North Atlantic Ocean surface currents

Reverdin, Gilles; Niiler, Pearn P.; Valdimarsson, Héðinn

doi:10.1029/2001jc001020

Cited by 188 publications

(157 citation statements)

References 69 publications

(139 reference statements)

Supporting

Mentioning

137

Contrasting

Order By: Relevance

“…The mean circulation of the regional model closely parallels observations in the Labrador and Irminger Seas (Lavender et al 2000, Reverdin et al 2003, exhibiting maximum intensities in the boundary currents that follow topography (i.e. the East Greenland, West Greenland, and Labrador Currents).…”

Section: Mean Circulationmentioning

confidence: 59%

The role of salinity in the decadal variability of the North Atlantic meridional overturning circulation

2009

View full text Add to dashboard Cite

An OGCM hindcast is used to investigate the linkages between North Atlantic Ocean salinity and circulation changes during . The focus is on the eastern subpolar region consisting of the Irminger Sea and the eastern North Atlantic where a careful assessment shows that the simulated interannual to decadal salinity changes in the upper 1500 m reproduce well those derived from the available record of hydrographic measurements. In the model, the variability of the Atlantic meridional overturning circulation (MOC) is primarily driven by changes in deep water formation taking place in the Irminger Sea and, to a lesser extent, the Labrador Sea. Both are strongly influenced by the North Atlantic Oscillation (NAO). The modeled interannual to decadal salinity changes in the subpolar basins are mostly controlled by circulation-driven anomalies of freshwater flux convergence, although surface salinity restoring to climatology and other boundary fluxes each account for approximately 25% of the variance. The NAO plays an important role: a positive NAO phase is associated with increased precipitation, reduced northward salt transport by the wind-driven intergyre gyre, and increased southward flows of freshwater across the Greenland-Scotland ridge. Since the NAO largely controlled deep convection in the subpolar gyre, fresher waters are found near the sinking region during convective events. This markedly differs from the active influence on the MOC that salinity exerts at decadal and longer timescales in most coupled models. The intensification of the MOC that follows a positive NAO phase by about 2 years does not lead to an increase in the northward salt transport into the subpolar domain at low frequencies because it is cancelled by the concomitant intensification of the subpolar gyre which shifts the subpolar front eastward and reduces the northward salt transport by the North Atlantic Current waters. This differs again from most coupled models, where the gyre intensification precedes that of the MOC by several years.3

show abstract

Section: Mean Circulationmentioning

confidence: 59%

The role of salinity in the decadal variability of the North Atlantic meridional overturning circulation

2009

View full text Add to dashboard Cite

show abstract

“…In measurement data from surface drifters (Reverdin et al 2003;Flatau et al 2003), the subpolar gyre consists of two distinct parts. The western part involves the Irminger Current flowing northward along the western flank of the Reykjanes Ridge, which then connects to the East Greenland, West Greenland, and Labrador currents.…”

Section: Resultsmentioning

confidence: 99%

Sensitivity of climate response to variations in freshwater hosing location

2009

View full text Add to dashboard Cite

In a recent intercomparison of the response of general circulation models (GCMs) to highlatitude freshwater forcing (Stouffer et al., J Climate 19(8):1365-1387, a number of the GCMs investigated showed a localised warming response in the high-latitude North Atlantic, as opposed to the cooling that the other models showed. We investigated the causes for this warming by testing the sensitivity of the meridional overturning circulation (MOC) to variations in freshwater forcing location, and then analysing in detail the causes of the warming. By analysing results from experiments with HadCM3, we are able to show that the high-latitude warming is independent of the exact location of the additional freshwater in the North Atlantic or Arctic Ocean basin. Instead, the addition of freshwater changes the circulation in the sub-polar gyre, which leads to enhanced advection of warm, saline, sub-surface water into the Greenland-IcelandNorwegian Sea despite the overall slowdown of the MOC. This sub-surface water is brought to the surface by convection, where it leads to a strong warming of the surface waters and the overlying atmosphere.

show abstract

“…Primary questions addressed to what extent faunal components from eastern and/or western slopes contributed to the MAR fauna, whether there was a latitudinal change in the fauna, and to what extent this was affected by two main hydrographic features: the Sub -Polar Front and the Charlie Gibbs Fracture Zone (see, for example, Krauss 1986 ;Rossby 1999 ;Reverdin et al 2003 ). A general pattern identifi ed was that the MAR supports high biodiversity which is not fundamentally different in structure and composition from the adjacent continental slopes.…”

Section: Discussionmentioning

confidence: 99%