A Multimodel Study of Sea Surface Temperature and Subsurface Density Fingerprints of the Atlantic Meridional Overturning Circulation

AbstractThe Atlantic meridional overturning circulation (AMOC) is an important component of the North Atlantic climate system. Here, simulations from 10 coupled climate models are used to calculate patterns of sea surface temperature (SST) and subsurface density change associated with decadal AMOC variability. The models are evaluated using observational constraints and it is shown that all 10 models suffer from North Atlantic Deep Water transports that are too shallow, although the biases are least severe in the Community Climate System Model, version 4 (CCSM4). In the models that best compare with observations, positive AMOC anomalies are associated with reduced Labrador Sea stratification and increased midocean (800–1800 m) densities in the subpolar gyre. Maximum correlations occur when AMOC anomalies lag Labrador Sea stratification and subsurface density anomalies by 2–6 yr and 0–3 yr, respectively. In all 10 models, North Atlantic warming follows positive AMOC anomalies, but the patterns and magnitud...

[1]  G. Danabasoglu,et al.  The Community Climate System Model Version 4 , 2011 .

[2]  Michael E. Schlesinger,et al.  An oscillation in the global climate system of period 65–70 years , 1994, Nature.

[3]  M. Huddleston,et al.  Quality control of ocean temperature and salinity profiles — Historical and real-time data , 2007 .

[4]  T. Delworth,et al.  Impact of Atlantic multidecadal oscillations on India/Sahel rainfall and Atlantic hurricanes , 2006 .

[5]  C. Jones,et al.  The HadGEM2 family of Met Office Unified Model climate configurations , 2011 .

[6]  Jeff Knight,et al.  A signature of persistent natural thermohaline circulation cycles in observed climate , 2005 .

[7]  R. Curry,et al.  Oceanic transport of subpolar climate signals to mid-depth subtropical waters , 1998, Nature.

[8]  Stefan Rahmstorf,et al.  On the driving processes of the Atlantic meridional overturning circulation , 2007 .

[9]  H. Douville,et al.  The CNRM-CM5.1 global climate model: description and basic evaluation , 2013, Climate Dynamics.

[10]  K. Emanuel,et al.  Atlantic hurricane trends linked to climate change , 2006 .

[11]  Andrei P. Sokolov,et al.  A model intercomparison of changes in the Atlantic thermohaline circulation in response to increasing atmospheric CO2 concentration , 2005 .

[12]  Michael Botzet,et al.  Reconstructing, Monitoring, and Predicting Multidecadal-Scale Changes in the North Atlantic Thermohaline Circulation with Sea Surface Temperature , 2004 .

[13]  C. Wunsch,et al.  Large-Scale Ocean Heat and Freshwater Transports during the World Ocean Circulation Experiment , 2003 .

[14]  Nicolas Bellouin,et al.  Aerosols implicated as a prime driver of twentieth-century North Atlantic climate variability , 2012, Nature.

[15]  Carsten Eden,et al.  Mechanism of Interannual to Decadal Variability of the North Atlantic Circulation , 2001 .

[16]  Simona Masina,et al.  Interannual to Decadal Climate Predictability in the North Atlantic: A Multimodel-Ensemble Study , 2006 .

[17]  S. Riser,et al.  The Argo Program : observing the global ocean with profiling floats , 2009 .

[18]  Kaoru Tachiiri,et al.  Stability of the Atlantic meridional overturning circulation: A model intercomparison , 2012 .

[19]  J. Marotzke,et al.  Timely detection of changes in the meridional overturning circulation at 26° N in the Atlantic , 2007 .

[20]  H. Bryden,et al.  Slowing of the Atlantic meridional overturning circulation at 25° N , 2005, Nature.

[21]  B. Dong,et al.  Atlantic Ocean influence on a shift in European climate in the 1990s , 2012 .

[22]  Christoph Heinze,et al.  Evaluation of the carbon cycle components in the Norwegian Earth System Model (NorESM) , 2012 .

[23]  M. Maqueda,et al.  The relation of meridional pressure gradients to North Atlantic deep water volume transport in an ocean general circulation model , 2006 .

[24]  T. Kanzow Monitoring the integrated deep meridional flow in the tropical North Atlantic , 2006 .

[25]  Michael E. Mann,et al.  Observed and Simulated Multidecadal Variability in the Northern Hemisphere , 1999 .

[26]  William E. Johns,et al.  Temporal Variability of the Atlantic Meridional Overturning Circulation at 26.5°N , 2007, Science.

[27]  J. Willis Can in situ floats and satellite altimeters detect long‐term changes in Atlantic Ocean overturning? , 2010 .

[28]  William E. Johns,et al.  Observed interannual variability of the Atlantic meridional overturning circulation at 26.5°N , 2012 .

[29]  R. Dickson,et al.  The production of North Atlantic Deep Water: Sources, rates, and pathways , 1994 .

[30]  Johanna Baehr,et al.  Detecting potential changes in the meridional overturning circulation at 26˚N in the Atlantic , 2008 .

[31]  J. Marotzke,et al.  Temporal Variability of the Atlantic Meridional Overturning Circulation at 26.5°N , 2007, Science.

[32]  Jonathan M. Gregory,et al.  Mechanisms Determining the Atlantic Thermohaline Circulation Response to Greenhouse Gas Forcing in a Non-Flux-Adjusted Coupled Climate Model , 2001 .

[33]  Y. Kushnir,et al.  Interdecadal Variations in North Atlantic Sea Surface Temperature and Associated Atmospheric Conditions , 1994 .

[34]  R. Käse,et al.  Interannual changes in the overflow from the Nordic Seas into the Atlantic Ocean through Denmark Strait , 2005 .

[35]  J. Marotzke,et al.  The contribution of eastern-boundary density variations to the Atlantic meridional overturning circulation at 26.5° N , 2009 .

[36]  H. Tsujino,et al.  A New Global Climate Model of the Meteorological Research Institute: MRI-CGCM3 —Model Description and Basic Performance— , 2012 .

[37]  C. Eden,et al.  Signal propagation related to the North Atlantic overturning , 2005 .

[38]  Kevin E. Trenberth,et al.  Atlantic hurricanes and natural variability in 2005 , 2006 .

[39]  O. Boucher,et al.  Reversibility in an Earth System model in response to CO2 concentration changes , 2012 .

[40]  J. Girton,et al.  Descent and Modification of the Overflow Plume in the Denmark Strait , 2003 .

[41]  Robert Hallberg,et al.  Simulation of Density-Driven Frictional Downslope Flow in Z-Coordinate Ocean Models , 1998 .

[42]  Young‐Gyu Park,et al.  The Stability of Thermohaline Circulation in a Two-Box Model , 1999 .

[43]  J. Toggweiler,et al.  Effect of Drake Passage on the global thermohaline circulation , 1995 .

[44]  G. Danabasoglu,et al.  Sensitivity of Atlantic Meridional Overturning Circulation Variability to Parameterized Nordic Sea Overflows in CCSM4 , 2012 .

[45]  A. Watson,et al.  Meridional density gradients do not control the Atlantic overturning circulation , 2010 .

[46]  T. Palmer,et al.  Sahel rainfall and worldwide sea temperatures, 1901–85 , 1986, Nature.

[47]  C. Mauritzen,et al.  Circulation and mixing in the Faroese Channels , 2005 .

[48]  Rory J. Bingham,et al.  Signature of the Atlantic meridional overturning circulation in sea level along the east coast of North America , 2009 .

[49]  Hartmut Peters,et al.  Improving Oceanic Overflow Representation in Climate Models: The Gravity Current Entrainment Climate Process Team , 2009 .

[50]  Corinna Hoose,et al.  The Norwegian Earth System Model, NorESM1-M - Part 1: Description and basic evaluation , 2012 .

[51]  John F. B. Mitchell,et al.  The simulation of SST, sea ice extents and ocean heat transports in a version of the Hadley Centre coupled model without flux adjustments , 2000 .

[52]  Katja Lohmann,et al.  Characteristics of the ocean simulations in the Max Planck Institute Ocean Model (MPIOM) the ocean component of the MPI‐Earth system model , 2013 .

[53]  S. Østerhus,et al.  Faroe Bank Channel overflow 1995–2005 , 2007 .

[54]  William E. Johns,et al.  Continuous, Array-Based Estimates of Atlantic Ocean Heat Transport at 26.5°N , 2011 .

[55]  M. Palmer,et al.  Detectability of changes to the Atlantic meridional overturning circulation in the Hadley Centre Climate Models , 2012, Climate Dynamics.

[56]  Rong‐Hua Zhang Anticorrelated multidecadal variations between surface and subsurface tropical North Atlantic , 2007 .

[57]  Jiayan Yang A linkage between decadal climate variations in the Labrador Sea and the tropical Atlantic Ocean , 1999 .

[58]  J. Toggweiler,et al.  On the Ocean’s Large-Scale Circulation near the Limit of No Vertical Mixing , 1998 .

[59]  A. Rosati,et al.  Predicting Atlantic meridional overturning circulation (AMOC) variations using subsurface and surface fingerprints , 2011 .

[60]  J. Baehr Detecting changes in the meridional overturning circulation at 26°N in the Atlantic from observations , 2011 .

[61]  Helge Drange,et al.  External forcing as a metronome for Atlantic multidecadal variability , 2010 .

[62]  R. Sutton,et al.  Atlantic Ocean Forcing of North American and European Summer Climate , 2005, Science.

[63]  Henry Stommel Thermohaline Convection with Two Stable Regimes of Flow , 1961 .