Scopus记录号: 2-s2.0-85047140580
论文题名: Ocean circulation drifts in multi-millennial climate simulations: the role of salinity corrections and climate feedbacks
作者: Dentith J.E. ; Ivanovic R.F. ; Gregoire L.J. ; Tindall J.C. ; Smith R.S.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2019
卷: 52, 期: 2019-03-04 起始页码: 1761
结束页码: 1781
语种: 英语
英文关键词: Drift
; FAMOUS
; General circulation model
; Meridional overturning circulation
; Multi-millennial
英文摘要: Low-resolution, complex general circulation models (GCMs) are valuable tools for studying the Earth system on multi-millennial timescales. However, slowly evolving salinity drifts can cause large shifts in climatic and oceanic regimes over thousands of years. We test two different schemes for neutralising unforced salinity drifts in the FAMOUS GCM: surface flux correction and volumetric flux correction. Although both methods successfully maintain a steady global mean salinity, local drifts and subsequent feedbacks promote cooling (≈ 4 °C over 6000 years) and freshening (≈ 2 psu over 6000 years) in the North Atlantic Ocean, and gradual warming (≈ 0.2 °C per millennium) and salinification (≈ 0.15 psu per millennium) in the North Pacific Ocean. Changes in the surface density in these regions affect the meridional overturning circulation (MOC), such that, after several millennia, the Atlantic MOC (AMOC) is in a collapsed state, and there is a strong, deep Pacific MOC (PMOC). Furthermore, the AMOC exhibits a period of metastability, which is only identifiable with run lengths in excess of 1500 years. We also compare simulations with two different land surface schemes, demonstrating that small biases in the surface climate may cause regional salinity drifts and significant shifts in the MOC (weakening of the AMOC and the initiation then invigoration of PMOC), even when the global hydrological cycle has been forcibly closed. Although there is no specific precursor to the simulated AMOC collapse, the northwest North Pacific and northeast North Atlantic are important areas that should be closely monitored for trends arising from such biases. © 2018, The Author(s). 资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/122406
Appears in Collections: 气候变化事实与影响
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作者单位: School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom; NCAS-Climate, Department of Meteorology, University of Reading, Reading, RG6 6BB, United Kingdom
Recommended Citation:
Dentith J.E.,Ivanovic R.F.,Gregoire L.J.,et al. Ocean circulation drifts in multi-millennial climate simulations: the role of salinity corrections and climate feedbacks[J]. Climate Dynamics,2019-01-01,52(2019-03-04)