DOI: 10.1007/s00382-016-3295-0
Scopus记录号: 2-s2.0-84983784431
论文题名: Characterizing, modelling and understanding the climate variability of the deep water formation in the North-Western Mediterranean Sea
作者: Somot S. ; Houpert L. ; Sevault F. ; Testor P. ; Bosse A. ; Taupier-Letage I. ; Bouin M.-N. ; Waldman R. ; Cassou C. ; Sanchez-Gomez E. ; Durrieu de Madron X. ; Adloff F. ; Nabat P. ; Herrmann M.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2018
卷: 51, 期: 3 起始页码: 1179
结束页码: 1210
语种: 英语
英文关键词: Climate trends
; Deep water formation
; Interannual variability
; Mediterranean Sea
; Open-sea deep convection
; Regional climate models
Scopus关键词: air-sea interaction
; annual variation
; climate change
; climate modeling
; deep water
; hindcasting
; North Atlantic Oscillation
; oceanic convection
; open ocean
; regional climate
; stratification
; trend analysis
; Gulf of Lion
; Mediterranean Sea
; Mediterranean Sea (Northwest)
英文摘要: Observing, modelling and understanding the climate-scale variability of the deep water formation (DWF) in the North-Western Mediterranean Sea remains today very challenging. In this study, we first characterize the interannual variability of this phenomenon by a thorough reanalysis of observations in order to establish reference time series. These quantitative indicators include 31 observed years for the yearly maximum mixed layer depth over the period 1980–2013 and a detailed multi-indicator description of the period 2007–2013. Then a 1980–2013 hindcast simulation is performed with a fully-coupled regional climate system model including the high-resolution representation of the regional atmosphere, ocean, land-surface and rivers. The simulation reproduces quantitatively well the mean behaviour and the large interannual variability of the DWF phenomenon. The model shows convection deeper than 1000 m in 2/3 of the modelled winters, a mean DWF rate equal to 0.35 Sv with maximum values of 1.7 (resp. 1.6) Sv in 2013 (resp. 2005). Using the model results, the winter-integrated buoyancy loss over the Gulf of Lions is identified as the primary driving factor of the DWF interannual variability and explains, alone, around 50 % of its variance. It is itself explained by the occurrence of few stormy days during winter. At daily scale, the Atlantic ridge weather regime is identified as favourable to strong buoyancy losses and therefore DWF, whereas the positive phase of the North Atlantic oscillation is unfavourable. The driving role of the vertical stratification in autumn, a measure of the water column inhibition to mixing, has also been analyzed. Combining both driving factors allows to explain more than 70 % of the interannual variance of the phenomenon and in particular the occurrence of the five strongest convective years of the model (1981, 1999, 2005, 2009, 2013). The model simulates qualitatively well the trends in the deep waters (warming, saltening, increase in the dense water volume, increase in the bottom water density) despite an underestimation of the salinity and density trends. These deep trends come from a heat and salt accumulation during the 1980s and the 1990s in the surface and intermediate layers of the Gulf of Lions before being transferred stepwise towards the deep layers when very convective years occur in 1999 and later. The salinity increase in the near Atlantic Ocean surface layers seems to be the external forcing that finally leads to these deep trends. In the future, our results may allow to better understand the behaviour of the DWF phenomenon in Mediterranean Sea simulations in hindcast, forecast, reanalysis or future climate change scenario modes. The robustness of the obtained results must be however confirmed in multi-model studies. © 2016, The Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109164
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: CNRM UMR 3589, Météo-France/CNRS, Centre National de Recherches Météorologiques, 42 Avenue Coriolis, Toulouse, 31057, France; Scottish Marine Institute, SAMS, Oban, Argyll, PA37 1QA, United Kingdom; UPMC Univ. Paris 06-CNRS-IRD-MNHN, UMR 7159, Laboratoire d’Océanographie et du Climat, IPSL, Sorbonne Universités, Paris, France; IRD, Mediterranean Institute of Oceanography (MIO) UM 110, Aix Marseille Université, CNRS/INSU, Université de Toulon, Antenne de la Seyne, CS 20330, La Seyne, 83507, France; CNRM, 13 rue du Chatellier, CS 12804, Brest, 29228, France; Laboratoire d’Océanographie Physique et Spatiale, UMR 6523, Ifremer, Pointe du Diable, CS 10070, Plouzané, 29280, France; SUC URA 1875, CERFACS/CNRS, 42 Avenue Coriolis, Toulouse, 31057, France; CEFREM UMR 5110, CNRS-Université de Perpignan, 52 Avenue Paul Alduy, Perpignan, 66860, France; UMR 5566, CNRS-CNES-IRD-Université de Toulouse, LEGOS, 13 Ave. Edouard Belin, Toulouse, 31400, France
Recommended Citation:
Somot S.,Houpert L.,Sevault F.,et al. Characterizing, modelling and understanding the climate variability of the deep water formation in the North-Western Mediterranean Sea[J]. Climate Dynamics,2018-01-01,51(3)