Description: Publication date: Available online 9 October 2015 Source: Polar Science Author(s): Nobuo Kokubun, Won-Young Lee, Jeong-Hoon Kim, Akinori Takahashi Identifying marine features that support high foraging performance of predators is useful to determine areas of ecological importance. This study aimed to identify marine features that are important for foraging of chinstrap penguins ( Pygoscelis antarcticus ), an abundant upper-trophic level predator in the Antarctic Peninsula region. We investigated the foraging locations of penguins breeding on King George Island using GPS-depth loggers. Tracking data from 18 birds (4,232 dives), 11 birds (2,095 dives), and 19 birds (3,947 dives) were obtained in 2007, 2010, and 2015, respectively. In all three years, penguins frequently visited an area near a seamount (Orca Seamount) in Bransfield Strait. The percentage of dives (27.8% in 2007, 36.1% in 2010, and 19.1% in 2015) and depth wiggles (27.1% in 2007, 37.2% in 2010, and 22.3% in 2015) performed in this area was higher than that expected from the size of the area and distance from the colony (8.4% for 2007, 14.7% for 2010, and 6.3% for 2015). Stomach content analysis showed that the penguins fed mainly on Antarctic krill. These results suggest that the seamount provided a favorable foraging area for breeding chinstrap penguins, with high availability of Antarctic krill, possibly related to local upwelling.

Description: Publication date: Available online 9 October 2015 Source: Polar Science Author(s): Badanal Siddaiah Mahesh, Anish Kumar Warrier, Rahul Mohan, Manish Tiwari, Anila Babu, Aswathi Chandran, Rajesh Asthana, Rasik Ravindra Sediments from the pristine lakes of ice-free regions of Antarctica are a great source for proxies to reconstruct the effect of past-climate on the lake evolution and its response to Antarctic climate. A 50 cm long sediment core retrieved from Long Lake, a periglacial lake of Schirmacher Oasis in Dronning Maud Land was measured for elemental (C%, N% and C/N), isotopic (δ 13 C, δ 15 N) and particle size (sand-silt-clay percent) variation. The radiocarbon dated core spanning the last 48 cal ka BP has been deciphered for the lake's response to Antarctic climate. The C/N ratio (atomic ratio) predominantly indicates that the productivity has been autochthonous for majority of the down-core while the top 0–3 cm indicates that there has been addition of terrestrial organic matter into the lake system owing to longer ice-free conditions. The organic carbon shows significantly lower values (0.2%) throughout the glacial period and major part of the Holocene while the core-top values are consistent with the presence of a microbial mat which is reflected as higher organic carbon (12%). The δ 13 C and δ 15 N range from −33 to −9‰ and 2–18‰, respectively. The isotopic signals vary marginally for the entire glacial period (48–8 cal ka BP) suggesting an intense cold period. The gradual increase in C/N ratio, sand content and δ 13 C and decrease in δ 15 N beginning at about 6 cal ka BP suggest that the Long Lake experienced longer ice-free conditions owing to sustained warmer Holocene conditions suggesting that the ice-cover over the Long Lake persisted well through early-Holocene. The sand and silt percent shows inverse correlation likely reflecting the warmer and colder conditions. The Holocene is characterised by higher sand content owing to melting of ice due to warmer conditions. The Long Lake's response to Antarctic climate is reflected in its response to the ice-cover conditions which regulates the productivity and sedimentation in the lake system.

Description: Publication date: Available online 21 September 2015 Source: Polar Science Author(s): Cui Xiangbin, Sun Bo, Guo Jingxue, Wang Tiantian, Zhang Dong A new deep ice core is being drilled at the Chinese Kunlun Station in the Dome A region. As ice thickness and subglacial topography in the area are important factors of estimating ice core age, we investigated this region using ice-penetrating radars in three austral seasons during CHINARE 21, 24 and 29 expeditions. Previous results from radar measurements during CHINARE 21 and 24 played critical role in locating the deep ice core drilling site, basal ice age modeling and study of geomorphology of the Gamburtsev Subglacial Mountains. Recent radio echo sounding in the area during CHINARE 29 improved on the grid’s resolution, intended for improving modeling results. All radar data from three austral seasons were processed to build more detailed maps of ice thickness and subglacial topography. The new maps show high resolution ice thickness distribution varying between 1548 m and 3347 m in the area. The small scale subglacial valley glaciated terrain is shown in great detail, such as mountain peaks and ridges, main deep valley and its branches, valley steps and overdeepened concavities. The results are essential for accurate regional ice sheet modeling in the area to study basal processes and ice age modeling, as well as locating new deep ice core drilling site.

Description: Publication date: Available online 21 September 2015 Source: Polar Science Author(s): Manfred Bölter, Felix Müller The topic of resilience is continuously gaining rising evidence in ecosystem theory, research concepts. It has become a valuable tool in analyzing the relationships between natural environments and various stressors, like global warming or direct human impacts. The resilience approach offers possibilities for management strategies at different system levels and can open an eye to future aspects of ecosystem changes. Polar systems have been recognized as very sensitive ecological entities with respect to global and local impacts. Records of changes, used as alarm signals by governmental and non-governmental institutions, are well documented in various reports. However, it still renders difficult to concretely define thresholds of disturbances, i.e. ways to evaluate actual natural states and to what extent it can be modified before it changes to new domains of the trophic system or – the worst scenario – it collapses. Some dominant drivers of such changes are analyzed with respect to both polar environments and their possible effects at the short-term and long-term scale. The paper reviews actual attempts to study properties and possibilities of polar ecosystems for coping environmental change by assessing the chance of resilient dynamics under different human disturbances. Further, we suggest the application of a customized DPSIR framework (Driving forces, Pressures, States, Impacts, and Responses) for a better understanding of the interactions between systems states and changes.

Description: Publication date: Available online 10 September 2015 Source: Polar Science Author(s): Suchana Chavanich, Voranop Viyakarn, Daiki Nomura, Kentaro Watanabe The feeding habits of the Antarctic fish Pseudotrematomus bernacchii (Previous name: Trematomus bernacchii ) under the fast ice around Japanese Syowa Station were investigated between the summer of 2004/2005 and 2009/2010. The results showed that amphipods and krill were the major prey. However, there was a significant difference in the proportions of larger invertebrates such as squids, octopus and other crustaceans found in the fish stomachs between 2009/2010 and the previous years. Moreover, the percentage of amphipods and krill in fish stomachs declined over the 5-year period in all fish size classes. Several factors including sea ice melting, habitat and environmental changes may influence the pattern of feeding behavior.

Description: Publication date: Available online 4 September 2015 Source: Polar Science Author(s): Jae-Ho Jung, Kyung-Min Park, Gi-Sik Min, Helmut Berger, Sanghee Kim The morphology of an Antarctic soil population of Paraholosticha muscicola , type species of Paraholosticha , is described from life and after protargol preparation. The data agree rather well with that of relevant descriptions, but the total variability of several features is relatively high in this species. Paraholosticha ovata and P. lichenicola are very likely junior synonyms. In addition, we sequenced the SSU rRNA gene of P. muscicola and thus we can estimate for the first time the phylogenetic position of a member of the Keronopsidae, the sole hypotrichs that divide in cysts. The molecular data basically support the position derived from morphological concepts, that is, Paraholosticha muscicola branches off outside the Dorsomarginalia because kinety fragmentation and dorsomarginal rows are lacking. However, as in many other molecular analyses, discrepancies with morphology-based hypothesis are present. The misclassification of Paraholosticha and its sister-group Keronopsis in the Keronidae, with Kerona pediculus as type species, is discussed.

Description: Publication date: Available online 4 September 2015 Source: Polar Science Author(s): Yeadong Kim, Jihoon Jeong The Asian Forum for Polar Sciences (AFoPS), an international forum of Asian polar research institutes, was established for the advancement of polar sciences among its members in 2004. The Forum has served as an important medium of Asian collective endeavors for polar affairs in human and information exchange, research collaboration, and logistics cooperation for the last decade. The historical development of the AFoPS in retrospect can be divided into four phases: inception and establishment (2003-2004), growth and expansion (2005-2007), review and restructuring (2008-2011), and achievements and further measures (2012-2014). The progress of the AFoPS has not been linear and this trend will continue into the next decades. The Forum, however, clearly made achievements in this period of time, realizing multilateral research and logistics cooperation that would have been previously unimaginable; by doing so, it has laid the foundation for the future. Responsible for a great portion of the world’s polar activities, the AFoPS will rise to meet the expectations of the world by producing notable research output, initiating international cooperative programs, and supporting non-polar Asian countries with education and research collaboration. These are the tasks of the AFoPS for the next decade and they require strategy that promotes and facilitates collaboration in a practical way and draws attention of non-polar Asian countries to the polar sciences.

Description: Publication date: Available online 28 August 2015 Source: Polar Science Author(s): Yoshihiro Tomikawa, Kaoru Sato, Naohiko Hirasawa, Masaki Tsutsumi, Takuji Nakamura Balloon-borne observations of lower stratospheric water vapor were conducted with the Cryogenic Frostpoint Hygrometer (CFH) in July, September, and November 2013 at Syowa Station (69.0 o S, 39.6 o E) in the Antarctic. High-precision and high vertical resolution data of water vapor concentration up to an altitude of about 28km were obtained successfully except for a contamination in the observation of July 2013. A comparison between the CFH and coincident satellite (i.e., Aura/MLS) observations showed a good agreement within their uncertainty. A position of Syowa Station relative to the stratospheric polar vortex edge varied depending on both the observation date and altitude. Temperature and pressure histories of the observed air parcels were examined by 10-day backward trajectories. These analyses clearly demonstrated that most air parcels observed in the lower stratosphere above Syowa Station experienced final dehydration inside the polar vortex. On the other hand, a clear signature of rehydration or incomplete dehydration was also observed around a 25 hPa pressure level in the observation of July 2013.

Description: Publication date: Available online 15 August 2015 Source: Polar Science Author(s): Ichiro Takeuchi A new species of amphipod crustacean (Amphipoda: Phtisicidae), Paraproto mccaini n. sp. is described based on specimens collected from south of Elephant Island, the South Shetland Islands near the Antarctic Peninsula. This species was first reported as Paraproto condylata ( Haswell, 1885 ) [ sensu lato ], recorded from a temperate region of Australia. Paraproto mccaini n. sp. is distinct from P. condylata [ sensu stricto ] by an elongated head with pereonite 1, presence of a mid-lateral projection on pereonites 2- 4, and lack of a distal round projection on the propodus of gnathopod 2. Paraproto differs from Pseudoprotomima , the most phylogenetically similar genus, in having gills on pereonites 3 and 4.

Description: Publication date: Available online 8 August 2015 Source: Polar Science Author(s): Shoji Kusunoki, Ryo Mizuta, Masahiro Hosaka Future changes in precipitation intensity over the Arctic were calculated based on three-member ensemble simulations using a global atmospheric model with a high horizontal resolution (60-km grid) for the period 1872–2099 (228 years). During 1872–2005, the model was forced with observed historical sea surface temperature (SST) data, while during 2006–2099, boundary SST data were estimated using the multi-model ensemble (MME) of the Coupled Model Intercomparison Project, Phase 3 (CMIP3) model, assuming the A1B emission scenario. The observed annual mean precipitation (PAVE), the simple daily precipitation intensity index (SDII), and the maximum 5-day precipitation total (R5d) averaged over the Arctic increased monotonically towards the end of the 21st century. Over the Arctic, the conversion rate from moisture to precipitation per one degree temperature increase is larger for PAVE than for R5d, which is opposite to the tropics and mid-latitudes. The observed increases in PAVE, SDII, and R5d can be partly attributed to an increase in water vapor associated with increasing temperatures, and to an increase in the horizontal transport of water vapor from low to high latitudes associated with transient eddies.