A study of Holocene Asian summer and winter monsoon change by an analog of climate factors between millennial and modern interannual scales

2019 ◽  
Vol 44 (3) ◽  
pp. 315-337
Author(s):  
Yu Li ◽  
Yichan Li ◽  
Wangting Ye ◽  
Simin Peng
Keyword(s):  
Asian Monsoon ◽  
East Asian Monsoon ◽  
East Asian ◽  
Driving Mechanism ◽  
Climatic Data ◽  
Low Latitude ◽  
Global Circulation ◽  
Asian Summer ◽  
Winter Insolation ◽  
Monsoon Indices

The East Asian monsoon exerts a profound influence on environmental change in the East Asian region. Various factors have been hypothesized as the dominant Asian monsoon forcings, however, the forcings can change from interannual to millennial timescales. The linkages between monsoon forcings at different timescales remain unclear. To better understand the connection of the variabilities and mechanisms of the East Asian monsoon at various timescales, we present a modern analog. Various climatic data, monsoon indices, and circulation factor calculations were used to identify the variabilities and controlling factors of the modern East Asian summer and winter monsoons. Paleo-climatic proxies from a region sensitive to both summer and winter monsoons were used in concert with monsoon simulation data to reconstruct and analyze paleo-monsoon variations and mechanisms. Results showed that the weakening of the Holocene Asian summer and winter monsoons is closely linked to low-latitude summer insolation and mid-latitude winter insolation, while modern summer and winter monsoons are related to global circulation, sea surface temperature, and sea ice change. We confirm that the driving mechanism of the monsoon was dependent on timescale.

scholarly journals Three exceptionally strong East-Asian summer monsoon events during glacial conditions in the past 470 kyr

2008 ◽  
Vol 4 (6) ◽  
pp. 1289-1317 ◽  
Author(s):  
D.-D. Rousseau ◽  
N. Wu ◽  
Y. Pei ◽  
F. Li
Keyword(s):  
Summer Monsoon ◽  
Asian Monsoon ◽  
East Asian Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Precipitation Regime ◽  
The Past ◽  
Ecological Requirements ◽  
Asian Summer ◽  
The Tropics

Abstract. Chinese loess sequences are interpreted as a reliable record of the past variation of the East Asian monsoon regime through the alternation of loess and paleosols units, dominated by the winter and summer monsoon, respectively. Different proxies have been used to describe this system, mostly geophysical, geochemical or sedimentological. Terrestrial mollusks are also a reliable proxy of past environmental conditions and are often preserved in large numbers in loess deposits. The analysis of the mollusk remains in the Luochuan sequence, comprising L5 loess to S0 soil, i.e. the last 500 ka, shows that for almost all identified species, the abundance is higher at the base of the interval (L5 to L4) than in the younger deposits. Using the present ecological requirements of the identified mollusk species in the Luochuan sequence allows the definition of two main mollusk groups varying during the last 500 kyr. The cold-aridiphilous individuals indicate the so-called Asian winter monsoon regime and predominantly occur during glacials, when dust is deposited. The thermal-humidiphilous mollusks are prevalent during interglacial or interstadial conditions of the Asian summer monsoon, when soil formation takes place. In the sequence, three events with exceptionally high abundance of the Asian summer monsoon indicators are recorded during the L5, L4 and L2 glacial intervals, i.e., at about 470, 360 and 170 kyr, respectively. The L5 and L4 events appear to be the strongest (high counts). Similar variations have also been identified in the Xifeng sequence, distant enough from Luochuan, but also in Lake Baikal further North, to suggest that this phenomenon is regional rather than local. The indicators of the summer monsoon within the glacial intervals imply a strengthened East-Asian monsoon interpreted as corresponding to marine isotope stages 6, 10 and 12, respectively. The L5 and L2 summer monsoons are coeval with Mediterranean sapropels S12 and S6, which characterize a strong African summer monsoon with relatively low surface water salinity in the Indian Ocean. Changes in the precipitation regime could correspond to a response to a particular astronomical configuration (low obliquity, low precession, summer solstice at perihelion) leading to an increased summer insolation gradient between the tropics and the high latitudes and resulting in enhanced atmospheric water transport from the tropics to the African and Asian continents. However, other climate drivers such as reorganization of marine and atmospheric circulations, tectonic, and the extent of the Northern Hemisphere ice sheet are also discussed.

scholarly journals Combined high- and low-latitude forcing of East Asian monsoon precipitation variability in the Pliocene warm period

2020 ◽  
Vol 6 (46) ◽  
pp. eabc2414
Author(s):  
Yichao Wang ◽  
Huayu Lu ◽  
Kexin Wang ◽  
Yao Wang ◽  
Yongxiang Li ◽  
...  
Keyword(s):  
Asian Monsoon ◽  
East Asian Monsoon ◽  
East Asian ◽  
Central China ◽  
Critical Threshold ◽  
Monsoon Precipitation ◽  
Low Latitude ◽  
Monsoon Variability ◽  
Precipitation Record ◽  
Response To Temperature

East Asian monsoon variability in the Pliocene warm world has not been sufficiently studied because of the lack of direct records. We present a high-resolution precipitation record from Pliocene fluvial-lacustrine sequences in the Weihe Basin, Central China, a region sensitive to the East Asian monsoon. The record shows an abrupt monsoon shift at ~4.2 million years ago, interpreted as the result of high-latitude cooling, with an extratropical temperature decrease across a critical threshold. The precipitation time series exhibits a pronounced ~100–thousand year periodicity and the presence of precession and half-precession cycles, which suggest low-latitude forcing. The synchronous phase but mismatched amplitudes of the East Asian monsoon precipitation proxy and eccentricity suggest a nonlinear but sensitive precipitation response to temperature forcing in the Pliocene warm world. These observations highlight the role of high- and low-latitude forcing of East Asian monsoon variations on tectonic and orbital time scales.

scholarly journals Mid-Pliocene East Asian monsoon climate simulated in the PlioMIP

2013 ◽  
Vol 9 (5) ◽  
pp. 2085-2099 ◽  
Author(s):  
R. Zhang ◽  
Q. Yan ◽  
Z. S. Zhang ◽  
D. Jiang ◽  
B. L. Otto-Bliesner ◽  
...  
Keyword(s):  
Asian Monsoon ◽  
Climate Models ◽  
East Asian Monsoon ◽  
Regional Climate ◽  
East Asian ◽  
Monsoon Climate ◽  
Ensemble Mean ◽  
Intercomparison Project ◽  
Asian Summer ◽  
Future Work

Abstract. Based on simulations with 15 climate models in the Pliocene Model Intercomparison Project (PlioMIP), the regional climate of East Asia (focusing on China) during the mid-Pliocene is investigated in this study. Compared to the pre-industrial, the multi-model ensemble mean (MMM) of all models shows the East Asian summer winds (EASWs) largely strengthen in monsoon China, and the East Asian winter winds (EAWWs) strengthen in south monsoon China but slightly weaken in north monsoon China in the mid-Pliocene. The MMM of all models also illustrates a warmer and wetter mid-Pliocene climate in China. The simulated weakened mid-Pliocene EAWWs in north monsoon China and intensified EASWs in monsoon China agree well with geological reconstructions. However, there is a large model–model discrepancy in simulating mid-Pliocene EAWW, which should be further addressed in the future work of PlioMIP.

scholarly journals Monthly insolation linked to the time-transgressive nature of the Holocene East Asian monsoon precipitation maximum

Geology ◽  
2021 ◽  
Author(s):  
Xin Zhou ◽  
Tao Zhan ◽  
Luyao Tu ◽  
John P. Smol ◽  
Shiwei Jiang ◽  
...  
Keyword(s):  
Asian Monsoon ◽  
East Asian Monsoon ◽  
East Asian ◽  
Western Pacific Subtropical High ◽  
Spatiotemporal Patterns ◽  
Monsoon Precipitation ◽  
Low Latitude ◽  
The Holocene ◽  
Forcing Mechanisms ◽  
Precipitation Changes

More than 10% of the world’s population lives in the East Asian monsoon (EAM) region, where precipitation patterns are critical to agricultural and industrial activities. However, the dominant forcing mechanisms driving spatiotemporal changes in the EAM remain unclear. We selected Holocene records tracking monsoon precipitation in the EAM region reconstructed from pollen data to explore the spatiotemporal patterns of monsoon precipitation changes. Our analysis shows a time-transgressive pattern of maximum precipitation, with earlier occurrence in the southern area and later occurrence in the northern area. The monthly insolation changes force monsoon precipitation in different parts of the EAM region through a shift in the Western Pacific Subtropical High. We conclude that low-latitude monthly insolation changes (rather than average summer insolation changes) were the main forcing mechanisms of the spatiotemporal patterns of the monsoon precipitation maximum during the Holocene.

scholarly journals East Asian monsoon climate simulated in the PlioMIP

2013 ◽  
Vol 9 (1) ◽  
pp. 1135-1164 ◽  
Author(s):  
R. Zhang ◽  
Q. Yan ◽  
Z. S. Zhang ◽  
D. Jiang ◽  
B. L. Otto-Bliesner ◽  
...  
Keyword(s):  
Asian Monsoon ◽  
Climate Models ◽  
East Asian Monsoon ◽  
Regional Climate ◽  
East Asian ◽  
Monsoon Climate ◽  
Ensemble Mean ◽  
Intercomparison Project ◽  
Asian Summer ◽  
Future Work

Abstract. Based on the simulations with fifteen climate models in the Pliocene Model Intercomparison Project (PlioMIP), the regional climate of East Asia (focusing on China) during the mid-Pliocene is investigated in this study. Compared to the pre-industrial, the multi-model ensemble mean (MMM) of all models shows the East Asian summer wind (EASW) largely strengthens in monsoon China, and the East Asian winter wind (EAWW) strengthens in south monsoon China but slightly weakens in north monsoon China in mid-Pliocene. The MMM of all models also illustrates a warmer and wetter mid-Pliocene climate in China. The simulated weakened mid-Pliocene EAWW in north monsoon China and intensified EASW in monsoon China agree well with geological reconstructions. However, the model-model discrepancy in simulating mid-Pliocene East Asian monsoon climate, in particular EAWW, should be further addressed in the future work of PlioMIP.

High and low- latitude forcing of East Asian monsoon precipitation change during the late Pliocene

2021 ◽  
Author(s):  
Hansheng Wang ◽  
Junsheng Nie ◽  
Zeng Luo
Keyword(s):  
Asian Monsoon ◽  
East Asian Monsoon ◽  
East Asian ◽  
Large Population ◽  
Ice Sheets ◽  
Chinese Loess Plateau ◽  
Monsoon Precipitation ◽  
Low Latitude ◽  
Late Pliocene ◽  
Precipitation Record

<p>3.6 Ma represents a time period when Earth transitioned from single pole ice sheets to permanent ice sheets existing in both hemispheres. However, it remains unclear how this transition had its impact on East Asian summer monsoon system, which controls living of a large population. Here, we present a high-resolution (2~4 kyr) monsoon precipitation record from the Chaona section on the central Chinese Loess Plateau during the 3.95-2.95 Ma, using the magnetic parameter-based precipitation proxy (χfd/HIRM). The results reveal intensified precessional and semiprecessional fluctuations during high eccentricity, emphasizing direction role of low latitude insolation played in forcing Asian monsoon precipitation. The precipitation records also show that the 41-kyr cycles intensified after 3.3 Ma, in contrast with decreased obliquity variation amplitude of summer insolation. We interpret the enlarged 41-kyr precipitation cycles in our records as a result of high latitude ice sheet forcing. Together, our work provides an example demonstrating both high and low latitude forcing of Asian monsoon precipitation during the late Pliocene.</p>

scholarly journals The East Asian Monsoon During MIS 2 Expressed in a Speleothem δ18O Record From Jintanwan Cave, Hunan, China

2010 ◽  
Vol 73 (3) ◽  
pp. 541-549 ◽  
Author(s):  
Jason Cosford ◽  
Hairuo Qing ◽  
Yin Lin ◽  
Bruce Eglington ◽  
Dave Mattey ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
East Asian Summer Monsoon ◽  
Asian Monsoon ◽  
East Asian Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Climatic Changes ◽  
Decadal Scale ◽  
Socotra Island ◽  
Asian Summer

Stalagmite J1 from Jintanwan Cave, Hunan, China, provides a precisely dated, decadally resolved δ18O proxy record of paleoclimatic changes associated with the East Asian monsoon from ∽29.5 to 14.7 ka and from ∽12.9 to 11.0 ka. At the time of the last glacial maximum (LGM), the East Asian summer monsoon weakened and then strengthened in response to changes in Northern Hemisphere insolation. As the ice sheets retreated the East Asian summer monsoon weakened, especially during Heinrich event H1, when atmospheric and oceanic teleconnections transferred the climatic changes around the North Atlantic to the monsoonal regions of Eastern Asia. A depositional hiatus between ∽14.7 and 12.9 ka leaves the deglacial record incomplete, but an abrupt shift in δ18O values at ∽11.5 ka marks the end of the Younger Dryas and the transition into the Holocene. Comparisons of the J1 record to other Chinese speleothem records indicate synchronous climatic changes throughout monsoonal China. Further comparisons to a speleothem record from western Asia (Socotra Island) and to Greenland ice cores support hemispherical-scale paleoclimatic change. Spectral and wavelet analyses reveal centennial- and decadal-scale periodicities that correspond to solar frequencies and to oscillations in atmospheric and oceanic circulation.

scholarly journals Three exceptionally strong East-Asian summer monsoon events during glacial times in the past 470 kyr

2009 ◽  
Vol 5 (2) ◽  
pp. 157-169 ◽  
Author(s):  
D.-D. Rousseau ◽  
N. Wu ◽  
Y. Pei ◽  
F. Li
Keyword(s):  
Summer Monsoon ◽  
Asian Monsoon ◽  
East Asian Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Precipitation Regime ◽  
The Past ◽  
Ecological Requirements ◽  
Asian Summer ◽  
The Tropics

Abstract. Chinese loess sequences are interpreted as a reliable record of the past variation of the East Asian monsoon regime through the alternation of loess and paleosols units, dominated by the winter and summer monsoon, respectively. Different proxies have been used to describe this system, mostly geophysical, geochemical or sedimentological. Terrestrial mollusks are also a reliable proxy of past environmental conditions and are often preserved in large numbers in loess deposits. The analysis of the mollusk remains in the Luochuan sequence, comprising L5 loess to S0 soil, i.e. the last 500 ka, shows that for almost all identified species, the abundance is higher at the base of the interval (L5 to L4) than in the younger deposits. Using the present ecological requirements of the identified mollusk species in the Luochuan sequence allows the definition of two main mollusk groups varying during the last 500 kyr. The cold-aridiphilous individuals indicate the so-called Asian winter monsoon regime and predominantly occur during glacials, when dust is deposited. The thermal-humidiphilous mollusks are prevalent during interglacial or interstadial conditions of the Asian summer monsoon, when soil formation takes place. In the sequence, three events with exceptionally high abundance of the Asian summer monsoon indicators are recorded during the L5, L4 and L2 glacial intervals, i.e., at about 470, 360 and 170 kyr, respectively. The L5 and L4 events appear to be the strongest (high counts). Similar variations have also been identified in the Xifeng sequence, distant enough from Luochuan, but also in Lake Baikal further North, to suggest that this phenomenon is regional rather than local. The indicators of the summer monsoon within the glacial intervals imply a strengthened East-Asian monsoon interpreted as corresponding to marine isotope stages 12, 10 and 6, respectively. The L5 and L2 summer monsoons are coeval with Mediterranean sapropels S12 and S6, which characterize a strong African summer monsoon with relatively low surface water salinity in the Indian Ocean. Changes in the precipitation regime could correspond to a response to a particular astronomical configuration (low obliquity, low precession, summer solstice at perihelion) leading to an increased summer insolation gradient between the tropics and the high latitudes and resulting in enhanced atmospheric water transport from the tropics to the African and Asian continents. However, other climate drivers such as reorganization of marine and atmospheric circulations, tectonic, and the extent of the Northern Hemisphere ice sheet are also discussed.

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.

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