Yihao Hu , Thomas J. Algeo , Tong Wang , Jingteng Guo , Zhifang Xiong , Tiegang Li
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引用次数: 0
Abstract
The relationship of marine productivity in the Southern Ocean (SO) to dynamics of the Antarctic icesheet (AIS) since the Late Pleistocene remains uncertain. Here, we investigated Late Pleistocene variation in productivity in the Antarctic Zone of the SO, and the response of the AIS to various potential forcing mechanisms. We analyzed secular variation in multiple biogenic components and ice-rafted debris (IRD) of a sediment core (ANT34/D5–12) from the Atlantic sector of the SO. Productivity, as tracked by the fluxes of excess Ba and opal, was controlled mainly by local mean summer insolation, which also modulated icesheet dynamics, as revealed by IRD. These records nonetheless show distinct precessional variability (∼20 kyr cycle) related to austral summer insolation. During high (low) insolation intervals, productivity was high (low), and the AIS contracted (expanded). Based on these data and published paleoclimate records, we propose that marine productivity and icesheet dynamics during the Late Pleistocene were primarily controlled by local Antarctic summer mean insolation through regulation of water-column stratification depth. These findings support hypotheses for the independent evolution of Antarctic climate (i.e., not paced by Northern Hemisphere summer insolation) and provide new insights into biogeochemical cycling in the SO and AIS dynamics.
期刊介绍:
The objective of the journal Global and Planetary Change is to provide a multi-disciplinary overview of the processes taking place in the Earth System and involved in planetary change over time. The journal focuses on records of the past and current state of the earth system, and future scenarios , and their link to global environmental change. Regional or process-oriented studies are welcome if they discuss global implications. Topics include, but are not limited to, changes in the dynamics and composition of the atmosphere, oceans and cryosphere, as well as climate change, sea level variation, observations/modelling of Earth processes from deep to (near-)surface and their coupling, global ecology, biogeography and the resilience/thresholds in ecosystems.
Key criteria for the consideration of manuscripts are (a) the relevance for the global scientific community and/or (b) the wider implications for global scale problems, preferably combined with (c) having a significance beyond a single discipline. A clear focus on key processes associated with planetary scale change is strongly encouraged.
Manuscripts can be submitted as either research contributions or as a review article. Every effort should be made towards the presentation of research outcomes in an understandable way for a broad readership.