DOI: 10.1175/JCLI-D-17-0092.1
Scopus记录号: 2-s2.0-85047100906
论文题名: Impacts of broad-scale surface freshening of the Southern Ocean in a coupled climate model
作者: Purich A. ; England M.H. ; Cai W. ; Sullivan A. ; Durack P.J.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2018
卷: 31, 期: 7 起始页码: 2613
结束页码: 2632
语种: 英语
英文关键词: Antarctica
; Coupled models
; Precipitation
; Southern Ocean
Scopus关键词: Atmospheric temperature
; Oceanography
; Precipitation (chemical)
; Sea ice
; Surface properties
; Surface waters
; Additional experiments
; Antarctica
; Coupled climate model
; Coupled models
; Pre-industrial conditions
; Sea surface temperature (SST)
; Southern ocean
; Surface temperatures
; Climate models
; climate modeling
; CMIP
; hydrography
; oceanic circulation
; precipitation (climatology)
; salinity
; sea ice
; sea surface temperature
; upwelling
; water column
; computer simulation
; trend analysis
; Antarctica
; Southern Ocean
英文摘要: The Southern Ocean surface has freshened in recent decades, increasing water column stability and reducing upwelling of warmer subsurface waters. The majority of CMIP5 models underestimate or fail to capture this historical surface freshening, yet little is known about the impact of this model bias on regional ocean circulation and hydrography. Here experiments are performed using a global coupled climate model with additional freshwater applied to the Southern Ocean to assess the influence of recent surface freshening. The simulations explore the impact of persistent and long-term broad-scale freshening as a result of processes including precipitation minus evaporation changes. Thus, unlike previous studies, the freshening is applied as far north as 55°S, beyond the Antarctic ice margin. It is found that imposing a large-scale surface freshening causes a surface cooling and sea ice increase under preindustrial conditions, because of a reduction in ocean convection and weakened entrainment of warm subsurface waters into the surface ocean. This is consistent with intermodel relationships between CMIP5 models and the simulations, suggesting that models with larger surface freshening also exhibit stronger surface cooling and increased sea ice. Additional experiments are conducted with surface salinity restoration applied to capture observed regional salinity trends. Remarkably, without any mechanical wind trend forcing, these simulations accurately represent the spatial pattern of observed surface temperature and sea ice trends around Antarctica. This study highlights the importance of accurately simulating changes in Southern Ocean salinity to capture changes in ocean circulation, sea surface temperature, and sea ice. © 2018 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/111608
Appears in Collections: 气候减缓与适应
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作者单位: Commonwealth Scientific and Industrial Research Organisation, Oceans and Atmosphere, Aspendale, VIC, Australia; Climate Change Research Centre and ARC Centre of Excellence for Climate System Science, University of New South Wales, Sydney, NSW, Australia; Centre for Southern Hemisphere Oceans Research, Commonwealth Scientific and Industrial Research Organisation Oceans and Atmosphere, Aspendale, VIC, Australia; Physical Oceanography Laboratory, Ocean University of China, China; Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; Program for Climate Model Diagnosis and Intercomparison, Lawrence Livermore National Laboratory, Livermore, CA, United States
Recommended Citation:
Purich A.,England M.H.,Cai W.,et al. Impacts of broad-scale surface freshening of the Southern Ocean in a coupled climate model[J]. Journal of Climate,2018-01-01,31(7)