Surface accumulation in Northern Central Greenland during the last 300 years

Karlsson, Nanna B.; Razik, Sebastian; Hörhold, Maria; Winter, Anna; Steinhage, Daniel; Binder, Tobias; Eisen, Olaf

doi:10.1017/aog.2020.30

Cited by 25 publications

(26 citation statements)

References 54 publications

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“…CC BY 4.0 License. (Weissbach et al, 2016) and the radar line (Karlsson et al, 2020) further supports such a spatial variability. The HIRHAM5 models capture less of the observed accumulation when moving eastwards off the divide.…”

Section: Resultsmentioning

confidence: 52%

Recent North Greenland temperature warming and accumulation

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Edwards

et al. 2021

Preprint

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Abstract. In a warming climate concise knowledge of the mass balance of the Greenland ice sheet is of utter importance. Speculations that current warming will increase the snow accumulation and mitigate mass balance losses are unconstrained as accumulation data across large regions of the northern ice sheet are scarce. We reconstructed the accumulation from six north Greenland shallow firn cores (~10 m) and eight snow cores (~2 m) to constrain recent accumulation patterns in northern Greenland and calculated recent warming in the same area using borehole temperature measurements. We find an increase in temperatures in the north Greenland interior of 0.9 to 2.5 °C (method and site dependent) per decade over the past two decades in line with an Arctic amplified anthropogenic warming. We compare annual reconstructed accumulation from the firn cores (1966–2015) to radar estimates and to annual re-analysis data (1980–2016) of precipitation subtracted evaporation from the regional climate model HIRHAM5, operated by the Danish Meteorological Institute. The spatial variability resembles that observed in earlier estimates with a clear increase west of the topographic divide and a low accumulation area across the north-eastern ice sheet. Our accumulation results are comparable to earlier firn core estimates, despite being larger in the east. We only find a positive significant trend in the accumulation for the period 2000–2010 to the northwest. In the vicinity of the EGRIP deep ice core drilling site, we find variable accumulation patterns for two 15 km apart firn cores likely owing to local topographic effects as a result of the North East Greenland Ice Stream dynamics.

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Section: Resultsmentioning

confidence: 52%

Recent North Greenland temperature warming and accumulation

Kjær

Zens

Edwards

et al. 2021

Preprint

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“…Eisen, 2008). Recent work in this area has been carried out on time-scales ranging from annual to centennial to millennial (Eisen and others, 2008; Medley and others, 2014; Nielsen and others, 2015; Grima and others, 2016; Karlsson and others, 2016; Koenig and others, 2016; Koutnik and others, 2016; MacGregor and others, 2016; Lewis and others, 2017; Cavitte and others, 2018; Karlsson and others, 2020; Montgomery and others, 2020). Efforts to automate layer tracing continue, which include methodologies that use seed points to initiate semi-automatic tracing routines as well as fully automatic schemes.…”

Section: Englacial Structurementioning

confidence: 99%

Five decades of radioglaciology

et al. 2020

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Radar sounding is a powerful geophysical approach for characterizing the subsurface conditions of terrestrial and planetary ice masses at local to global scales. As a result, a wide array of orbital, airborne, ground-based, and in situ instruments, platforms and data analysis approaches for radioglaciology have been developed, applied or proposed. Terrestrially, airborne radar sounding has been used in glaciology to observe ice thickness, basal topography and englacial layers for five decades. More recently, radar sounding data have also been exploited to estimate the extent and configuration of subglacial water, the geometry of subglacial bedforms and the subglacial and englacial thermal states of ice sheets. Planetary radar sounders have observed, or are planned to observe, the subsurfaces and near-surfaces of Mars, Earth's Moon, comets and the icy moons of Jupiter. In this review paper, and the thematic issue of the Annals of Glaciology on ‘Five decades of radioglaciology’ to which it belongs, we present recent advances in the fields of radar systems, missions, signal processing, data analysis, modeling and scientific interpretation. Our review presents progress in these fields since the last radio-glaciological Annals of Glaciology issue of 2014, the context of their history and future prospects.

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“…2. Airborne radar transects in the accumulation zone from Karlsson et al (2016Karlsson et al ( , 2020. For all of these measurements, the annual mean over 1980-2012 is used as comparison, and as for the ice cores, outputs are interpolated using the four nearest inverse-distance-weighted grid cells to the common 1 km ISMIP6 grid.…”

Section: Ice Core and Smb Measurementsmentioning

confidence: 99%

“…These quantities are integrated over the six basins defined in King et al (2018) and based on basin configurations from Sasgen et al (2012). The correction for glacial isostatic adjustment is based on the model of Khan et al (2016). Finally, in King et al (2018), monthly glacier discharge estimates were combined with RACMO2.3p2-based SMB and compared to the resulting total mass balance estimate from the GRACE product as will be done in this study for each model.…”

Section: Grace Estimationmentioning

confidence: 99%

GrSMBMIP: intercomparison of the modelled 1980–2012 surface mass balance over the Greenland Ice Sheet

et al. 2020

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Abstract. Observations and models agree that the Greenland Ice Sheet (GrIS) surface mass balance (SMB) has decreased since the end of the 1990s due to an increase in meltwater runoff and that this trend will accelerate in the future. However, large uncertainties remain, partly due to different approaches for modelling the GrIS SMB, which have to weigh physical complexity or low computing time, different spatial and temporal resolutions, different forcing fields, and different ice sheet topographies and extents, which collectively make an inter-comparison difficult. Our GrIS SMB model intercomparison project (GrSMBMIP) aims to refine these uncertainties by intercomparing 13 models of four types which were forced with the same ERA-Interim reanalysis forcing fields, except for two global models. We interpolate all modelled SMB fields onto a common ice sheet mask at 1 km horizontal resolution for the period 1980–2012 and score the outputs against (1) SMB estimates from a combination of gravimetric remote sensing data from GRACE and measured ice discharge; (2) ice cores, snow pits and in situ SMB observations; and (3) remotely sensed bare ice extent from MODerate-resolution Imaging Spectroradiometer (MODIS). Spatially, the largest spread among models can be found around the margins of the ice sheet, highlighting model deficiencies in an accurate representation of the GrIS ablation zone extent and processes related to surface melt and runoff. Overall, polar regional climate models (RCMs) perform the best compared to observations, in particular for simulating precipitation patterns. However, other simpler and faster models have biases of the same order as RCMs compared with observations and therefore remain useful tools for long-term simulations or coupling with ice sheet models. Finally, it is interesting to note that the ensemble mean of the 13 models produces the best estimate of the present-day SMB relative to observations, suggesting that biases are not systematic among models and that this ensemble estimate can be used as a reference for current climate when carrying out future model developments. However, a higher density of in situ SMB observations is required, especially in the south-east accumulation zone, where the model spread can reach 2 m w.e. yr−1 due to large discrepancies in modelled snowfall accumulation.

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Surface accumulation in Northern Central Greenland during the last 300 years

Cited by 25 publications

References 54 publications

Recent North Greenland temperature warming and accumulation

Recent North Greenland temperature warming and accumulation

Five decades of radioglaciology

GrSMBMIP: intercomparison of the modelled 1980–2012 surface mass balance over the Greenland Ice Sheet

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