Fant 10084 publikasjoner. Viser side 396 av 404:
Intrusion Detection Systems (IDS) are critical in safeguarding network infrastructures against malicious attacks. Traditional IDSs often struggle with knowledge representation, real-time detection, and accuracy, especially when dealing with high-throughput data. This paper proposes a novel IDS framework that leverages machine learning models, streaming data, and semantic knowledge representation to enhance intrusion detection accuracy and scalability. Additionally, the study incorporates the concept of Digital Sovereignty, ensuring that data control, security, and privacy are maintained according to national and regional regulations. The proposed system integrates Apache Kafka for real-time data processing, an automatic machine learning pipeline (e.g., Tree-based Pipeline Optimization Tool (TPOT)) for classifying network traffic, and OWL-based semantic reasoning for advanced threat detection. The proposed system, evaluated on NSL-KDD and CIC-IDS-2017 datasets, demonstrated qualitative outcomes such as local compliance, reduced data storage needs due to real-time processing, and improved adaptability to local data laws. Experimental results reveal significant improvements in detection accuracy, processing efficiency, and Sovereignty alignment.
2025
Skogens helsetilstand i Norge. Resultater fra skogskadeovervåkingen i 2023
Skogens helsetilstand påvirkes i stor grad av klima og værforhold, enten direkte ved tørke, frost og vind, eller indirekte ved at klimaet påvirker omfanget av soppsykdommer og insektangrep. Klimaendringene og den forventede økningen i klimarelaterte skogskader gir store utfordringer for forvaltningen av framtidas skogressurser. Det samme gjør invaderende skadegjørere, både allerede etablerte arter og nye som kan komme til Norge i nær framtid. I denne rapporten presenteres resultater fra skogskadeovervåkingen i Norge i 2023 og trender over tid for følgende temaer:
(i) Landsrepresentativ skogovervåking;
(ii) Intensiv skogovervåking;
(iii) Overvåking av bjørkemålere i Troms og Finnmark;
(iv) Barkbilleovervåkingen 2023: økende fangster – særlig i stormrammede områder;
(v) Søk etter Ips-arter utenfor det nordvestlige hjørnet av granas utbredelse i Europa;
(vi) Askeskuddsyke;
(vii) Andre spesielle skogskader i 2023.
NIBIO
2025
2025
2025
2025
An important prerequisite for accurately characterizing economic exposure from climate change at the national scale is a spatial inventory of economic activity and value creation. Current options for such inventories are limited, being either spatially precise but economically bounded sector-specific or owner-specific datasets, or gridded gross domestic product (GDP) products with coarse spatial resolution and inadequate sectoral resolution. To address these limitations, we develop a map of national GDP with high spatial and sectoral resolution. We stress this with meter-scale flood hazard maps to characterize GDP at risk from flooding. We further couple this to a macroeconomic input–output analysis to use the new sectoral resolution to estimate the scope of indirect economic exposure to flood at a national scale.
2025
Environmental pollutants in the terrestrial and urban environment 2024
Samples from the urban terrestrial environment in the Oslo area were analysed for metals and a large number of organic environmental pollutants. The selected sample types that were analysed were soil, earthworm, fieldfare and sparrowhawk eggs, liver samples of brown rat, red fox and badger and blood serum from dog. Biomagnification potential was estimated based on detected data for relevant predator-prey pairs.
NILU
2025
This report gives an overview of annual statistics and results from the monitoring programme of ozone in EMEP 2023.
NILU
2025
State of the Climate in 2024: The Arctic
The Arctic environment in 2024 continued on a trajectory that has put it in a state far different from that of the twentieth century. Ongoing accumulation of greenhouse gases in the atmosphere continues to quickly warm the Arctic, resulting in rapid changes in the cryosphere that are driving cascading impacts to climate, ecological, and societal systems.
Many weather- and climate-related impacts in the Arctic are the result of compounding change, such as increased riverbank erosion, which is proximately due to increased river discharge from higher seasonal precipitation, yet is also exacerbated by thawing permafrost. However, even individual storms occur within very different ocean and ice conditions than were typically present in the late twentieth century. As a result, the impacts, including high winds, excessive precipitation, and coastal inundation, may be quite different nowadays, as exemplified by the October 2024 storm in northwest Alaska that produced severe coastal flooding in several communities. To share some of these impacts with a wider audience, select extreme weather impacts around the greater Arctic have been highlighted through the inclusion of sidebars in recent State of the Climate Arctic chapters (e.g., Benestad et al. 2023; Thoman et al. 2024).
Average surface air temperatures for the Arctic overall (poleward of 60°N) for 2024 averaged 1.27°C above the 1991–2020 baseline average, the second-highest annual temperature since records began in 1900. For the 11th consecutive year, the Arctic annual temperature anomaly was larger than the global average anomaly. Seasonally, summer (July–September) 2024 ranked as the third-highest average temperature, and autumn (October–December) 2024 saw its highest average temperature on record. At the subseasonal scale, an intense August heatwave brought all-time record high temperatures to parts of the northwest North American Arctic. Closely but not completely tied to spring and summer air temperature trends, productivity of tundra and boreal forest vegetation has dramatically increased in recent decades. Overall “tundra greenness” was the fifth highest since 1982. However, local to regional “browning” (reduced vegetation productivity) shows that disturbance factors besides temperatures, such as wildfire, can be important.
Sea ice is one of the most iconic features of the Arctic environment and plays an important role in regulating global climate, regional ecosystems, and economic activities. Sea ice extent typically reaches the annual maximum in March, and in 2024 the maximum was near the 1991–2020 average overall, but somewhat below average in the Barents Sea and Gulf of St. Lawrence. The annual minimum sea ice extent occurs in September, and in 2024 the September monthly average was the sixth lowest in the 46-year satellite record. The Northern Sea Route along the north Russia coast opened later than the past 20 years’ average due to persistent ice in the southwest Chukchi Sea. The Northwest Passage’s southern route through northwest Canada opened again this year and, quite unusually, the deepwater northern route was also almost entirely ice free at the end of September.
Decreasing sea ice extent during the late spring and summer months exposes larger areas of ocean to direct warming during the time of year of high incoming solar radiation. Poleward of 65°N, open ocean surface temperatures typically peak in August. In 2024, late summer sea surface temperature anomalies showed significant regional variability, with the waters in the Barents and Kara Seas 2°C–4°C warmer than normal. In sharp regional contrast, Chukchi Sea sea surface temperatures were the lowest in more than 40 years, while just to the east, sea surface temperatures in the southern Beaufort Sea were significantly above the 1991–2020 average.
Like sea ice, permafrost (soils or other earth materials that have remained frozen for at least two years) is an important feature of Arctic environments that occurs widely on land and throughout some submarine continental shelf areas that were exposed land during the last Ice Age (about 15,000 years ago). Unlike many parts of the Arctic environmental system, permafrost temperatures and the summer surface thaw zone cannot be monitored from space-borne instruments and depend on in situ measurements. While long-term observations are not available over most of the Asian Arctic, observations elsewhere show multi-decade warming of deeper permafrost continuing across the Arctic, with some sites in North America and Svalbard having seen their highest temperatures on record in 2024. Overall, colder permafrost is warming more rapidly; areas where permafrost temperatures are close to freezing have slower rates of warming as ice changes phase to liquid water.
Precipitation monitoring in the Arctic has historically been limited due to the lack of in situ measurements over the Arctic Ocean, a sparse land station network, and significant problems with solid precipitation undercatch because of the inherent difficulties in capturing solid precipitation in strong wind environments. Recent advances in reanalyses that combine observations and computer simulations now allow for more robust regional-scale precipitation analysis and historical comparisons. In 2024, Arctic-wide annual precipitation was the third highest on record, and summer (July through September) precipitation was the highest since 1950. Rivers serve as regional integrators of precipitation. Arctic river discharge overall for both 2023 and 2024 was close to the 1991–2020 average, albeit with significant differences across basins. For example, in North America, Mackenzie River discharge was well below average in both years, but Yukon River discharge was above average in both years; most basins in Eurasia saw above-normal discharge in 2024 but below-average discharge in 2023.
In much of the Arctic, snow is the dominant form of precipitation for most of the year, and the presence or absence of snow cover is a critical factor in many climate and environmental processes. During the 2023/24 snow season, there were marked regional and continental scale differences in snow cover duration. The snow cover duration varied from the shortest to date in the twenty-first century over parts of Canada to at or near the longest in this century in parts of the Nordic and Asian Arctic.
Melt and discharge from the Greenland Ice Sheet play important roles in modulating North Atlantic weather and climate. In 2024, the total amount of ice decreased, as it has every year since the late 1990s, but the loss was 50%−80% less than the 2002 − 23 annual average. This was the result of an unusual but persistent weather pattern that inhibited the development and persistence of warm air masses over Greenland during the summer. Ongoing monitoring of the Greenland Ice Sheet, which holds enough water to raise global sea levels by more than seven meters if entirely melted, is critical for understanding drivers of melt and ice sheet dynamics.
The Arctic stratosphere experienced two major sudden warming events early in 2024 that resulted in enhanced ozone transport into the region from lower latitudes. As a result, surface ultraviolet radiation was reduced in parts of the Asian Arctic in spring and the central Arctic and North America in summer.
Special Notes: The 1991–2020 baseline is used in this chapter except where data availability requires use of a different baseline. This chapter includes a focus on Arctic river discharge (section 5h), which alternates yearly with a section on glaciers and ice caps outside of Greenland.
2025
Skogens helsetilstand i Norge. Resultater fra skogskadeovervåkingen i 2024
Skog dekker nærmere 40 % av Norges landareal. Skogene bidrar til karbonbinding både over og under bakken, forsyner oss med råvarer, spiller en viktig rolle for friluftslivet og er leveområdet for utallige arter. Skogens viktige rolle som leverandør av slike økosystemtjenester forutsetter imidlertid et intakt skogøkosystem, en god skoghelse og en langsiktig og bærekraftig forvaltning.
Skogens helsetilstand påvirkes i stor grad av klima og værforhold, enten direkte ved tørke, frost, snø og vind, eller indirekte ved at klimaet påvirker omfanget og spredningen av soppsykdommer og insektangrep.
Klimaendringene og den forventede økningen i klimarelaterte skogskader gir store utfordringer for forvaltningen av framtidas skogressurser. Det samme gjør invaderende skadegjørere, både allerede etablerte arter og nye som kan komme til Norge i nær framtid. Uansett hvilke utfordringer skogen står overfor, er det viktig med langsiktige skogovervåkingsprogrammer for å kunne oppdage endringer og iverksette tiltak mot truslene. I denne rapporten presenteres resultater fra skogskadeovervåkingen i Norge i 2024 og trender over tid for følgende temaer:
1. Landsrepresentativ skogovervåking;
2. Intensiv skogovervåking;
3. Barkbilleovervåkingen 2024: Fortsatt høye fangster i stormrammede områder;
4. Overvåking av fremmede trelevende insekter;
5. Almesyken sprer seg til nye områder;
6. Overvåking av askas naturlige foryngelse i skog angrepet av askeskuddsyke;
7. Andre spesielle skogskader i 2024.
NIBIO
2025
2025
Methane in Svalbard (SvalGaSess)
Methane is a powerful greenhouse gas whose emission into the atmosphere from Arctic environments is increasing in response to climate change. At present, the increase in atmospheric methane concentrations recorded at Ny-Ålesund and globally threatens the Paris Agreement goal of limiting warming to 2 degrees, preferably 1.5 degrees, by increasing the need for abatements. However, our understanding of the physical, chemical and biological processes that control methane in the Arctic are strongly biased towards just a few lowland sites that are not at all like Svalbard and other similar mountainous, ice-covered regions. Svalbard can therefore be used to better understand these locations. Svalbard’s methane stocks include vast reserves of ancient, geogenic methane trapped beneath glaciers and permafrost. This methane supplements the younger, microbial methane mostly produced in waterlogged soils and wetlands during the summer and early winter. Knowledge about the production, removal and migration of these two methane sources in Svalbard’s complex landscapes and coastal environments has grown rapidly in recent years. However, the need to exploit this knowledge to produce reliable estimates of present-day and future emissions of methane from across the Svalbard landscape is now paramount. This is because understanding these quantities is absolutely necessary when we seek to define how society must adjust in order to better manage greenhouse gases in Earth’s atmosphere
2025
2025
2025
Removal Processes of the Stratospheric SO2 Volcanic Plume From the 2015 Calbuco Eruption
Abstract We analyze the volcanic plume from the April 2015 Calbuco eruption over a 35‐day period using simulations from Meso‐NH, a non‐hydrostatic mesoscale atmospheric model. A dedicated parameterization of the deep injection of the plume into the stratosphere ensures a realistic representation when compared to Infrared Atmospheric Sounding Interferometer satellite observations. During the first 12 hr of the eruption, on 22 April 2015, SO 2 mixing ratio reached 29 ppmv between 15 and 18 km for the first eruption pulse, and 38 ppmv between 12 and 16 km for the second. Most SO 2 was injected directly into the stratosphere, with a stratospheric load reaching 308 ktS (kilotons of atomic sulfur, i.e. 616 kilotons of SO 2 ) after the eruption. After 1 month, both stratospheric and tropospheric SO 2 loads returned to near‐background levels. During analysis, the chemical conversion of SO 2 into H 2 SO 4 removed a part of SO 2 from the stratosphere. During the long‐range advection, the co‐location between the subtropical jet stream and the Calbuco plume led to three significant stratospheric intrusions on 24, 26 and 28 April 2015. These events transferred stratospheric SO 2 into the troposphere, SO 2 mixing ratios in the upper troposphere reaching 15 ppmv, 26 and 15 ppbv, respectively. SO 2 is gradually oxidized into H 2 SO 4 , with up to 5 ktS of gaseous H 2 SO 4 in the stratosphere on 30 April, but dynamical processes dominate the SO 2 atmospheric budget over chemical transformations. This study demonstrates that stratospheric intrusions can play a critical role in the removal of volcanic material from the stratosphere following a major eruption.
2025
2025
At the same time Arctic ecosystems experiences rapid climate change, at a rate four times faster than the global average, they remain burdened by long-range transported pollution, notably with legacy polychlorinated biphenyls (PCBs). The present study investigates the potential impact of climate change on seabird exposure to PCB-153 using the established Nested Exposure Model (NEM), here expanded with three seabird species, i.e. common eider (Somateria mollissima), black-legged kittiwake (Rissa tridactyla) and glaucous gull (Larus hyperboreus), as well as the filter feeder blue mussel (Mytulis edulis). The model's performance was evaluated using empirical time trends of the seabird species in Kongsfjorden, Svalbard, and using tissue concentrations from filter feeders along the northern Norwegian coast. NEM successfully replicated empirical PCB-153 concentrations, confirming its ability to simulate PCB-153 bioaccumulation in the studied seabird species within an order of magnitude. Based on global PCB-153 emission estimates, simulations run until the year 2100 predicted seabird blood concentrations 99% lower than in year 2000. Model scenarios with climate change-induced altered dietary composition and lipid dynamics showed to have minimal impact on future PCB-153 exposure, compared to temporal changes in primary emissions of PCB-153. The present study suggests the potential of mechanistic modelling in assessing POP exposure in Arctic seabirds within a multiple stressor context.
2025
2025
2025
Sources of ultrafine particles at a rural midland site in Switzerland
Ultrafine particles (UFPs; i.e., atmospheric aerosol particles smaller than 100 nm in diameter) are known to be responsible for a series of adverse health effects as they can deposit in humans' bodies. So far, most field campaigns studying the sources of UFPs have focused on urban environments. This study investigates the outdoor sources of UFPs at the atmospheric monitoring station in Payerne, which represents a typical rural location in Switzerland. We aim to quantify the primary and secondary fractions of UFPs based on specific measurements between July 2020 and July 2021 complementing a series of operational meteorological, trace gas and in situ aerosol observations. To distinguish between primary and secondary contributions, we use a method that relies on measuring the fraction of non-volatile particles as a proxy for primary particles. We further compare our measurement results to previously established methods. We find that primary particles resulting from traffic and residential wood burning (direct emissions – mostly non-volatile BC-rich) contribute less than 40 % to the total number of UFPs, mostly in the Aitken mode. On the other hand, we observe local new particle formation (NPF) events (observed from ∼ 1 nm) evident from the increase in cluster ions (1.5–3 nm) and nucleation-mode particle (2.5–25 nm) concentrations, especially in spring and summer. These events, mediated by sulfuric acid, contribute to increasing the UFP number concentration, especially in the nucleation mode. Besides NPF, the chemical processing of particles emitted from multiple sources (including traffic and residential wood burning) contributes substantially to the nucleation-mode particle concentration. Under the present conditions investigated here, we find that secondary processes mediate the increase in UFP concentration to levels equivalent to those in urban locations, affecting both air quality and human health.
2025