Фильтры: Язык: Английский × Тип статьи: Исследовательская статья ×

Øyvind Nordli,

Przemysław Wyszyński,

Herdis M. Gjelten,

Ketil Isaksen,

Ewa Łupikasza,

Tadeusz Niedźwiedź,

Rajmund Przybylak

Polar Research, Год журнала: 2020, Номер 39, С. 1 - 5

Опубликована Июнь 27, 2020

The Svalbard Airport composite series spanning the period from 1898 to the present represents one of very few long-term instrumental temperature series from the High Arctic. A homogenized monthly temperature series is available since 2014. Here we increase the resolution from a monthly to daily basis, and further digitization of historical data has reduced the uncertainty of the series. The most pronounced changes in the 120-year record occur during the last three decades. For the 1991–2018 period the number of days warmer than 0 and 5 °C has increased by 25 (21%) and 22 (59%), respectively, per year compared to …

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Henrik Kylin

Polar Research, Год журнала: 2020, Номер 39, С. 1 - 13

Опубликована Ноя. 6, 2020

In August 2005, marine debris was counted on two Arctic beaches in the Russian Far East. On the north coast of the Chukchi Peninsula east of Kolyuchin Bay, a beach stretch of ca. 2.4 km held a total of 736 items, 0.024 items m‑2, while no more than 0.0011 items m‑2, 12 items in total, were found on a beach stretch of ca. 1.2 km on southern Wrangel Island. The likely explanation for this difference is that the area around the mainland beach is ice-free for a longer period each year, but a contributing factor may be that late spring …

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Piotr Jadwiszczak

Polar Research, Год журнала: 2020, Номер 39, С. 1 - 15

Опубликована Июнь 11, 2020

Humeri have been useful bones in taxonomic determinations of extinct penguins. In the context of neontological taxonomic studies, however, their potential remains unsatisfactorily explored. Here, the variation of the overall closed-outline shape of 60 humeri, assignable to five genera of extant penguins, was investigated. A set of normalized outlines was quantified via elliptical Fourier analysis and subjected to linear discriminant analysis on principal component scores extracted from harmonic coefficients. These geometric representations proved to be a source of easily extractable genus-level taxonomic information. The constructed model provided meaningful discrimination between taxa: the first two linear discriminants captured almost 90% of …

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Ken Maeda,

Noriaki Kimura,

Hajime Yamaguchi

Polar Research, Год журнала: 2020, Номер 39, С. 1 - 15

Опубликована Ноя. 26, 2020

This paper examines the temporal and spatial change in the characteristics of sea-ice motion in the Arctic. Ice motion is generally expressed by a motion at a constant ratio (wind factor) of wind speed, with a certain angle (turning angle) from the wind direction, and ocean currents. This study aimed to reveal the recent changes of the wind factor and turning angle using satellite observation data. We first prepared a daily ice-velocity data set from data for 2003–2017 collected by the satellite microwave sensor Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) and its successor, AMSR2. Monthly values …

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Tracy A. Romano,

Laura A. Thompson,

Maureen V. Driscoll,

Ebru Unal,

Allison D. Tuttle,

Gayle Sirpenski,

Mary Ellen Mateleska,

Dale Wolbrink

Polar Research, Год журнала: 2021, Номер №40, С. 1 - 16

Опубликована Ноя. 26, 2021

Aquaria that care for and maintain belugas (Delphinapterus leucas) under professional care have the opportunity to contribute to the conservation of wild belugas through research, expertise in animal care and husbandry, and engaging and educating the public about threats to the species’ health and population sustainability. In an aquarium setting, belugas can be studied under controlled conditions, with known variables that are often difficult to discern when studying wild belugas. Information on nutrition, health status and environmental parameters can be easily obtained in a controlled setting. Biological samples are collected from professionally trained whales that voluntarily participate in informative experimental …

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Véronique Lesage

Polar Research, Год журнала: 2021, Номер №40, С. 1 - 18

Опубликована Сен. 3, 2021

Until 2012, the St. Lawrence Estuary beluga population was considered stable with about 1100 individuals. An abnormally high number of calves reported dead that year triggered a population status reassessment. This review article summarizes the findings from this reassessment and various studies subsequent to it and provides an updated analysis of carcass recovery rates up to 2019. The 2013 review indicated a decreased incidence of cancer in adults, suggesting positive impacts from the regulation of toxic substances (e.g., PCBs and PAHs). However, the review also revealed that the population initiated a decline of ca. 1% per year in the early …

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Christian Lydersen,

Kit M. Kovacs

Polar Research, Год журнала: 2021, Номер №40, С. 1 - 13

Опубликована Июль 15, 2021

The Norwegian Polar Institute initiated a research programme on white whales in 1995 to gather biological information relevant for the species’ management; the results of which are reviewed herein. Satellite tracking from two periods (1995–2001 and 2013–16), between which sea ice diminished markedly, showed that the whales in waters off the archipelago of Svalbard spent most of their time foraging close to tidewater glaciers. Transits between glaciers typically followed the coastline, with the whales moving rapidly from one glacier to another. During the later period, the whales spent some time out in the fjords, suggesting that they might be targeting …

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Valeria Vergara,

Jason Wood,

Véronique Lesage,

Audra Ames,

Marie-Ana Mikus,

Robert Michaud

Polar Research, Год журнала: 2021, Номер №40, С. 1 - 19

Опубликована Июль 15, 2021

Noise and anthropogenic disturbances from vessel traffic are an important threat to the recovery of the endangered St. Lawrence Estuary (SLE) beluga population. The consequences of acoustic masking could be particularly adverse in the case of critical vocalizations that maintain contact between mothers and their dependent but mobile calves. This study models the communication range of adults, sub-adults and newborn beluga contact calls in the presence and absence of vessels in an important summering area for this population. Ambient noise measurements, a composite beluga audiogram and apparent source levels of adult/sub-adult and newborn calls, informed the model. Apparent source levels …

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Jackson R. Ham,

Malin K. Lilley,

Malin R. Miller,

Heather M. Manitzas Hill

Polar Research, Год журнала: 2021, Номер №40, С. 1 - 13

Опубликована Июль 15, 2021

Belugas (Delphinapterus leucas) in managed care have been reported to show seasonal variation in socio-sexual behaviour, hormone levels and respiration rates; however, little is known about the social interactions of wild belugas when they are not in summer, near-shore congregations. To better understand if belugas show seasonal variation in social interactions, this study recorded the behaviour of 10 belugas (five females, five males, ranging from birth to 10 years of age) housed in managed care. Social interactions typically peaked in the summer months but persisted at very low levels during the rest of the year. Seasonal variation was most dramatic …

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Chuan Chen

Polar Research, Год журнала: 2022, Номер 41, С. 1 - 7

Опубликована Март 17, 2022

With China becoming more active in Greenland, worries abound that China might have hidden intentions. Despite that, the Greenlandic government is showing an increasing interest in deepening its cooperation with China. This article explores Greenland’s motivation behind its positive attitude towards China and examines whether China will be a threat to Greenland’s independence. For Greenland, China is both a deep-pocketed investor and a huge consumer market, especially in the mining, fishing and tourism industries. Greenland, therefore, views China as an important partner in its economic development, which is necessary for its independence from Denmark. Considering China’s relationship with Denmark, its …

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