1928 research outputs found
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An assessment of China’s participation in polar subregional organizations
Full text linkInternational cooperation is vital for the polar regions. China’s past polar cooperation has tended to focus on intergovernmental and bilateral mechanisms rather than regional cooperation. However, regional and subregional cooperation is playing an increasing role in the polar regions with the rapid development of geopolitics and global climate change. Involvement in three subregional polar organizations—the Asian Forum for Polar Sciences (AFoPS), the Pacific Arctic Group (PAG), and the China-Nordic Arctic Research Center (CNARC)—in the last two decades reflects China’s improved skills and flexibility in participating in international polar cooperation and represents an exercise in the “win-win” principle under China’s Arctic policy. This paper presents a review of the development of polar subregional cooperation, examines China’s participation in three of subregional organizations and provides feasible suggestions for China’s future engagement with these organizations
Physical-chemical and biological control of the zooplankton community in the Amundsen Sea, Antarctica
Full text linkZooplankton are critical components of the Southern Ocean ecosystems, acting as trophic links between phytoplankton and higher-level species. The composition, abundance, carbon biomass, and community structure of zooplankton were studied based on samples collected with a Norpac net (330-μm mesh, 0.5-m2 net mouth) during the austral summers of 2017/2018. Three communities in a latitudinal gradient were identified based on both a zooplankton abundance dataset and a biomass dataset. Zooplankton were mainly dominated by small copepods (e.g., Oithona similis and Ctenocalanus citer) in terms of abundance, while the total zooplankton biomass was dominated by krill (Euphausia superba and Thysanoessa macrura) and large copepods (e.g., Calanoides acutus, Calanus propinquus, and Metridia gerlachei). Redundancy analysis demonstrated that environmental factors (e.g., temperature, nitrate, dissolved oxygen, ammonium) accounted for more than 40% of the variance in zooplankton abundance/biomass. This indicates that physical processes significantly affect the zooplankton community. Meanwhile, a significant positive correlation was found between the abundance/biomass of zooplankton and that of dominant phytoplankton and ciliates, which suggests trophic links among various plankton functional groups. Our results reveal that both physical processes and biological factors shape the community structure of zooplankton in the Amundsen Sea
Modified Circumpolar Deep Water inflow to the Dotson-Getz Trough in the summers of 2020 and 2022
Full text linkThe melting of the West Antarctic Ice Shelf has increased since the 1990s, driven by the relatively warm Circumpolar Deep Water (CDW) that penetrates into the West Antarctic Ice Shelf cavities through submarine glacial troughs across the continental shelf. In this study, temperature, salinity, and current velocity data obtained by the Chinese National Antarctic Research Expedition in the Dotson-Getz Trough (DGT) shows clear differences in distribution of modified Circumpolar Deep Water (mCDW) in the summers of 2020 and 2022. Combined with contemporaneous wind data and additional temperature and salinity data from instrumented seals, the processes and mechanisms responsible for this variation are discussed. Compared with 2020, there is a significant increase in mCDW thickness in 2022, with a doubling of total heat content as the mCDW inflow path across the DGT shifts towards the eastern bank. We propose that a southward shift in the westerly winds in the summer of 2022 moved the upper oceanic divergence zone southward towards the continental slope, promoting the upwelling of mCDW above 500 m. Concurrently, stronger westerly winds over the continental slope strengthened the eastward undercurrent, increasing the transport of this mCDW and its associated heat content to the DGT through Ekman dynamics. These observations show there is strong interannual variability in the strength, path and extent of mCDW inflows to the DGT and that care must be taken when planning observation programs for long-term monitoring of the oceanic heat input to the ice shelves of this globally significant region
No wasted energy - Uncovering the electricity efficiency potential in Iceland
Full text linkIceland is a country of abundant renewable energy resources. Renewable energy for both electricity and heat have been easily available at a low cost. More recently, however, the country’s energy supply, particularly the supply of electricity, has come under increased pressure. Electricity demand has been growing steadily for a number of years (about 15% over the last 10 years and about 40% in sectors other than
aluminium), and power curtailments have become a more frequent occurrence. This has spurred a prominent conversation about the security of electricity supply
The roles of phosphate in shaping the structure and dynamics of Antarctic soil microbiomes
Full text linkOne major consequence of global warming in the Antarctic region is increased ice-free zones. Subsequent colonization of these ice-free areas by penguins alters their biogeochemistry, with one prominent example being elevation of inorganic phosphate concentrations around feces depositions. The complex soil biochemistry in the region makes it difficult to define the causal factors of these changes using common research approaches. Here, we addressed the effects of phosphate alone on microbiome structure and dynamics over time by adding external phosphate to selected soils in the Antarctic region. We then analyzed the soil bacterial community composition and diversity using 16S rRNA amplicon sequencing and compared these data with phosphate levels. Parallel geochemical analysis revealed changes in nine soil geochemical factors upon phosphate addition, all of which were relevant to microbiome structure, with soil pH showing the highest correlation. Links between geochemical factors and composition were identified, as were interactions between bacterial taxa. Additionally, Sphingobacteriia, Sphingobacteriales and Chitinophagaceae were found to be more abundant in phosphate-treated soils. Co-occurrence network analysis revealed significantly increased levels of associations in all major network properties over time after phosphate supplementation. Therefore, we conclude phosphate addition has diverse effects on Antarctic soil microbiomes
Performance of surface radiation products of Greenland Ice Sheet using in-situ measurements
Full text linkRadiation is the direct energy source of the surface natural environment and the main driving force of climate change. It has increasingly become an important meteorological factor affecting the surface heat exchange and glacier mass balance, especially in the glacier changes of the Greenland Ice Sheet (GrIS). Due to the harsh climatic conditions of GrIS and sparse observed data, it has become an important way to obtain radiation data from reanalysis datasets. However, the applicability of these radiation data on GrIS is uncertain and worth exploring. In this work, we evaluate five reanalysis datasets (the fifth generation of European Centre for Medium-Range Weather Forecasts (ERA5), European Centre for Medium-Range Weather Forecasts Interim Reanalysis (ERA-Interim), Japanese 55-year Reanalysis (JRA55), National Centers for Environmental Prediction Reanalysis II (NCEP2) and Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2)) during 1997–2022 using observations from 26 Program for Monitoring the Greenland Ice Sheet (PROMICE) automatic weather stations (AWSs) and 3 K-transect AWSs on GrIS. The conclusions are as follows: ERA5 has the best performances in downward shortwave radiation (SWD) as well as downward and upward longwave radiation (LWD and LWU), but the performance is not the best in upward shortwave radiation (SWU). Based on the radiation budget analysis with ERA5 during 1979–2022, the fluctuation of longwave radiation is greater than that of shortwave radiation. The seasonal variation of shortwave radiation is obvious, while that of longwave radiation is small. The increasing trend of longwave radiation may result from global warming, in which ice sheets absorb more solar radiation and the surface heats up significantly, emitting more LWU
Synthesis Report on the Environmental Impacts of Research and Logistics in the Polar Regions
Full text linkPolar sciences are crucial to understand the effects of climate change. 6 out of 9 eco-tipping points identified by the IPCC are situated in the polar regions. Potential rising sea levels, altered weather patterns and changes in sea-currents are all connected to environmental change in the polar regions
The Outer Limits of the Extended Continental Shelf of the United States of America
Full text linkThis Executive Summary provides information on the outer limits of the U.S. continental shelf in areas beyond 200 nautical miles from the territorial sea baselines (referred to as the “extended continental shelf”). The United States has delineated these outer limits in accordance with the relevant provisions of the 1982 United Nations Convention on the Law of the Sea (Convention) and the Scientific and Technical Guidelines of the Commission on the Limits of the Continental Shelf
2023 Global Youth Forum Results Report
Full text linkThe 2023 cycle of the World Food Forum (WFF) demonstrated an incredible acceleration toward a better food future for all. In its third year, the Forum brought together many tens of thousands of participants both in-person and online, and shared ideas and
solutions that reached billions around the globe. This is an unprecedented movement that is stepping up in the face of unprecedented climatic and agrifood systems challenges.
Currently, agrifood systems account for one-third of human-caused greenhouse gas emissions, 90 percent of global deforestation and 70 percent of water use globally. They are the single greatest cause of terrestrial biodiversity loss, putting pressure on
food value chains. We also lose or waste enough food to feed 1.3 billion hungry people every year
