气候变化领域集成服务门户(CCPortal): Simulation of early Eocene water isotopes using an Earth system model and its implication for past climate reconstruction

CCPortal

DOI	10.1016/j.epsl.2020.116164
	Simulation of early Eocene water isotopes using an Earth system model and its implication for past climate reconstruction
	Zhu J.; Poulsen C.J.; Otto-Bliesner B.L.; Liu Z.; Brady E.C.; Noone D.C.
发表日期	2020
ISSN	0012821X
卷号	537
英文摘要	Our understanding of past climate conditions largely comes from paleoclimate proxies, such as oxygen isotope ratios (δ18Oc) in marine fossils. The marine δ18Oc signal primarily reflects a mixture of seawater temperature and oxygen isotopic composition of seawater (δ18Ow) at the time of calcification. Knowledge of δ18Ow is critical for the interpretation of marine δ18Oc records but remains poor for past hothouse climates. Here, we conduct water isotope-enabled simulations of the early Eocene using CO2 levels of 1×, 3×, 6×, and 9× the preindustrial value. We calculate model δ18Oc using simulated δ18Ow and ocean temperature, and make direct comparison with proxy records. Model δ18Oc matches the proxy values well for the early Eocene and Paleocene–Eocene Thermal Maximum with root-mean-squared errors approaching the standard error in individual records. Eocene δ18Ow in the model exhibits strong variation depending on states of the hydrological cycle and ocean circulation. Differences in the mean δ18Ow between regions of net evaporation and precipitation increase monotonically with the magnitude of the net atmospheric moisture transport that connects them; however, this relationship breaks at the regional scale due to ocean circulation changes. In particular, an increase in ocean ventilation brings more 18O-enriched deep water into the mixed layer, increasing sea-surface δ18Ow near the ventilation site and in certain remote regions through fast upper ocean currents. δ18Ow variations and the linkage to both hydrological cycle and ocean circulation bring challenges for an accurate interpretation of marine δ18Oc records. Our study illustrates the value of using water isotope-enabled simulations and model-data comparison for learning past climate changes. © 2020 Elsevier B.V.
关键词	early Eocene hydrological cycle isotope-enabled simulation ocean circulation oxygen isotopes Paleocene–Eocene Thermal Maximum
英文关键词	Atmospheric movements; Biomineralization; Climate change; Isotopes; Mean square error; Ocean currents; Oxygen; Seawater; Surface waters; Early Eocene; Hydrological cycles; Ocean circulation; Oxygen isotopes; Thermal maxima; Climate models; hydrological cycle; isotopic composition; numerical model; oxygen isotope; paleoceanography; Paleocene-Eocene boundary; paleoclimate; reconstruction; water chemistry
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203010
作者单位	Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, United States; Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, CO, United States; Atmospheric Science Program, Department of Geography, The Ohio State University, Columbus, OH, United States; College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, United States
推荐引用方式 GB/T 7714	Zhu J.,Poulsen C.J.,Otto-Bliesner B.L.,et al. Simulation of early Eocene water isotopes using an Earth system model and its implication for past climate reconstruction[J],2020,537.
APA	Zhu J.,Poulsen C.J.,Otto-Bliesner B.L.,Liu Z.,Brady E.C.,&Noone D.C..(2020).Simulation of early Eocene water isotopes using an Earth system model and its implication for past climate reconstruction.Earth and Planetary Science Letters,537.
MLA	Zhu J.,et al."Simulation of early Eocene water isotopes using an Earth system model and its implication for past climate reconstruction".Earth and Planetary Science Letters 537(2020).