The relationship between dissolved solids yield and the presence of snow cover in the periglacial basin of the Obruchev Glacier (Polar Urals) during the ablation season

Hydrochemical investigations were carried out in the periglacial basin of Obruchev Glacier (Polar Urals, Russia) in order to provide a quantitative and qualitative comparison of dissolved solids yields during the ablation season with and without snow cover taking into account the mineral composition of rocks and deposits occurring in the studied area. The concentration of dissolved solids in the waters of the investigated basin is very low (about 7.0–8.9 μS cm^{-1}). It is most of all due to harsh local climate conditions as well as the presence of minerals resistant to weathering in the parent material. Both factors contribute to the low rate of chemical weathering in the area. Results obtained indicate that a larger dissolved solids yield was transported during the period with snow cover (106 kg km^{-2} day^{-1}, on average), than at the same time of the year but without snow cover (13 kg km^{-2} day^{-1}, on average) indicating that melting snow is an important factor influencing the yield of dissolved solids in surface waters

Which Drivers Control the Suspended Sediment Flux in a High Arctic Glacierized Basin (Werenskioldbreen, Spitsbergen)?

A unique data set of suspended sediment transport from the Breelva, which drains the Werenskioldbreen (Southwestern Spitsbergen), is reported for the period 2007–2012. This basin is thoroughly described hydrologically, glaciologically, and chemically. However, until now there was a lack of full recognition of mechanical denudation. This study extends the information on quantitative suspended sediment load (SSL), amounting to 37.30–130.94 kt per year, and also underlines the importance of its modification by high discharge events, triggered by intense snowmelt or heavy rainfall. The large floods during the hydrologically active season transported even 83% of the total SSL. The variability of the SSL is controlled by glacial storage and release mechanisms. Particularly interesting is the second half of the hydrologically active season when intense rainfall events plays a key role in shaping the sediment supply pattern. The main source of fine mineral matter is the basal moraine, drained by subglacial outflows. Their higher mobilization occurs when the hydrostatic pressure increases, often as a result of rainwater supply to the glacier system. An increasing precipitation trend for Hornsund fjord region determines a positive trend predicted for sediment flux

SEM-EDS and water chemistry characteristics at the early stages of glacier recession reveal biogeochemical coupling between proglacial sediments and meltwater

Most glaciers worldwide are undergoing climate-forced recession, but the impact of glacier changes on biogeochemical cycles is unclear. This study examines the influence of proglacial sediment weathering on meltwater chemistry at the early stages of glacier recession in the High Arctic of Svalbard. Scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) in combination with a wide range of geochemical analyses were used in this study. The SEM-EDS analyses of sediments collected in front of Werenskioldbreen show general degradation of pyrite and carbonate grains with age. The outer parts of pyrite grains have a gradual decrease in sulphur and gradual increase in iron oxides due to pyrite oxidation. This process was less advanced in the proglacial zone younger than 100 years compared to older sites such as the terminal moraine from the Little Ice Age. In both the proglacial zone and the terminal moraine, physical weathering of mineral grains, including formation of microcracks and microfractures, clearly enhanced pyrite oxidation. A consequence of proglacial sediment weathering is that the river chemistry is strongly affected by carbonate dissolution driven by sulphuric acid from sulphide oxidation. Also, reactive iron oxides, a product of sulphide oxidation, are mobilized in the proglacial zone. The results of this study show that proglacial weathering in the High Arctic of Svalbard is strongly coupled to river geochemistry, especially during the early stages of proglacial exposure after glacier recession

Glacier naled evolution and relation to the subglacial drainage system based on water chemistry and GPR surveys (Werenskioldbreen, SW Svalbard)

Glacier naledi are extrusive ice masses that appear in front of glaciers as a consequence of refreezing of meltwater seepage during the accumulation season. These structures provide a unique opportunity to understand subglacial drainage activity during the accumulation season; however, only few detailed studies have previously focused on their characteristics. Here, we investigated glacier-derived naled assemblages in the proglacial zone of the polythermal glacier Werenskioldbreen (27.4 km2) in SW Svalbard. We determined the spatial distribution of naledi using ground penetrating radar surveys. The main subglacial drainage pattern was related to a channel under the medial moraine, and three sources are linked to a distributed subglacial drainage network. The relation between atmospherically-corrected (Ca2+ + Mg2+) and (SO4 2-) in sub-naled waters was closely related to sulphide oxidation coupled with carbonate dissolution (r = 0.99; slope = 1.6). This is consistent with the local lithology, which is dominated by schist containing carbonates. We also found high carbonate saturation indices in pale white ice layers within the naled. We conclude that sulphide oxidation coupled with carbonate dissolution is the dominant chemical weathering process in the subglacial drainage system of Werenskioldbreen during the accumulation season

Impact of volcanic eruptions on the occurrence of PAHs compounds in the aquatic ecosystem of the southern part of West Spitsbergen (Hornsund fjord, Svalbard)

The paper presents changes in concentration levels of dioxin-like compounds that can be observed over the course of four study seasons in water samples collected from the Arctic watershed of Svalbard. The conducted analysis involved anthropogenic and natural factors that may affect the concentration of PAHs in the study samples of water. An attempt is made to indicate the emission source of the compounds being deposited and to identify the extent to which the substances under analysis actually affect the Arctic ecosystems. Moreover, the work employs the following: diagnostic ratios PAHs, air masses backward trajectory analysis, Lidar observations and land relief analysis in order to provide a multi-level interpretation of the obtained data. Natural environment constitutes a complex system of subtle correlations that need to be perceived as a dynamic medium, in which multi-faceted processes take place

Climate indices of environmental change in the High Arctic: Study from Hornsund, SW Spitsbergen, 1979–2019

An analysis of a suite of climatological indices was undertaken on the basis of long-term (1979–2019) climatological data from the Polish Polar Station in Hornsund, SW Spitsbergen. It was followed by an attempt to assess the scale of their impact on the local environment. The temperature and precipitation indices were based on percentiles of the variables calculated for a population of daily values from the climate normals for 1981–2010. A greater share of both cyclonic and anticyclonic circulations from the S and SW sectors, forcing the advection of warm air masses from the south, was decisive for the trends of change in comparison with the long-term mean. Both extreme precipitation and drought events depend on the 500 hPa geopotential height and precipitable water anomalies, determined by the baric field over the North Atlantic. Climate changes impact on the dynamics of local geoecosystems by causing faster glacier ablation and retreat, permafrost degradation, intensification of the hydrological cycle in glaciated and unglaciated catchments, and changes in the condition and growth of tundra vegetation

The relationship between dissolved solids yield and the presence of snow cover in the periglacial basin of the Obruchev Glacier (Polar Urals) during the ablation season

Hydrochemical investigations were carried out in the periglacial basin of Obruchev Glacier (Polar Urals, Russia) in order to provide a quantitative and qualitative comparison of dissolved solids yields during the ablation season with and without snow cover taking into account the mineral composition of rocks and deposits occurring in the studied area. The concentration of dissolved solids in the waters of the investigated basin is very low (about 7.0–8.9 μS cm–1). It is most of all due to harsh local climate conditions as well as the presence of minerals resistant to weathering in the parent material. Both factors contribute to the low rate of chemical weathering in the area. Results obtained indicate that a larger dissolved solids yield was transported during the period with snow cover (106 kg km–2 day–1, on average), than at the same time of the year but without snow cover (13 kg km–2 day–1, on average) indicating that melting snow is an important factor influencing the yield of dissolved solids in surface waters