Hochreuther, P., Neckel, N., Reimann, N., Humbert, A. & Braun, M.: Fully Automated Detection of Supraglacial Lake Area for Northeast Greenland Using Sentinel-2 Time-Series. Remote Sensing 2021, 13(2), 205, https://doi.org/10.3390/rs13020205.
Here, we present a sequence of algorithms that allow for an automated Sentinel-2 data search, download, processing, and generation of a consistent and dense melt pond area time-series based on open-source software. We test our approach for a ~82,000 km2 area at the 79 °N Glacier (Nioghalvfjerdsbrae) in northeast Greenland, covering the years 2016, 2017, 2018 and 2019. [...] We identified 880 individual lakes, traceable over 479 time-steps throughout 2016–2019, with an average size of 64,212 m2. Of the four years, 2019 had the most extensive lake area coverage with a maximum of 333 km2 and a maximum individual lake size of 30 km2. With 1.5 days average observation interval, our time-series allows for a comparison with climate data of daily resolution, enabling a better understanding of short-term climate-glacier feedbacks.
Schaffer, J., Kanzow, T., von Appen, W. et al. Bathymetry constrains ocean heat supply to Greenland’s largest glacier tongue. Nat. Geosci. 13, 227–231 (2020). https://doi.org/10.1038/s41561-019-0529-x.
We use ship-based profiles, bathymetric data and moored time series from 2016 to 2017 of temperature, salinity and water velocity collected in front of the floating tongue of the 79 North Glacier in Northeast Greenland. These observations indicate that a year-round bottom-intensified inflow of warm Atlantic Water through a narrow channel is constrained by a sill. The associated heat transport leads to a mean melt rate of 10.4 ± 3.1 m yr–1 on the bottom of the floating glacier tongue. The interface height between warm Atlantic Water and colder overlying water above the sill controls the ocean heat transport’s temporal variability...
Turton, J. V., Mölg, T., and Collier, E.: High-resolution (1 km) Polar WRF output for 79° N Glacier and the northeast of Greenland from 2014 to 2018, Earth Syst. Sci. Data, 12, 1191–1202, https://doi.org/10.5194/essd-12-1191-2020, 2020.
Here we present a high-spatial-resolution (1 km) and high-temporal-resolution (up to hourly) atmospheric modelling dataset, NEGIS_WRF, for the 79https://doi.org/10.17605/OSF.IO/53E6Z) is now available for a wide variety of applications in the atmospheric, hydrological, and oceanic sciences in the study region.N and northeast Greenland region from 2014 to 2018 and an evaluation of the model's success at representing daily near-surface meteorology when compared with automatic weather station records. The dataset (Turton et al., 2019b:
Wagner, P., S. Rühs, F. Schwarzkopf, I. Koszalka, and A. Biastoch, 2019: Can Lagrangian tracking simulate tracer spreading in a high-resolution Ocean General Circulation Model? Journal of Physical Oceanography (2019) 49 (5): 1141–1157.
To model tracer spreading in the ocean, Lagrangian simulations in an offline framework are a practical and efficient alternative to solving the advective-diffusive tracer equations online. Differences in both approaches raise the question whether both methods are comparable. Lagrangian simulations usually use model output averaged in time, and trajectories are not subject to parameterized subgrid diffusion which is included in the advection-diffusion equations of ocean models...
The Nioghalvfjerdsfjorden glacier (the 79 fjord, henceforth referred to as 79N) has been thinning and accelerating since the early 2000s, as a result of calving episodes at the front of the glacier. As 8% of the Greenland Ice Sheet area drains into 79N, changes in the stability of 79N could propagate into the interior of Greenland. Despite this concern, relatively little is known about the atmospheric conditions over 79N. We present the surface atmospheric processes and climatology of the 79N region from analyses of data from four automatic weather stations (AWS) and reanalysis data from ERA-Interim..
Recinos, B., Maussion, F., Rothenpieler, T., and Marzeion, B.: Impact of frontal ablation on the ice thickness estimation of marine-terminating glaciers in Alaska, The Cryosphere, 13, 2657–2672, https://doi.org/10.5194/tc-13-2657-2019, 2019.
Frontal ablation is a major component of the mass budget of tidewater glaciers, strongly affecting their dynamics. Most global scale ice volume estimates to date still suffer from considerable uncertainties related to i) the implemented frontal ablation parameterisation or ii) for not accounting for frontal ablation at all in the glacier model. To improve estimates of the ice thickness distribution of glaciers it is thus important to identify and test low-cost and robust parameterisations of this fundamental process. By implementing such parameterisation into the ice-thickness estimation module of the Open Global Glacier Model (OGGM v1.0.1), we conduct a first assessment of the impact of accounting for frontal ablation on the estimate of ice stored in glaciers in Alaska.
The retreat and acceleration of marine-terminating glaciers around the coast of Greenland observed over the last two decades have partly been attributed to a warming of Atlantic Water (AW) circulating around the subpolar North Atlantic. This thesis investigates the impact of the ocean circulation on the 79 North Glacier (79NG), which has Greenland’s largest floating ice tongue. One overall hypothesis tested in this thesis is whether a long-term warming of AW in Fram Strait has spread across the continental shelf o ↵ Northeast Greenland (NEG) toward the 79NG, which may explain the recent thinning observed at the floating ice tongue.
Blau, Manuel (2020): Glacier-Atmosphere Modelling with COSIPY Surface Energy and Mass Balance Model at the Nioghalvfjerdsfjorden Glacier. (Masterarbeit), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Germany, 95 pp.
Greenland's largest floating ice tongue at the Nioghalvfjerdsfjorden Glacier (79 North Glacier) is thinning, most likely triggered by enhanced submarine melting. The strength of the cavity circulation beneath the floating ice tongue is essentially responsible for the ocean heat flux to the glacier ice and variability in the circulation may have consequences on the basal melt rate. Analyzing four moored records (summers 2016-2017) from the 79 North Glacier calving front, this study characterizes the variability of the cavity circulation and the relative importance of its local and regional drivers. The focus lies on the variability in the currents in Dijmphna Sund, the most relevant export pathway
Specht, Mia S. (2018): Variability of Atlantic Water inflow onto the shelf of North-East Greenland. (Masterarbeit), Christian-Albrechts-Universität Kiel, Kiel, Germany, 67 pp.
Lunz, Susanne: Analyse von GNSS-Messungen zur Bestimmung der rezenten Deformation der Erdkruste in Nordost-Grönland, Masterarbeit, TU Dresden, 2018
Kappelsberger, Maria: Untersuchungen zur Ermittlung von Eismassenänderungen zund Krustendeformationen in Grönland aus der Kombination von Satellitenaltimetrie und Satellitengravimetrie Masterarbeit, TU Dresden, 2019