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Percorrer por autor "Pang, Xiaolei"

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  • Depth fluctuations of mediterranean outflow water along its northward propagation during the late pleistocene
    Publication . Chen, Xinyang; Wu, Jiawang; Pang, Xiaolei; Dang, Haowen; Zhong, Lifeng; Yu, Jimin; Colin, Christophe; Liu, Zhifei; Lange, Gert J. de; Kaboth‐Bahr, Stefanie; Xuan, Chuang; Ikeda, Hisashi; Herbert, Timothy D.; Huang, Huai‐Hsuan May; Zarikian, Carlos A. Alvarez; Abrantes, Fatima; Hodell, David A.
    Mediterranean Outflow Water (MOW) critically influences the Atlantic Meridional OverturningCirculation, yet its northward transport dynamics along the Iberian Margin remain unclear. Using terrigenousgrain‐size sortable silt and benthic foraminiferal carbon isotopes from two depth‐strategic sites (U1389:644 m vs. U1588: 1,339 m), we constrain MOW's northward depth fluctuations over the last 250 kyr. Resultsshow that MOW progressively deepened from ∼100 to 60 ka, then stabilized—synchronized with theprevalence of millennial‐scale climate variability. During interglacials, MOW directly influenced U1588,while deepened below this site during glacials. Flow speed gradients between Sites U1389 and U1588 showpronounced precession cycles. At precession maxima—Northern Hemisphere summer insolation minima—when flow intensified, MOW underwent enhanced mixing and dilution during northward transport. Thisresults from increased density contrasts between MOW and ambient waters, indicating deeper MOWpenetration. We demonstrate precessional forcing on both the strength and depth of MOW's northward propagation.
    2025-07-11Artigo científico Acesso aberto Ver mais
  • Distinct seasonal changes and precession forcing of surface and subsurface temperatures in the mid-latitudinal North Atlantic during the onset of the Late Pliocene
    Publication . Pang, Xiaolei; Voelker, Antje; Lu, Sihua; Ding, Xuan
    The Late Pliocene marks the intensification of Northern Hemisphere glaciation (iNHG), offering a unique opportunity to study climate evolution and ice-sheet-related feedback mechanisms. In this study, we present high-resolution Mg / Ca-based sea surface temperatures (SSTs) and subsurface temperatures (SubTs) derived from the foraminiferal species Globigerinoides ruber and Globorotalia hirsuta, respectively, at the Integrated Ocean Drilling Program (IODP) Expedition 306 Site U1313 in the mid-latitudinal North Atlantic during the early Late Pliocene, 3.65-3.37 million years ago (Ma). We find distinct differences between our new G. ruber Mg / Ca-based SST record and previously published alkenone-based SST records from the same location. These discrepancies in both absolute values and variations highlight distinctly different seasonal influences on the proxies. The G. ruber Mg / Ca-based SST data were primarily influenced by local summer insolation, showing a dominant precession cycle. Conversely, the variations in alkenone-based SST, dominated by the obliquity and lacking the precession cycle, are found to be more indicative of cold-season changes, despite previous interpretations of these records as reflecting annual mean temperatures. A simultaneous decline in Mg / Ca-based SST and SubT records from 3.65 to 3.5 Ma suggests a diminished poleward oceanic heat transport, implying a weakening of the North Atlantic Current (NAC). A comparison with Early Pleistocene G. ruber Mg / Ca-based SST records shows a shift in the dominant climatic cycle from precession to obliquity, alongside a marked increase in amplitude, indicating an enhanced influence of obliquity cycles correlated with the expansion of Northern Hemisphere ice sheets.
    2024-09-23Artigo científico Acesso aberto Ver mais