Distribution of cold and temperate ice and water in glaciers at Nordenskiöld Land, Svalbard, according to data on ground-based radio-echo sounding

The distribution of cold and temperate ice and water in polythermal glaciers is an important characteristic in studying their thermal regime, hydrology, and response to climate change. Data analysis of ground-based radio-echo sounding of 16 glaciers in Nordenskiöld Land in Spitsbergen shows that 4 of them are of cold type and 12 are of polythermal type. The mean thickness of cold and temperate ice in polythermal glaciers varies from 11±2 to 66±6 m and from 6±2 to 96±9 m, respectively, and their ratio varies from 0.30 to 5.31. The volume of temperate ice in polythermal glaciers varies from 0.0009 to 3.733 (±10%) km3. With water content of 2% in temperate ice in these glaciers they might contain in total up to ~93.5 × 106 m3 of liquid water. Radar data suggest the greater water content or greater size of water inclusions in near-bottom temperate ice

Estimation of absolute water content in Spitsbergen glaciers from radar sounding data

Field data available on radio-wave velocities and power reflection coefficients from the cold/temperate ice boundary have been used to estimate the absolute water content and its variations in the temperate ice of two-layered galciers on Spitsbergen. The data have been interpreted with certain assumptions concerning radio-wave propagation and reflection models. The study shows that in cold periods, the average total water content in the upper part of the temperate ice varies in different glaciers from 2.8 to 9.1%. Macro inclusions might contain the major part of the total water content volume. Within one glacier, the spatial variability of water content in the upper part of the temperate ice varies in different galciers from 2.8 to 9.1%. Macro inclusions might contain the major part of the total water volume. Within one glacier, the spatial variability of water content in the upper part of the temperature ice is 1.7 - 11.9%. Seasonal variation of the total water content in the temperate layer reaches 2.3% (from 0.1% in spring to 2.4% in summer). Water content distribution with depth can vary: either it has a maximum up to 5.0% (even in spring) in the upper 30–60 m of the temperate ic, then decreases downward: or it is more uniform. Water content in the upper part of temperate ice and bedrock reflection coefficients reveal a rather close relation with surficial melting rate at the ELA and with ice facies zones. Water storage in the temperate layer is enough to feed englacial run-off during the whole cold period

Surface elevation change rates of most glaciers on Franz Josef Land, Severnaya Zemlya and Novaya Zemlya between 2010 and 2017

Glaciers in the Russian High Arctic have been subject to large environmental changes due to global warming. Here we provide surface elevation change rates of most glaciers on Franz Josef Land, Severnaya Zemlya and Novaya Zemlya between 2010 and 2017. The dataset includes glacier elevation change maps of glaciers of the Russian Arctic archipelagos (Franz Josef Land, Severnaya Zemlya & Novaya Zemlya) for the period winter 2010/11 to winter 2016/17. Elevation change rates (unit: m/a) are calculated from differencing interferometric Digital Elevation Models (DEMs) of the TanDEM-X satellite mission. Glacier areas are derived from the Randolph Glacier Inventory V6.0 (09_rgi60_RussianArctic). All elevation change maps are provided as GeoTiffs with a spatial resolution of 30m (EPSG:3995). Additionally, raster files with the observation period in years per cell are included

SPRI Time-and Position-Tagged Radio Echo Profiles for Severnaya Zemlya (SZ), 1997, plus derived Ice Thickness point data and Digital Elevation Models (DEMs)

This data set contains radar sounder echo strength profiles from the SPRI 100 MHz ice penetrating radar instrument deployed over Severnaya Zemlya (SZ), Russian Arctic, in 1997 as well as ice thickness and related products generated from these data. The data were collected during survey flights between 9 and 24 April 1997 under funding from: U.K. Natural Environment Research Council (NERC) grants GR3/9958 and GST/02/2195; EU Environment Programme grants ENV4CT97-0490 and 0426; Alfred-Wegener-Institut, Germany; and Russian Fund for Fundamental Studies. Participants from the Scott Polar Research Institute (SPRI)/Bristol Glaciology Centre were J. A. Dowdeswell, M. R. Gorman and R. P. Bassford. The project was a collaboration between UK scientists and those from Russian institutions, principally the Institute of Geography at the Russian Academy of Sciences, Moscow (Drs A.F Glazovsky and Y.Y. Macheret). Dataset prepared for archive by J. A. Dowdeswell, T. J. Benham and F. D. W. Christie of SPRI, 2023. Total file size: 1.60 Gb (zipped); 6.11 Gb (unzipped)The research program was funded by the following institutions: U.K. Natural Environment Research Council (grants GR3/9958 and GST/02/2195); EU Environment Programme (grants ENV4CT97-0490 and 0426); Alfred-Wegener-Institut, Germany; and Russian Fund for Fundamental Studies. We thank C. Smirnov, V. Potapinko, and A. Mazhaev for logistical organization in Severnaya Zemlya

Retrieval of Svalbard ice flow velocities using Sentinel 1A/1B three-pass Differential SAR Interferometry

Glacier velocity is an important parameter to characterize glacier dynamics and to derive ice thickness and mass balance. The 2-pass/3-pass Differential Synthetic Aperture Radar Interferometry (DInSAR) techniques are advantageous in estimating glacier movements. However, the 2-pass DInSAR requires an external Digital Elevation Model (DEM), whereas the 3-pass DInSAR does not. The 3-pass DInSAR technique is adopted with Sentinel-1A/1B to map the Svalbard glacier flow velocities. Furthermore, the effect of glacier surface elevation change on the 2-pass DInSAR results were revealed by comparing glacier velocity with the two time period topographic information. The coherence indicates that Sentinel-1A/1B has a high potential to infer operational glacier velocity using the 3-pass DInSAR method with an average atmospheric uncertainty of 0.24 cm/day over the studied region. The precision of the 3-pass DInSAR is analyzed by comparing 2-pass derived line-of-sight (LOS) velocity on the same dates. The 3-pass DInSAR achieves high-resolution and detailed information

Glacier Flow Dynamics of the Severnaya Zemlya Archipelago in Russian High Arctic Using the Differential SAR Interferometry (DInSAR) Technique

Glacier velocity is one of the most important parameters to understand glacier dynamics. The Severnaya Zemlya archipelago is host to many glaciers of which four major ice caps encompassing these glaciers are studied, namely, Academy of Sciences, Rusanov, Karpinsky, and University. In this study, we adopted the differential interferometric synthetic aperture radar (DInSAR) method utilizing ALOS-2/PALSAR-2 datasets, with a temporal resolution of 14 days. The observed maximum velocity for one of the marine-terminating glaciers in the Academy of Sciences Ice Cap was 72.24 cm/day (≈263 m/a). For the same glacier, an increment of 3.75 times the flow rate was observed in 23 years, compared to a previous study. This has been attributed to deformation in the bed topography of the glacier. Glaciers in other ice caps showed a comparatively lower surface velocity, ranging from 7.43 to 32.12 cm/day. For estimating the error value in velocity, we selected three ice-free regions and calculated the average value of their observed movement rates by considering the fact that there is zero movement for ice-free areas. The average value observed for the ice-free area was 0.09 cm/day, and we added this value in our uncertainty analysis. Further, it was observed that marine-terminating glaciers have a higher velocity than land-terminating glaciers. Such important observations were identified in this research, which are expected to facilitate future glacier velocity studies

The unquantified mass loss of Northern Hemisphere marine-terminating glaciers from 2000-2020.

In the Northern Hemisphere, ~1500 glaciers, accounting for 28% of glacierized area outside the Greenland Ice Sheet, terminate in the ocean. Glacier mass loss at their ice-ocean interface, known as frontal ablation, has not yet been comprehensively quantified. Here, we estimate decadal frontal ablation from measurements of ice discharge and terminus position change from 2000 to 2020. We bias-correct and cross-validate estimates and uncertainties using independent sources. Frontal ablation of marine-terminating glaciers contributed an average of 44.47 ± 6.23 Gt a-1 of ice to the ocean from 2000 to 2010, and 51.98 ± 4.62 Gt a-1 from 2010 to 2020. Ice discharge from 2000 to 2020 was equivalent to 2.10 ± 0.22 mm of sea-level rise and comprised approximately 79% of frontal ablation, with the remainder from terminus retreat. Near-coastal areas most impacted include Austfonna, Svalbard, and central Severnaya Zemlya, the Russian Arctic, and a few Alaskan fjords

Progress toward globally complete frontal ablation estimates of marine-terminating glaciers

peer reviewedKnowledge of frontal ablation from marine-terminating glaciers (i.e., mass lost at the calving face) is critical for constraining glacier mass balance, improving projections of mass change, and identifying the processes that govern frontal mass loss. Here, we discuss the challenges involved in computing frontal ablation and the unique issues pertaining to both glaciers and ice sheets. Frontal ablation estimates require numerous datasets, including glacier terminus area change, thickness, surface velocity, density, and climatic mass balance. Observations and models of these variables have improved over the past decade, but significant gaps and regional discrepancies remain, and better quantification of temporal variability in frontal ablation is needed. Despite major advances in satellite-derived large-scale datasets, large uncertainties remain with respect to ice thickness, depth-averaged velocities, and the bulk density of glacier ice close to calving termini or grounding lines. We suggest ways in which we can move toward globally complete frontal ablation estimates, highlighting areas where we need improved datasets and increased collaboration