气候变化领域集成服务门户(CCPortal): In and out of glacial extremes by way of dust−climate feedbacks

CCPortal

DOI	10.1073/pnas.1708174115
	In and out of glacial extremes by way of dust−climate feedbacks
	Shaffer G.; Lambert F.
发表日期	2018
ISSN	0027-8424
起始页码	2026
结束页码	2031
卷号	115 期号:9
英文摘要	Mineral dust aerosols cool Earth directly by scattering incoming solar radiation and indirectly by affecting clouds and biogeochemical cycles. Recent Earth history has featured quasi-100,000-y, glacial−interglacial climate cycles with lower/higher temperatures and greenhouse gas concentrations during glacials/interglacials. Global average, glacial maxima dust levels were more than 3 times higher than during interglacials, thereby contributing to glacial cooling. However, the timing, strength, and overall role of dust−climate feedbacks over these cycles remain unclear. Here we use dust deposition data and temperature reconstructions from ice sheet, ocean sediment, and land archives to construct dust−climate relationships. Although absolute dust deposition rates vary greatly among these archives, they all exhibit striking, nonlinear increases toward coldest glacial conditions. From these relationships and reconstructed temperature time series, we diagnose glacial−interglacial time series of dust radiative forcing and iron fertilization of ocean biota, and use these time series to force Earth system model simulations. The results of these simulations show that dust−climate feedbacks, perhaps set off by orbital forcing, push the system in and out of extreme cold conditions such as glacial maxima. Without these dust effects, glacial temperature and atmospheric CO2 concentrations would have been much more stable at higher, intermediate glacial levels. The structure of residual anomalies over the glacial−interglacial climate cycles after subtraction of dust effects provides constraints for the strength and timing of other processes governing these cycles.
英文关键词	Carbon cycling; Dust forcing; Earth system modeling; Glacial−interglacial climate cycles
语种	英语
scopus关键词	carbon dioxide; ice; atmospheric deposition; climate; cold; concentration (parameters); Conference Paper; controlled study; dust; dust radiative forcing; environmental parameters; glacial maxima; glacial period; glaciation; interglacial; iron fertilization forcing; land use; priority journal; sea; sediment; simulation; temperature; time series analysis
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/160540
作者单位	Shaffer, G., GAIA, Antartica Research Center, University of Magallanes, Punta Arenas, Chile, Niels Bohr Institute, University of Copenhagen, Copenhagen OE, 2100, Denmark; Lambert, F., Department of Physical Geography, Pontifical Catholic University of Chile, Santiago, Chile, Center for Climate and Resilience Research, University of Chile, Santiago, Chile
推荐引用方式 GB/T 7714	Shaffer G.,Lambert F.. In and out of glacial extremes by way of dust−climate feedbacks[J],2018,115(9).
APA	Shaffer G.,&Lambert F..(2018).In and out of glacial extremes by way of dust−climate feedbacks.Proceedings of the National Academy of Sciences of the United States of America,115(9).
MLA	Shaffer G.,et al."In and out of glacial extremes by way of dust−climate feedbacks".Proceedings of the National Academy of Sciences of the United States of America 115.9(2018).