FN Archimer Export Format
PT J
TI Characterizing, modelling and understanding the climate variability of the deep water formation in the North-Western Mediterranean Sea
BT 
AF SOMOT, Samuel
   HOUPERT, Loic
   SEVAULT, Florence
   TESTOR, Pierre
   BOSSE, Anthony
   TAUPIER-LETAGE, Isabelle
   BOUIN, Marie-Noelle
   WALDMAN, Robin
   CASSOU, Christophe
   SANCHEZ-GOMEZ, Emilia
   DURRIEU DE MADRON, Xavier
   ADLOFF, Fanny
   NABAT, Pierre
   HERRMANN, Marine
AS 1:1;2:2;3:1;4:3;5:3;6:4;7:5,6;8:1;9:7;10:7;11:8;12:1;13:1;14:9;
FF 1:;2:;3:;4:;5:;6:;7:;8:;9:;10:;11:;12:;13:;14:;
C1 Meteo France, CNRM, CNRS, UMR 3589, F-31057 Toulouse, France.
   SAMS, Scottish Marine Inst, Oban PA37 1QA, Argyll, Scotland.
   Sorbonne Univ, UPMC Univ Paris 06, Lab Oceanog & Climat, CNRS,IRD,MNHN,UMR 7159,IPSL, Paris, France.
   Univ Toulon & Var, Aix Marseille Univ, Mediterranean Inst Oceanog MIO, IRD,UM 110,CNRS,INSU, CS 20330, F-83507 La Seyne Sur Mer, France.
   CNRM, 13 Rue Chatellier,CS 12804, F-29228 Brest, France.
   IFREMER, Lab Oceanog Phys & Spatiale, UMR 6523, CS 10070, F-29280 Plouzane, France.
   CNRS, CERFACS, SUC URA 1875, 42 Ave Coriolis, F-31057 Toulouse, France.
   Univ Perpignan, CNRS, CEFREM, UMR 5110, 52 Ave Paul Alduy, F-66860 Perpignan, France.
   Univ Toulouse, IRD, CNRS, CNES,UMR 5566,LEGOS, 13 Ave Edouard Belin, F-31400 Toulouse, France.
C2 CNRM (METEO FRANCE), FRANCE
   SAMS, UK
   UNIV PARIS 06, FRANCE
   UNIV TOULON, FRANCE
   CNRM, FRANCE
   CNRM, FRANCE
   CNRS, FRANCE
   UNIV PERPIGNAN, FRANCE
   UNIV TOULOUSE, FRANCE
UM LOPS
IF 4.048
TC 74
UR https://archimer.ifremer.fr/doc/00348/45948/45654.pdf
LA English
DT Article
CR DEWEX-MERMEX 2013 LEG1
   DEWEX-MERMEX 2013 LEG2
   MOOSE-GE
BO Le Suroît
DE ;Deep water formation;Open-sea deep convection;Interannual variability;Mediterranean Sea;Regional climate models;Climate trends
AB 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.
PY 2018
PD AUG
SO Climate Dynamics
SN 0930-7575
PU Springer
VL 51
IS 3
UT 000439141800024
BP 1179
EP 1210
DI 10.1007/s00382-016-3295-0
ID 45948
ER

EF