Surface circulation in the Western Labrador Sea

LeBlond, Paul H.; Osborn, Thomas R.; Hodgins, Donald O.; Goodman, R. H.; Metge, M

doi:10.1016/0198-0149(81)90129-1

Cited by 32 publications

(26 citation statements)

References 5 publications

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“…Cuny et al (2005) have examined data from moored instruments and hydrographic surveys to estimate the fluxes of volume and freshwater through Davis Strait. Their calculation of a net southward flux is consistent with earlier hydrographic surveys (LeBlond et al 1981;Smith et al 1937), which indicated that surface waters from Baffin Bay and the Arctic Ocean move southward on the Labrador shelf and contribute substantially to the buoyancy of the Labrador Current (Khatiwala et al 1999). Moreover, Zweng and Münchow (2006) have found a significant decrease over time in salinity [Ϫ0.05 Ϯ 0.03 (10 yr)…”

Section: Introductionsupporting

confidence: 76%

An Observational Estimate of Volume and Freshwater Flux Leaving the Arctic Ocean through Nares Strait

Münchow

Melling

Falkner

2006

Journal of Physical Oceanography

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The Arctic Ocean is an important link in the global hydrological cycle, storing freshwater and releasing it to the North Atlantic Ocean in a variable fashion as pack ice and freshened seawater. An unknown fraction of this return flow passes through Nares Strait between northern Canada and Greenland. Surveys of ocean current and salinity in Nares Strait were completed in the summer of 2003. High-resolution data acquired by ship-based acoustic Doppler current profiler and via hydrographic casts revealed subtidal volume and freshwater fluxes of 0.8 Ϯ 0.3 Sv and -25 Ϯ 12 mSv (Sv ϭ 10 3 mSv ϭ 10 6 m 3 s Ϫ1 ), respectively. The observations resolved the dominant spatial scale of variability, the internal Rossby radius of deformation (L D ϳ9 km), and revealed a complex, yet coherent along-channel flow with a Rossby number of about 0.13, close to geostrophic balance. Approximately one-third of the total volume flux was associated with across-channel slope of the sea surface and two-thirds (68%) with across-channel slope of isopycnal surfaces. During the period of observation, sustained wind from the southwest weakened the average downchannel flow at the surface. The speed of tidal currents exceeded subtidal components by a factor of 2. Tidal signals were resolved and removed from the observations here using two independent methods resolving horizontal and vertical variability of tidal properties, respectively. Tidal current predictions from a barotropic model agreed well with depth-averaged observations in both amplitude and phase. However, because estimates of freshwater flux require accurate surface currents (and salinity), a least squares fitting procedure using velocity data was judged more reliable, since it permits quantification of vertical tidal current variations.

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Section: Introductionsupporting

confidence: 76%

An Observational Estimate of Volume and Freshwater Flux Leaving the Arctic Ocean through Nares Strait

Münchow

Melling

Falkner

2006

Journal of Physical Oceanography

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“…Outflow from the mouth of Hudson Strait is restricted to its southern half and is deflected southward onto the continental shelf, where it forms the shoremost branch of the Labrador Current (LeBlond et al,1981). The circulation pattern computed by Reynaud et al (1995) confirms that the circulation in the Labrador Sea and its coastal shelves is largely along isobaths.…”

Section: Freshwater Export To the Labrador Seasupporting

confidence: 55%

Can Regulation of Freshwater Runoff in Hudson Bay Affect the Climate of the North Atlantic?

LeBlond¹,

Lazier²,

Weaver³

1996

ARCTIC

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ABSTRACT. A sequence of phenomena links anthropogenic changes in the timing of freshwater runoff in Hudson Bay to a possible impact on the North Atlantic thermohaline circulation. The chain of events starts with the spreading of estuarine plumes under ice and continues with the effect of lowered salinity on the rate of ice formation, regional effects on the scale of Hudson Bay, the export of freshwater to the Labrador Sea, its impact on deep convection in that area, and the relative importance of such changes to the North Atlantic circulation. At each step we compare anthropogenic effects with other factors and place them within the perspective of natural variability.Our conclusion does not support the contention that freshwater runoff regulation, even of all rivers in the basins of Hudson and James Bays, could have a significant or even a detectable effect on the climate of the North Atlantic.Key words: freshwater regulation, Hudson Bay, climate RÉSUMÉ. Une séquence de phénomènes relie des changements anthropiques dans le moment où les eaux douces commencent à s'écouler dans la baie d'Hudson à leur répercussion possible sur les courants thermiques des eaux marines. La séquence débute par la formation d'un panache estuarien sous la glace et se poursuit avec l'effet de la baisse de salinité sur la vitesse de formation de la glace, des répercussions régionales affectant toute la baie d'Hudson, l'exportation d'eau douce vers la mer du Labrador et ses retombées sur la convection profonde dans cette zone, ainsi qu'avec l'importance relative de tels changements sur les courants nord-atlantiques. À chaque étape, on compare les influences anthropiques avec d'autres facteurs pour les situer dans un contexte de variabilité.Notre conclusion n'appuie pas la thèse que la régulation de l'écoulement des eaux douces, même si elle s'étendait à tous les cours d'eau des bassins de la baie d'Hudson et de la baie James, pourrait avoir des répercussions notables ou même détectables sur le climat nord-atlantique.Mots clés: régulation des eaux douces, baie d'Hudson, climat Traduit pour la revue Arctic par Nésida Loyer.

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“…The mouth of the Strait is characterized by strong, turbulent flows and persistent eddies, due to the interaction of the strong tidal flow with the numerous channels and islands (LeBlond, 1981), which would make it difficult to extract the mean flow and secure moorings. Also the region between the section occupied and the mouth of the strait is characterized by a strong recirculation which would render distinguishing the throughflow from the recirculating portion arduous.…”

Section: Mooring Datamentioning

confidence: 99%

“…Flow in the strait is in opposite directions along the two coasts: into the HBS along Baffin Island and out of the HBS along Quebec ( Figure 1; LeBlond 1981;Drinkwater 1988). This southeasterly flow, here termed the Hudson Strait outflow, combines with that from Davis Strait and with the retroflection of the West Greenland Current to form the Labrador Current (Mertz et al, 1993;Loder et al 1998) a fresh water laden current which flows south along the Labrador coast.…”

Section: Introductionmentioning

confidence: 99%