DOI: 10.1175/JCLI-D-16-0819.1
Scopus记录号: 2-s2.0-85022334880
论文题名: The eastern subtropical pacific origin of the equatorial cold bias in climate models: A Lagrangian perspective
作者: Thomas M.D. ; Fedorov A.V.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2017
卷: 30, 期: 15 起始页码: 5885
结束页码: 5900
语种: 英语
Scopus关键词: Atmospheric movements
; Atmospheric temperature
; Lagrange multipliers
; Oceanography
; Surface properties
; Tropics
; Eastern equatorial Pacific
; Equatorial undercurrents
; Global climate model
; Lagrangian circulation/transport
; Lagrangian particles
; Model errors
; Sea surface temperature (SST)
; Teleconnections
; Climate models
英文摘要: Global climate models frequently exhibit cold biases in tropical sea surface temperature (SST) in the central and eastern equatorial Pacific. Here, Lagrangian particle back trajectories are used to investigate the source regions of the water that upwells along the equator in the IPSL climate model to test and confirm the hypothesis that the SST biases are caused by remote biases advected in fromthe extratropics and to identify the dominant source regions. Water in the model is found to be sourced primarily from localized regions along the western and eastern flanks of the subtropical gyres. However, while the model SST bias is especially large in the northwestern subtropical Pacific (about 258C), it is found that the eastern subtropics contribute to the equatorial bias the most. This is due to two distinct subsurface pathways connecting these regions to the equator. The first pathway, originating in the northwestern subtropical Pacific, has relatively long advection time scales close to or exceeding 60 yr, wherein particles recirculate around the subtropical gyres while descending to approximately 500m before then shoaling toward the equatorial undercurrent. The second pathway, from the eastern subtropics, has time scales close to 10 yr, with particles following a shallow and more direct route to the equator within the upper 200 m. The deeper and longer pathway taken by the western subtropical water ensures that vertical mixing can erode the bias. Ultimately, it is estimated that relatively confined regions in the eastern subtropics of both hemispheres control approximately half of the equatorial bias. © 2017 American Meteorological Society. 资助项目: NOAA, National Oceanic and Atmospheric Administration
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/48757
Appears in Collections: 气候减缓与适应 气候变化与战略
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作者单位: Department of Geology and Geophysics, Yale University, New Haven, CT, United States
Recommended Citation:
Thomas M.D.,Fedorov A.V.. The eastern subtropical pacific origin of the equatorial cold bias in climate models: A Lagrangian perspective[J]. Journal of Climate,2017-01-01,30(15)