DOI: 10.1029/2018GB006121
论文题名: Variations in Ocean Deoxygenation Across Earth System Models: Isolating the Role of Parameterized Lateral Mixing
作者: Bahl A. ; Gnanadesikan A. ; Pradal M.-A.
刊名: Global Biogeochemical Cycles
ISSN: 0886-6236
EISSN: 1944-9224
出版年: 2019
卷: 33, 期: 6 语种: 英语
英文关键词: anthropogenic effect
; climate change
; climate modeling
; CMIP
; global warming
; hypoxic conditions
; large eddy simulation
; mesoscale eddy
; mixing
; ocean
; oxygenation
; parameterization
学科: climate change
; mesoscale eddy mixing
; modeling
; ocean deoxygenation
; parameterization
中文摘要: Modern Earth system models (ESMs) disagree on the impacts of anthropogenic global warming on the distribution of oxygen and associated low-oxygen waters. A sensitivity study using the GFDL CM2Mc model points to the representation of lateral mesoscale eddy transport as a potentially important factor in such disagreement. Because mesoscale eddies are smaller than the spatial scale of ESM ocean grids, their impact must be parameterized using a lateral mixing coefficient AREDI. The value of AREDI varies across modern ESMs and nonlinearly impacts oxygen distributions. This study shows that an increase in atmospheric CO2 results in a decline in productivity and a decrease in ventilation age in the tropics, increasing oxygen concentrations in the upper thermocline. In high latitudes global warming causes shallowing of deep convection, reducing the supply of oxygen to the deep. The net impact of these processes depends on AREDI, with an increase in hypoxic volume yet smaller total deoxygenation in the low-mixing models, but a decrease in hypoxic volume yet larger total deoxygenation in the high-mixing models. All models show decreases in suboxic volume, which are largest in the low-mixing models. A subset of Coupled Model Intercomparison Project Phase 5 models exhibits a similar range of responses to global warming and similar decoupling between total deoxygenation and change in hypoxic volume. Uncertainty in lateral mixing remains an important contributor to uncertainty in projecting ocean deoxygenation. ©2019. American Geophysical Union. All Rights Reserved.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/160128
Appears in Collections: 气候变化与战略
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作者单位: Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD, United States
Recommended Citation:
Bahl A.,Gnanadesikan A.,Pradal M.-A.. Variations in Ocean Deoxygenation Across Earth System Models: Isolating the Role of Parameterized Lateral Mixing[J]. Global Biogeochemical Cycles,2019-01-01,33(6)