DOI: 10.1016/j.epsl.2020.116164
论文题名: Simulation of early Eocene water isotopes using an Earth system model and its implication for past climate reconstruction
作者: Zhu J. ; Poulsen C.J. ; Otto-Bliesner B.L. ; Liu Z. ; Brady E.C. ; Noone D.C.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 537 语种: 英语
中文关键词: 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
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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165388
Appears in Collections: 气候变化与战略
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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
Recommended Citation:
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]. Earth and Planetary Science Letters,2020-01-01,537