气候变化领域集成服务门户(CCPortal): Spiky fluctuations and scaling in high-resolution EPICA ice core dust fluxes

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DOI	10.5194/cp-15-1999-2019
	Spiky fluctuations and scaling in high-resolution EPICA ice core dust fluxes
	Lovejoy S.; Lambert F.
发表日期	2019
ISSN	18149324
起始页码	1999
结束页码	2017
卷号	15 期号:6
英文摘要	Atmospheric variability as a function of scale has been divided in various dynamical regimes with alternating increasing and decreasing fluctuations: weather, macroweather, climate, macroclimate, and megaclimate. Although a vast amount of data are available at small scales, the larger picture is not well constrained due to the scarcity and low resolution of long paleoclimatic time series. Using statistical techniques originally developed for the study of turbulence, we analyse the fluctuations of a centimetricresolution dust flux time series from the EPICA Dome C ice core in Antarctica that spans the past 800 000 years. The temporal resolution ranges from annual at the top of the core to 25 years at the bottom, enabling the detailed statistical analysis and comparison of eight glaciation cycles and the subdivision of each cycle into eight consecutive phases. The unique span and resolution of the dataset allows us to analyse the macroweather and climate scales in detail. We find that the interglacial and glacial maximum phases of each cycle showed particularly large macroweather to climate transition scale τc (around 2 kyr), whereas midglacial phases feature centennial transition scales (average of 300 years). This suggests that interglacials and glacial maxima are exceptionally stable when compared with the rest of a glacial cycle. The Holocene (with τc ≈ 7:9 kyr) had a particularly large τc, but it was not an outlier when compared with the phases 1 and 2 of other cycles. We hypothesize that dust variability at larger (climate) scales appears to be predominantly driven by slow changes in glaciers and vegetation cover, whereas at small (macroweather) scales atmospheric processes and changes in the hydrological cycles are the main drivers. For each phase, we quantified the drift, intermittency, amplitude, and extremeness of the variability. Phases close to the interglacials (1, 2, 8) show low drift, moderate intermittency, and strong extremes, while the "glacial" middle phases 3-7 display strong drift, weak intermittency, and weaker extremes. In other words, our results suggest that glacial maxima, interglacials, and glacial inceptions were characterized by relatively stable atmospheric conditions but punctuated by frequent and severe droughts, whereas the mid-glacial climate was inherently more unstable. © 2019 Royal Society of Chemistry. All rights reserved.
语种	英语
scopus关键词	dust; extreme event; flux measurement; glaciation; hydrological cycle; ice core; interglacial; Last Glacial Maximum; paleoclimate; resolution; scale effect; time series analysis; Antarctica; Dome Concordia; East Antarctica
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/146766
作者单位	Physics Department, McGill University, 3600 University St., Montréal, QC H3A 2T8, Canada; Department of Physical Geography, Pontificia Universidad Catolica de Chile, Vicuna Mackenna 4860, Santiago, Chile; Millennium Nucleus Paleoclimate, Santiago, Chile
推荐引用方式 GB/T 7714	Lovejoy S.,Lambert F.. Spiky fluctuations and scaling in high-resolution EPICA ice core dust fluxes[J],2019,15(6).
APA	Lovejoy S.,&Lambert F..(2019).Spiky fluctuations and scaling in high-resolution EPICA ice core dust fluxes.Climate of the Past,15(6).
MLA	Lovejoy S.,et al."Spiky fluctuations and scaling in high-resolution EPICA ice core dust fluxes".Climate of the Past 15.6(2019).