Two-stage mid-Brunhes climate transition and mid-Pleistocene human diversification

Abstract

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A 1200 ka Stable Isotope Record From the Center of the Badain Jaran Desert, Northwestern China: Implications for the Variation and Interplay of the Westerlies and the Asian Summer Monsoon

“…On the CLP, the prominent paleosol S5 developed during MIS15‐13 (Guo et al., 1998), and it can be readily correlated with LL‐3 in the WEDP02 drill core (Wang et al., 2015). Multiproxy indicators of loess records from the CLP also showed that the intensified ASM precipitation and temperature after 600 ka (Ao et al., 2020; Guo et al., 1998; Meng, et al., 2018; Sun et al., 2010). In addition, the lacustrine environment formed or further enlarged in the inland deserts of northern China including Tengger Desert (Li et al., 2014), Badain Jaran Desert (Gao et al., 2006; Wang et al., 2015), Gobi Desert (Li et al., 2017), and Ulan Buh Desert (Li et al., 2015) during the interglacial intervals from MIS15‐13, suggesting the intensification of ASM.…”

“…Moreover, numerous records suggested that this enhancement not only occurred in the ASM region, Indian, and African summer monsoons circulation also clearly intensified and Greenland, European, and North American continents all get warmer than prior time during MIS13‐15 stages, signaling a warmer Northern Hemisphere (Ao et al., 2020; Shi et al., 2020; Yin & Guo, 2008) which contrast with the cooler Southern Hemisphere during this time (Ao et al., 2020; Guo et al., 2009). This strong asymmetry of hemispheric climates may modulate the position of the intertropical convergence zone (ITCZ) and land‐sea thermal contrasts and finally intensify the North Hemispheric monsoon circulations (Ao et al., 2020; Guo et al., 2009). Model simulations further confirm this hypothesis, which indicated that when Greenland ice sheet is absence and a large Antarctic ice sheet is obtained, there is an enhancement of ASM precipitation up to ∼7%, consistent with the results by proxy reconstructions (Shi et al., 2020).…”

“…Combined proxy data and sensitive experiments about the ASM suggested that global ice sheets and CO 2 concentration have significant impact on the ASM, especially in the northern China (Lu et al., 2013; Stevens et al., 2018; Sun et al., 2015). Thus, due to the warmer condition in the interglacial stages after MBE, not only the strength of ASM intensified (Ao et al., 2020), but also the seasonality of ASM precipitation further enhanced (Sun et al., 2012) which led to the C4 expansion over the CLP and the Badain Jaran area. In addition, from MBE, the ASM hydrology as evidenced by the δ 18 O carb of WEDP02 core shows high frequency with large amplitude.…”

“…As mentioned above, ASM significantly intensified from 600 ka or MIS13‐15 stages. Moreover, numerous records suggested that this enhancement not only occurred in the ASM region, Indian, and African summer monsoons circulation also clearly intensified and Greenland, European, and North American continents all get warmer than prior time during MIS13‐15 stages, signaling a warmer Northern Hemisphere (Ao et al., 2020; Shi et al., 2020; Yin & Guo, 2008) which contrast with the cooler Southern Hemisphere during this time (Ao et al., 2020; Guo et al., 2009). This strong asymmetry of hemispheric climates may modulate the position of the intertropical convergence zone (ITCZ) and land‐sea thermal contrasts and finally intensify the North Hemispheric monsoon circulations (Ao et al., 2020; Guo et al., 2009).…”

Hominin evolution and diversity: a comparison of earlier-Middle and later-Middle Pleistocene hominin fossil variation in China

“…The MIS 11 interglacial was characterized by millennial-scale oscillations, particularly in the Northern Hemisphere, and was a significantly unstable period in northwestern China [43,44]. Both of these climatic conditions—warming and instability—have historically been associated with population movements [45–47], and models linking hominin variability to climatic instability have been proposed for Middle Pleistocene Europe [48] and for eastern Eurasia and Africa, particularly with respect to lineage diversification [49].…”