DOI: 10.1175/JCLI-D-11-00549.1
Scopus记录号: 2-s2.0-84867686854
论文题名: Mechanisms behind the temporary shutdown of deep convection in the labrador sea: Lessons from the great salinity anomaly years 1968-71
作者: Gelderloos R. ; Straneo F. ; Katsman C.A.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2012
卷: 25, 期: 19 起始页码: 6743
结束页码: 6755
语种: 英语
Scopus关键词: Arctic ocean
; Atmosphere-ocean interactions
; Atmospheric data
; Atmospheric forcing
; Deep convection
; Dense waters
; Freshwater fluxes
; Greenland Ice Sheet
; Labrador Sea
; Mixed-layer models
; Oceanic variability
; Sea surface temperature (SST)
; Subsurface waters
; Surface freshening
; Thermal expansion coefficients
; Tight coupling
; Heat flux
; Oceanography
; Water
; advection
; atmosphere-hydrosphere interaction
; heat flux
; intermediate water
; oceanic convection
; salinity
; sea surface temperature
; temperature gradient
; Arctic
; Arctic Ocean
; Atlantic Ocean
; Atlantic Ocean (North)
; Greenland
; Greenland Ice Sheet
; Labrador Sea
英文摘要: From 1969 to 1971 convection in the Labrador Sea shut down, thus interrupting the formation of the intermediate/ dense water masses. The shutdown has been attributed to the surface freshening induced by the Great SalinityAnomaly (GSA), a freshwater anomaly in the subpolarNorth Atlantic. The abrupt resumption of convection in 1972, in contrast, is attributed to the extreme atmospheric forcing of that winter. Here oceanic and atmospheric data collected in the Labrador Sea atOceanWeather Station Bravo and a one-dimensional mixed layer model are used to examine the causes of the shutdown and resumption of convection in detail. These results highlight the tight coupling of the ocean and atmosphere in convection regions and the need to resolve both components to correctly represent convective processes in the ocean. They are also relevant to present-day conditions given the increased ice melt in the Arctic Ocean and from the Greenland Ice Sheet. The analysis herein shows that the shutdown was initiated by theGSA-induced freshening as well as themild 1968/69 winter. After the shutdown had begun, however, the continuing lateral freshwater flux as well as two positive feedbacks [both associated with the sea surface temperature (SST) decrease due to lack of convectivemixing with warmer subsurface water] further inhibited convection. First, the SST decrease reduced the heat flux to the atmosphere by reducing the air-sea temperature gradient. Second, it further reduced the surface buoyancy loss by reducing the thermal expansion coefficient of the surfacewater. In 1972 convection resumed because of both the extreme atmospheric forcing and advection of saltier waters into the convection region. © 2012 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/52185
Appears in Collections: 气候变化事实与影响
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作者单位: Royal Netherlands Meteorological Institute, De Bilt, Netherlands; Woods Hole Oceanographic Institution, Woods Hole, MA, United States
Recommended Citation:
Gelderloos R.,Straneo F.,Katsman C.A.. Mechanisms behind the temporary shutdown of deep convection in the labrador sea: Lessons from the great salinity anomaly years 1968-71[J]. Journal of Climate,2012-01-01,25(19)