Water mass distributions and transports for the 2014 GEOVIDE cruise in the North Atlantic

García-Ibáñez, Maribel I.; Pérez, Fíz F.; Lherminier, Pascale; Zunino, Patricia; Tréguer, Paul

doi:10.5194/bg-2017-355

Cited by 10 publications

(17 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Schematic of key AMOC‐related components of the North Atlantic Ocean (modified from García‐Ibáñez et al, ). Abbreviations are as follows: NRG = Northern Recirculation Gyre; LC = Labrador Current; DWBC = Deep Western Boundary Current; IC = Irminger Current; EGIC = East Greenland‐Irminger Current.…”

Section: Amoc and The North Atlantic Ocean Circulationmentioning

confidence: 99%

The Relationship Between U.S. East Coast Sea Level and the Atlantic Meridional Overturning Circulation: A Review

Little

Hughes

et al. 2019

JGR Oceans

View full text Add to dashboard Cite

Scientific and societal interest in the relationship between the Atlantic Meridional Overturning Circulation (AMOC) and U.S. East Coast sea level has intensified over the past decade, largely due to (1) projected, and potentially ongoing, enhancement of sea level rise associated with AMOC weakening and (2) the potential for observations of U.S. East Coast sea level to inform reconstructions of North Atlantic circulation and climate. These implications have inspired a wealth of model‐ and observation‐based analyses. Here, we review this research, finding consistent support in numerical models for an antiphase relationship between AMOC strength and dynamic sea level. However, simulations exhibit substantial along‐coast and intermodel differences in the amplitude of AMOC‐associated dynamic sea level variability. Observational analyses focusing on shorter (generally less than decadal) timescales show robust relationships between some components of the North Atlantic large‐scale circulation and coastal sea level variability, but the causal relationships between different observational metrics, AMOC, and sea level are often unclear. We highlight the importance of existing and future research seeking to understand relationships between AMOC and its component currents, the role of ageostrophic processes near the coast, and the interplay of local and remote forcing. Such research will help reconcile the results of different numerical simulations with each other and with observations, inform the physical origins of covariability, and reveal the sensitivity of scaling relationships to forcing, timescale, and model representation. This information will, in turn, provide a more complete characterization of uncertainty in relevant relationships, leading to more robust reconstructions and projections.

show abstract

Section: Amoc and The North Atlantic Ocean Circulationmentioning

confidence: 99%

The Relationship Between U.S. East Coast Sea Level and the Atlantic Meridional Overturning Circulation: A Review

Little

Hughes

et al. 2019

JGR Oceans

View full text Add to dashboard Cite

show abstract

“…A full description of the oceanographic context of the GEOVIDE cruise is given by García-Ibáñez et al (2017). The distributions of salinity and potential density (σ θ ) along the section (Fig.…”

Section: Water Masses Identificationmentioning

confidence: 99%

Sources, cycling and transfer of mercury in the Labrador Sea (Geotraces-Geovide cruise)

et al. 2018

View full text Add to dashboard Cite

The Labrador Sea links the Arctic and North Atlantic oceans and constitutes one of the main entrances of atmospheric inputs into the Ocean's interior. We report here the first high-resolution Hg distribution pattern along a transect from Greenland to Labrador coasts sampled after the 2014 winter convection. Total Hg concentrations in unfiltered (HgTUNF) samples ranged from 0.25 pmol L− 1 to 0.67 pmol L− 1 averaging 0.44 ± 0.10 pmol L− 1 (n = 113, 1σ). Concentrations in filtered samples (HgTF, < 0.45 μm) represented from 62 to 92% of the HgTUNF and exhibited a similar distribution. High HgTUNF concentrations were found (i) in the waters of the Labrador Current, which receive desalted waters from the Canadian Arctic Archipelago, and (ii) in the waters over the Labrador shelf and rise. In the Labrador Sea Waters formed during the 2014 winter convection, HgTUNF concentrations were low (0.38 ± 0.05 pmol L− 1, n = 23), and increased gradually with depth (up to > 0.5 pmol L− 1) in the Northeast Atlantic Deep Waters. HgTF correlates with apparent oxygen utilization implying that atmospheric deposition, biological uptake, and microbial respiration control the Hg distribution in the Labrador Sea. Subtracting the amount of Hg released during organic matter remineralization allows us to identify a Hg and organic matter enriched fraction, which originates from fluvial sources in the Canadian Arctic Archipelago waters. This fraction is transferred southward, in surface waters with the Labrador Current, and at depth with the lower limb of the Atlantic Meridional Overturning Circulation. Climate warming, which will increase the mobilization of Hg from thawing permafrost, would consequently increase the Arctic export of Hg initially associated with organic matter. Highlights ► The Labrador Sea Water formed during the 2014 winter convection contains very low Hg. ► The Labrador Current waters, from the Canadian Arctic Archipelago, are Hg-enriched. ► Hg exhibits a nutrient-like distribution in the central Labrador Sea.

show abstract

“…Our isotopic mixing model based on the eOMP performed by Carracedo et al (2016) shows that the signature of MW NO 3 − δ 15 N is 4.42‰ ± 0.13‰. Using this MW signature and the eOMP performed by García-Ibáñez et al (2018), the resulting NO 3 − δ 15 N profiles returned by our isotopic mixing model (i.e., thick purple lines in Figure 6) at the selected stations (based on their proximity to the Iberian Peninsula) reveal that an advection of the Mediterranean signal is indeed able to reproduce the low NO 3 − δ 15 N values observed between 600 and 1500 m depth south of the SAF (i.e., red profiles in Figure 6). 3) and modeled NO 3 − δ 15 N (‰) profiles (thick purple lines) generated using an isotopic mixing model coupled with the results of an extended Optimum Multi-Parameters (eOMP) analysis to study the influence of the Mediterranean Water (see text for details) along the eastern part of the GEOTRACES GA01 (GEOVIDE) transect with increasing distance from the Iberian margin (from station 1 to station 26).…”

Section: N 2 Fixation and Influence Of The Mediterranean Outflowmentioning

confidence: 83%

“…To assess the influence of MW on NO 3 − δ 15 N profiles along the transect, we used an isotopic mixing model coupled with the results of an extended Optimum Multi-Parameter (eOMP) analysis performed for the GEOVIDE cruise, which returns the mixing proportions of different source water types (García-Ibáñez et al, 2018). First, we built a "flat" NO 3 − δ 15 N profile by setting the NO 3 − δ 15 N of all the water masses to the average deep ocean value (4.82‰ ± 0.05‰) reported by Marconi et al (2019).…”

Section: N 2 Fixation and Influence Of The Mediterranean Outflowmentioning

confidence: 99%

Nitrate Supply Routes and Impact of Internal Cycling in the North Atlantic Ocean Inferred From Nitrate Isotopic Composition

Deman

Fonseca-Batista

Roukaerts

et al. 2021

Global Biogeochemical Cycles

Self Cite

View full text Add to dashboard Cite

The biological carbon pump plays a crucial role in the regulation of Earth's climate and the distribution of biogeochemical properties in the ocean, by exporting to the deep ocean CO 2 that is fixed into biomass during photosynthesis in the sunlit surface layer, through the sinking of particles and their subsequent remineralization. Phytoplankton requires macro-nutrients for the synthesis of organic matter. Nitrogen (N) is considered as one of the most important nutrients since it limits productivity in many oceanic regions (Moore et al., 2013). The North Atlantic Ocean, which hosts one of the most productive spring phytoplankton blooms of the world's ocean (Longhurst, 2007), is estimated to be a significant contributor to the global oceanic export production (Falkowski et al., 1998;Sanders et al., 2014).The North Atlantic Ocean is characterized by the classical double gyre system of the subtropical and subpolar gyres (Figure 1). Both gyres harbor contrasting physical and biogeochemical features (Sanders et al., 2014) and are separated by a strong transition area, the North Atlantic Current (NAC). In addition, the Atlantic Meridional Overturning Circulation is a key component of the Earth's climate system, with the NAC carrying a northward flow of warm and salty waters balanced by a southward flow of colder deep waters (North Atlantic Deep Water) (Buckley & Marshall, 2016). The North Atlantic subtropical gyre is considered to be a year-round stratified oligotrophic N-limited area (Moore et al., 2008(Moore et al., , 2013, where N 2 fixation performed by diazotrophs plays an important role in providing fixed N (or bioavailable N) to the surface waters (Capone et al., 2005(Capone et al., , 2008. In contrast, a strong seasonality is observed in the North Atlantic subpolar gyre. The relief of winter light limitation induces the onset of a spring phytoplankton bloom supported by

show abstract

Water mass distributions and transports for the 2014 GEOVIDE cruise in the North Atlantic

Cited by 10 publications

References 56 publications

The Relationship Between U.S. East Coast Sea Level and the Atlantic Meridional Overturning Circulation: A Review

The Relationship Between U.S. East Coast Sea Level and the Atlantic Meridional Overturning Circulation: A Review

Sources, cycling and transfer of mercury in the Labrador Sea (Geotraces-Geovide cruise)

Nitrate Supply Routes and Impact of Internal Cycling in the North Atlantic Ocean Inferred From Nitrate Isotopic Composition

Contact Info

Product

Resources

About