Found 9759 publications. Showing page 225 of 391:
2015
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
2011
2013
NILU and GIOS, Poland, are implementing the project "Strengthening the air quality assessment system in Poland, based on Norwegian experience" as part of the programme "Improving Environmental Monitoring and Inspection" within the framework of the European Economic Area 2009-2014. This report provides method and tools for the spatial analysis of concentrations of air pollutants in the frame of the assessment of air quality under in Poland, in support of the implementation of European Air Quality legislation.
2014
A method was developed to analytically distinguish between the ventilated (v) and nonventilated (nv) fractions of water-soluble ions in deposits of particle indoors. The indicative method was based on low-cost passive outdoor and indoor sampling of the particle and ion deposits and NO2 gas and analysis of the regression values and residuals of the correlations between these parameters. The method was applied to measurements in the Pieskowa Skała Castle Museum in Poland. A dominating source of “soil and building dust” was indicated all year round, probably partly from renovation works of the castle, with larger total infiltration in the winter–spring (W-S) but with a higher proportion of ventilation ingress in the summer–autumn (S-A). About 60%–80%, by mass, of the water-soluble ions in the soil and building dust were calcium and probably some magnesium bicarbonate (Ca(HCO3)2, Mg(HCO3)2) and about 10%–20% sulfates (SO4−−) with calcium (Ca++) and several other cations. The other main source of the ion deposits was indicated to be air pollution, with chloride (Cl−), sulfate (SO4−−), and nitrate (NO3−), from outdoor combustion sources, like traffic, residential heating, and industry. These were mainly v from outdoors in the colder parts of the year, but also to the more open locations in the S-A. A small source of nv sulfate (SO4−−) was identified inside two showcases in the S-A. The study showed good enclosure protection of the museum objects against exposure to particle pollution, but also the need to avoid the trapping of particle pollution inside showcases or closed rooms. The identification of the probable different amounts and sources of v and nv ions in the castle aided preventive actions to reduce the pollution exposure.
John Wiley & Sons
2024
2018
Method for high resolution emission estimations from construction sites. Phase I: Mapping input data
Denne rapporten presenterer resultatene fra analyse av tilgjengelige inngangsdata for å utvikle en modell for estimering av luftforurensende stoffer og klimagassutslipp basert på en «bottom-up»-tilnærming, inkludert både eksos- og ikke-eksosutslipp. Tilgjengeligheten av pålitelige inngangsdata er den begrensende faktoren og den mest kritiske delen av utformingen av en slik «bottom-up»-tilnærming. I denne studien har vi fokusert på å vurdere inngangsdata som gjør det mulig å definere; i) den nøyaktige plasseringen og området som påvirkes under bygging og konstruksjon, ii) start- og sluttdatoer; iii) typen byggeaktivitet; iv) aktiviteter med ikke-veigående mobile maskiner (NRMM) innen bygg og anlegg; v) veier i nærheten av byggeplasser.
NILU
2021
Method for retrieval of aerosol optical depth from multichannel irradiance measurements
We present, to the best of our knowledge, a new method for retrieval of aerosol optical depth from multichannel irradiance measurements. A radiative transfer model is used to simulate measurements to create the new aerosol optical depth retrieval method. A description of the algorithm, simulations, proof of principle, merits, possible future developments and implementations is provided. As a demonstration, measurements in the New York City area are simulated based on the specific channel configuration of an existing multichannel irradiance instrument. Verification of the method with irradiance measurement data is also provided.
Optical Society of America
2023
Methodological improvements on interpolating European air quality maps. ETC/ACC Technical Paper, 2009/16
2010
Methods for estimating air pollutant emissions. PART 1: Review and source of input data. NILU OR
This report is part of the development of a National Modelling System for local air quality (the "Nasjonalt Beregningsverktøy" or NBV project). The work focussed on the methods to estimate emissions and identified the main information sources of the needed input data for emissions. This report presents the most common methods to determine emissions and includes recommendations for future improvement of the emission calculations. The main purpose of the report is to identify the most relevant sources of emission information and the emission input data requirements necessary for modelling air quality in Norwegian cities and agglomerations.
2015
1999
METROPOLIS. Work Package WP3/Deliverable 4. On-line data presentation and data distribution. NILU OR
2004
MetVed v.2.0. Improvement and update of the MetVed emission model for residential wood combustion
This report presents the update of the MetVed-model (Grythe et al., 2019). Among the updates are new emission factors and several new species that include climate gases (CO2, CH4 and N2O). There is now a new parameter that describes the emission altitude and a new and improved time variation. Activity data has been updated to the most recent year (2019), which also has required updates to the model and model input variables. The largest update has been the holiday cabin emission module, which is an entirely new addition. Emissions from cabins differ in several ways from residential emissions. The most notable difference is that cabins are spread over more rural areas and are more dispersed than the residential dwellings. The model differentiates alpine and coastal cabins, which is an important distinction as a high density of cabins exists along the coast and they are mainly used during summer.
NILU
2020
Microfibers (MF) are one of the major classes of microplastic found in the marine environment on a global scale. Very little is known about how they move and distribute from point sources such as wastewater effluents into the ocean. We chose Adventfjorden near the settlement of Longyearbyen on the Arctic Svalbard archipelago as a case study to investigate how microfibers emitted with untreated wastewater will distribute in the fjord, both on a spatial and temporal scale. Fiber abundance in the effluent was estimated from wastewater samples taken during two one-week periods in June and September 2017. Large emissions of MFs were detected, similar in scale to a modern WWTP serving 1.3 million people and providing evidence of the importance of untreated wastewater from small settlements as major local sources for MF emissions in the Arctic. Fiber movement and distribution in the fjord mapped using an online-coupled hydrodynamic-drift model (FVCOM-FABM). For parameterizing a wider spectrum of fibers from synthetic to wool, four different density classes of MFs, i.e., buoyant, neutral, sinking, and fast sinking fibers are introduced to the modeling framework. The results clearly show that fiber class has a large impact on the fiber distributions. Light fibers remained in the surface layers and left the fjord quickly with outgoing currents, while heavy fibers mostly sank to the bottom and deposited in the inner parts of the fjord and along the northern shore. A number of accumulation sites were identified within the fjord. The southern shore, in contrast, was much less affected, with low fiber concentrations throughout the modeling period. Fiber distributions were then compared with published pelagic and benthic fauna distributions in different seasons at selected stations around the fjord. The ratios of fibers to organisms showed a very wide range, indicating hot spots of encounter risk for pelagic and benthic biota. This approach, in combination with in-situ ground-truthing, can be instrumental in understanding microplastic pathways and fate in fjord systems and coastal areas and help authorities develop monitoring and mitigation strategies for microfiber and microplastic pollution in their local waters.
Frontiers Media S.A.
2021