Foraging ecology of ringed seals (Pusa hispida), beluga whales (Delphinapterus leucas) and narwhals (Monodon monoceros) in the Canadian High Arctic determined by stomach content and stable isotope analysis

Jordan K. Matley,

Terry A. Dick,

Aaron T. Fisk

Опубликована Май 18, 2015

Stomach content and stable isotope analysis (δ13C and δ15N from liver and muscle) were used to identify habitat and seasonal prey selection by ringed seals (Pusa hispida; n=21), beluga whales (Delphinapterus leucas; n=13) and narwhals (Monodon monoceros; n=3) in the eastern Canadian Arctic. Arctic cod (Boreogadus saida) was the main prey item of all three species. Diet reconstruction from otoliths and stable isotope analysis revealed that while ringed seal size influenced prey selection patterns, it was variable. Prey-size selection and on-site observations found that ringed seals foraged on smaller, non-schooling cod whereas belugas and narwhals consumed larger individuals in schools. …

Modelling snow ice and superimposed ice on landfast sea ice in Kongsfjorden, Svalbard

Caixin Wang,

Bin Cheng,

Keguang Wang,

Sebastian Gerland,

Olga Pavlova

Опубликована Авг. 24, 2015

Snow ice and superimposed ice formation on landfast sea ice in a Svalbard fjord, Kongsfjorden, was investigated with a high-resolution thermodynamic snow and sea-ice model, applying meteorological weather station data as external forcing. The model shows that sea-ice formation occurs both at the ice bottom and at the snow/ice interface. Modelling results indicated that the total snow ice and superimposed ice, which formed at the snow/ice interface, was about 14 cm during the simulation period, accounting for about 15% of the total ice mass and 35% of the total ice growth. Introducing a time-dependent snow density improved the modelled results, …

Patterns and trends of macrobenthic abundance, biomass and production in the deep Arctic Ocean

Renate Degen,

Antje Boetius,

Thomas Brey,

Andrey Vedenin,

Manuela Gusky

Опубликована Авг. 26, 2015

Little is known about the distribution and dynamics of macrobenthic communities of the deep Arctic Ocean. The few previous studies report low standing stocks and confirm a gradient with declining biomass from the slopes down to the basins, as commonly reported for deep-sea benthos. In this study, we investigated regional differences of faunal abundance and biomass, and made for the first time ever estimates of deep Arctic community production by using a multi-parameter artificial neural network model. The underlying data set combines data from recent field studies with published and unpublished data from the past 20 years, to analyse the …

Observing the Arctic Ocean carbon cycle in a changing environment

Leif G. Anderson,

Robie W. Macdonald

Опубликована Дек. 10, 2015

Climate warming is especially pronounced in the Arctic, which has led to decreased sea-ice coverage and substantial permafrost thawing. These changes have a profound impact on the carbon cycle that directly affects the air–sea exchange of carbon dioxide (CO2), possibly leading to substantial feedback on atmospheric CO2 concentration. Several recent studies have indicated such feedback but the future quantitative impact is very uncertain. To minimize these uncertainties, there is a need for extensive field studies in order to achieve both a better process understanding as well as to detect probable trends in these processes. In this contribution, we describe a …

The significant inputs of trace elements and rare earth elements from melting glaciers in Antarctic coastal waters

Intae Kim,

Guebuem Kim,

Eun Jung Choy

Опубликована Май 7, 2015

To evaluate the impact of modern glacier melting on the chemical enrichment of Antarctic coastal waters, we measured trace elements, including dissolved iron (Fe) and rare earth elements (REEs), together with dissolved inorganic nitrogen, phosphorous, silicate and dissolved organic carbon (DOC) in ice, snow and coastal seawater of Marian Cove in the northernmost part of Antarctica (62°S). There was an increase in the concentrations of Fe and other trace elements (Al, Mn, Cr, Ni, Co, Pb and REEs) between the bay mouth and the glacier valleys. Good correlations between salinity and these chemical elements indicate that the trend was mainly …

Mapping lichen distribution on the Antarctic Peninsula using remote sensing, lichen spectra and photographic documentation by citizen scientists

Paula Casanovas,

Martin Black,

Peter Fretwell,

Peter Convey

Опубликована Дек. 26, 2015

On the Antarctic Peninsula, lichens are the most diverse botanical component of the terrestrial ecosystem. However, detailed information on the distribution of lichens on the Antarctic Peninsula region is scarce, and the data available exhibit significant heterogeneity in sampling frequency and effort. Satellite remote sensing, in particular the use of the Normalized Difference Vegetation Index (NDVI), has facilitated determination of vegetation richness and cover distribution in some remote and otherwise inaccessible environments. However, it is known that using NDVI for the detection of vegetation can overlook the presence of lichens even if their land cover is extensive. We tested the …

Arctic climate change in an ensemble of regional CORDEX simulations

Torben Koenigk,

Peter Berg,

Ralf Döscher

Опубликована Март 9, 2015

Fifth phase Climate Model Intercomparison Project historical and scenario simulations from four global climate models (GCMs) using the Representative Concentration Pathways greenhouse gas concentration trajectories RCP4.5 and RCP8.5 are downscaled over the Arctic with the regional Rossby Centre Atmosphere model (RCA). The regional model simulations largely reflect the circulation bias patterns of the driving global models in the historical period, indicating the importance of lateral and lower boundary conditions. However, local differences occur as a reduced winter 2-m air temperature bias over the Arctic Ocean and increased cold biases over land areas in RCA. The projected changes are dominated by …

Ice - ocean coupled computations for sea-ice prediction to support ice navigation in Arctic sea routes

Liyanarachchi Waruna Arampath De Silva,

Hajime Yamaguchi,

Jun Ono

Опубликована Ноя. 23, 2015

With the recent rapid decrease in summer sea ice in the Arctic Ocean extending the navigation period in the Arctic sea routes (ASR), the precise prediction of ice distribution is crucial for safe and efficient navigation in the Arctic Ocean. In general, however, most of the available numerical models have exhibited significant uncertainties in short-term and narrow-area predictions, especially in marginal ice zones such as the ASR. In this study, we predict short-term sea-ice conditions in the ASR by using a mesoscale eddy-resolving ice–ocean coupled model that explicitly treats ice floe collisions in marginal ice zones. First, numerical issues associated …

The role of atmospheric precipitation in introducing contaminants to the surface waters of the Fuglebekken catchment, Spitsbergen

Katarzyna Kozak,

Krystyna Kozioł,

Bartłomiej Luks,

Stanisław Chmiel,

Marek Ruman,

Mariusz Marć,

Jacek Namieśnik,

Żaneta Polkowska

Опубликована Ноя. 23, 2015

Although the Svalbard Archipelago is located at a high latitude, far from potential contaminant sources, it is not free from anthropogenic impact. Towards the Fuglebekken catchment, in the southern part of Spitsbergen, north of Hornsund fjord, contaminants can be transported from mainland pollution sources. In the precipitation and surface water collected in the catchment, the following elements were detected and quantified: Ag, Al, As, B, Ba, Bi, Ca, Cd, Co, Cr, Cu, Cs, Mo, Ni, Pb, Sb, Se, Sr, Tl, U, V and Zn. Additionally, pH, electrical conductivity and total organic carbon (TOC) were determined in those samples. The acidic …

Application of remotely piloted aircraft systems in observing the atmospheric boundary layer over Antarctic sea ice in winter

Marius O. Jonassen,

Andreas Scholtz,

Timo Vihma,

Astrid Lampert,

Gert König-Langlo,

Christof Lüpkes,

Priit Tisler,

Barbara Altstädter

Опубликована Окт. 8, 2015

The main aim of this paper is to explore the potential of combining measurements from fixed- and rotary-wing remotely piloted aircraft systems (RPAS) to complement data sets from radio soundings as well as ship and sea-ice-based instrumentation for atmospheric boundary layer (ABL) profiling. This study represents a proof-of-concept of RPAS observations in the Antarctic sea-ice zone. We present first results from the RV Polarstern Antarctic winter expedition in the Weddell Sea in June–August 2013, during which three RPAS were operated to measure temperature, humidity and wind; a fixed-wing small unmanned meteorological observer (SUMO), a fixed-wing meteorological mini-aerial vehicle, and an …