气候变化领域集成服务门户(CCPortal): Nutrient utilization and diatom productivity changes in the low-latitude south-eastern Atlantic over the past 70 ka: Response to Southern Ocean leakage

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DOI	10.5194/cp-17-603-2021
	Nutrient utilization and diatom productivity changes in the low-latitude south-eastern Atlantic over the past 70 ka: Response to Southern Ocean leakage
	Hendry K.; Romero O.; Pashley V.
发表日期	2021
ISSN	1814-9324
起始页码	543
结束页码	554
卷号	17 期号:2
英文摘要	Eastern boundary upwellings (EBUs) are some of the key loci of biogenic silica (opal) burial in the modern ocean, representing important productive coastal systems that extraordinarily contribute to marine organic carbon fixation. The Benguela upwelling system (BUS), in the lowlatitude south-eastern Atlantic, is one of the major EBUs and is under the direct influence of nutrient-rich Southern Ocean waters. Quantification of past changes in diatom productivity through time, in response to late Quaternary climatic change, feeds into our understanding of the sensitivity of EBUs to future climatic perturbations. Existing sediment archives of silica cycling include opal burial fluxes, diatom assemblages, and opaline silicon isotopic variations (denoted by δ30Si). Burial fluxes and siliceous assemblages are limited to recording the remains reaching the sediment (i.e. export), and δ30Si variations are complicated by species-specific influences and seasonality. Here, we present the first combined δ30Si record of two large centric diatoms from the BUS, encompassing full glacial conditions to the Holocene. In addition to export, our new data allow us to reconstruct the utilization of dissolved Si in surface waters in an area with strong input from Southern Ocean waters. Our new archives show that there was enhanced upwelling of Southern Ocean Si-rich water accompanied by strong silicic acid utilization by coastal dwelling diatoms during Marine Isotope Stage 3 (MIS3; 60-40 ka). This pulse of strong silicic acid utilization was followed by a weakening of upwelling and coastal diatom Si utilization into MIS2, before an increase in pelagic diatom Si utilization across the deglaciation. We combine our findings with mass balance model experiments to show that changes in surface water silica cycling through time are a function of both upwelling intensity and utilization changes, illustrating the sensitivity of EBUs to climatic change on glacial-interglacial scales. © 2021 Copernicus GmbH. All rights reserved.
来源期刊	Climate of the Past
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/183595
作者单位	University of Bristol, School of Earth Sciences, Bristol, BS8 1RJ, United Kingdom; MARUM-Center for Marine Environmental Sciences, University of Bremen, Bremen, 28359, Germany; Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, 27568, Germany; Geochronology and Tracers Facility, British Geological Survey, Keyworth, NG12 5GG, United Kingdom
推荐引用方式 GB/T 7714	Hendry K.,Romero O.,Pashley V.. Nutrient utilization and diatom productivity changes in the low-latitude south-eastern Atlantic over the past 70 ka: Response to Southern Ocean leakage[J],2021,17(2).
APA	Hendry K.,Romero O.,&Pashley V..(2021).Nutrient utilization and diatom productivity changes in the low-latitude south-eastern Atlantic over the past 70 ka: Response to Southern Ocean leakage.Climate of the Past,17(2).
MLA	Hendry K.,et al."Nutrient utilization and diatom productivity changes in the low-latitude south-eastern Atlantic over the past 70 ka: Response to Southern Ocean leakage".Climate of the Past 17.2(2021).