Submarine Meltwater From Nioghalvfjerdsbræ (79 North Glacier), Northeast Greenland

Abstract

The Greenland Ice Sheet (GrIS) faces accelerated melting under a warming climate, and the GrIS mass loss contributed about 25% to the global sea-level rise in the time period 2006(Oppenheimer et al., 2019. The involved processes are surface melting, iceberg calving, and submarine melting through the contact of warm water with marine-terminating glaciers and floating ice tongues. N. Wilson et al. (2017) showed that the latter mechanism is the major contributor for mass loss of the three largest floating ice tongues in northern Greenland. The meltwater from the GrIS is not only contributing to global sea-level rise, but could affect the regional circulation by changing the seawater density structure (e.g., Grivault et al., 2017). When transferred into the basin interior of the Labrador and Irminger seas, this additional freshwater might have consequences for the water mass transformation of Atlantic Meridional Overturning Circulation components (Böning et al., 2016). The analysis of noble gas data revealed that the presence of submarine meltwater

Arctic – Atlantic Exchange of the Dissolved Micronutrients Iron, Manganese, Cobalt, Nickel, Copper and Zinc With a Focus on Fram Strait

“…The water column of Fram Strait as of 2016, and the EGC more specifically, showed a similar relationship between 228 Ra/ 226 Ra and meteoric freshwater content, although with a less pronounced slope (0.031 S, 0.81 R 2 for all stations in Fram Strait; 0.039 S, 0.97 R 2 in the EGC; Figure S8 in Supporting Information S1), implying that compared to observations in the Central Arctic Ocean, 228 Ra in Fram Strait was ⁓2‐fold depleted relative to 226 Ra. On the Northeast Greenland Shelf both the meteoric freshwater content and the 228 Ra activity are enhanced by local sources (Krisch, Hopwood, et al., 2021), but for the EGC beyond the shelf break such a local source is unlikely to be a major influence (Huhn et al., 2021; Laukert et al., 2017). We explain the reduction in 228 Ra/ 226 Ra as the result of radioactive decay of 228 Ra during transit from the Siberian shelves to Fram Strait, which can in part occur during the residence of surface waters in the Canada Basin (Kipp et al., 2019).…”

“…Although glacial discharge is likely the source of observed dFe, dMn, dCo, dNi and dCu maxima near coastal Greenland (stations 20–22, Figure 2; Krause et al., 2021; Krisch, Hopwood, et al., 2021), Greenland Ice Sheet discharge is unlikely a substantial contributor to the EGC beyond the shelf break (Huhn et al., 2021; Laukert et al., 2017). Efficient estuarine removal, particularly of dFe (Krause et al., 2021; Zhang et al., 2015), and the limited potential to stabilize additional quantities of ligand‐bound micronutrients (Ardiningsih et al., 2020; Krisch, Hopwood, et al., 2021) are major constraints on Greenland Ice Sheet micronutrient export.…”

Impacts of glacier and sea ice melt on methane pathways on the Northeast Greenland shelf

“…WML and KW are influenced by brine release during sea ice formation in their respective formation regions (Figs. 5g and 7a; Budéus and Schneider, 1995;Huhn et al, 2021). In addition, MWL, WML and KW are localised within the water masses on the shelf without direct contact with the seafloor.…”

“…1), a site of intense water mass transformations. The properties of Polar Surface Water (PSW) are influenced by sea ice freeze and melt cycles (Budéus and Schneider, 1995), as well as surface runoff from glaciers, subglacial meltwater runoff (Huhn et al, 2021), frontal meltwater runoff, and submarine melting of icebergs (Enderlin et al, 2016). Subglacial discharge plumes are sometimes observed at the ocean surface during the summer season, as reported in a fjord system in central West Greenland (Mankoff et al, 2016).…”

An Improved and Observationally‐Constrained Melt Rate Parameterization for Vertical Ice Fronts of Marine Terminating Glaciers

“…Melting by deep, warm waters increases undercutting of glacier termini, thereby inducing calving (Wood et al., 2021) and glacier front retreat (King et al., 2020), leading to a dynamic mass loss that adds to sea level rise (Mouginot et al., 2019). Freshwater input resulting from submarine melt controls the stratification and buoyancy driven circulation within Greenland's fjords (Straneo et al., 2011), and affects the adjacent shelf sea (Huhn et al., 2021; Le Bras et al., 2018) and global scale ocean circulation patterns (Bakker et al., 2016; Böning et al., 2016; Frajka‐Williams et al., 2016; Thornalley et al., 2018; Yang et al., 2016). Given the important role of submarine melting, a precise constraint of the ice‐ocean interaction at marine terminating vertical glacier fronts is crucial to derive melt parameterizations for ocean circulation models (Straneo & Cenedese, 2015).…”