Publikasjoner

Estimating residential air pollution exposure among citizens in Oslo 1974-1998 using a geographical information system.

Gram, F.; Nafstad, P.; Håheim, L.L.

Estimating methane emissions in the Arctic nations using surface observations from 2008 to 2019

Wittig, Sophie; Berchet, Antoine; Pison, Isabelle; Saunois, Marielle; Thanwerdas, Joel; Martinez, Adrien; Paris, Jean-Daniel; Machida, Toshinobu; Sasakawa, Motoki; Worthy, Doug E.J.; Lan, Xin; Thompson, Rona Louise; Sollum, Espen; Arshinov, Mikhail

The Arctic is a critical region in terms of global warming. Environmental changes are already progressing steadily in high northern latitudes, whereby, among other effects, a high potential for enhanced methane (CH4) emissions is induced. With CH4 being a potent greenhouse gas, additional emissions from Arctic regions may intensify global warming in the future through positive feedback. Various natural and anthropogenic sources are currently contributing to the Arctic's CH4 budget; however, the quantification of those emissions remains challenging. Assessing the amount of CH4 emissions in the Arctic and their contribution to the global budget still remains challenging. On the one hand, this is due to the difficulties in carrying out accurate measurements in such remote areas. Besides, large variations in the spatial distribution of methane sources and a poor understanding of the effects of ongoing changes in carbon decomposition, vegetation and hydrology also complicate the assessment. Therefore, the aim of this work is to reduce uncertainties in current bottom-up estimates of CH4 emissions as well as soil oxidation by implementing an inverse modelling approach in order to better quantify CH4 sources and sinks for the most recent years (2008 to 2019). More precisely, the objective is to detect occurring trends in the CH4 emissions and potential changes in seasonal emission patterns. The implementation of the inversion included footprint simulations obtained with the atmospheric transport model FLEXPART (FLEXible PARTicle dispersion model), various emission estimates from inventories and land surface models, and data on atmospheric CH4 concentrations from 41 surface observation sites in the Arctic nations. The results of the inversion showed that the majority of the CH4 sources currently present in high northern latitudes are poorly constrained by the existing observation network. Therefore, conclusions on trends and changes in the seasonal cycle could not be obtained for the corresponding CH4 sectors. Only CH4 fluxes from wetlands are adequately constrained, predominantly in North America. Within the period under study, wetland emissions show a slight negative trend in North America and a slight positive trend in East Eurasia. Overall, the estimated CH4 emissions are lower compared to the bottom-up estimates but higher than similar results from global inversions.

Estimating High Resolution Surface PM2.5 Over Europe Using Satellite AOD Datasets, CAMS Forecast and Machine Learning

Shetty, Shobitha; Schneider, Philipp; Stebel, Kerstin; Hamer, Paul David; Kylling, Arve; Berntsen, Terje Koren

Estimating high resolution daily surface PM2.5 over Europe using CAMS PM forecast, satellite AOD, and a Machine Learning Model.

Shetty, Shobitha; Schneider, Philipp; Hamer, Paul David; Stebel, Kerstin; Kylling, Arve; Berntsen, Terje Koren

Estimating emissions of per- and polyfluoroalkyl substances from imported consumer products. NILU F

Vestergren, R.; Cousins, I. T.; Herzke, D.

Estimating domestic wood burning emissions in Nordic countries using ambient air observations, receptor and dispersion modelling.

Denby, B.; Karl, M.; Laupsa, H.; Johansson, C.; Pohjola, M.; Karppinen, A.; Kukkonen, J.; Ketzel, M.; Wählin, P.

Estimating CH4 and N2O Emissions

Thompson, Rona Louise

Estimates of oceanic nitrous-oxide emissions from global biogeochemistry models

Suntharalingam, Parvadha; Battaglia, Gianna; Berthet, Sarah; Buithenuis, Erik; Landolfi, Angela; Manizza, Manfredi; Martinez-Rey, Jorge; Andrews, Oliver; Thompson, Rona Louise; Nevison, Cynthia D.; Joos, Fortunat; Canadell, Josep G.

Estimates of fumarolic SO2 fluxes from Putana volcano, Chile, using an ultraviolet imaging camera. NILU PP

Stebel, K.; Amigo, A.; Thomas, H.; Prata, F.

Estimated equivalency of vitamin D production from natural sun exposure versus oral vitamin D supplementation across seasons at 2 U.S. latitudes.

Terushkin, V, Bender, A.; Psaty, E.L.; Engelsen, O.; Wang, S.Q.; Halpern, A.C.

Establishment of killer whale (Orcinus orca) primary fibroblast cell cultures and their transcriptomic responses to pollutant exposure

Bjørneset, J.; Blévin, P.; Bjørnstad, P.M.; Dalmo, R.A.; Goksøyr, A.; Harju, M.; Limonta, G.; Panti, C.; Rikardsen, A.H.; Sundaram, A.Y.M.; Yadetie, F.; Routti, H.

Populations of killer whale (Orcinus orca) contain some of the most polluted animals on Earth. Yet, the knowledge on effects of chemical pollutants is limited in this species. Cell cultures and in vitro exposure experiments are pertinent tools to study effects of pollutants in free-ranging marine mammals. To investigate transcriptional responses to pollutants in killer whale cells, we collected skin biopsies of killer whales from the Northern Norwegian fjords and successfully established primary fibroblast cell cultures from the dermis of 4 out of 5 of them. Cells from the individual with the highest cell yield were exposed to three different concentrations of a mixture of persistent organic pollutants (POPs) that reflects the composition of the 10 most abundant POPs found in Norwegian killer whales (p,p’-DDE, trans-nonachlor, PCB52, 99, 101, 118, 138, 153, 180, 187). Transcriptional responses of 13 selected target genes were studied using digital droplet PCR, and whole transcriptome responses were investigated utilizing RNA sequencing. Among the target genes analysed, CYP1A1 was significantly downregulated in the cells exposed to medium (11.6 µM) and high (116 µM) concentrations of the pollutant mixture, while seven genes involved in endocrine functions showed a non-significant tendency to be upregulated at the highest exposure concentration. Bioinformatic analyses of RNA-seq data indicated that 13 and 43 genes were differentially expressed in the cells exposed to low and high concentrations of the mixture, respectively, in comparison to solvent control. Subsequent pathway and functional analyses of the differentially expressed genes indicated that the enriched pathways were mainly related to lipid metabolism, myogenesis and glucocorticoid receptor regulation. The current study results support previous correlative studies and provide cause-effect relationships, which is highly relevant for chemical and environmental management.

Elsevier

Establishment of Decadal-scale UV climatologies for high-latitude ecosystems studies. AMAP Report, 2004:4

Hansen, G.; Engelsen, O.; Edvardsen, K.; Verdebout, J.; Meerkoetter, R.; Bugliaro, L.; Borja, A.

Establishing maximum limits for hazardous organic contaminants in fertilisers and soil products in secondary raw materials used in fertilisers and soil products

Eggen, Trine; Heimstad, Eldbjørg Sofie; Nikiforov, Vladimir; Vogelsang, Christian