On the Path of the Gulf Stream and the Atlantic Meridional Overturning Circulation

Joyce, Terrence M.; Zhang, Rong

doi:10.1175/2010jcli3310.1

Cited by 89 publications

(87 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand, Zhang (2008) suggested, based on the GFDL CM2.1 control integration, that the observed decrease in subpolar gyre intensity was correlated with a strengthening of the AMOC and a southward shift of the Gulf Stream due to the increased deep western boundary current (see Zhang and Vallis 2006). Such relation between Gulf Stream shifts 6 and the AMOC seems consistent with the observations (Joyce and Zhang 2010), but the Gulf Stream has not really shifted since the1990s (Peña-Molino and Joyce 2008).…”

supporting

confidence: 88%

Stochastically-driven multidecadal variability of the Atlantic meridional overturning circulation in CCSM3

Kwon

Frankignoul

2011

Clim Dyn

View full text Add to dashboard Cite

The Atlantic meridional overturning circulation (AMOC) in the last 250 years of the 700-yearlong present-day control integration of the Community Climate System Model version 3 with T85 atmospheric resolution exhibits a red noise-like irregular multi-decadal variability with a persistence longer than 10 years, which markedly contrasts with the preceding ~300 years of very regular and stronger AMOC variability with ~20 year periodicity. The red noise-like multidecadal AMOC variability is primarily forced by the surface fluxes associated with stochastic changes in the North Atlantic Oscillation (NAO) that intensify and shift northward the deep convection in the Labrador Sea. However, the persistence of the AMOC and the associated oceanic anomalies that are directly forced by the NAO forcing does not exceed about 5 years.The additional persistence originates from anomalous horizontal advection and vertical mixing, which generate density anomalies on the continental shelf along the eastern boundary of the subpolar gyre. These anomalies are subsequently advected by the mean boundary current into the northern part of the Labrador Sea convection region, reinforcing the density changes directly forced by the NAO. As no evidence was found of a clear two-way coupling with the atmosphere, the multi-decadal AMOC variability in the last 250 years of the integration is an ocean-only response to stochastic NAO forcing with a delayed positive feedback caused by the changes in the horizontal ocean circulation.

show abstract

supporting

confidence: 88%

Stochastically-driven multidecadal variability of the Atlantic meridional overturning circulation in CCSM3

Kwon

Frankignoul

2011

Clim Dyn

View full text Add to dashboard Cite

show abstract

“…The opposite was found by Zhang (2008), who attributed this difference to the coupling with the atmosphere. The recent work in Joyce and Zhang (2010), adding to Zhang's (2008) findings, presented some observational evidence supporting the connection between the strengthening of the MOC and a southerly Gulf Stream path. Those authors also pointed out that the resolution in most of the models discussed by Coetlogon et al (2006) was not sufficient to properly resolve the Gulf Stream recirculations, thus they would likely miss interactions between the DWBC and the Gulf Stream.…”

Section: Introductionmentioning

confidence: 68%

Variability in the North Atlantic Deep Western Boundary Current : upstream causes and downstream effects as observed at Line W

Peña‐Molino¹

2010

View full text Add to dashboard Cite

“…Indeed, oceanic hindcasts generally show that the GS shifts northward when the AMOC and the subpolar gyre strengthen in response to NAO forcing (e.g., de Coëlogon et al 2006;Kwon et al 2010), while in the Geophysical Fluid Dynamics Laboratory Climate Model, version 2.1 (GFDL CM2.1), an AMOC strengthening is associated with a weaker subpolar gyre and a southward GS (Zhang 2008). Joyce and Zhang (2010) give some observational support for the latter relation, but there is little consensus on past AMOC variations or the relation between subpolar gyre and AMOC changes. The different GS shifts influence differently the oceanic heat release to the atmosphere and the low-level baroclinicity in the storm track.…”

Section: Discussionmentioning

confidence: 99%

The Influence of the AMOC Variability on the Atmosphere in CCSM3

2013

View full text Add to dashboard Cite

The influence of the Atlantic meridional overturning circulation (AMOC) variability on the atmospheric circulation is investigated in a control simulation of the NCAR Community Climate System Model, version 3 (CCSM3), where the AMOC evolves from an oscillatory regime into a red noise regime. In the latter, an AMOC intensification is followed during winter by a positive North Atlantic Oscillation (NAO). The atmospheric response is robust and controlled by AMOC-driven SST anomalies, which shift the heat release to the atmosphere northward near the Gulf Stream/North Atlantic Current. This alters the low-level atmospheric baroclinicity and shifts the maximum eddy growth northward, affecting the storm track and favoring a positive NAO. The AMOC influence is detected in the relation between seasonal upper-ocean heat content or SST anomalies and winter sea level pressure. In the oscillatory regime, no direct AMOC influence is detected in winter. However, an upper-ocean heat content anomaly resembling the AMOC footprint precedes a negative NAO. This opposite NAO polarity seems due to the southward shift of the Gulf Stream during AMOC intensification, displacing the maximum baroclinicity southward near the jet exit. As the mode has somewhat different patterns when using SST, the wintertime impact of the AMOC lacks robustness in this regime. However, none of the signals compares well with the observed influence of North Atlantic SST anomalies on the NAO because SST is dominated in CCSM3 by the meridional shifts of the Gulf Stream/ North Atlantic Current that covary with the AMOC. Hence, although there is some potential climate predictability in CCSM3, it is not realistic.

show abstract

On the Path of the Gulf Stream and the Atlantic Meridional Overturning Circulation

Cited by 89 publications

References 33 publications

Stochastically-driven multidecadal variability of the Atlantic meridional overturning circulation in CCSM3

Stochastically-driven multidecadal variability of the Atlantic meridional overturning circulation in CCSM3

Variability in the North Atlantic Deep Western Boundary Current : upstream causes and downstream effects as observed at Line W

The Influence of the AMOC Variability on the Atmosphere in CCSM3

Contact Info

Product

Resources

About