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The observed variations in intense geomagnetic flux lobes have a significant impact on regional geomagnetic fields, and produce unique geomagnetic characteristics. To investigate the time‐dependent effect of the Siberian flux lobe on the geomagnetic field in East Asia, we reconstructed a stacked full‐vector paleomagnetic secular variation record (since 2000 BCE) from three sediment cores collected in the Bohai Sea, China. Age models of the studied cores were established through a combination of radiocarbon 14C dating and inter‐profile correlation of mass‐normalized magnetic susceptibility. Rock magnetic results indicate that fine‐grained magnetite is the primary remanent carrier. We found that the paleomagnetic field records in the Bohai Sea correspond more closely with those from the middle latitudes, rather than the low latitudes. This was primarily attributed to the variation of the Siberian flux lobe. This study provides a better understanding of the contrasting patterns of regional geomagnetic fields in East Asia, and emphasizes the significant role played by the Siberian flux intensity lobe in shaping their formation. Plain Language Summary: The Earth's magnetic field is in a constant state of flux, both temporally and spatially, and plays a crucial role in protecting our planet from solar wind and cosmic rays. The long‐term variation of the Earth's magnetic field is closely linked with the magnetic flux patch situated at the core‐mantle boundary. However, our understanding of the evolution of magnetic flux patches has been limited by the use of short‐term instrumental data and discrete archeomagnetic data. In this paper, we reconstruct a ∼4,000‐year high‐resolution full‐vector paleomagnetic record from sediments in the Bohai Sea, China. Our findings reveal a clear contrast in the paleomagnetic variations between the middle and low latitudes of East Asia. We proposed that the Siberian flux intensity lobe likely played an important role in the observed paleomagnetic behavior discrepancy between the low‐ and mid‐latitudes of East Asia. Key Points: A multi‐decadal resolution paleomagnetic record spanning approximately 4,000 years has been derived from sediments in the Bohai Sea, ChinaThe paleomagnetic behavior differs between middle and low latitudes across East Asia, indicating the variation of the Siberian flux lobeThe disparity in inclination between the Chinese and Levantine spikes implies that these spikes arise from separate magnetic flux patches [ABSTRACT FROM AUTHOR]

Across the Miocene–Pliocene boundary (MPB; 5.3 million years ago, Ma), late Miocene cooling gave way to the early-to-middle Pliocene Warm Period. This transition, across which atmospheric CO2 concentrations increased to levels similar to present, holds potential for deciphering regional climate responses in Asia—currently home to more than half of the world's population— to global climate change. Here we find that CO2-induced MPB warming both increased summer monsoon moisture transport over East Asia, and enhanced aridification over large parts of Central Asia by increasing evaporation, based on integration of our ~1–2-thousand-year (kyr) resolution summer monsoon records from the Chinese Loess Plateau aeolian red clay with existing terrestrial records, land-sea correlations, and climate model simulations. Our results offer palaeoclimate-based support for 'wet-gets-wetter and dry-gets-drier' projections of future regional hydroclimate responses to sustained anthropogenic forcing. Moreover, our high-resolution monsoon records reveal a dynamic response to eccentricity modulation of solar insolation, with predominant 405-kyr and ~100-kyr periodicities between 8.1 and 3.4 Ma. Global warming drove 'wet gets wetter and dry gets drier' climate shifts in Asia ~5.3 million years ago with monsoon pacing by ~400,000 and ~ 100,000 year cycles. This could be a template for future Asian climate response to anthropogenic warming. [ABSTRACT FROM AUTHOR]

• A refined magnetostratigraphy for the last 6.5 Ma is reconstructed. • A greigite-bearing layer occurs at 2.53-2.55 Ma. • Magnetic parameters record the East Asian monsoon evolution since 6.5 Ma. The South China Sea (SCS) has become a global focus for paleoclimatic and paleoceanographic studies due to its location, which makes it highly sensitive to the East Asian monsoon and to Pacific Ocean changes. We present here a refined magnetostratigraphy for the last 6.5 Ma for Hole U1431D, which was recovered during IODP Expedition 349 in the central SCS. Magnetic analyses demonstrate that magnetite is the dominant magnetic carrier except for within a greigite-bearing layer at 130.5-132.0 meters below sea floor. The greigite layer coincides with the timing of intensification of northern hemisphere glaciation and records an oceanographic response to this event. Environmental magnetic results indicate that the East Asian summer and winter monsoon were stable from 6.5 to 5 Ma. The summer monsoon intensified at 5 Ma, and then weakened gradually since 3.8 Ma. In contrast, the winter monsoon weakened at 5 Ma, and has then been enhanced since 3.8 Ma and more stable from 0.6 Ma. Spectral analysis indicates that the East Asian summer monsoon was driven directly by low-latitude insolation changes before ∼3.2 Ma, and that it has been affected by both low-latitude insolation and high-latitude ice volume changes since ∼3.2 Ma. [ABSTRACT FROM AUTHOR]

• First sub-orbital scale hydrological record of PETM in East Asia. • Eccentricity forcing coincides with multi-phased precipitation variability. • Precession and half-precession cycles control precipitation intensity. • Orbital forcing of low-latitude insolation develops in East Asia during the PETM. The Paleocene-Eocene Thermal Maximum (PETM, ∼56 Ma) was an abrupt global warming event linked to massive carbon release into the ocean-atmosphere system. As such, it is considered a potentially useful analogue for present and future climate change. Consequently, deciphering its impact on the hydroclimate is important for predicting future changes under high p CO 2 and temperature conditions, especially in East Asia where more than a quarter of the world's population lives. Here, we use magnetic and geochemical data obtained through a thick lacustrine record of the PETM from China to demonstrate a large-scale increase in weathering and precipitation coeval with the PETM. Moreover, we show that precipitation variations through the PETM were strongly controlled by eccentricity, precession and half-precession climate cycles. Our results show that orbital forcing of low-latitude insolation played a key role in driving hydroclimate fluctuations and multi-phase changes in precipitation during the PETM, emphasizing the sensitivity of East Asian hydroclimate to subtle changes in insolation under conditions of high temperature and p CO 2 , perhaps similar to those expected in the future. [ABSTRACT FROM AUTHOR]

Abstract: Rapid East Asian Monsoon oscillations recorded by Chinese loess are thought to be dynamically linked to north Atlantic climate. However, few efforts have been made to assess the effects of post-depositional processes (e.g., surface mixing and pedogenesis) on loess paleoclimatic records. Here a detailed optically stimulated luminescence dating of a thick loess sequence from the western Loess Plateau is presented, offering a reliable chronology for last glacial deposits. Magnetic susceptibility and mean grain size records from three loess–paleosol sequences along a northwest–southeast transect are investigated to evaluate impacts of post-depositional processes on these loess-based proxy records. Our results indicate that: (1) loess sequences developed within the flat tableland of the central and western Loess Plateau are nearly continuous during the last glaciation; and (2) post-depositional processes have distinct impacts on rapid monsoon signals recorded in loess sequences from different regions. In the central Loess Plateau, rapid monsoon signals have been attenuated to various degrees depending on the sedimentation rate and pedogenic intensity. In the northwestern Loess Plateau, however, due to high sedimentation rate and relatively weak pedogenesis, high-resolution grain size oscillations reliably record rapid monsoon changes and can be well correlated to rapid climate changes recorded in the Greenland ice core and Hulu cave stalagmite. [Copyright &y& Elsevier]

A high-resolution environmental magnetic records from a sediment profile in Mountain Ganhai Lake, has provided new insights into modulation of the East Asian summer monsoon (EASM) on climatic changes in North China from the final period of last deglacial stage to Holocene. Large pseudo-single-domain (PSD) to multidomain (MD) detrital magnetite grains are identified in the lake samples. The upwards decreasing magnetic susceptibility (χ) and anhysteretic remanent magnetic susceptibility (χ ARM ) are consistent with the dominant vegetation changes: grassland (~13.0–10.5 ka) under dry and cold conditions, shrub-forest-grassland (~10.5–5.8 ka) in a warm and humid climate, and forest where the Pinus trees increase rapidly to be the dominant taxa, indicating the climate changes from warm and humid to cooler but drier between ~5.8 ka and ~4.0 ka. The lower S -100mT and S -300mT ratios coincide with the higher degree of soil stability and a stable lake stage at ~11.8–6.5 ka. Changes in magnetic anisotropy are also linked to environmental and climatic changes, with T parameters showing higher values during warm/interglacial periods. The anisotropy patterns indicate three different stages of the lake evolution: (1) an early stage of the lake, accompanied by a disturbed high-energy flow, a coarse average mineral particle diameter (MPD) distribution (>16.28 μm) and scattered subvertical minimum direction ( K 3 ) at ~13.0–11.8 ka; (2) a fairly stable lake environment between ~11.8 ka and 6.5 ka, indicated by a low-energy flow, finer MPD (~9.69 μm) and subvertical K 3 axes; (3) an unstable, high-energy flow and coarse MPD (~20.03 μm) with tilted K 3 axes, thus indicating a transition from lake-center to lakeside (~6.5–4.0 ka). These multi-proxy records reveal a weak EASM activity in the final period of the last deglaciation (~13.0–11.8 ka), a high EASM intensity in the early-mid Holocene (~11.8–4.8 ka), an EASM maxima in the mid-Holocene (~8.0–5.8 ka), which then generally weakens at ~4.3–4.2 ka. Overall, this study suggests the anisotropy and climatic changes in the alpine lake are significantly affected by the insolation-driven EASM. [ABSTRACT FROM AUTHOR]

Abstract: Magnetostratigraphic studies have established a first-order chronological framework for the Paleolithic sites in the Nihewan Basin (North China), which enabled tracking early human evolution in East Asia. However, to fully understand how well early humans were adapted to climate change, a truly precise dating of the Paleolithic sites is required. Here, we established a high-resolution astronomical timescale for the Xiantai and Donggutuo fluvio-lacustrine successions at the eastern margin of the Nihewan Basin employing low-field magnetic susceptibility (χ) as a climatic indicator, aiming to further refine the ages of the Xiantai, Donggutuo and Maliang Paleolithic sites. Starting from an initial age model constrained by geomagnetic reversals, larger-scale χ cycles were firstly tuned to orbital obliquity using an automatic orbital tuning method. This first-order tuning was followed by simultaneously tuning χ to both obliquity and precession. The finally tuned χ records can be correlated almost cycle-by-cycle with the quartz grain-size record of the Chinese loess sequence and the marine δ 18O record. The astronomically estimated age of the Xiantai Paleolithic site is ca. 1.48Ma, corresponding to paleosol layer S20 of the Chinese loess sequences or marine oxygen isotope stage (MIS) 49, an interglacial period. The astronomical estimate for the Donggutuo Paleolithic site ranges from ~1.06Ma to 1.12Ma, corresponding to paleosol/loess layers S11–S12 or MIS 31–33, spanning both interglacial and glacial periods. The astronomically estimated age of the Maliang Paleolithic site is ~0.79Ma, corresponding to loess layer L8 or MIS 20, a glacial period. This astronomical finding further implies that early humans may have permanently occupied China as far north as 40oN since at least 1.1Ma, and before this time the occupation may be intermittent. [ABSTRACT FROM AUTHOR]

Abstract: The Nihewan fluvio-lacustrine sequence (North China) has recorded late Pliocene–Pleistocene climatic and environmental changes, and contains valuable information on early human evolution in high-latitude East Asia. We carried out a combined mineral-magnetic and geochemical investigation on a sequence from the Xiantai section, eastern Nihewan Basin. Results suggest that large-amplitude magnetic-property variations between so-called ‘high-magnetic’ and ‘low-magnetic’ units mainly result from preservation/dissolution cycles of detrital magnetic minerals in alternating oxic and anoxic depositional environments. In our preservation/dissolution model, the high- and low-magnetic units represent glacial and interglacial deposits, respectively. This contributes to a better understanding of the link between magnetic properties and climate in the Xiantai fluvio-lacustrine sequence. Based upon this relationship, early humans may have occupied the Xiantai and Xiaochangliang sites during an interglacial period, during both interglacial and glacial periods at the Donggutuo site, and during a glacial period at the Maliang site. Our work provides a paleoenvironmental context for early human adaptation and occupation in mainland East Asia during the early Pleistocene. [Copyright &y& Elsevier]

Global climate shifted to markedly warmer interglacial conditions across the "mid-Brunhes transition" (MBT, ~400 ka). However, a global MBT synthesis that spans marine and terrestrial evidence remains elusive, which limits our understanding of the role of the MBT in mid-Pleistocene human evolution. We synthesize Asian precipitation reconstructions within a context of global palaeoclimatic records and find that the MBT occurred in two stages. First, stronger warming of northern hemisphere continents, weaker southern hemisphere warming, and related more extensive northward displacement of the intertropical convergence zone (ITCZ) during interglacial marine isotope stage (MIS) 13 intensified and expanded precipitation in Asian monsoon regions and in other widespread northern hemisphere regions, with accompanying carbon reservoir changes featuring globally high marine benthic δ13C values because of vegetation expansion at ~500 ka. Subdued southern hemisphere warming and northward ITCZ displacement decreased southern hemisphere precipitation simultaneously during MIS 13. Second, a shift to globally warmer interglacials at ~400 ka, with elevated atmospheric CO 2 concentrations, smaller ice volume, and higher sea level resulted in sustained high interglacial precipitation in East Asia from MIS 11 onward and sustained high marine benthic δ13C values during MIS 11. We also synthesize palaeoanthropological data and find that the climate and ecosystem changes across the MBT coincided with the timing of human lineage diversification, including the emergence of Neanderthals and Denisovans in Eurasia and Homo sapiens in Africa, and their potential coexistence with H. heidelbergensis , H. erectus , H. floresiensis , H. naledi , and other Homo archaics. The timing of the MBT also coincided with novel hominin behavioural developments, including fire control and the transition from handaxe industries to more versatile Levallois techniques. Combined with environmental theories of human evolution, this chronological coincidence suggests a potential link between mid-Pleistocene environmental changes and human evolution. [ABSTRACT FROM AUTHOR]