1928 research outputs found
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Marginal weakening promoted rift propagation of the Petermann Ice Shelf in northwestern Greenland from 2016 to 2022
Full text linkIce-shelf rifts are precursors of glacier calving, and thus they serve as indicators of ice shelf instability, especially under oceanic and atmospheric warming conditions. Therefore, understanding the dynamic processes underlying rift propagation and the associated damage mechanisms is essential to evaluate ice-shelf instability and to predict glacier calving. In this study, we investigated the effect of marginal weakening on rift propagation on the ice shelf of the Petermann Glacier, among the largest in Greenland, during 2016–2022. First, we analyzed satellite optical images to monitor rift growth (length and width) by tracking the tip trajectory of three large rifts identified on the Petermann Ice Shelf. Then, we estimated rift depth using ArcticDEM and ICESat-2 data. Our results indicated consistent increases of the rift widths and depths over the study period, with mean values of 133 m·a−1 and 0.3 m·a−1, respectively. We also combined remote-sensing observations with an ice-sheet numerical model to calculate the stress and damage fields on the Petermann Ice Shelf and to assess the ice shelf margin stability and strength. We determined that damage and lateral shear in the fracture zone degraded ice shelf integrity by decreasing the contact length with the fjord wall. In conclusion, marginal weakening effectively promoted rift propagation on the Petermann Ice Shelf, increasing the risk of future glacier calving
Chemical composition of natural waters at Broknes Peninsula, Larsemann Hills, Antarctica
Full text linkThe article contributes to the study of the content of major and trace elements in various types of natural waters of the Broknes Peninsula, Larsemann Hills, Antarctica collected in January–February 2014 and 2020 during the 7th and 12th Belarusian Antarctic Expeditions. Samples of old (13 samples) and newly fallen snow (5), lakes (23) and groundwater (8) were analyzed. The content of 25 major and trace elements was determined using ICP-MS method, main anions was determined by titrimetric and turbidimetric methods. Good similarity chemical composition of snow, groundwater and lake waters in spite of differences in the content of major ions and trace elements has been obtained. The influence of marine salts on natural waters are analyzed, and their accumulation in lake waters especially in the endorheic small and shallow lakes in spite of ultra-oligotrophic atmospheric precipitates are shown. The spatial heterogeneity of groundwater and temporal and spatial heterogeneity of lake waters have been demonstrated. The results are important for understanding the variabilities of major and trace elements content in snow, groundwater and lake waters, and their relationship, as well as for identifying trends in their change, taking into account anthropogenic loads in the region and climate change
Arctic Art & Culture
Full text linkThe popular science review includes the materials about educational,
research, scientific and practical activity of the team from the Arctic State
Institute of Culture and Arts, their partners, and the Northern Forum
regions facilitating the modern image-making of the North and Arctic
Mesozooplankton distribution and diversity from the Bering Sea shelf to the Chukchi Sea
Full text linkIn recent decades, environmental changes in the Arctic have aroused widespread concern around the world. To better understand ecology issues such as ecosystem dynamics, the Arctic and the subarctic regions were integrated as the “pan-Arctic” region. In this study, mesozooplankton were sampled from the Bering Sea shelf to the northern Chukchi Sea during the 10th Chinese National Arctic Research Expedition in 2019. Based on the species composition and abundance, three geographical communities were identified: the Bering Sea shelf community (BSS), the Bering Strait transitional community (BST), and the Chukchi Sea shelf community (CSS). The BSS was characterized by Bering Sea oceanic species such as Eucalanus bungii; the BST was mainly composed of the pan-Arctic distributed Calanus glacialis, meroplankton of benthos, and neritic species such as Centropages abdominalis; copepods, especially the copepodite of C. glacialis, were predominant in the CSS community. The BSS community structure was strongly affected by the inflow of Bering Shelf Water, while those of BST and CSS were determined by the recruitment of local species. The zooplankton community structure is influenced by both advection and environmental changes such as warming and a prolonged productivity period. Here, it was difficult to distinguish the changes induced by climate change from the effects of the Bering Sea Water. The key to solving this problem is the accumulation of comparable data, which requires continuous monitoring of key species such as C. glacialis and Calanus hyperboreus
Variations and relations between chlorophyll concentrations and physical-ecological processes near the West Antarctic Peninsula
Full text linkThe West Antarctic Peninsula (WAP) region is one of the most productive marine ecosystems in the Southern Ocean that support the food web for phytoplankton, krill spawning or recruitment and several krill consumers at higher-trophic level like penguins and Antarctic fur seals. Characterized by channels and islands, the complex topography of the WAP generates interconnected circulation patterns, strongly influencing vertical stratification, nutrient availability and distribution of marine organisms. Additionally, rapid climate change associated with major climate modes like the Southern Annular Mode (SAM) and El Niño-Southern Oscillation (ENSO) has significant effects on long-term variations of physical environments and biological production. The objective of this study is to reveal the spatial-temporal variations of phytoplankton biomass in the WAP region and the modulating physical-ecological processes. By using 9-year hydrographic and ecological data of five transects collected by the Palmer Long-Term Ecosystem Research, the horizontal and vertical distributions of several physical and ecological properties, with a particular focus on chlorophyll (Chl) concentration were explored. Regression analysis among area-averaged properties and properties at single stations was performed to reveal the relationship between the interannual variations of physical and ecological processes. The correlation results showed that Chl concentration exhibited a positive relationship with both the circumpolar deep water (CDW) intrusion and vertical stratification, but showed a negative correlation with SAM at some specific stations. However, certain processes or mechanisms may only be dominant for specific stations and not applicable to the entire region. No single physical or ecological factors have been found to significantly influence the Chl distribution throughout the WAP region, which may be attributed to the heterogeneity of sea ice conditions, geometry and hydrodynamic features as well as variations in nutrient sources
Carbon isotope ratios of n-alkanoic acids: new organic proxies for paleo-productivity in Antarctic ponds
Full text linkPrimary productivity in the Antarctic aquatic environment with simple ecosystems is sensitive to climate and environmental fluctuations. We investigated δ13C values for n-alkanoic acids derived from phototrophic organisms in a lacustrine sediment core (IIL3) to indicate primary productivity in ponds on Inexpressible Island in the western Ross Sea, Antarctica. Short-chain n-alkanoic acids (C14–C18) were abundant in the IIL3 sediment profile. The carbon isotope ratios of short-chain n-alkanoic acids in the sediment samples and floating microbial mats were similar, indicating that the short-chain n-alkanoic acids in the IIL3 sediment profile predominantly originated from phototrophic organisms. The δ13C values for the short-chain n-alkanoic acids varied widely through the sediment profile, and 13C-enrichment of n-alkanoic acids was most likely related to high productivity due to carbon-limited conditions caused by enhanced photosynthetic efficiency. The δ13C values for the n-alkanoic acids changed over the past 3200 years in similar ways to organic proxies for aquatic productivity (n-alkanoic acid and sterol sedimentary fluxes). C16 n-alkanoic acid was enriched in 13C in periods of high aquatic productivity ~750–1650 and 3000–3200 a BP but depleted in 13C in periods of relatively low productivity ~150–600 and 2500–3000 a BP. The results indicated that carbon isotope ratios of lipids from phototrophic organisms could be used as new proxies to reconstruct paleo-productivity in Antarctic lakes and ponds and therefore improve our understanding of past climate changes
Looking North: The UK and the Arctic. The United Kingdom's Arctic Policy Framework
Full text linkThe Arctic is one of the most rapidly changing regions of the world. While the United Kingdom is not an Arctic State, we have a strong and enduring connection to the region as the Arctic’s nearest neighbour. We know that changes in the Arctic environment are already affecting the UK through global sea-level rise, changes to our climate and weather patterns, and threats to our shared biodiversity
Analysis of the record-breaking August 2021 rainfall over the Greenland Ice Sheet
Full text linkRainfall was witnessed for the first time at the highest area of the Greenland Ice Sheet on 14 August, 2021. The thermodynamic mechanisms supporting the rainfall are revealed by ERA5 reanalysis, in-situ and satellite data. We find that a strong southward intrusion of the polar vortex favored the maintenance of a deep cyclone over Baffin Island and an amplification of anticyclonic circulation over the southeastern ice sheet, which pumped warm and moist air toward Greenland from anomalously warm waters south of Greenland. Across a wide swath of the ice sheet, atmospheric uplift maintained above-melting and rainfall conditions via condensation and enhanced downward infrared irradiance. Without the low-level liquid clouds, the spatial extent and duration of the rainfall would have been smaller. Over the ice sheet topographic summit, the air temperature from the ground to 250 hPa level was ~2 °C higher than the previous record set on 12 July, 2012. Such events may occur more frequently with the decreased temperature contrast between the Arctic and the mid-latitude regions that drives highly amplified jet streams. Thus, this extreme event serves as a harbinger of a more likely wet surface condition across all elevations of the ice sheet
Arctic Art & Culture
Full text linkThe popular science journal includes the materials about educational, research, scientific and practical activity of the team from the Arctic State Institute of Culture and Arts and the Northern Forum regions facilitating the image-making of the North and Arctic
Norway's Chairship Arctic Council 2023 - 2025
Full text linkThe Arctic Council is the leading intergovernmental forum for Arctic
issues. The overall objective for Norway’s chairship of the Council will be to promote stability and constructive cooperation. We will focus on the core issues the Council deals with, including impacts of climate change, sustainable development, and efforts to enhance the well-being of people living in the region.
Norway will continue to support ongoing activities and projects run by the Council’s six working groups and its expert groups. Our national priorities are based on the first Arctic Council Strategic Plan, which was adopted in Reykjavik in 2021. Through four priority topics: the oceans; climate and environment; sustainable economic development; and people in the north, we will continue to pursue the long-term approach taken by the Council in its important efforts to ensure a vibrant and sustainable Arctic region. A mid-term review of the Strategic Plan is to be carried out in 2025