Variation of summer monsoon intensity on the Loess Plateau of Central China during the last 130 000 a

1997 ◽  
Vol 42 (6) ◽  
pp. 473-476 ◽  
Author(s):  
Jun Chen ◽  
Gang Qiu ◽  
Huayu Lu ◽  
Junfeng Ji
Keyword(s):  
Loess Plateau ◽  
Summer Monsoon ◽  
Central China ◽  
The Loess Plateau ◽  
Monsoon Intensity

Magnetic susceptibility evidence of monsoon variation on the Loess Plateau of central China during the last 130,000 years

1991 ◽  
Vol 36 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Zhisheng An ◽  
George J. Kukla ◽  
Stephen C. Porter ◽  
Jule Xiao
Keyword(s):  
Magnetic Susceptibility ◽  
Loess Plateau ◽  
Summer Monsoon ◽  
Central China ◽  
Chinese Loess Plateau ◽  
Climate Index ◽  
Chinese Loess ◽  
Monsoon Variability ◽  
Monsoon Intensity ◽  
Isotope Record

AbstractThe magnetic susceptibility of loess and paleosols in central China represents a proxy climate index closely related to past changes of precipitation and vegetation, and thus to summer monsoon intensity. Time series of magnetic susceptibility constructed for three loess-paleosol sequences in the southern part of the Chinese Loess Plateau document the history of summer monsoon variation during the last 130,000 yr. They correlate closely with the oxygen isotope record of stages 1 to 5 in deep-sea sediments. Soils were forming during intervals of strong summer monsoon, whereas loess units were deposited at times of reduced monsoon intensity. The Chinese loess-paleosol sequence can thus be viewed as a proxy record of Asian monsoon variability extending over the last 2.5 myr.

scholarly journals Chronology of the Baxie Loess Profile and the History of Monsoon Climates in China Between 17,000 and 6000 Years BP

Radiocarbon ◽  
1992 ◽  
Vol 34 (3) ◽  
pp. 818-825 ◽  
Author(s):  
Weijian Zhou ◽  
Zhisheng An ◽  
Benhai Lin ◽  
Jule Xiao ◽  
Jinzhao Zhang ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Organic Content ◽  
Central China ◽  
Organic Component ◽  
Monsoon Circulation ◽  
The Loess Plateau ◽  
Asian Summer ◽  
Loess Profile

The valley of the Baxie River, situated in the western region of the Loess Plateau in central China, contains a loess profile 15 m thick, which can be considered representative of loess-paleosol sequences formed over the last 17 ka. Both thermoluminescence (TL) determinations on fine-grained sediment (4–11 μm) and 14C determinations on various organic fractions of paleosols from the profile have provided an extremely useful chronological framework for these sequences. These sequences indicate a weakened summer monsoon during the last glacial maximum followed by a strengthening of the summer monsoon, beginning ca. 13 ka cal bp. An abrupt change to a weakened summer monsoon regime lasted from ca. 10.9 to 10.2 ka cal bp. The Asian summer monsoon circulation, recording the Holocene optimum, then increased and lasted from ca. 10.2 to 6 ka cal bp. The organic component of samples taken down the profile has δ13C values ranging from −21 to −24‰ with respect to the PDB standard. The more positive δ13C values suggest that the proportion of C4-type plants in river valleys of the Loess Plateau increased as Asian summer monsoon influence weakened, and C3-type vegetation increased as the summer monsoon influence strengthened. Magnetic susceptibility and organic content were low during loess deposition, also reflecting weakening of summer monsoon. Two 14C determinations on the humin fraction of the organic component near the top of the lower paleosol and the base of the upper paleosol complex gave ages of 10.2 and 10.9 ka cal BP, respectively. These ages mark the beginning and termination of a brief event involving increased dust influx under weakened summer monsoon conditions.

scholarly journals Effects of climatic variability and human activity on runoff in the Loess Plateau of China

2013 ◽  
Vol 89 (02) ◽  
pp. 153-161 ◽  
Author(s):  
Yang Zhao ◽  
Xinxiao Yu
Keyword(s):  
Soil Water ◽  
Loess Plateau ◽  
Water Conservation ◽  
Human Activities ◽  
Climatic Variability ◽  
Land Use Changes ◽  
Annual Runoff ◽  
Central China ◽  
Vegetative Cover ◽  
The Loess Plateau

The Loess Plateau in north-central China has a long history of human activities. As a result of climate change, deforestation and sparse vegetative cover, the region suffers from water shortages and severe soil erosion, significantly influencing efforts for sustainable social development. In order to understand the impacts of climatic variability and human activities on runoff and other hydrological factors in this region, the Luoyugou catchment and its paired catchments (Qiaozidong and Qiaozixi) were selected. Statistical analysis indicated precipitation did not vary significantly whereas the annual runoff decreased from 1986 to 2008, with an abrupt change in 1994. Actual evapotranspiration (AET) increased slightly but not significantly. A comparison of runoff in the paired catchments showed land use changes reduced runoff by more than 38% under the same rainfall conditions. Human activities were the strongest contributor to changes in runoff and AET, at 67% and 90% respectively, while the remaining contributor was climate variation. The influence of various human activities on runoff is quite different, and soil-water conservation initiatives have a greater impact on runoff (about 41%). Thus, human activities were the primary reason for the reduction in runoff in the study catchment compared to climate. Greater emphasis should be given to afforestation and soil-water conservation measures.

scholarly journals Shimao and Erlitou: new perspectives on the origins of the bronze industry in central China

Antiquity ◽  
2017 ◽  
Vol 91 (355) ◽  
Author(s):  
J. Rawson
Keyword(s):  
Loess Plateau ◽  
Central China ◽  
Shaanxi Province ◽  
The Loess Plateau ◽  
International Conference ◽  
Large Stone ◽  
Northern Edge ◽  
Bronze Casting

Over the last five years, excavation of a large, stone, fortified site at Shimao, on the northern edge of the Loess Plateau in Shaanxi Province, China, has radically changed our understanding of the events that precipitated the development of the first bronze casting in central China at Erlitou (Figure 1). An international conference on the Shimao site, held at Shenmu in August 2016, explored many aspects of this major discovery.

scholarly journals Variation in the Asian monsoon intensity and dry–wet conditions since the Little Ice Age in central China revealed by an aragonite stalagmite

2014 ◽  
Vol 10 (5) ◽  
pp. 1803-1816 ◽  
Author(s):  
J.-J. Yin ◽  
D.-X. Yuan ◽  
H.-C. Li ◽  
H. Cheng ◽  
T.-Y. Li ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
El Niño ◽  
El Nino ◽  
Asian Summer Monsoon ◽  
Eastern China ◽  
Central China ◽  
Solar Irradiation ◽  
Mountain Area ◽  
Monsoon Intensity ◽  
Asian Summer

Abstract. This paper focuses on the climate variability in central China since AD 1300, involving: (1) a well-dated, 1.5-year resolution stalagmite δ18O record from Lianhua Cave, central China (2) links of the δ18O record with regional dry–wet conditions, monsoon intensity, and temperature over eastern China (3) correlations among drought events in the Lianhua record, solar irradiation, and ENSO (El Niño–Southern Oscillation) variation. We present a highly precise, 230Th / U-dated, 1.5-year resolution δ18O record of an aragonite stalagmite (LHD1) collected from Lianhua Cave in the Wuling Mountain area of central China. The comparison of the δ18O record with the local instrumental record and historical documents indicates that (1) the stalagmite δ18O record reveals variations in the summer monsoon intensity and dry–wet conditions in the Wuling Mountain area. (2) A stronger East Asian summer monsoon (EASM) enhances the tropical monsoon trough controlled by ITCZ (Intertropical Convergence Zone), which produces higher spring quarter rainfall and isotopically light monsoonal moisture in the central China. (3) The summer quarter/spring quarter rainfall ratio in central China can be a potential indicator of the EASM strength: a lower ratio corresponds to stronger EASM and higher spring rainfall. The ratio changed from <1 to >1 after 1950, reflecting that the summer quarter rainfall of the study area became dominant under stronger influence of the Northwestern Pacific High. Eastern China temperatures varied with the solar activity, showing higher temperatures under stronger solar irradiation, which produced stronger summer monsoons. During Maunder, Dalton and 1900 sunspot minima, more severe drought events occurred, indicating a weakening of the summer monsoon when solar activity decreased on decadal timescales. On an interannual timescale, dry conditions in the study area prevailed under El Niño conditions, which is also supported by the spectrum analysis. Hence, our record illustrates the linkage of Asian summer monsoon precipitation to solar irradiation and ENSO: wetter conditions in the study area under stronger summer monsoon during warm periods, and vice versa. During cold periods, the Walker Circulation will shift toward the central Pacific under El Niño conditions, resulting in a further weakening of Asian summer monsoons.

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