气候变化领域集成服务门户(CCPortal): Hot Air, Hot Lakes, or Both? Exploring Mid-Holocene African Temperatures Using Proxy System Modeling

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DOI	10.1029/2020JD033269
	Hot Air, Hot Lakes, or Both? Exploring Mid-Holocene African Temperatures Using Proxy System Modeling
	Dee S.G.; Morrill C.; Kim S.H.; Russell J.M.
发表日期	2021
ISSN	2169897X
卷号	126 期号:10
英文摘要	Climate models predict Africa will warm by up to 5°C in the coming century, stressing African societies. To provide independent constraints on model predictions, this study compares two notable reconstructions of East African temperatures to those predicted by Paleoclimate Model Intercomparison Project (PMIP3) and transient TraCE (Transient Climate Evolution) simulations, focusing on the Mid-Holocene (MH, 5–8 kyr B.P.). Reconstructions of tropical African temperature derived from lake sedimentary archives indicate 1–2.5°C of warming during the MH relative to the 20th century, but most climate models do not replicate the warming observed in these paleoclimate data. We investigate this discrepancy using a new lake proxy system model, with attention to the (potentially non-stationary) relationship between lake temperature and air temperature. We find amplified lake surface temperature changes compared to air temperature during the MH due to heightened seasonality and precessional forcing. Lacustrine processes account for some of the warming, and highlight how the lake heat budget leads to a rectification of the seasonal cycle; however, the simulated lake heating bias is insufficient to reconcile the full discrepancy between the models and the proxy-derived MH warming. We find further evidence of changes in mixing depth over time, potentially driven by changes in cloud cover and shortwave radiative fluxes penetrating the lake surface. This may confound interpretation for glycerol dialkyl glycerol tetraethers (GDGT) compounds which exist in the mixed layer, and suggests a need for independent constraints on mixed layer depth. This work provides a new interpretive framework for invaluable paleoclimate records of temperature changes over the African continent. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	Africa; climate change; lake sediments; paleoclimate; proxy system models
语种	英语
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/185194
作者单位	Department of Earth, Environmental, and Planetary Sciences, Rice University, Houston, TX, United States; NOAA's National Centers for Environmental Information, Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, United States; Department of Earth, Environmental, and Planetary Sciences, Brown University, Providence, RI, United States
推荐引用方式 GB/T 7714	Dee S.G.,Morrill C.,Kim S.H.,et al. Hot Air, Hot Lakes, or Both? Exploring Mid-Holocene African Temperatures Using Proxy System Modeling[J],2021,126(10).
APA	Dee S.G.,Morrill C.,Kim S.H.,&Russell J.M..(2021).Hot Air, Hot Lakes, or Both? Exploring Mid-Holocene African Temperatures Using Proxy System Modeling.Journal of Geophysical Research: Atmospheres,126(10).
MLA	Dee S.G.,et al."Hot Air, Hot Lakes, or Both? Exploring Mid-Holocene African Temperatures Using Proxy System Modeling".Journal of Geophysical Research: Atmospheres 126.10(2021).