Late Holocene Indian summer monsoon precipitation history at Lake Lugu, northwestern Yunnan Province, southwestern China

Earth Surf Processes Landf

et al. 2016

Self Cite

Multi‐proxy indices retrieved from sediments in Lake Chaonaqiu, an alpine lake on the western Loess Plateau (LP) of China, were used to reconstruct a precipitation history over the last ~300 years. The results correlate well with records from tree rings and historical documents in neighboring regions. We show that the lake oscillated between two states, i.e. wetter climatic conditions, which favored denser vegetation cover, and promoted weaker catchment soil erosion; and drier climatic conditions, which lead to less vegetation coverage, correlate with stronger surface soil erosion. Several intensive soil erosion events were identified in the sediment cores, and most of these occurred during decadal/multi‐decadal dry periods, and correlate well with flood events documented in historical literature. The results of this study show that soil erosion by flood events is particularly intense during dry periods, and further highlights the role of vegetation cover in the conservation of water and soil in small lake basins on the Chinese LP. Copyright © 2016 John Wiley & Sons, Ltd.

Section: Discussionmentioning

confidence: 99%

Climate change and soil erosion in a small alpine lake basin on the Loess Plateau, China

Earth Surf Processes Landf

et al. 2016

Self Cite

“…3 ) 7 12 . Sediment grain size at Lake Lugu increased as compared with those both before and after the LIA 13 ( Fig. 3 ).…”

Section: Climatic Changes Over S-etp Areasmentioning

confidence: 92%

“…3 ), suggesting weakened surface runoff intensity 13 . Both TOC content and C/N ratio values of sedimentary organic matter from Lake Lugu decreased appreciably as well, suggesting decreased influx of terrestrial organic matter due to decreased monsoon precipitation during this period 13 .…”

Section: Climatic Changes Over S-etp Areasmentioning

confidence: 99%

Hydroclimatic contrasts over Asian monsoon areas and linkages to tropical Pacific SSTs

Sheng

et al. 2016

Sci Rep

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Knowledge of spatial and temporal hydroclimatic differences is critical in understanding climatic mechanisms. Here we show striking hydroclimatic contrasts between northern and southern parts of the eastern margin of the Tibetan Plateau (ETP), and those between East Asian summer monsoon (EASM) and Indian summer monsoon (ISM) areas during the past ~2,000 years. During the Medieval Period, and the last 100 to 200 years, the southern ETP (S-ETP) area was generally dry (on average), while the northern ETP (N-ETP) area was wet. During the Little Ice Age (LIA), hydroclimate over S-ETP areas was wet, while that over N-ETP area was dry (on average). Such hydroclimatic contrasts can be broadly extended to ISM and EASM areas. We contend that changes in sea surface temperatures (SSTs) of the tropical Pacific Ocean could have played important roles in producing these hydroclimatic contrasts, by forcing the north-south movement of the Intertropical Convergence Zone (ITCZ) and intensification/slowdown of Walker circulation. The results of sensitivity experiments also support such a proposition.

“…Linear regression method has been widely used to estimate the old carbon reservoir age (e.g., Fontes et al, 1996;Sheng et al, 2015;Zhang et al, 2016). Ages of the surface sediments are generally considered to be the time when they were sampled, then the intercept between the linear regression line and age coordinate (at the water-sediment interface) is regarded as the carbon reservoir age.…”

Section: Linear Regressionmentioning

confidence: 99%

Variable Late Holocene 14C Reservoir Ages in Lake Bosten, Northwestern China

et al. 2020

Front. Earth Sci.

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Radiocarbon (14 C) dating has been widely used in paleoclimate reconstruction. However, the reliability of the 14 C age in lake sediments is sensitive to the 14 C reservoir effect, especially for a lake in arid regions. In this study, we evaluated the 14 C reservoir ages under different hydroclimatic conditions over the past ∼2300 years in Lake Bosten, northwestern China, by comparing with different dating results and with multi-proxy indices of a vertical-down sediment core collected in this lake. The 14 C reservoir ages during ∼1800 to 650 BP (a dry interval) are estimated to be approximately 1170 years older than those during ∼650-100 BP and those during 2200-1800 BP (wet intervals). We proposed that variation in 14 C exchange rate between the dissolved CO 2 in lake water and CO 2 in the atmosphere, as well as the changing proportion of organic matter in the lake and the catchment, could have contributed to the variable 14 C reservoir ages in Lake Bosten. The result of this study suggests that the 14 C reservoir effect may be larger in dry periods than in wet periods in the arid/semi-arid area, which should be considered when establishing age models of lake sediment cores from these regions.