DOI: 10.1038/ngeo2763
论文题名: Flat meridional temperature gradient in the early Eocene in the subsurface rather than surface ocean
作者: Ho S.L. ; Laepple T.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2016
卷: 9, 期: 8 起始页码: 606
结束页码: 610
语种: 英语
Scopus关键词: atmospheric gas
; climate modeling
; Eocene
; geothermometry
; latitudinal gradient
; magnitude
; meridional circulation
; paleoclimate
; proxy climate record
; sea surface temperature
; temperature gradient
; Archaea
英文摘要: The early Eocene (49-55 million years ago) is a time interval characterized by elevated surface temperatures and atmospheric CO 2 (refs,), and a flatter-than-present latitudinal surface temperature gradient. The multi-proxy-derived flat temperature gradient has been a challenge to reproduce in model simulations, especially the subtropical warmth at the high-latitude surface oceans, inferred from the archaeal lipid-based palaeothermometry,. Here we revisit the interpretation by analysing a global collection of multi-proxy temperature estimates from sediment cores spanning millennia to millions of years. Comparing the variability between proxy types, we demonstrate that the present interpretation overestimates the magnitude of past climate changes on all timescales. We attribute this to an inappropriate calibration, which reflects subsurface ocean but is calibrated to the sea surface, where the latitudinal temperature gradient is steeper. Recalibrating the proxy to the temperatures of subsurface ocean, where the signal is probably formed, yields colder -temperatures and latitudinal gradient consistent with standard climate model simulations of the Eocene climate, invalidating the apparent, extremely warm polar sea surface temperatures. We conclude that there is a need to reinterpret -inferred marine temperature records in the literature, especially for reconstructions of past warm climates that rely heavily on this proxy as reflecting subsurface ocean. © 2016 Macmillan Publishers Limited. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/105955
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Telegrafenberg A43, Potsdam, Germany; University of Bergen, Bjerknes Centre for Climate Research, Allegaten 41, Bergen, Norway
Recommended Citation:
Ho S.L.,Laepple T.. Flat meridional temperature gradient in the early Eocene in the subsurface rather than surface ocean[J]. Nature Geoscience,2016-01-01,9(8)