Polar Research (E-Journal)
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Variation in summer nitrogen and phosphorus uptake among Siberian headwater streams
No full textArctic streams are likely to receive increased inputs of dissolved nutrients and organic matter from thawing permafrost as climate warms. Documenting how Arctic streams process inorganic nutrients is necessary to understand mechanisms that regulate watershed fluxes of permafrost-derived materials to downstream ecosystems. We report on summer nitrogen (N) and phosphorus (P) uptake in streams draining upland soils from the Pleistocene, and lowland floodplain soils from the Holocene, in Siberia’s Kolyma River watershed. Uptake of N and P differed between upland and floodplain streams, suggesting topographic variation in nutrient limitation. In floodplain streams, P uptake rate and uptake velocity were higher than N, while upland streams had similar values for all N and P uptake metrics. Phosphorus uptake velocity and size of the transient hydrologic storage zone were negatively related across all study streams, indicating strong influence of hydrologic processes on nutrient fluxes. Physical sorption of P was higher in floodplain stream sediments relative to upland stream sediments, suggesting more physically driven uptake in floodplain streams and higher biological activity in upland streams. Overall, these results demonstrate that high-latitude headwater streams actively retain N and P during summer base flows; however, floodplain and upland streams varied substantially in N and P uptake and may respond differently to inorganic nutrient and organic matter inputs. Our results highlight the need for a comprehensive assessment of N and P uptake and retention in Arctic streams in order to fully understand the impact of permafrost-derived materials on ecosystem processes, and their fate in continental drainage networks.Keywords: Arctic streams; nutrient uptake; hydrologic transient storage; phosphorus sorption; coupled N and P cycling.(Published: 6 June 2016)To access the supplementary material for this article, please see the supplementary files in the column to the right (under Article Tools).Citation: Polar Research 2016, 35, 24571, http://dx.doi.org/10.3402/polar.v35.2457
Scleractinian corals recorded in the Argentinean Antarctic expeditions between 2012 and 2014, with comments on Flabellum (Flabellum) areum Cairns, 1982
No full textIn this contribution, we provide a list of the scleractinian corals recorded during the Argentinean Antarctic expeditions on board the oceanographic vessel Puerto Deseado (Argentina) in the austral summers in 2012, 2013 and 2014. The identified taxa consist of six solitary species (Flabellum impensum, F. flexuosum, F. areum, Caryophyllia antarctica, Paraconotrochus antarcticus and Javania antarctica), recorded from 19 sampling sites located off the Antarctic Peninsula and South Shetland and South Orkney islands. We also update the information of F. areum, previously known only from south-west Atlantic waters, extending its distribution range to Antarctic waters and its upper bathymetric range to 218 m.Keywords: cold-water corals; Antarctica; range extension; bathymetric range extension; Scleractinia.(Published. 4 July 2016)To access the supplementary material for this article, please see the supplementary files in the column to the right (under Article Tools).Citation: Polar Research 2016, 35, 29762, http://dx.doi.org/10.3402/polar.v35.2976
On Roald Amundsen’s scientific achievements
No full textThis paper describes the significant direct and indirect contributions to science made by the Norwegian polar explorer Roald Amundsen in the period 1897–1924. It documents that his expeditions through the North-west Passage (1903–06) with Gjøa, to the South Pole (1910–12) with Fram and through the North-east Passage (1918–1920) and the Chukchi and East Siberian seas (1921–25) with Maud yielded vast amounts of published scientific material on meteorology, terrestrial magnetism, geology, palaeontology, oceanography, ethnography, zoology and botany, which, though celebrated at the time, have since received scant recognition in more recent assessments of Amundsen’s achievements.Keywords: Fridtjof Nansen; polar exploration; South Pole; North-west Passage; North-east Passage; H.U. Sverdrup(Published: 10 March 2016)To access the supplementary material for this article, please see the supplementary file in the column to the right (under Article Tools).Citation: Polar Research 2016, 35, 31319, http://dx.doi.org/10.3402/polar.v35.3131
Review of The polar regions: an environmental history, by Adrian Howkins
No full textNo abstract available.
(Published: 27 September 2016)
Citation: Polar Research 2016, 35, 33308,http://dx.doi.org/10.3402/polar.v35.3330
Air warming trends linked to permafrost warming in the sub-Arctic catchment of Tarfala, Sweden
No full textRecent ground temperature records from the 100-m-deep borehole near the Tarfala Research Station in northern Sweden reveal that permafrost is warming at a pace consistent with the rate of measured air temperature increase at the site. Here we investigate whether air temperature increase is the main driver of the observed change in the permafrost thermal regime using a non-isothermal hydrogeological numerical model for partially frozen ground. The local site is investigated with different ground surface temperature scenarios representing different integrated effects of surficial heat attenuation processes. Results indicate that despite a short-term sensitivity to heat attenuation processes including snow conditions, the main driver of change in the permafrost thermal regime during the past decade is warming air temperatures. Additionally, the approach used here is shown to be particularly pertinent for modelling warming trends, despite limited prior knowledge of site-specific conditions and geological properties. Understanding the main driving mechanisms of changing permafrost is useful for assessing the suitability of borehole temperature records as proxies for past environmental conditions as well as for modelling possible future climatic impacts.Keywords: Permafrost; warming ground; PACE borehole; numerical modelling; climate change.(Published: 29 September 2016)To access the supplementary material for this article, please see the supplementary files in the column to the right (under Article Tools).Citation: Polar Research 2016, 35, 28978, http://dx.doi.org/10.3402/polar.v35.2897
The black-legged kittiwake preen gland - an overlooked organ for depuration of fat-soluble contaminants?
No full textMost birds preen their feathers with an oily excrete from the uropygial (preen) gland. This oily excrete contains persistent organic pollutants (POPs), which make the preen gland a potential route of depuration of POPs in birds. Black-legged kittiwakes (Rissa tridactyla) were studied during two periods of high energy demand: incubation and chick-rearing. A rather high concentration of POPs in preen gland tissue indicates that the preen gland secrete is an excretory pathway for POPs in kittiwakes. The similarity in the POP profile detected in this study of liver, preen gland and feathers suggests that POPs found in the feathers are excreted through the preen gland. The finding also indicates that excretion of POPs through the preen gland is compound unspecific. This qualitative study should be followed up by a new quantitative study to determine the importance of excretion of POPs through the preen gland.Keywords: Feather; organochlorinated pesticides; polychlorinated biphenyls; Rissa tridactyla.(Published: 18 August 2016)To access the supplementary material for this article, please see the supplementary files in the column to the right (under Article Tools).Citation: Polar Research 2016, 35, 29651, http://dx.doi.org/10.3402/polar.v35.2965
Re-assessment of recent (2008 - 2013) surface mass balance over Dome Argus, Antarctica
No full textAt Dome Argus, East Antarctica, the surface mass balance (SMB) from 2008 to 2013 was evaluated using 49 stakes installed across a 30×30 km area. Spatial analysis showed that at least 12 and 20 stakes are needed to obtain reliable estimates of SMB at local scales (a few hundred square metres) and regional scales (tens of square kilometres), respectively. The estimated annual mean SMB was 22.9±5.9 kg m−2 yr−1, including a net loss by sublimation of −2.22±0.02 kg m−2 yr−1 and a mass gain by deposition of 1.37±0.01 kg m−2 yr−1. Therefore, ca. 14.3% of precipitation was modified after deposition, which should be considered when interpreting snow or ice core records produced by future drilling projects. The surface snow density and SMB in the western portion of Dome Argus are higher than in other areas, and these differences are likely related to the katabatic wind, which is strengthened by topography in this sector. A new digital elevation model (DEM) of Dome Argus was generated, confirming that both peaks of the dome can be considered as the summit of the East Antarctic Ice Sheet. Findings from this study should be valuable for validating SMB estimates obtained from regional climate models and DEMs established using remote-sensing data.Keywords: Snow accumulation; Kunlun Station; CHINARE; digital elevation model; deep ice core sites; East Antarctic Ice Sheet.(Published: 12 April 2016)To access the supplementary material for this article, please see the supplementary file in the column to the right (under Article Tools).Citation: Polar Research 2016, 35, 26133, http://dx.doi.org/10.3402/polar.v35.2613
Review of Asian countries and the Arctic future, edited by Leiv Lunde, Yang Jian & Iselin Stensdal
No full textNo abstract available.
(Published: 9 February 2016)
Citation: Polar Research 2016, 35, 31052, http://dx.doi.org/10.3402/polar.v35.3105
The first magnetotelluric image of the lithospheric-scale geological architecture in central Svalbard, Arctic Norway
No full textMagnetotelluric data, collected from 30 stations on Spitsbergen as part of a reconnaissance geothermal resource assessment along a profile with 0.5–3-km spacing in 0.003–1000-s period range, were used to develop a lithospheric-scale two-dimensional (2D) resistivity model, heretofore unavailable for the region. Inverting the determinant of the impedance tensor in 2D, we found the smoothest model fitting the data within a specified tolerance level. We justified the model by perturbing it, performing sensitivity analysis and re-running the inversion with a different algorithm and starting models. From our final model, we constructed a crustal-scale stratigraphic framework, using it to estimate the depth of major geological features and to locate structural deformations. The 2D resistivity model indicates a shallow low resistive (<100 Ωm) Paleozoic–Mesozoic sedimentary sequence, varying laterally in thickness (2–4 km), obstructed by a gently dipping Permian–Carboniferous succession (>1000 Ωm) east of the Billefjorden Fault Zone. Underneath, a (possibly Devonian) basin is imaged as a thick conductive anomaly stretching >15 km downwards. Beneath a deformed Paleozoic–Mesozoic successions, an uplifted pre-Devonian shallow basement (>3000 Ωm) is revealed. We estimated a thin lithosphere, in the range of ca. 55–100 km thick, that could explain the area’s elevated surface heat flow (ca. 60–90 mW/m2), consistent with the calculated depth of thermal lithosphere heat-base boundaries for a partially melting mantle. The model indicates a possible replenishment pathway of upward heat transport from the shallow convective mantle to the composite crustal conductive units. This is encouraging for low-enthalpy geothermal development.Keywords: Magnetotellurics; 2D modelling; lithosphere architecture; geothermal; Svalbard.(Published: 17 December 2015)Citation: Polar Research 2015, 34, 26766, http://dx.doi.org/10.3402/polar.v34.2676
Search for tick-borne pathogens in the Svalbard Archipelago and Jan Mayen
No full textThe tick species Ixodes uriae, parasitizing seabirds in the Arctic, may transmit many pathogens including various arboviruses, Borrelia spirochetes and Babesia apicomplexans. These pathogens may pose an important additional stress to seabirds, which are already stressed by environmental changes such as pollutants and decreased food availability. Here, we present the results of the first screening for arboviruses of the genera Flavivirus, Alphavirus, Orthobunyavirus, Phlebovirus and Orbivirus, as well as Borrelia spirochetes and Babesia apicomplexans from Svalbard and Jan Mayen. Using polymerase chain reaction technology with genus-specific primers, we tested 89 ticks collected on Jan Mayen, Bjørnøya and Spitsbergen between 2008 and 2012. We did not detect any of the screened tick-borne pathogens. Nevertheless, these pathogens may be introduced to Svalbard and Jan Mayen by migratory birds in the near future. The increasing numbers of ticks appearing in the studied areas make this introduction even more likely. Such an introduction would have serious impact on seabird ecology as well as on human public health. Therefore, continuous careful surveillance and monitoring of possible tick-borne pathogen introductions is important.Keywords: Tick; Ixodes uriae; tick-borne pathogens; arboviruses; Borrelia spirochetes; Babesia apicomplexans.(Published: 20 October 2015)To access the supplementary material for this article, please see supplementary files in the column to the right (under Article Tools).Citation: Polar Research 2015, 34, 27466, http://dx.doi.org/10.3402/polar.v34.2746