Beschreibung: The visible reflectance spectroscopy (VRS) and chlorophyll a concentration were determined in three sediment profiles collected from East Antarctica to investigate the potential application of VRS in reconstructing historical changes in Antarctic lake primary productivity. The results showed that the appearance of a trough at 650–700 nm is an important marker for chlorophyll a concentration and can therefore be used to distinguish the sedimentary organic matter source from guano and algae. The measured chlorophyll a content had significant positive correlations with the trough area between 650 and 700 nm, and no distinct trough was found in the sediments with organic matter completely derived from guano. Modelling results showed that the spectra spectrally inferred chlorophyll a content, and the measured data exhibit consistent trends with depth, showing that the dimensionless trough area can serve as an independent proxy for reconstructing historical fluctuations in the primary production of Antarctic ponds. The correlation of phosphorus (P) with measured and inferred chlorophyll a contents in ornithogenic sediments near penguin colonies indicates that the change in primary productivity in the Antarctic ponds investigated was closely related to the amount of guano input from these birds. Keywords : Reflectance spectroscopy; ornithogenic sediments; chlorophyll a ; Antarctic ponds; primary productivity; VRS. (Published: 27 December 2013) Citation: Polar Research 2013, 32 , 19932, http://dx.doi.org/10.3402/polar.v32i0.19932

Beschreibung: Monitoring ice-sheet snowmelt is fundamental to understanding global climate change. A simple and automated snowmelt detection process is critical to the establishment of an ice-sheet snowmelt monitoring system. However, different ice-sheet snowmelt detection methods are based on a variety of thresholding schemes using different melt signals for dry and wet snow; these complicate the regular operation of an ice-sheet snowmelt monitoring. We propose an automated melt signal detection method developed using melt signals derived from the cross-gradient polarization ratio snowmelt detection method over Greenland and the wavelet transformation-based snowmelt detection method over Antarctica. Initial results indicate that the proposed method not only increases computational efficiency, practicability and operability but is also more accurate. Keywords: Ice sheet; snowmelt detection; radiometer; cross-gradient polarization ratio; wavelet transformation; generalized Gaussian model. (Published: 27 December 2013) To access the supplementary material for this article, please see Supplementary files in the column to the right (under Article Tools) Citation: Polar Research 2013, 32 , 19746, http://dx.doi.org/10.3402/polar.v32i0.19746

Beschreibung: Of all the polar heroes of the 19th century, Sir John Franklin might be regarded as the most tragic one. He was appointed the commander of a well-organized Arctic expedition in 1845, equipped with all that should be needed for surviving in the frozen wilderness, included two ships loaded with a thousand books and three years’ worth of food supplies. His order was to sail through and to map the North-west Passage. But he never returned with his men. Their fate will forever be a mystery. Though there were reports on some of his men from indigenous people in the years after, the greatest mystery is what caused the deaths of Franklin and his men. One hundred and forty years later, in 1997, one of many discovery expeditions concluded that blade-cut marks on the bones of some of the crew found on King William Island proved the rumours to be true, that the Franklin expedition ended in cannibalism. (Published: 20 December 2013) Citation: Polar Research 2013, 32 , 23457, http://dx.doi.org/10.3402/polar.v32i0.23457

Beschreibung: The author, Paul Wassmann, is a professor of marine biology at the University of Tromsø, and the designer, Rudi Caeyers, is a photographer and graphic designer at the same university. Svalbard life is a generously illustrated coffee-table book on the Svalbard Archipelago and surrounding seas. (Published: 11 December 2013) Citation: Polar Research 2013, 32 , 23400, http://dx.doi.org/10.3402/polar.v32i0.23400

Beschreibung: Inland water systems are generally supersaturated in carbon dioxide (CO 2 ) and are increasingly recognized as playing an important role in the global carbon cycle. The Arctic may be particularly important in this respect, given the abundance of inland waters and carbon contained in Arctic soils; however, a lack of trace gas measurements from small streams in the Arctic currently limits this understanding.We investigated the spatial variability of CO 2 evasion during the summer low-flow period from streams and rivers in the northern portion of the Kolyma River basin in north-eastern Siberia. To this end, partial pressure of carbon dioxide ( p CO 2 ) and gas exchange velocities ( k ) were measured at a diverse set of streams and rivers to calculate CO 2 evasion fluxes. We combined these CO2 evasion estimates with satellite remote sensing and geographic information system techniques to calculate total areal CO 2 emissions. Our results show that small streams are substantial sources of atmospheric CO 2 owing to high p CO 2 and k , despite being a small portion of total inland water surface area. In contrast, large rivers were generally near equilibrium with atmospheric CO 2 . Extrapolating our findings across the Panteleikha-Ambolikha sub-watersheds demonstrated that small streams play a major role in CO 2 evasion, accounting for 86% of the total summer CO 2 emissions from inland waters within these two sub-watersheds. Further expansion of these regional CO 2 emission estimates across time and space will be critical to accurately quantify and understand the role of Arctic streams and rivers in the global carbon budget. Keywords: Arctic streams and rivers; CO 2 evasion; inland water surface area; Kolyma River; p CO 2 ; Siberia (Published: 5 December 2013) Citation: Polar Research 2013, 32 , 19704, http://dx.doi.org/10.3402/polar.v32i0.19704

Beschreibung: Distribution and abundance of the amphipod Caprella septentrionalis in relation to environmental conditions and habitat preferences were investigated in a kelp forest in Hornsund, Spitsbergen. Three sampling sites differed in hydrodynamics, organic and inorganic suspension concentration, and sedimentation rates. None of these abiotic factors or species of a macroalgal host appeared to have a significant influence on C. septentrionalis abundance and size range. An apparent preference towards the blade parts of the algal thalli was observed. These results support the idea of C. septentrionalis as a generalist Arcticboreal species that takes advantage of the protective nature of kelp forests. Keywords: Caprellid amphipod; Arctic fjord; kelp forest; population structure; distribution; macroalgae (Published: 20 November 2013) Citation: Polar Research 2013, 32 , 21037, http://dx.doi.org/10.3402/polar.v32i0.21037

Beschreibung: The first investigations of the tardigrades of Svalbard took place in the early 20th century and 30 papers on the subject have been published to date. In this article, we summarize available information on the distribution of tardigrades in this Arctic archipelago with remarks on the dubious species and records. Additionally, we examined 28 new moss, lichen and soil samples collected from the islands of Nordaustlandet, Edgeøya and Prins Karls Forland. These samples yielded 324 specimens, 15 exuvia and 132 free-laid eggs belonging to 16 limnoterrestrial species (Heterotardigrada and Eutardigrada). These include five first records of water bears from Nordaustlandet, eight new records for Edgeøya and four for Prince Karls Forland. The most dense population of tardigrades was found in a sample with 253 specimens/10 g of dry material and the least dense population in a sample with three specimens/10 g of dry material. The most frequently recorded species in samples collected in this study were Testechiniscus spitsbergensis Scourfield, 1897, Macrobiotus harmsworthi harmsworthi Murray, 1907, and M. islandicus islandicus Richters, 1904. This article also provides the first ever scanning electron microscope photomicrographs of Tenuibiotus voronkovi Tumanov, 2007. Keywords: Checklist; Edgeøya; new species; Prins Karls Forland; soil fauna; Svalbard biodiversity (Published: 20 November 2013) To access the supplementary material for this article, please see Supplementary files  in the column to the right (under Article Tools). Citation: Polar Research 2013, 32 , 20886, http://dx.doi.org/10.3402/polar.v32i0.20886

Beschreibung: Maitri Station (70.76°S; 11.73°E) is located in Schirmacher Oasis, a coastal nunatak in north-central Dronning Maud Land covering an area of 35 km2. Here, we report results from the first magnetotelluric experiments and delineate the deep electrical conductivity structure under Schirmacher Oasis using the data acquired during the 24th Indian Antarctic Scientific Expedition. The magnetotelluric method has the advantage of shallow to deeper level coverage as the data acquisition covers a wide frequency band of 10 -3 10 3 Hz, permitting different penetration depths depending on the frequency and conductivity of the layer under investigation. The modelling results indicate the presence of a highly resistive (8000-10 000 ohm m) upper crust, which shows a lateral variation in thickness from 20 km (below site 6) in the east to 10 km (between sites 1 and 2) in the west. It is underlain by a less resistive (500-600 ohm m) lower crust. The highly resistive upper crustal structure supports the existing notion that western Dronning Maud Land is a stable, cratonic platform. Results of free-air gravity, seismic, geomagnetic and surface wave dispersion investigations in East Antarctica also indicate a cratonic-type crust. The results of our study allow us to identify a westward thinning of the upper crust with a marked boundary between sites 1 and 2. We also find evidence for the continuity of the Mozambique mobile belt in East Antarctica on the western side of Schirmacher Oasis. Keywords: Magnetotellurics; Schirmacher Oasis crustal structure; East Antarctica; Mozambique Belt; electrical conductivity (Published: 20 November 2013) Citation: Polar Research 2013, 32 , 17309, http://dx.doi.org/10.3402/polar.v32i0.17309

Beschreibung: Summer sea-ice cover in the Arctic varies largely from year to year owing to several factors. This study examines one such factor, the relationship between interannual difference in winter ice motion and ice area in the following summer. A daily-ice velocity product on a 37.5-km resolution grid is prepared using the satellite passive microwave sensor Advanced Microwave Scanning Radiometer*Earth Observing System data for the nine years of 2003-2011. Derived daily-ice motion reveals the dynamic modification of the winter ice cover. The winter ice divergence/convergence is strongly related to the summer ice cover in some regions; the correlation coefficient between the winter ice convergence and summer ice area ranges between 0.5 and 0.9 in areas with high interannual variability. This relation implies that the winter ice redistribution controls the spring ice thickness and the summer ice cover. Keywords: Sea ice; Arctic; satellite remote-sensing; interannual variability; AMSR-E data (Published: 8 November 2013) Citation: Polar Research 2013, 32 , 20193, http://dx.doi.org/10.3402/polar.v32i0.20193

Beschreibung: For over the past 50 years the tag line for Antarctica has been ‘‘A continent for peace and science,’’ leaving the rest of human activities rather adrift. Yes, there have been several valiant attempts to look at non-scientific subjects other than exploration history, geopolitics and international law but there was little on a continuing basis until the Scientific Committee on Antarctic Research (SCAR) agreed to host the Social Sciences Action Group and the History Expert Group. These offered a focus for a growing diversity of humanities scholars to come together and develop a stream of ideas complementary to the river of science running alongside. This book is the output from the first SCAR Social Sciences Action Group Workshop held at Gateway Antarctica in December 2011. (Published: 8 November 2013) Citation: Polar Research 2013, 32 , 23052, http://dx.doi.org/10.3402/polar.v32i0.23052