DOI: 10.1175/JCLI-D-16-0200.1
Scopus记录号: 2-s2.0-85014016595
论文题名: Multidecadal indian ocean variability linked to the pacific and implications for preconditioning indian ocean dipole events
作者: Ummenhofer C.C. ; Biastoch A. ; Böning C.W.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2017
卷: 30, 期: 5 起始页码: 1739
结束页码: 1751
语种: 英语
Scopus关键词: Enthalpy
; Mechanical waves
; Oceanography
; Stream flow
; Indian ocean dipoles
; Indonesian throughflow
; Low frequency variability
; Low-frequency changes
; Multidecadal variability
; Multidecadal variations
; Pacific decadal oscillation
; Tropical Indian ocean
; Ocean currents
; decadal variation
; Indian Ocean Dipole
; Rossby wave
; temperature anomaly
; thermocline
; water temperature
; wave propagation
; wind forcing
; Indian Ocean
英文摘要: The Indian Ocean has sustained robust surface warming in recent decades, but the role of multidecadal variability remains unclear. Using ocean model hindcasts, characteristics of low-frequency Indian Ocean temperature variations are explored. Simulated upper-ocean temperature changes across the Indian Ocean in the hindcast are consistent with those recorded in observational products and ocean reanalyses. Indian Ocean temperatures exhibit strong warming trends since the 1950s limited to the surface and south of 30°S, while extensive subsurface cooling occurs over much of the tropical Indian Ocean. Previous work focused on diagnosing causes of these long-term trends in the Indian Ocean over the second half of the twentieth century. Instead, the temporal evolution of Indian Ocean subsurface heat content is shown here to reveal distinct multidecadal variations associated with the Pacific decadal oscillation, and the long-term trends are thus interpreted to result from aliasing of the low-frequency variability. Transmission of the multidecadal signal occurs via an oceanic pathway through the Indonesian Throughflow and is manifest across the Indian Ocean centered along 12°S as westward-propagating Rossby waves modulating thermocline and subsurface heat content variations. Resulting low-frequency changes in the eastern Indian Ocean thermocline depth are associated with decadal variations in the frequency of Indian Ocean dipole (IOD) events, with positive IOD events unusually common in the 1960s and 1990s with a relatively shallow thermocline. In contrast, the deeper thermocline depth in the 1970s and 1980s is associated with frequent negative IOD and rare positive IOD events. Changes in Pacific wind forcing in recent decades and associated rapid increases in Indian Ocean subsurface heat content can thus affect the basin's leading mode of variability, with implications for regional climate and vulnerable societies in surrounding countries. © 2017 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49825
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods Hole, MA, United States; GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Recommended Citation:
Ummenhofer C.C.,Biastoch A.,Böning C.W.. Multidecadal indian ocean variability linked to the pacific and implications for preconditioning indian ocean dipole events[J]. Journal of Climate,2017-01-01,30(5)