Polar Research (E-Journal)
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Special issue in connection with Professor John 0. Krog’s 65th birthday
No full textJohn Krog was born in Meldal, Norway on the 29th of August, 1918. He graduated (cand. real.) at the University of Oslo in 1949, with zoology as his major subject, and in 1964 obtained his doctorate at the same university
The effect of sea-ice loss on beluga whales (Delphinapterus leucas) in West Greenland
No full textAn aerial survey was conducted to estimate the abundance of belugas (Delphinapterus leucas) on their wintering ground in West Greenland in March–April 2006 and 2008. The survey was conducted as a double platform aerial line transect survey, and sampled approximately 17% of the total survey area of ca. 125 000 km2. The abundance of belugas was 10 595 (95% confidence interval 4904–24 650). The largest abundance was found at the northern part of Store Hellefiske Bank, at the eastern edge of the Baffin Bay pack ice, a pattern similar to that found in eight systematic surveys conducted since 1981. A clear relationship between decreasing sea-ice cover and increasing offshore distance of beluga sightings was established from all previous surveys, suggesting that belugas expand their distribution westward as new areas on the banks of West Greenland open up earlier in spring with reduced sea-ice coverage or early annual ice recession. This is in contrast to the relatively confined distribution of belugas near the coast in limited open areas in the early 1980s, when sea-ice cover was greater. However, the effects of the changes in coastal availability of belugas can also be observed with the correlation between catches from the local Inuit hunt and sea-ice cover, where the catches increased significantly with increasing sea-ice coverage during the period 1954–2006. These results, based on nearly 30 years of dedicated survey effort, are among the first available evidence showing a shift in distribution of an Arctic cetacean in response to changes in sea-ice coverage
Late Quaternary foraminiferal record in Murchisonfjorden, Nordaustlandet, Svalbard
No full textBenthic foraminiferal assemblages from Nordaustlandet, Svalbard, are described for the first time with the objective of reconstructing the palaeoenvironmental conditions in the area during the late Quaternary. Investigations were carried out on marine deposits exposed along the southern shores of Murchisonfjorden. Five foraminiferal assemblages (A1–A5), representing different palaeoenvironmental conditions, were identified from the marine intervals, i.e., the Cassidulina reniforme–Elphidium albiumbilicatum assemblage (A1) from the Early Weichselian, the Islandiella helenae–Cibicides lobatulus assemblage (A2) from the Early Weichselian, the Cibicides lobatulus–Cassidulina reniforme assemblage (A3) from marine isotope stage 3, the Elphidium albiumbilicatum assemblage (A4) from the early Holocene and the Astrononion gallowayi assemblage (A5) from the mid-Holocene. Assemblages A1–A5 are compared with modern and fossil Quaternary assemblages from Arctic regions. Particularly notable is the fact that a well-defined Middle Weichselian assemblage in Svalbard is described for the first time, i.e., the Cibicides lobatulus– Cassidulina reniforme assemblage. All the assemblages from Nordaustlandet represent glacier-distal, inner-shelf environments with an open connection to the ocean. The results reveal the occurrence of three marine intervals (ice-free periods) in the north-western part of Nordaustlandet during the Weichselian, as well as ice-free conditions during most of the Holocene. A comparison of the assemblages from Nordaustlandet with previously published foraminiferal zones from onshore sections elsewhere in Svalbard show some degree of similarity, but also show considerable variation in species compositions, presumably caused by local environmental differences
Seasonal variation and source areas of airborne lead-210 at Ny-Ålesund in the High Arctic
No full textHigh-volume aerosol particle samples were collected onto glass-fibre filters at Mount Zeppelin Global Atmosphere Watch station, Ny-Ålesund, Svalbard, in 2001–05. The filters were assayed for lead-210 (210Pb) by measuring the alpha particles of its in-grown daughter nuclide polonium-210 (210Po). The observed 210Pb activity concentrations at Mount Zeppelin vary between <4 and 1060 mBq m-3, with an arithmetic mean of 130 mBq m-3 and a median of 74 mBq m-3. The lowest 210Pb activity concentrations are found during summer and the highest are found in winter. This variation is caused by seasonal differences in the mixing conditions of the troposphere, the level of precipitation and the speed of atmospheric chemistry induced by solar radiation. The performed source area analysis, which is based on air mass back trajectories, indicated that in summer, 210Pb can be used as a tracer for air masses coming into contact with land areas within the past 5 days. In winter this cannot be performed because of the accumulation of 210Pb-carrying aerosol particles into the Arctic atmosphere during the Arctic night. But even in winter a low 210Pb activity concentration indicates that the associated air mass has had little if any contact with land areas
Review of Snow and climate: physical processes, surface energy exchange and modeling, edited by Richard L Armstrong & Eric Brun
No full textAt its peak extent, snow can cover more than 40% of the Northern Hemisphere land surface, greatly affecting surface exchange processes, and hence global climate. Snow is one of the most dynamic surface types and its distinct physical properties imply that it requires special attention when modelling short-term weather conditions and long-term climate. Natural hazards such as avalanches, reduced visibility from blowing snow, and snowmelt-induced flooding all necessitate the precise monitoring and modelling of snowpack evolution and attendant atmospheric conditions. It is therefore critical that we develop a better understanding of snow accumulation/ablation processes and their impacts on climate
Review of 100 facts: polar lands; 365 penguins; Amazing Arctic & Antarctic projects you can build yourself; Apun: the Arctic snow; Matthew Henson: the quest for the North Pole; Polar bears in danger; Polar regions; Race to the South Poleetc.
No full textThe polar regions have captured the world’s attention, and children’s book authors and publishers are no exception. These dozen titles are just a sample of the bucketload of polar-themed children’s books that have been published during the last couple of years
Winter climate change at different temporal scales in Vaccinium myrtillus, an Arctic and alpine dwarf shrub
No full textSnow cover strongly influences plant growth in Arctic and alpine ecosystems. Snow characteristics and snowmelt timing are likely to change in a warmer climate. We studied year rings and shoot growth of the dwarf shrub bilberry (Vaccinium myrtillus), and species abundances of the vegetation, in response to early or late snowmelt at a study site in the Central Alps, near Davos, Switzerland. Snowmelt was manipulated on experimental plots for 3 and 30 years. Additional plots were set up along a natural snowmelt gradient, and at high and low elevation. Growth ring data showed an increasing trend in annual growth increment over the last 20 years, especially in the extraordinarily hot summer of 2003. Comparing high and low elevation sites, growth rings were wider at low elevation, but only in cold years. In years with relatively cold summers, however, xylem ring width was greater in plots with late rather than early snowmelt along the natural snowmelt gradient, possibly indicating drought stress in early snowmelt plots. Snow cover had a strong influence on species abundances along the natural snowmelt gradient, and change (not yet significant) was beginning to be seen in plots with 30 years of snow manipulation. Our results indicate that beneficial effects of early snowmelt for shrub growth may be offset in cold summers. Although early snowmelt prolongs the growing season, harsh conditions and frost events early in the growing season may become more likely, and hamper plant growth, and this could affect plant growth in all Arctic and alpine snow-dominated ecosystems
Release of reactive organic halogens by the brown macroalga Saccharina latissima after exposure to ultraviolet radiation
No full textThe brown macroalga Saccharina latissima (Linnaeus) C.E. Lane, C. Mayes, Druehl & G.W. Saunders (formerly Laminaria saccharina [L.] Lamouroux) was exposed to ultraviolet radiation (UVR) in the mW UV-A and mW UV-B range in the laboratory for up to 28 days. The release rates of volatile organohalogens, such as chloroform, bromoform, dibromomethane and methyl iodide, were determined. From these rates, the total emission of reactive organic halogens was calculated. The results revealed that exposure to UVR significantly affected the emission of reactive organic halogens by the macroalga under investigation. An increase in the release of reactive organic iodine was observed for the algal species. In contrast, for reactive organic bromine and reactive organic chlorine, a decrease in emission by the macroalga was observed. Apparently, the potential for increased levels of UVR resulting from further ongoing destruction of the stratospheric ozone layer may increase the importance of marine macroalgae in atmospheric reactions involving organic halogens
The Chief Editor welcomes you to a free, green Polar Research
No full textPolar Research is now an open-access journal, freely available to anyone with a computer and connection to the internet. Now readers around the world will have free access to the latest scientific articles on climate, biodiversity, polar history and other diverse topics that are investigated in the polar regions. Doing away with a regular print edition has slashed the journal’s carbon footprint. As Polar Research’s Chief Editor for the last 12 years, I’ve shepherded the journal through several significant transitions, but none compares to this milestone in the publication’s 28-year history. (Published: 1 January 2010) Citation: Polar Research 2011, 30: 5935 - DOI: 10.3402/polar.v30i0.593