A dominance of the East Asian monsoon in the southeast Qaidam Basin during the mid- to late Holocene

2019 ◽  
Author(s):  
SJ Zhao ◽  
W Sun ◽  
HY Pei ◽  
H Yang ◽  
SC Xie
Keyword(s):  
Late Holocene ◽  
Asian Monsoon ◽  
East Asian Monsoon ◽  
Qaidam Basin ◽  
East Asian

Holocene climate variations from Zhuyeze terminal lake records in East Asian monsoon margin in arid northern China

2010 ◽  
Vol 74 (1) ◽  
pp. 46-56 ◽  
Author(s):  
Hao Long ◽  
ZhongPing Lai ◽  
NaiAng Wang ◽  
Yu Li
Keyword(s):  
Late Holocene ◽  
Asian Monsoon ◽  
East Asian Monsoon ◽  
East Asian ◽  
Northern China ◽  
Optically Stimulated Luminescence ◽  
Early Holocene ◽  
Climate Variations ◽  
The Holocene ◽  
Geomorphic Features

AbstractZhuyeze palaeolake is a terminal lake situated in the arid northern China in the East Asian monsoon margin. In order to examine the Holocene palaeoclimatic change in the East Asian monsoon margin, Qingtu Lake section (QTL) from Zhuyeze palaeolake is sampled in high resolution. Palaeoclimatic proxies such as grain size, carbonate, TOC, C/N and δ13C of organic matter, were analyzed; eleven 14C samples and six optically stimulated luminescence (OSL) samples were dated to provide chronological control. We also investigated the geomorphic features of lake shorelines in this area. The results show that the climate was warm and dry in early-Holocene (9.5–7.0 cal ka BP), cool and humid in mid-Holocene (7.0–4.8 cal ka BP), and increasingly drier in late-Holocene (since 4.8 cal ka BP). Comparisons of our records with other records in adjacent areas, as well as with the records in the Asian monsoon areas, suggested that changes in effective moisture was synchronous in East Asian monsoon marginal zone (i.e. the pattern of dry early-Holocene, humid mid-Holocene, and aridity-increasing late-Holocene), and that the moisture optimum during the Holocene was out-of-phase between Asian monsoon margin and Asian monsoonal dominated region, possibly due to the high temperature at that time.

scholarly journals Reconstruction of Climate Changes on Based δ18Ocarb on the Northeastern Tibetan Plateau: A 16.1-cal kyr BP Record From Hurleg Lake

2021 ◽  
Vol 9 ◽  
Author(s):  
Xueyun Ma ◽  
Zhifu Wei ◽  
Yongli Wang ◽  
Gen Wang ◽  
Ting Zhang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Late Holocene ◽  
Asian Monsoon ◽  
East Asian Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Climatic Conditions ◽  
The Tibetan Plateau ◽  
Moisture Variation ◽  
Wet Climate

Hydroclimate evolution history and changes in the Tibetan Plateau play significant roles in depicting paleoclimate and evaluating climatic conditions in the coming future. However, the interaction of the westerlies and the Asian monsoon complicates our understanding of the mechanism of climate variation over the Tibetan Plateau. In this study, we assessed the paleoclimate of Hurleg Lake, which was previously located in the convergence area of the East Asian monsoon and westerly wind. We first reconstructed the climatic conditions based on fined-grained authigenic carbonate δ18O (δ18Ocarb), plant-derived proxies of C/N, and n-alkane-derived δ13C31. In the Hurleg Lake, δ18Ocarb was controlled by δ18O changes of the lake water and evaporation. The climate evolution since ∼16.1 cal kyr BP can be classified into three stages. The Lateglacial (16.1–11.0 cal kyr BP) was characterized by a warm-wet climate in the beginning, followed by a cold-dry climate since 12.0 cal kyr BP. Typical warm and cold phases occurred during 14.8–12.0 cal kyr BP and 12.0–11.1 cal kyr BP, which may correspond to the Bølling/Allerød (B/A) and Younger Dryas periods, respectively. The early to mid-Holocene was generally characterized by a warm-wet climate; however, notable cold-dry intervals occurred at ∼8.3 cal kyr BP. The Late Holocene (after 4.8 cal kyr BP) displayed a significantly cold-wet climate. Finally, we examined the possible mechanisms responsible for the climate variability in the study area. The results showed that the long-term warm trend in the Lateglacial and colder trend after early Holocene was controlled by insolation. The Asian summer monsoon and the westerlies played a significant role in determining moisture sources during the Lateglacial. The East Asian monsoon contributed greatly to the moisture variation from the early to mid-Holocene, whereas the westerly winds dominated during the late Holocene. Combined, our findings highlight the complex changes in hydroclimate conditions since the last glacial in the Tibetan Plateau and provide crucial implications for comprehending the hydroclimate pattern in the transition zone of westerlies and Asian monsoon.

scholarly journals Linking Holocene East Asian monsoon variability to solar forcing and ENSO activity: Multi-proxy evidence from a peatland in Northeastern China

The Holocene ◽  
2021 ◽  
pp. 095968362199466
Author(s):  
Nannan Li ◽  
Arash Sharifi ◽  
Frank M Chambers ◽  
Yong Ge ◽  
Nathalie Dubois ◽  
...  
Keyword(s):  
Asian Monsoon ◽  
East Asian Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Northeastern China ◽  
Solar Irradiation ◽  
Enso Events ◽  
Monsoon Area ◽  
Wavelet Coherency ◽  
Cross Wavelet

High-resolution proxy-based paleoenvironmental records derived from peatlands provide important insights into climate changes over centennial to millennial timescales. In this study, we present a composite climatic index (CCI) for the Hani peatland from northeastern China, based on an innovative combination of pollen-spore, phytolith, and grain size data. We use the CCI to reconstruct variations of the East Asian summer monsoon (EASM) intensity during the Holocene. This is accomplished with complete ensemble empirical mode decomposition (CEEMD), REDFIT, and cross-wavelet coherency analysis to reveal the periodicities (frequencies) of the multi-proxy derived CCI sequences and to assess potential external forcing of the EASM. The results showed that periodicities of ca. 300–350, 475, 600, 1075, and 1875 years were present in the Hani CCI sequence. Those periodicities are consistent with previously published periodicities in East Asia, indicating they are a product of external climate controls over an extensive region, rather than random variations caused by peatland-specific factors. Cross-wavelet coherency analysis between the decomposed CCI components and past solar activity reconstructions suggests that variations of solar irradiation are most likely responsible for the cyclic characteristics at 500-year frequency. We propose a conceptual model to interpret how the sun regulates the monsoon climate via coupling with oceanic and atmospheric circulations. It seems that slight solar irradiation changes can be amplified by coupling with ENSO events, which result in a significant impact on the regional climate in the East Asian monsoon area.

scholarly journals Changes in Paleovegetation and Paleoclimate in China Since the Late Middle Pleistocene: A Case Study of the Dajiuhu Basin

2021 ◽  
Vol 13 (9) ◽  
pp. 4848
Author(s):  
Liwei Wu ◽  
Xinling Li ◽  
Qinghai Xu ◽  
Manyue Li ◽  
Qiufeng Zheng ◽  
...  
Keyword(s):  
Grain Size ◽  
Asian Monsoon ◽  
East Asian Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Central China ◽  
Middle Pleistocene ◽  
Pollen Record ◽  
The Difference ◽  
Late Middle Pleistocene

The East Asian monsoon system is an important part of global atmospheric circulation; however, records of the East Asian monsoon from different regions exhibit different evolutionary rhythms. Here, we show a high-resolution record of grain size and pollen data from a lacustrine sediment core of Dajiuhu Lake in Shennongjia, Hubei Province, China, in order to reconstruct the paleovegetation and paleoeclimate evolution of the Dajiuhu Basin since the late Middle Pleistocene (~237.9 ka to the present). The results show that grain size and pollen record of the core DJH-2 are consistent with the δ18O record of stalagmites from Sanbao Cave in the same area, which is closely related to the changes of insolation at the precessional (~20-kyr) scale in the Northern Hemisphere. This is different from the records of the Asian summer monsoon recorded in the Loess Plateau of North China, which exhibited dominant 100-kyr change cyclicities. We suggest that the difference between paleoclimatic records from North and South China is closely related to the east–west-oriented mountain ranges of the Qinling Mountains in central China that blocked weakened East Asia summer monsoons across the mountains during glacial periods.

scholarly journals Tectonic and climatic drivers of Asian monsoon evolution

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
James R. Thomson ◽  
Philip B. Holden ◽  
Pallavi Anand ◽  
Neil R. Edwards ◽  
Cécile A. Porchier ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
Indian Summer Monsoon ◽  
Asian Monsoon ◽  
Monsoon Rainfall ◽  
East Asian Monsoon ◽  
East Asian ◽  
Meridional Overturning Circulation ◽  
Great Debate ◽  
Climatic Drivers ◽  
Meridional Overturning

AbstractAsian Monsoon rainfall supports the livelihood of billions of people, yet the relative importance of different drivers remains an issue of great debate. Here, we present 30 million-year model-based reconstructions of Indian summer monsoon and South East Asian monsoon rainfall at millennial resolution. We show that precession is the dominant direct driver of orbital variability, although variability on obliquity timescales is driven through the ice sheets. Orographic development dominated the evolution of the South East Asian monsoon, but Indian summer monsoon evolution involved a complex mix of contributions from orography (39%), precession (25%), atmospheric CO2 (21%), ice-sheet state (5%) and ocean gateways (5%). Prior to 15 Ma, the Indian summer monsoon was broadly stable, albeit with substantial orbital variability. From 15 Ma to 5 Ma, strengthening was driven by a combination of orography and glaciation, while closure of the Panama gateway provided the prerequisite for the modern Indian summer monsoon state through a strengthened Atlantic meridional overturning circulation.

scholarly journals Effect of the El Niño Decaying Pace on the East Asian Summer Monsoon Circulation Pattern during Post-El Niño Summers

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 140
Author(s):  
Wenping Jiang ◽  
Gen Li ◽  
Gongjie Wang
Keyword(s):  
El Niño ◽  
Asian Monsoon ◽  
East Asian Monsoon ◽  
El Nino ◽  
East Asian ◽  
Circulation Pattern ◽  
Northwest Pacific ◽  
Monsoon Circulation ◽  
Circulation Patterns ◽  
Sst Anomalies

El Niño events vary from case to case with different decaying paces. In this study, we demonstrate that the different El Niño decaying paces have distinct impacts on the East Asian monsoon circulation pattern during post-El Niño summers. For fast decaying (FD) El Niño summers, a large-scale anomalous anticyclone dominates over East Asia and the North Pacific from subtropical to mid-latitude; whereas, the East Asian monsoon circulation display a dipole pattern with anomalous northern cyclone and southern anticyclone for slow decaying (SD) El Niño summers. The difference in anomalous East Asian monsoon circulation patterns was closely associated with the sea surface temperature (SST) anomaly patterns in the tropics. In FD El Niño summers, the cold SST anomalies in the tropical central-eastern Pacific and warm SST anomalies in the Maritime Continent induce the anticyclone anomalies over the Northwest Pacific. In contrast, the warm Kelvin wave anchored over the tropical Indian Ocean during SD El Niño summers plays a crucial role in sustaining the anticyclone anomalies over the Northwest Pacific. In particular, the opposite atmospheric circulation anomaly patterns over Northeast Asia and the mid-latitude North Pacific are mainly modulated by the stationary Rossby wave trains triggered by the opposite SST anomalies in the tropical eastern Pacific during FD and SD El Niño summers. Finally, the effect of distinct summer monsoon circulation patterns associated with the El Niño decay pace on the summer climate over East Asia are also discussed.

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