Quantitative precipitation estimates for the northeastern Qinghai‐Tibetan Plateau over the last 18,000 years

Abstract

Quantitative information regarding the long‐term variability of precipitation and vegetation during the period covering both the Late Glacial and the Holocene on the Qinghai‐Tibetan Plateau (QTP) is scarce. Herein, we provide new and numerical reconstructions for annual mean precipitation (PANN) and vegetation history over the last 18,000 years using high‐resolution pollen data from Lakes Dalianhai and Qinghai on the northeastern QTP. Hitherto, five calibration techniques including weighted averaging, weighted average‐partial least squares regression, modern analogue technique, locally weighted weighted averaging regression, and maximum likelihood were first employed to construct robust inference models and to produce reliable PANN estimates on the QTP. The biomization method was applied for reconstructing the vegetation dynamics. The study area was dominated by steppe and characterized with a highly variable, relatively dry climate at ~18,000–11,000 cal years B.P. PANN increased since the early Holocene, obtained a maximum at ~8000–3000 cal years B.P. with coniferous‐temperate mixed forest as the dominant biome, and thereafter declined to present. The PANN reconstructions are broadly consistent with other proxy‐based paleoclimatic records from the northeastern QTP and the northern region of monsoonal China. The possible mechanisms behind the precipitation changes may be tentatively attributed to the internal feedback processes of higher latitude (e.g., North Atlantic) and lower latitude (e.g., subtropical monsoon) competing climatic regimes, which are primarily modulated by solar energy output as the external driving force. These findings may provide important insights into understanding the future Asian precipitation dynamics under the projected global warming.

A conceptual model for the interpretation of aeolian sediments from a semiarid high-mountain environment since the late glacial

“…However, because the accumulation of sediments continued for ~5 ka, further mechanisms must be taken into account. First, the increase in moisture was a gradual process as indicated by various proxy records (Shen et al, 2005; Herzschuh, 2006; Li and Liu, 2017; Li et al, 2017). This resulted in a gradual reduction in sediment availability.…”

Spatiotemporal variations in extreme precipitation and their potential driving factors in non-monsoon regions of China during 1961–2017

“…In this study, the range of NMRs in China is mainly based on the summer monsoon boundary proposed in 1962 by Gao et al (1962), which has been accepted by many researchers and is widely used in the climate research field (Chen et al 2016, Gao et al 2017, Li et al 2017 (figure 1). The NMR in China is mainly located in the western and northern parts of the country, with a range of 73°-121°E, 35°-53°N and an area of approximately 3.9×10 6 km 2 .…”

Winter-to-summer seasonal migration of microlithic human activities on the Qinghai-Tibet Plateau

“…Due to the applicability of microlithic technology in the harsh environment, a large number of microlithic sites were found in the QTP during the middle Holocene, such as Jiangxigou 2 34 and Yeniugou 35 . Additionally, quantitatively reconstructed precipitation based on pollen data from Lake Luanhaizi 36 , Lake Yidun 37 and Lake Qinghai 38 on the eastern QTP indicated that there was more precipitation in the early and middle Holocene 39 , less aeolian deposits weakly 40 , paleosols were formed mainly during 9.5–4.0 ka BP 41 . With the above background, QTP is likely to have seen the emergence of hunter-gatherers all year-round in the early and middle Holocene.…”