Polar Research (E-Journal)
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Post-moult distribution and abundance of white-fronted geese and Canada geese in West Greenland in 2007
No full textRapid increases in North American Canada geese (Branta canadensis) summering in West Greenland since the mid-1980s compare with declines in the endemic population of white-fronted geese (Anser albifrons flavirostris) nesting in the same region since 1999 (wintering in Europe). To provide information on the distribution and abundance of the two species in Greenland during the prelude to the autumn migration back to winter quarters, we here report on the first ever post-moult aerial surveys of West Greenland between 64° and 73°N (from regular transects and transit reconnaissance flights in August 2007), which located 1888 Greenland white-fronted geese and 6071 Canada geese. Strip transect surveys found 733 Greenland white-fronted geese and 1318 Canada geese in the 993 km2 surveyed, which, given a white-fronted goose global population of 23 200 in winter 2007/08, suggests more than 41 500 Canada geese inWest Greenland post-moult in 2007. Virtually no geese were found south of 66°N. The Eqalummiut nunaat–Nassuttuup nunaa and Naternaq Ramsar wetlands of international importance, and lowland Disko Island, Saqqaqdalen and Svartenhuk supported the highest densities of both species. Results confirmed that areas important for both species during spring, nesting and moulting periods retain high densities of post-moulting geese. Canada and white-fronted geese rarely occurred together within 2.5 km ¥ 400 m transect sectors, as found during breeding surveys. Only in western Svartenhuk and western Disko were there Canada goose concentrations that could potentially support an intensive autumn hunt, whilst avoiding disturbance to white-fronted geese
Review of The North Pole, by Kathan Brown
No full textAt fi rst glance a medium brick sized book entitled The North Pole seems a promising read to anyone interested in the Arctic, such as this reviewer. Unfortunately it does not quite deliver according to expectations, presuming you expect solid information about the polar region. If, however, you are particularly interested in the personal experiences of Arctic tourists with a dash of environmental concern, this book may not be a complete waste of time
One-year records of current and bottom pressure in the strait between Nordaustlandet and Kvitøya, Svalbard, 1980-81
No full textWe have obtained one year of measurements from a subsurface instrumented mooring carrying two current meters and one bottom pressure recorder in the strait between Nordaustlandet and Kvitøya in the northeastern Svalbard archipelago. The observations show a mixed tide with typical amplitudes 0.4 db and 1Ocm sec-I. The semidiurnal tide is characterized by a progressive wave propagating toward the south. together with a cross-channel baroclinic mode. The annual average (non-tidal) current is less than 2 cm secc’ toward the north-east, suggesting that the transport into the Arctic Ocean is approximately 0.2 x lo6 m3 SK
Karstic surface in the Lower Permian sabkha sequence of the Gipshuken Formation, central Spitsbergen, Svalbard
No full textSome unusual karst structures occur in the upper part of the evaporite-dominated sequence of the Gipshuken Formation. This Lower Permian unit is characterized by interbedded anhydrite and dolomites, and is now interpreted in terms of superimposed sabkha cycles. The karst structures are found in the inner part of Skansdalen in Dickson Land, and have not yet been observed elsewhere in corresponding horizons in Svalbard. These structures, often seen as linked hemispheroids. consist of almost pure anhydrite and are here interpreted as representing the remnants of consolidated sabkhas; the original sabkha plain was flooded and partly dissolved, and abandoned channels between the hemispheroidal structures were then filled with sediments of later sabkha cycle. The younger sediments which fill the relief between and above the structures contain small enterolithic folds which indicate primary formed anhydrite. Anhydrite is still the most common subsurface mineral in these sulphatic deposits. an3 there is no evidence of gravitational or tectonic movements within these beds
Cold-season soil respiration in response to grazing and warming in High-Arctic Svalbard
No full textThe influence of goose grazing intensity and open-topped chambers (OTCs) on near-surface quantities and qualities of soil organic carbon (SOC) was evaluated in wet and mesic ecosystems in Svalbard. This study followed up a field experiment carried out in 2003–05 (part of the project Fragility of Arctic Goose Habitat: Impacts of Land Use, Conservation and Elevated Temperatures). New measurements of soil CO2 effluxes, temperatures and water contents were regularly made from July to November 2007. SOC stocks were quantified, and the reactivity and composition measured by basal soil respiration (BSR) and solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Results reveal variations in soil carbon cycling, with significant seasonal trends controlled by temperature, water content and snow. Experimental warming (OTCs) increased near-surface temperatures in the growing season, resulting in significantly higher CO2 effluxes. Different grazing intensities had no significant effects on observed soil respiration, but BSR rates at the mesic site (13– 23 mg CO2 g soil-C-1 h-1) were highest with moderate grazing and lowest in the absence of grazing. A limited effect of grazing on microbial respiration is consistent with a lack of significant differences in SOC quantity and quality. NMR data show that the composition of A-horizon SOC is dominated by O-N-alkyl C and alkyl C groups, and less by carboxyl C and aromatic C groups: but again no marked variation in response to grazing was evident. It can be concluded that two years after a goose grazing experiment, SOC cycling was less than the natural variation within contrasting vegetation types
Antarctic clouds
No full textSensitivity studies with global climate models show that, by their influence on the radiation balance, Antarctic clouds play a major role in the climate system, both directly at high southern latitudes and indirectly globally, as the local circulation changes lead to global teleconnections. Unfortunately, observations of cloud distribution in the Antarctic are limited and often of low quality because of the practical difficulty in observing clouds in the harsh Antarctic environment. The best surface observations suggest that the fractional cloud cover at the South Pole is around 50–60% in all seasons, whereas the cloud cover rises to around 80–90% close to the coast of the continent. Microphysical observations of cloud parameters are also very sparse in the Antarctic. However, the few measurements that do exist show predominantly ice-crystal clouds across the interior, with mixed-phase clouds close to the coasts. Crystal sizes vary from 5 to 30 mm (effective radius) in the interior to somewhat larger ice crystals and water drops near the coast. A wide range of crystal shapes is observed at all sites. This review considers the available cloud observations and highlights the importance of Antarctic clouds and the need for better observations in the future
Low protein variability and genetic similarity between populations of the polar bear (Ursus maritimus)
No full textBlood samples from a total of 460 polar bears (Ursus maritimus) from various Arctic regions, but excluding the USSR, were collected during the period 1967-1981 to study electrophoretic variation in different proteins. Two hundred and one samples from Alaska, 48 from the Canadian Arctic, 89 from Svalbard, and 21 from Northeast Greenland were collected during the period 1967-1973 and were analysed by vertical polyacrylamide gel electrophoresis to study transferrin and hemoglobin polymorphism, Thirty-one samples collected in 1974 were analysed by starch gel electrophoresis for 14 enzyme systems in serum and red blood cells. Seventy samples collected from Alaska, the Barents Sea, and Canada in 198&81 were studied by starch gel electrophoresis, and further analysed for protein variation by thin-layer isoelectric focusing, horizontal polyacrylamide gel electrophoresis, and two-dimensional electrophoresis. In all, about 75 loci were analysed for variation. The degree of protein and enzyme variation in the polar bear was observed to be relatively low. Starch gel electrophoresis revealed variation of an unidentified serum protein. The distribution of this protein indicates a closer connection between bears in Alaska and Canada compared to those in Greenland and Svalbard, but the differences were not significant. As in many large mammals, the information from protein variation in polar bears has limited use for management purposes. We could not find any simple system usable for identification of discrete populations. On the basis of protein variation as sole criterion, the populations investigated could not be separated. Possible explanations for the uniformity of blood proteins can be exchange of bears between geographical areas and/or a high selective pressure in polar bears
The importance of winter in annual ecosystem respiration in the High Arctic: effects of snow depth in two vegetation types
No full textWinter respiration in snow-covered ecosystems strongly influences annual carbon cycling, underlining the importance of processes related to the timing and quantity of snow. Fences were used to increase snow depth from 30 to 150 cm, and impacts on respiration were investigated in heath and mesic meadow, two common vegetation types in Svalbard. We manually measured ecosystem respiration from July 2007 to July 2008 at a temporal resolution greater than previously achieved in the High Arctic (campaigns: summer, eight; autumn, six; winter, 17; spring, nine). Moisture contents of unfrozen soil and soil temperatures throughout the year were also recorded. The increased snow depth resulted in significantly higher winter soil temperatures and increased ecosystem respiration. A temperature–efflux model explained most of the variation of observed effluxes: meadows, 94 (controls) and 93% (fences); heaths, 84 and 77%, respectively. Snow fences increased the total non-growing season efflux from 70 to 92 (heaths) and from 68 to 125 g CO2-C m-2 (meadows). The non-growing season contributed to 56 (heaths) and 42% (meadows) of the total annual carbon respired. This proportion increased with deeper snow to 64% in both vegetation types. Summer respiration rates were unaffected by snow fences, but the total growing season respiration was lower behind fences because of the considerably delayed snowmelt. Meadows had higher summer respiration rates than heaths. In addition, non-steady state CO2 effluxes were measured as bursts lasting several days during spring soil thawing, and when ice layers were broken to carry out winter efflux measurements
Seismic and radar investigations of Fourcade Glacier on King George Island, Antarctica
No full textTo determine P- and S-wave velocities, elastic properties and subglacial topography of the polythermal Fourcade Glacier, surface seismic and radar surveys were conducted along a 470-m profile in November 2006. P- and S-wave velocity structures were determined by travel-time tomography and inversion of Rayleigh wave dispersion curves, respectively. The average P- and S-wave velocities of ice are 3466 and 1839 m s-1, respectively. Radar velocities were obtained by migration velocity analysis of 112 diffraction events. An estimate of 920 kg m-3 for the bulk density of wet ice corresponds to water contents of 5.1 and 3.2%, which were derived from the average P-wave and radar velocities, respectively. Using this density and the average P- and S-wave velocities, we estimate that the corresponding incompressibility and rigidity of the ice are 6.925 and 3.119 GPa, respectively. Synergistic interpretation of the radar profile and P- and S-wave velocities indicates the presence of a fracture zone above a subglacial high. Here, the P- and S-wave velocities are approximately 5 and 3% less than in the ice above a subglacial valley, respectively. The S-wave velocities indicate that warmer and less rigid ice underlies 10–15 m of colder ice near the surface of the glacier. Such layering is characteristic of polythermal glaciers. As a relatively simple non-invasive approach, integration of P-wave tomography, Rayleigh wave inversion and ground-towed radar is effective for various glaciological studies, including the elastic properties of englacial and subglacial materials, cold/warm ice interfaces, topography of a glacier bed and location of fracture zones