Mass Balance of Novaya Zemlya Archipelago, Russian High Arctic, Using Time-Variable Gravity from GRACE and Altimetry Data from ICESat and CryoSat-2

Abstract

We examine the mass balance of the glaciers in the Novaya Zemlya Archipelago, located in the Russian High Arctic using time series of time-variable gravity from the NASA/DLR Gravity Recovery and Climate Experiment (GRACE) mission, laser altimetry data from the NASA Ice Cloud and land Elevation Satellite (ICESat) mission, and radar altimetry data from the European Space Agency (ESA) CryoSat-2 mission. We present a new algorithm for detecting changes in glacier elevation from these satellite altimetry data and evaluate its performance in the case of Novaya Zemlya by comparing the results with GRACE. We find that the mass loss of Novaya Zemlya glaciers increased from 10 ± 5 Gt/year over 2003–2009 to 14 ± 4 Gt/year over 2010–2016, with a brief period of near-zero mass balance between 2009 and 2011. The results are consistent across the gravimetric and altimetric methods. Furthermore, the analysis of elevation change from CryoSat-2 indicates that the mass loss occurs at elevation below 700 m, where the highest thinning rates are found. We also find that marine-terminating glaciers in Novaya Zemlya are thinning significantly faster than land-terminating glaciers, which indicates an important role of ice dynamics of marine-terminating glaciers. We posit that the glacier changes have been caused by changes in atmospheric and ocean temperatures. We find that the increase in mass loss after 2010 is associated with a warming in air temperatures, which increased the surface melt rates. There is not enough information on the ocean temperature at the front of the glaciers to conclude on the role of the ocean, but we posit that the temperature of subsurface ocean waters must have increased during the observation period.

Spread of Svalbard Glacier Mass Loss to Barents Sea Margins Revealed by CryoSat‐2

“…Thinning in Novaya Zemlya has been most rapid on marine‐terminating glaciers of the Barents Sea coast (Melkonian et al., 2016), while calving front retreat is prevalent on both the Barents Sea and Kara Sea coasts (Carr et al., 2014, 2017). Furthermore, the temporal patterns of mass loss appear similar across the archipelagos of the Norwegian and Russian Arctic (Figure 5 here versus Figure 2 of Ciracì et al., 2018).…”

“…In contrast, temperature changes higher in the atmosphere (850‐mb level) were less pronounced, with the greatest increases to the north, and lower magnitude changes in the Barents Sea (Figures 6j–6l). This pattern was interrupted in 2013 (Figure S10) when westerly atmospheric circulation caused an exceptionally warm summer (Lang et al., 2015) with high mass losses throughout Svalbard (Figures 4 and 5) and the Russian Arctic (Ciracì et al., 2018).…”

“…In general, thinning is greatest at the low‐elevation margins, with lower magnitude changes at higher elevation, including the gradual thickening of some (high elevation) ice cap interiors (Figure 3), a pattern that is common throughout the Arctic (Ciracì et al., 2018; Foresta et al., 2016; Gardner et al., 2011). This pattern is superimposed on a southwest to northeast gradient in thinning.…”

“…CryoSat‐2 has a 30‐day orbital subcycle, suggesting the possibility to resolve elevation changes at monthly resolution (Ciracì et al., 2018; Noël et al., 2018). A similar hypsometric polynomial approach was used to extrapolate monthly elevation residuals, except that a first‐order polynomial was chosen due to the sparser data coverage.…”

Vertical Land Motion From Present‐Day Deglaciation in the Wider Arctic

“…This ensured that the lower parts of glaciers are thinning, while upper parts experience small elevation gains. This “slope steepening” of glaciers is characteristic of glaciers of many regions (Cirací et al, 2018; Foresta et al, 2016; Nuth et al, 2010) and is assumed to apply to all glaciers included in this study (see Supporting Information S1 for an enhanced description of glacial elevation change).…”