Nutrient release to oceans from buoyancy-driven upwelling at Greenland tidewater glaciers

Cape, Mattias Rolf; Straneo, Fiammetta; Beaird, Nicholas; Bundy, Randelle M.; Charette, Matthew A.

doi:10.1038/s41561-018-0268-4

Cited by 95 publications

(140 citation statements)

References 73 publications

Supporting

Mentioning

119

Contrasting

Unclassified

Order By: Relevance

“…This is broadly consistent with the 6-53% range reported for estuarine gradients in more temperate estuaries (Windom et al, 1991). Conversely, Hawkings et al 2017 Bowdoin Fjord (Kanna et al, 2018), Kongsfjorden (Fransson et al, 2016;van de Poll et al, 2018), Sermilik Fjord (Cape et al, 2019), Leverett Glacier (Hawkings et al, 2017), Godthåbsfjord (Hopwood et al, 2016;Meire et al, 2016b), and the Gulf of Alaska (Brown et al, 2010). Linear regressions are shown for surface (<20 m depth) data only.…”

Section: Non-conservative Mixing Processes For Fe and Sisupporting

confidence: 71%

“…Furthermore, macronutrient distributions in Bowdoin, Godthåbsfjord, and Sermilik unambiguously show that the main macronutrient supply associated with glacier discharge originates from mixing, rather than from sediment dissolution or freshwater addition (Meire et al, 2016a;Kanna et al, 2018;Cape et al, 2019). The apparently anomalous extent of Si dissolution downstream of Leverett Glacier (Hawkings et al, 2017) may therefore largely reflect underestimation of both the saline (assumed to be negligible) and freshwater endmembers, rather than unusually prolific particulate Si dissolution.…”

Section: Non-conservative Mixing Processes For Fe and Simentioning

confidence: 94%

“…Fe profiles around the Arctic show strong spatial variability in TdFe concentrations, ranging from unusually high concentrations of up to 20 µM found intermittently close to turbid glacial outflows (Zhang et al, 2015;Markussen et al, 2016;Hopwood et al, 2018) to generally low nanomolar concentrations at the interface between shelf and fjord waters (Zhang et al, 2015;Crusius et al, 2017;Cape et al, 2019). An interesting feature of some of these profiles around Greenland is the presence of peak Fe at ~50 m depth, suggesting that much of the Fe-transport away from glaciers may occur in subsurface glacially modified waters (Hopwood et al, 2018;Cape et al, 2019). The spatial extent of Fe enrichment downstream of glaciers around the Arctic is still uncertain, but there is evidence of variability downstream of glaciers on the scale of 10-100 km (Gerringa et al, 2012;Annett et al, 2017;Crusius et al, 2017).…”

Section: Kongsfjorden (W Svalbard) 79° N 012° Ementioning

confidence: 99%

See 2 more Smart Citations

Review Article: How does glacier discharge affect marine biogeochemistry and primary production in the Arctic?

Hopwood¹,

Carroll²,

Dunse³

et al. 2019

Preprint

View full text Add to dashboard Cite

Abstract. Freshwater discharge from glaciers is increasing across the Artic in response to anthropogenic climate change, which raises questions about the potential downstream effects in the marine environment. Whilst a combination of long-term monitoring programmes and intensive Arctic field campaigns have improved our knowledge of glacier-ocean interactions in recent years, especially with respect to fjord/ocean circulation in the marine environment, there are extensive knowledge gaps concerning how glaciers affect marine biogeochemistry and productivity. Following two cross-cutting disciplinary International Arctic Science Committee (IASC) workshops addressing ‘The importance of glaciers for the marine ecosystem’, here we review the state of the art concerning how freshwater discharge affects the marine environment with a specific focus on marine biogeochemistry and biological productivity. Using a series of Arctic case studies (Nuup Kangerlua/Godthåbsfjord, Kongsfjorden, Bowdoin Fjord, Young Sound, and Sermilik Fjord), the interconnected effects of freshwater discharge on fjord-shelf exchange, nutrient availability, the carbonate system, and the microbial foodweb are investigated. Key findings are that whether the effect of glacier discharge on marine primary production is positive, or negative is highly dependent on a combination of factors. These include glacier type (marine- or land-terminating) and the limiting resource for phytoplankton growth in a specific spatiotemporal region (light, macronutrients or micronutrients). Glacier fjords therefore often exhibit distinct discharge-productivity relationships and multiple case-studies must be considered in order to understand the net effects of glacier discharge on Arctic marine ecosystems.

show abstract

Section: Non-conservative Mixing Processes For Fe and Sisupporting

confidence: 71%

Section: Non-conservative Mixing Processes For Fe and Simentioning

confidence: 94%

Section: Kongsfjorden (W Svalbard) 79° N 012° Ementioning

confidence: 99%

See 1 more Smart Citation

Review Article: How does glacier discharge affect marine biogeochemistry and primary production in the Arctic?

Hopwood¹,

Carroll²,

Dunse³

et al. 2019

Preprint

View full text Add to dashboard Cite

show abstract

“…Interactions between the ocean and ice sheet fundamentally impact the biogeochemistry and structure of marine ecosystems in glacial fjords along the coast of Greenland. High rates of summertime primary productivity and phytoplankton biomass, coincident with nutrient enrichment of the upper water column downstream of marine-terminating glaciers, have been attributed to the sustained upwelling of deep, nutrient-rich ocean waters entrained as a result of subglacial discharge (Meire et al, 2017;Overeem et al, 2017;Hopwood et al, 2018;Kanna et al, 2018;Cape et al, 2019). This upwelling of nutrients is also thought to contribute to a lengthening of the growth season within glacial fjords, with secondary summer blooms accounting for an unusually large fraction of annual primary production (Juul-Pedersen et al, 2015).…”

Section: Impact On Ocean Biogeochemistry and Marine Ecosystemsmentioning

confidence: 99%

The Case for a Sustained Greenland Ice Sheet-Ocean Observing System (GrIOOS)

et al. 2019

Self Cite

View full text Add to dashboard Cite

Rapid mass loss from the Greenland Ice Sheet (GrIS) is affecting sea level and, through increased freshwater and sediment discharge, ocean circulation, sea-ice, biogeochemistry, and marine ecosystems around Greenland. Key to interpreting ongoing and projecting future ice loss, and its impact on the ocean, is understanding exchanges of heat, freshwater, and nutrients that occur at the GrIS marine margins. Processes governing these exchanges are not well understood because of limited observations from the regions where glaciers terminate into the ocean and the challenge of modeling the spatial and temporal scales involved. Thus, notwithstanding their importance, ice sheet/ocean exchanges are poorly represented or not accounted for in models used for projection studies. Widespread community consensus maintains that concurrent and long-term records of glaciological, oceanic, and atmospheric parameters at the ice sheet/ocean margins are key to addressing this knowledge gap by informing understanding, and constraining and validating models. Through a series of workshops and documents endorsed by the community-at-large, a framework for an international, collaborative, Greenland Ice sheet-Ocean Observing System (GrIOOS), that addresses the needs of society in relation to a changing GrIS, has been proposed. This system would consist of a set of ocean, glacier, and atmosphere essential variables to be collected at a number of diverse sites around Greenland for a minimum of two decades. Internationally agreed upon data protocols and data sharing policies would guarantee uniformity and availability of the information for the broader community. Its

show abstract

“…A turbid water layer is observed at the subsurface where subglacial discharge spreads after the upwelling (Chauché et al, 2014;Stevens et al, 2016). Because the ambient deep water delivered by the plume is rich in nutrients, subglacial plume formation can enhance marine biological productivity (Arendt et al, 2011;Cape et al, 2019;Kanna et al, 2018;Lydersen et al, 2014;Meire et al, 2017). Conversely, high concentrations of suspended sediments near the fjord surface might reduce light availability (Retamal et al, 2008).…”

mentioning

confidence: 99%

Water mass structure and the effect of subglacial discharge in Bowdoin Fjord, northwestern Greenland

Ohashi

Aoki

Matsumura

et al. 2019

Preprint

View full text Add to dashboard Cite

Abstract. Subglacial discharge has significant impacts on water circulation, material transport, and biological productivity in proglacial fjords of Greenland. To help clarify the fjord water properties and the effect of subglacial discharge, we investigated the water mass structures of Bowdoin Fjord in northwestern Greenland based on summer hydrographic observations, including turbidity, in 2014 and 2016. We estimated the fraction of subglacial discharge from the observational data and interpreted the observed differences in subglacial discharge behavior between two summer seasons with the numerical model results. At a depth of 60–80 m, temperature profiles were distinctively different in 2014 and 2016, and a larger fraction of submarine meltwater was detected in 2014. At a depth of 15–40 m, where the most turbid water was observed, the maximum subglacial discharge fractions near the ice front were estimated to be ~ 6 % in 2014 and ~ 4 % in 2016. The higher discharge fraction in 2014 was due to the stronger stratification, as suggested by numerical experiments performed with different initial stratifications. Turbidity near the surface was higher in 2016 than in 2014, suggesting a stronger influence of turbid subglacial discharge. The higher turbidity in 2016 could primarily be attributed to a greater amount of subglacial discharge, as inferred from the numerical experiments forced by different amounts of discharge. This study indicates that ambient fjord stratification difference is an important factor controlling the vertical distribution of subglacial discharge, together with its amount.

show abstract

Nutrient release to oceans from buoyancy-driven upwelling at Greenland tidewater glaciers

Cited by 95 publications

References 73 publications

Review Article: How does glacier discharge affect marine biogeochemistry and primary production in the Arctic?

Review Article: How does glacier discharge affect marine biogeochemistry and primary production in the Arctic?

The Case for a Sustained Greenland Ice Sheet-Ocean Observing System (GrIOOS)

Water mass structure and the effect of subglacial discharge in Bowdoin Fjord, northwestern Greenland

Contact Info

Product

Resources

About