The University Centre in Svalbard (Norwegian: Universitetssenteret på Svalbard AS; UNIS) is a Norwegian state-owned limited company that is involved in research and provides some university-level education in Arctic studies. The company is wholly owned by the Ministry of Education and Research, and the universities of Oslo, Bergen, Tromsø, NTNU and NMBU appoint the board of directors. It is led by a director appointed by the board for a four-year term. The centre is the world’s northernmost research and higher education institution, in Longyearbyen at 78° N latitude. The courses offered fall into four main science disciplines: Arctic biology, Arctic geology, Arctic geophysics and Arctic technology.
Marine nematodes dominate the meiofauna of benthic sediments, but few have investigated their trophic roles. We studied the eukaryote diet composition of nematodes from sediments on the Arctic Barents Sea shelf, shelf break and adjacent Nansen Basin, during four seasons, using prey metabarcoding of the 18S ribosomal RNA gene. Monhysterida (n = 35 individuals), Chromadorida (34), Araeolaimida (27) and Enoplida (22) nematodes were most frequently observed across the study area, and diets were composed of diverse metazoan, fungal, and protist prey. In contrast to ambient sediment communities, prey followed a strong seasonal pattern, and ordination indicated two distinct seasonal prey clusters. In March and May prey were characterized by high relative abundances of fungi (42
Off Northeast Greenland, the Wandel Sea extends between Morris Jesup Rise and Gakkel Ridge as an area where rapid environmental changes are driven by complex interactions between the ice sheet, ocean, and sea ice. However, geological data that can illuminate long-term trends are virtually missing. We hereby present novel sub-bottom and swath bathymetry data acquired on the Arctic margin of Northeast Greenland in 2024. They allow characterization of the regional sedimentary features, which provide unique insights into the recent cryospheric and oceanographic history of Northeast Greenland. Mega-scale glacial lineations and iceberg plough marks point to extensive glacial activity on the continental shelf, where potentially two northeastward flowing ice streams reached the shelf edge during recent glacial periods. Extensive mass transport deposits in the area are interpreted as glaciogenic debris flows, thus, further supporting recent cross-shelf glaciations. Finally, the described asymmetric channel-levee systems and sediment waves suggest a southward-flowing oceanic bottom current as the Arctic Throughflow. The results of this study provide context for further research concerning sedimentary control factors along the Northeast Greenland margin.
Arctic ecosystems are facing increases in heavy summer rainfall events and increased year-to-year hydrological variability. However, the evidence base of impacts of heavy rainfall on Arctic vegetation is limited. The role of seasonal timing in determining heavy rainfall impacts on plant growth and the legacy impacts of such effects have not been quantified. We set up an irrigation experiment in several sites on the High Arctic archipelago of Svalbard, in which we simulated a doubling of average summer rainfall (50 mm) in individual additions of 10 mm at different timings throughout the season (early or late summer). Plant growth and phenology indicators (normalized difference vegetation index, vegetation height, specific leaf area, and senescence) of key plant species were monitored under irrigation and in the years after to capture legacy effects. Late-summer irrigation delayed end-of-summer declines in NDVI compared with control and early-summer irrigation treatments. We found subtle positive legacy effects of early as well as late-summer irrigation on NDVI in the following growing season. Irrigation only delayed senescence in Salix polaris at sites and moments where rainfall treatment compensated for low soil moisture levels prior to senescence. Other vegetation parameters did not show significant responses. Positive associations of plant growth variables with local soil moisture were strongest in late summer. Synthesis. Our findings indicate that the impact of heavy rainfall events on plant growth in the High Arctic is mediated by seasonal timing and local moisture regimes. Late-summer rainfall can extend the growing season for plants experiencing end-of-season water-limitation by delaying onset of senescence. Local soil moisture retention capacity appears to regulate this potential for growing season extension, implying that outcomes may be scalable across (micro)topographical and pedological gradients. The existence of subtle legacy effects suggests that previous years' hydrological conditions may marginally affect following years' plant growth.
The Lower Thermosphere–Ionosphere (LTI) is the interface region between the Earth’s atmosphere and space. It is modulated by the energy and momentum deposition from the magnetosphere above and by the impacting waves from the lower atmosphere. The LTI region is defined by the co-existence and interaction of neutral and ionized species within the region’s electric and magnetic fields. This interplay results in unique and complex interactions between neutrals and plasmas, that are not fully understood and quantified to this date. In this paper we present an overview of some of the most important open questions related to ion/neutral coupling and the resulting collisional electrodynamics, collisional energetics and collisional dynamics processes. We outline the key reasons for addressing these questions, and highlight methodologies that can lead to their closure in the upcoming years.
