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Arctic sea ice incorporates and transports sediment, releasing it back into the water column during the melting season. This process constitutes an important aspect of marine sediment transport and biogeochemical cycling. Sediment incorporation into sea ice is considered to occur mainly through underwater interaction between frazil ice and resuspended sediment, referred to as suspension freezing. However, harsh environmental conditions have greatly limited field observations of this phenomenon. Analysis of mooring data from a coastal polynya in the northeastern Chukchi Sea, in conjunction with coastal ice radar and meteorological data, indicates that suspension freezing is a key mechanism for sediment entrainment into sea ice. During polynya episodes, acoustic backscatter data obtained by an Acoustic Doppler Current Profiler showed the presence of frazil ice from the surface down to 20‐ to 25‐m depth, coinciding with in situ and potential supercooling. Underwater frazil ice persisted over 1 week under windy, turbulent water column conditions. A combination of the turbidity and Acoustic Doppler Current Profiler backscatter data revealed upward sediment dispersion associated with strong currents during the polynya episodes. The fact that frazil ice and resuspended sediment were detected at the same depth and time strongly suggests the interaction between ice crystals and sediment particles, that is, suspension freezing. Plain Language Summary: Sea ice incorporates, transports, and releases particulate matter. These processes constitute an important aspect of the biology, biogeochemical cycling, and pollutant transport in polar oceans. Seafloor sediments serve as the most important source of such particulate matter; however, the process of sediment incorporation into sea ice remains poorly explored. We conducted a year‐long study of sediment resuspension and entrainment processes, using underwater sensors deployed in the Chukchi Sea. During winter, wind‐driven offshore transport of sea ice created area of open water and newly grown thin ice that persisted for several days, so‐called coastal polynya or flaw lead system. Our sensors recorded small ice crystals, so‐called frazil ice, that formed in the water column when water temperatures were below freezing point (supercooling). During some of these episodes, sediment was resuspended from the seafloor and dispersed upward by the strong currents, bringing it into water depths at which frazil ice was encountered. Such conditions provide for opportunities that allow frazil ice crystals or aggregates to capture resuspended sediment, a process referred to as suspension freezing. Based on this study, we propose that suspension freezing commonly occurs in shallow Arctic polynyas, serving as a key process of sediment incorporation into sea ice. Key Points: ADCP data provided evidence of frazil ice penetrating to ~25 m in the water column during supercooling episodes in a coastal polynyaThe combination of acoustic and optical measurements revealed underwater frazil ice‐sediment interaction at water depths of 10–25 mSuspension freezing can often occur in shallow polynyas and is suggested to be the dominant process of sediment incorporation into sea ice [ABSTRACT FROM AUTHOR]

Climate change, ocean acidification (OA) and the subsequent changes in marine productivity may affect fisheries and eventually the whole economy in the Arctic. We analysed how changes in climate and ocean pH under scenarios of anthropogenic CO2 emissions are likely to affect the economics of marine fisheries in the Arctic. We applied a Dynamic Bioclimate Envelope Model (DBEM) and outputs from four different Earth System Models (ESMs) to project future changes in the distribution and maximum catch potential of exploited marine fishes and invertebrates. We projected that total fisheries revenue in the Arctic region may increase by 39% (14-59%) by 2050 relative to 2000 under the Special Reports on Emission Scenario (SRES) A2. Simultaneously, total fishing costs, fishers' incomes, household incomes and economy-wide impacts in the Arctic are also projected to increase. Climate change with OA is expected to reduce the potential increases in catch and the economic indicators studied herein. Although the projections suggest that Arctic countries are likely to be 'winners' under climate change in comparison with tropical developing countries, the effects of OA will lower the expected future benefits in the Arctic. The predicted impacts are likely to be conservative as we consider only the direct effects of OA on fishes and calcifiers, of which there are only a few in the Arctic. Results of this study would be useful for designing effective adaptation strategies to climate change and measures to mitigate the potential negative impacts of OA in the Arctic. [ABSTRACT FROM AUTHOR]

DNA sequences offer powerful tools for describing the members and interactions of natural communities. In this study, we establish the to-date most comprehensive library of DNA barcodes for a terrestrial site, including all known macroscopic animals and vascular plants of an intensively studied area of the High Arctic, the Zackenberg Valley in Northeast Greenland. To demonstrate its utility, we apply the library to identify nearly 20 000 arthropod individuals from two Malaise traps, each operated for two summers. Drawing on this material, we estimate the coverage of previous morphology-based species inventories, derive a snapshot of faunal turnover in space and time and describe the abundance and phenology of species in the rapidly changing arctic environment. Overall, 403 terrestrial animal and 160 vascular plant species were recorded by morphology-based techniques. DNA barcodes ( CO1) offered high resolution in discriminating among the local animal taxa, with 92% of morphologically distinguishable taxa assigned to unique Barcode Index Numbers ( BINs) and 93% to monophyletic clusters. For vascular plants, resolution was lower, with 54% of species forming monophyletic clusters based on barcode regions rbcL a and ITS2. Malaise catches revealed 122 BINs not detected by previous sampling and DNA barcoding. The insect community was dominated by a few highly abundant taxa. Even closely related taxa differed in phenology, emphasizing the need for species-level resolution when describing ongoing shifts in arctic communities and ecosystems. The DNA barcode library now established for Zackenberg offers new scope for such explorations, and for the detailed dissection of interspecific interactions throughout the community. [ABSTRACT FROM AUTHOR]

The article presents a study which examines whether cold climate is related to poorer health in diverse Arctic populations. The research involves finding the mean January and July temperatures for 27 Arctic regions based on weather station data from 1961-1990 and its relation to health outcome assessed by correlation and multiple linear analyses. Furthermore, it shows that cold climate is related to infant deaths, deaths from respiratory diseases, and total fertility rate.

The role of the Arctic in future global change processes is predicted to be important because of the large carbon (C) stocks contained in frozen soils and peatlands. Lakes are an important component of arctic landscapes although their role in storing C is not well prescribed. The area around Kangerlussuaq, SW Greenland (66–68°N, 49–54°W) has extremely high lake density, with ∼20 000 lakes that cover about 14% of the land area. C accumulation rates and standing stock (kg C m−2), representing late- to mid-Holocene C burial, were calculated from AMS 14C-dated sediment cores from 11 lakes. Lake ages range from ∼10 000 cal yr bp to ∼5400 cal yr bp, and reflect the withdrawal of the ice sheet from west to east. Total standing stock of C accumulated in the studied lakes for the last ∼8000 years ranged from 28 to 71 kg C m−2, (mean: ∼42 kg C m−2). These standing stock determinations yield organic C accumulation rates of 3.5–11.5 g C m−2 yr−1 (mean: ∼6 g C m−2 yr−1) for the last 4500 years. Mean C accumulation rates are not different for the periods 8–4.5 and 4.5–0 ka, despite cooling trends associated with the neoglacial period after 4.5 ka. We used the mean C standing stock to estimate the total C pool in small lakes (<100 ha) of the Kangerlussuaq region to be ∼4.9 × 1013 g C. This C stock is about half of that estimated for the soil pool in this region (but in 5% of the land area) and indicates the importance of incorporating lakes into models of regional C balance at high latitudes. [ABSTRACT FROM AUTHOR]

The role of northern fulmars (Fulmarus glacialis) was investigated for the transport of nutrients and trace elements to a series of 10 ponds located along a gradient of seabird influence below a fulmar colony in the high Arctic (Cape Vera, Devon Island, Canada). Phosphorus, Cd, K, Zn, and As were identified as seabird-derived elements, having both a high concentration in fulmar guano and a low concentration in background pond sediments (i.e., a high biogenic enrichment factor). Fluxes of these elements were highest in the pond closest to the colony and declined exponentially with distance. Sediments in several of the ponds exceeded Canadian Sediment Quality Guidelines for the Protection of Aquatic Life set for As (5.9 mg/kg) and Cd (0.6 mg/kg), and in the pond closest to the colony, which receives the most seabird subsidies, sediments contained 343 mg/kg Zn, exceeding the threshold for probable adverse biological effects. Although nutrient subsidies from fulmars create an Arctic oasis at Cape Vera, which supports a variety of flora and fauna, the same biological transport pathway puts at risk some of these species by creating sedimentary As, Cd, and Zn concentrations at this remote site similar to those usually observed only near industrialized locations. [ABSTRACT FROM AUTHOR]

Twenty-five essential and nonessential elements were analyzed in Arctic seabirds to study the influence of phylogeny, tissue, Arctic region, and diet on avian element accumulation and to identify co-occurrence among metals. Muscle and liver concentrations were positively correlated, generally being higher in liver than in muscle, and generally did not differ by sex. Zinc showed the highest absolute concentrations in all samples (mean, 11.2-26.7 μg/g in muscle, depending on species and area), followed by copper (5.2-7.5 μg/g), arsenic (0.5-5.4 μg/g), selenium (1.0-5.8 μg/g), rubidium (1.4-2.2 μg/g), and cadmium (0.04-1.2 μg/g). Mercury levels ranged from 0.05 to 0.8 μg/g in muscle. The concentrations varied among species (dovekie [Alle alle], black guillemot [Cepphus grylle], thick-billed murre [Uria lomvia], black-legged kittiwake [Rissa tridactyla], northern fulmar [Fulmaris glacialis], ivory gull [Pagophila eburnean], Thayer's gull [Larus thayeri], and glaucous gull [Larus hyperboreus]), and between the northern Baffin Bay (Canada) and the Barents Sea, depending on the element. Whereas some elements (e.g., mercury and zinc) increased in absolute and standardized concentrations with trophic level in the northern Baffin Bay, most elements showed no relationship with trophic level or other dietary descriptors. In absolute concentrations, nonessential elements differed between regions, whereas essential elements differed among species but not within a species across the two regions. Standardized concentrations (element pattern) of both essential elements and nonessential elements generally did not differ between regions but was highly species specific and, thus, determined by the phylogenetic element regulation capacity. The usefulness of multivariate ordination in element wildlife studies is illustrated, which provides additional insight regarding element co-occurrence in wildlife, allows inclusion of species with low sample number, and reduces the possibility of type II errors created by low sample size. [ABSTRACT FROM AUTHOR]

Offers a detailed analysis of intraseasonal (within season) and interannual (between years) temperature variability for the whole Arctic for the period 1951?1990. For this purpose four temperature variables were used: average (TMEAN), maximum (TMAX) and minimum (TMIN) temperatures, and the diurnal temperature range (DTR). The source data for the analysis were the daily TMAX and TMIN for ten stations representing almost all climatic regions in the Arctic. The authors assert that the absence of significant changes in intraseasonal and interannual variability of TMEAN, TMAX, TMIN and DTR is additional evidence (besides the average temperature) that in the Arctic during this period no tangible manifestations of the greenhouse effect can be identified.

Discusses the use of remotely sensed data to study the nature of atmosphere-cryosphere interactions in the Polar Basin and how they contribute to an understanding of climate change and variability. Role of remote sensing; Remote sensing capabilities for cryosphere monitoring proposed for the satellite systems of the mid-1990s; More.

The article focuses on a report about the reduction in the acidification of arctic region released by the Arctic Monitoring and Assessment Programme in Oslo, Norway in late 2006. According to the report, various regulations has led to reduction in the level of sulphur dioxide and improvement in acidified lakes. The report mainly records the trends in haze and sulphur and nitrogen oxide pollution in various regions. There is a growing concern over increasing emission of nitrogen oxides as it has the potential to increase arctic haze and change the climate of the region.

Provides information on a meeting of several scientists in Seattle, Washington in November 2003 to chart a groundbreaking research plan for the Arctic and promote the future research aims of the Study of Environmental Arctic Change (SEARCH) program. Importance of the further investigation of polar feedbacks to greater global climate resolution; Types of terrestrial laboratories recommended by researchers in addition to marine surveys; Current contributions for freshwater survey and SEARCH planning efforts.