An Interdisciplinary Perspective on Greenland’s Changing Coastal Margins

Abstract

Greenland’s coastal margins are influenced by the confluence of Arctic and Atlantic waters, sea ice, icebergs, and meltwater from the ice sheet. Hundreds of spectacular glacial fjords cut through the coastline and support thriving marine ecosystems and, in some places, adjacent Greenlandic communities. Rising air and ocean temperatures, as well as glacier and sea-ice retreat, are impacting the conditions that support these systems. Projecting how these regions and their communities will evolve requires understanding both the large-scale climate variability and the regional-scale web of physical, biological, and social interactions. Here, we describe pan-Greenland physical, biological, and social settings and show how they are shaped by the ocean, the atmosphere, and the ice sheet. Next, we focus on two communities, Qaanaaq in Northwest Greenland, exposed to Arctic variability, and Ammassalik in Southeast Greenland, exposed to Atlantic variability. We show that while their climates today are similar to those of the warm 1930s­–1940s, temperatures are projected to soon exceed those of the last 100 years at both locations. Existing biological records, including fisheries, provide some insight on ecosystem variability, but they are too short to discern robust patterns. To determine how these systems will evolve in the future requires an improved understanding of the linkages and external factors shaping the ecosystem and community response. This interdisciplinary study exemplifies a first step in a systems approach to investigating the evolution of Greenland’s coastal margins.

Bias Correction and Statistical Modeling of Variable Oceanic Forcing of Greenland Outlet Glaciers

“…The limit between low-and high-predictability areas is likely attributable to the location of the southern edge of sea-ice in winter and to the respective influences of Atlantic and Arctic waters (Straneo et al, 2022).…”

“…Finally, the predictor for Petermann glacier shows that predictability for TF in the Northern most latitudes is very low for the rest of the ocean around Greenland. The limit between low‐ and high‐predictability areas is likely attributable to the location of the southern edge of sea‐ice in winter and to the respective influences of Atlantic and Arctic waters (Straneo et al., 2022).…”

Comparison of selected surface level ERA5 variables against in‐situ observations in the continental Arctic

“…Coastal regions around Greenland are topographically complex and are hence potentially challenging to simulate by ERA5 (Køltzow et al ., 2022). At the same time, Greenlandic coastal regions are undergoing a drastic change (Coulson et al ., 2022; Straneo et al ., 2022), and hence long‐term climate variable information is critical. Radiation data were collected from pyranometers in the baseline surface radiation network (BSRN), which have a wavelength spectrum of 0.25–3 μm (Driemel et al ., 2018).…”

Low mercury concentrations in a Greenland glacial fjord attributed to oceanic sources

“…We calculate the mean annual SGR input to Sermilik Fjord from Helheim and Fenris Glaciers using the dataset of Mankoff et al (2020). Following Cape et al (2019), the associated AW upwelling flux is calculated, applying 3 values of the entrainment ratio fAW fSGR ranging from 30-80 based on published estimates (Beaird et al, 2018;Cape et al, 2019;Slater et al, 2022). This value is then converted to Hg(II) flux by approximating that the Hg(II) concentration of inflowing AW is constant, and that a constant proportion of Hg(II) ranging from 0.2-0.4 pM is removed from upwelled AW that is exported with GMW throughout the melt season.…”

“…The implications of these findings are especially concerning because glacial fjords support productive marine ecosystems that local communities depend upon for their livelihood (Meire et al, 2017;Nuttall, 2020;Muntjewerf et al, 2020;Straneo et al, 2022).…”