ◽  
...  
Keyword(s):  
Oxygen Isotope ◽  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Mainland China ◽  
Walker Circulation ◽  
Interglacial Period ◽  
Trade Winds ◽  
Comprehensive Picture ◽  
Isotope Record ◽  
Asian Summer

Abstract. The orbital-timescale dynamics of the Quaternary Asian summer monsoons (ASM) are frequently attributed to precession-dominated Northern Hemisphere summer insolation. However, this ASM variability is inferred primarily from oxygen isotope records of stalagmites, mainly from Sanbao cave in mainland China, and may not provide a comprehensive picture of ASM evolution. A new spliced stalagmite oxygen isotope record from Yangkou cave tracks summer monsoon precipitation variation from 124–206 thousand years ago in Chongqing, southwest China. When superimposed on the Sanbao record, the Yangkou-inferred precipitation time series is shown to support the strong ASM periods at marine isotope stages (MIS) 6.3, 6.5, and 7.1 and weak ASM intervals at MIS 6.2, 6.4, and 7.0. This consistency confirms that ASM events affected most of mainland China. We show that change in glacial/interglacial (G/IG) ASM intensity was also governed by the Walker Circulation by combining our results with published paleo-Pacific thermal and salinity records. One of the strongest ASM events over the past fiver G/IG cycles, at MIS 6.5, was enhanced by such zonal forcing associated with prevailing trade winds in the Pacific.

scholarly journals Assessing Future Changes in the East Asian Summer Monsoon Using CMIP5 Coupled Models

2013 ◽  
Vol 26 (19) ◽  
pp. 7662-7675 ◽  
Author(s):  
Kyong-Hwan Seo ◽  
Jung Ok ◽  
Jun-Hyeok Son ◽  
Dong-Hyun Cha
Keyword(s):  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Moisture Flux ◽  
Moisture Convergence ◽  
Cmip5 Models ◽  
Moisture Flux Convergence ◽  
The North ◽  
Asian Summer

Abstract Future changes in the East Asian summer monsoon (EASM) are estimated from historical and Representative Concentration Pathway 6.0 (RCP6) experiments of the fifth phase of the Coupled Model Intercomparison Project (CMIP5). The historical runs show that, like the CMIP3 models, the CMIP5 models produce slightly smaller precipitation. A moisture budget analysis illustrates that this precipitation deficit is due to an underestimation in evaporation and ensuing moisture flux convergence. Of the two components of the moisture flux convergence (i.e., moisture convergence and horizontal moist advection), moisture convergence associated with mass convergence is underestimated to a greater degree. Precipitation is anticipated to increase by 10%–15% toward the end of the twenty-first century over the major monsoonal front region. A statistically significant increase is predicted to occur mostly over the Baiu region and to the north and northeast of the Korean Peninsula. This increase is attributed to an increase in evaporation and moist flux convergence (with enhanced moisture convergence contributing the most) induced by the northwestward strengthening of the North Pacific subtropical high (NPSH), a characteristic feature of the future EASM that occurred in CMIP5 simulations. Along the northern and northwestern flank of the strengthened NPSH, intensified southerly or southwesterly winds lead to the increase in moist convergence, enhancing precipitation over these areas. However, future precipitation over the East China Sea is projected to decrease. In the EASM domain, a local mechanism prevails, with increased moisture and moisture convergence leading to a greater increase in moist static energy in the lower troposphere than in the upper troposphere, reducing tropospheric stability.

scholarly journals Understanding the Interdecadal Variability of East Asian Summer Monsoon Precipitation: Joint Influence of Three Oceanic Signals

2018 ◽  
Vol 31 (14) ◽  
pp. 5485-5506 ◽  
Author(s):  
Zhiqi Zhang ◽  
Xuguang Sun ◽  
Xiu-Qun Yang
Keyword(s):  
Summer Monsoon ◽  
North Atlantic ◽  
Asian Summer Monsoon ◽  
Wave Train ◽  
Eastern China ◽  
Monsoon Precipitation ◽  
The North ◽  
Joint Influence ◽  
Asian Summer ◽  
Precipitation Anomalies

Abstract East Asian summer monsoon precipitation (EASMP) features complicated interdecadal variability with multiple time periods and spatial patterns. Using century-long datasets of HadISST, CRU precipitation, and the ECMWF twentieth-century reanalysis (ERA-20C), this study examines the joint influence of three oceanic interdecadal signals [i.e., Pacific decadal oscillation (PDO), Atlantic multidecadal oscillation (AMO), and Indian Ocean Basin mode (IOBM)] on the EASMP, which, however, is found not to be simply a linear combination of their individual effects. When PDO and AMO are out of phase, the same-sign SST anomalies occur in the North Pacific and North Atlantic, and a zonally orientated teleconnection wave train appears across the Eurasian mid-to-high latitudes, propagating from the North Atlantic to northern East Asia along the Asian westerly jet waveguide. Correspondingly, the interdecadal precipitation anomalies are characterized by a meridional tripole mode over eastern China. When PDO and AMO are in phase, with opposite sign SST anomalies in the North Pacific and North Atlantic, the sandwich pattern of anomalous stationary Rossby wavenumber tends to reduce the effect of the waveguide in the eastern Mediterranean region, and the teleconnection wave train from the North Atlantic travels only to western central Asia along a great circle route, causing Indian summer monsoon precipitation (ISMP) anomalies. The ISMP anomalies, in turn, interact with the teleconnection wave train induced by the PDO and AMO, leading to a meridional dipole mode of interdecadal precipitation anomalies over eastern China. Through the impact on the ISMP, the IOBM exerts significantly linear modulation on the combined impacts of PDO and AMO, especially over northern East Asia.

scholarly journals Climatic Effects of China Large-Scale Urbanization on East Asian Summer Monsoon under Different Phases of Pacific Decadal Oscillation

Atmosphere ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 90
Author(s):  
Yongxiao Liang ◽  
Pengfeng Xiao
Keyword(s):  
Summer Monsoon ◽  
Pacific Decadal Oscillation ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Eastern China ◽  
Vertical Motion ◽  
Positive Phase ◽  
The North ◽  
Asian Summer

The effects of urbanization over eastern China on the East Asian summer monsoon (EASM) under different sea surface temperature background are compared using a Community Atmosphere Model (CAM5.1). Experiments of urbanization investigated by comparing two climate simulations with and without urban land cover under both positive and negative phases of Pacific Decadal Oscillation (PDO) show the spatial distribution of precipitation with ‘southern flood and northern drought’ and weakening status of EASM. The climate effect of urbanization in eastern China is significantly different from north to south. Anomalous vertical ascending motion due to the role of urbanization in the south of 30° N have induced an increase in convective available potential energy (CAPE) and precipitation increase over southern China. At the same time, the downward vertical motion occurs in the north of 30° N which cause warming over northern China. Due to the anti-cyclonic anomalies in the upper and lower layers of the north, the monsoon circulation is weakened which can reduce the precipitation. However, urbanization impact under various phases of PDO show different effect. In the 1956–1970 urbanization experiments of negative PDO phase, the downward vertical motion and anti-cyclonic anomalies in the north of 30° N are also weaker than that of positive phase of PDO in 1982–1996. In terms of this situation, the urbanization experiments of negative phase of PDO reveal that the range of the warming area over the north of 40° N is small, and the warming intensity is weak, but the precipitation change is more obvious compared with the background of positive phase of PDO.

scholarly journals Association of the pre-monsoon thermal field over north India and the western Tibetan Plateau with summer monsoon rainfall over India

2015 ◽  
Vol 33 (8) ◽  
pp. 1051-1058 ◽  
Author(s):  
S. D. Bansod ◽  
S. Fadnavis ◽  
S. P. Ghanekar
Keyword(s):  
Tibetan Plateau ◽  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Summer Monsoon Rainfall ◽  
North India ◽  
Monsoon Region ◽  
The North ◽  
Western Tibetan Plateau ◽  
Asian Summer ◽  
Summer Monsoon Region

Abstract. In this paper, interannual variability of tropospheric air temperatures over the Asian summer monsoon region during the pre-monsoon months is examined in relation to Indian summer monsoon rainfall (ISMR; June to September total rainfall). For this purpose, monthly grid-point temperatures in the entire troposphere over the Asian summer monsoon region and ISMR data for the period 1949–2012 have been used. Spatial correlation patterns are investigated between the temperature field in the lower tropospheric levels during May over the Asian summer monsoon region and ISMR. The results indicate a strong and significant northwest–southeast dipole structure in the spatial correlations over the Indian region, with highly significant positive (negative) correlations over the regions of north India and the western Tibetan Plateau region – region R1 (north Bay of Bengal: region R2). The observed dipole is seen significantly up to a level of 850 hPa and eventually disappears at 700 hPa. Thermal indices evaluated at 850 hPa level, based on average air temperatures over the north India and western Tibetan Plateau region (TI1) and the north Bay of Bengal region (TI2) during May, show a strong, significant relationship with the ISMR. The results are found to be consistent and robust, especially in the case of TI1 during the period of analysis. A physical mechanism for the relationship between these indices and ISMR is proposed. Finally the composite annual cycle of tropospheric air temperature over R1 during flood/drought years of ISMR is examined. The study brings out the importance of the TI1 in the prediction of flood/drought conditions over the Indian subcontinent.

scholarly journals A 338-year tree-ring oxygen isotope record from Thai teak captures the variations in the Asian summer monsoon system

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nathsuda Pumijumnong ◽  
Achim Bräuning ◽  
Masaki Sano ◽  
Takeshi Nakatsuka ◽  
Chotika Muangsong ◽  
...  
Keyword(s):  
Oxygen Isotope ◽  
Tree Ring ◽  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Oxygen Isotope Record ◽  
Isotope Record ◽  
Monsoon System ◽  
Asian Summer

Decoupling of stalagmite-derived Asian summer monsoon records from North Atlantic temperature change during marine oxygen isotope stage 5d

2008 ◽  
Vol 70 (2) ◽  
pp. 315-321 ◽  
Author(s):  
Houyun Zhou ◽  
Jianxin Zhao ◽  
Pingzhong Zhang ◽  
Chuan-Chou Shen ◽  
Baoquan Chi ◽  
...  
Keyword(s):  
East Asia ◽  
Summer Monsoon ◽  
North Atlantic ◽  
Asian Summer Monsoon ◽  
North Atlantic Region ◽  
Atlantic Region ◽  
Oxygen Isotope Stage ◽  
The North ◽  
Asian Summer ◽  
The North Atlantic

AbstractThe Asian monsoon is an important component of the global climate system. Seasonal variations in wind, rainfall, and temperature associated with the Asian monsoon systems affect a vast expanse of tropical and subtropical Asia. Speleothem-derived summer monsoon variation in East Asia was previously found to be closely associated with millennial-scale change in temperature in the North Atlantic region between 75 and 10 ka. New evidence recovered from East Asia, however, suggests that the teleconnection between summer monsoon in East Asia and temperature change in the North Atlantic region may have significantly reduced during 120 to ~ 110 ka, a period directly after the full last interglaciation and corresponding roughly to marine oxygen isotope stage 5d. This reduction may be due to the low ice volume in the North Hemisphere at that time, which makes the millennial-scale change in temperature in the North Atlantic region less effective in influencing the Asian summer monsoon. This is important for investigating the mechanisms controlling the Asian summer monsoon and the paleoclimatic teleconnection between East Asia and the North Atlantic region, and for predicting monsoon-associated precipitation in East Asia under a global-warming trend.

scholarly journals Potential CO2 forcing and Asian summer monsoon precipitation trends during the last 2,000 years

2021 ◽  
Vol 13 (1) ◽  
pp. 1552-1560
Author(s):  
Weihe Ren ◽  
Quan Li ◽  
Feng Qin ◽  
Guitian Yi
Keyword(s):  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Dominant Factor ◽  
Monsoon Precipitation ◽  
Monsoon Climate ◽  
Solar Insolation ◽  
Physical Mechanisms ◽  
Humid Condition ◽  
Climate Reconstructions ◽  
Asian Summer

Abstract Holocene records for the Asian Summer Monsoon (ASM) indicate that, apart for the last 2,000 years (“2 kyr shift”), solar insolation was the dominant factor controlling the monsoon climate. The aim of this review is to provide a synopsis of climate characteristics over the last 2 kyr, clarifying mechanisms for the diverse trend with Northern Hemisphere Summer Insolation (NHSI) records. Here, we initially review proxy-based climate reconstructions for the last 2 kyr, and then compare them with records from the last five interglacial periods. Finally, we examine potential physical mechanisms responsible for the “2 kyr shift.” Findings from this review indicate that the “2 kyr shift” is a representative pattern of Holocene climate change within the core area of the ASM, and the “2 kyr shift” could be mainly controlled by changes in atmospheric CO2 concentration. In addition, suggestions to address a more humid condition dominating the Asian monsoonal margin zones are offered.

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