New insights on Chinese cave δ18O records and their paleoclimatic significance

Orbital-scale Asian summer monsoon variations: Paradox and exploration

“…The absence of precession variations in the sea surface water δ 18 O record at IODP Site U1429 ) is understandable as well, since the precipitation in the middle-lower reaches of the Yangtze River, its source of freshwater, has little precession changes itself (Figure 1a). This explanation may partially clarify the aforementioned "sea-land precession phase paradox" and relevant misunderstandings (e.g., Liu et al, 2020b). The precession phase of freshwater variations at ODP Site 1146 in the South China Sea may depend on the relative contributions of runoff from the Pearl River and local precipitation.…”

Vegetation History and Precipitation Changes in the NE Qinghai‐Tibet Plateau: A 7,900‐years Pollen Record From Caodalian Lake

“…The P ann index for the Qinghai Lake basin is also not completely consistent with speleothem oxygen isotope records from the ISM region, which are regarded as an indicator of ISM intensity (Dutt et al., 2015; Fleitmann et al., 2003; Kathayat et al., 2017; Neff et al., 2001). A δ 18 O stack consisting of the records from Qunf Cave (Fleitmann et al., 2003), Sahiya Cave (Kathayat et al., 2017), Hoti Cave (Neff et al., 2001), and Mawmluh Cave (Dutt et al., 2015), indicates that maximum ISM precipitation occurred between 10 and 7 ka (Figure 8c; X. K. Liu et al., 2020), with a ∼2 kyr lead relative to the end of the precipitation maximum in the Qinghai Lake basin. In addition, the P ann index for the Qinghai Lake basin is inconsistent with a summer precipitation record from the LJW10 loess section in Xinjiang, where the climate is dominated by the westerlies circulation (Chen et al., 2019).…”

“… Comparison of (a) composite P ann record for the Qinghai Lake basin with (b) pollen‐based P ann record from Gonghai Lake (Chen et al., 2015), (c) integrated ISM proxy based on four cave δ 18 O records (Sahiya, Hoti, Mawmluh, and Qunf) (X. K. Liu et al., 2020), (d) summer precipitation record from the LJW10 loess section (Xie et al., 2018). (e) Relationship between curve (a) and standardized curves (b) and (c).…”

“…Modern pollen calibration dateset is available through Xu et al, (2010); Lu, Wu, et al ( 2011) and Zheng et al (2014); the fossil pollen assemblage from Qinghai Lake is available through Liu et al (2002); precipitation data from Qinghai Lake in Figure 3c are available through Herzschuh et al (2010) and J. Li et al (2017); precipitation data from Gonghai Lake is available through Chen et al (2015); integrated ISM proxy based on four cave δ 18 O records (Sahiya, Hoti, Mawmluh, and Qunf) is available through X. K. Liu et al (2020); precipitation data from LJW10 loess section is available through Xie et al (2018); ostracod δ 18 O record from Qinghai Lake is available through An et al (2012); long-chain leaf wax δD record from Qinghai Lake is available through Tomas et al (2016); bacteriophaeophytin a (Bph-a) record from Qinghai Lake is available through Ji et al (2009); tree pollen percentages from Qinghai Lake is available through Shen et al (2005); summer temperature record from Qinghai Lake is available through Hou et al (2016); thaum (%) record from Qinghai Lake is available through Wang et al (2014); reconstructed shoreline history of Qinghai Lake is available through J. . Professors Xingqi Liu and Ji Shen for providing fossil pollen data from Qinghai Lake, Professors Houyuan Lu and Haibin Wu for providing the interpolated climate data at the sampling sites, Professor John W. Williams and Dr. Shengrui Zhang for valuable discussion, Dr. Jan Bloemendal for improving the English language, and the China Scholarship Council (201806180096) for funding Feiya Lv to study abroad.…”

A Rapid Cooling Event Over the Western Pacific Region During the Middle Bronze Age

“…The opposite situations occurred when the Asian summer monsoon became weaker. However, Chinese stalagmite δ 18 O record does not necessarily represent the amount of summer monsoon precipitation and its interpretation is time scale dependent (Hu et al., 2019; X Liu et al., 2020). The stalagmite δ 18 O is possibly also associated with the change in moisture source controlled by the intensity of monsoonal circulation at interannual scales, and increased moisture delivery from remote source regions will lead to more negative precipitation δ 18 O over China when the Asian summer monsoon is stronger (Hu et al., 2019).…”