Found 9883 publications. Showing page 165 of 396:
Model inter-comparison for ash dispersion for better understanding of uncertainties. NILU OR
The 3 transport models EEMEP, SNAP and FLEXPART have simulated ash dispersion and deposition from the Eyjafjalljökull eruption in 2010. All models have been run with identical source term, and the model results have been compared in detail against each other and against observations. This provides a better understanding of the models' ability to simulate ash dispersion, and of the differences between model results that often occur, especially during an ash situation in real time.
2014
While carbon dioxide is the main cause for global warming, modeling short-lived climate forcers (SLCFs) such as methane, ozone, and particles in the Arctic allows us to simulate near-term climate and health impacts for a sensitive, pristine region that is warming at 3 times the global rate. Atmospheric modeling is critical for understanding the long-range transport of pollutants to the Arctic, as well as the abundance and distribution of SLCFs throughout the Arctic atmosphere. Modeling is also used as a tool to determine SLCF impacts on climate and health in the present and in future emissions scenarios.
In this study, we evaluate 18 state-of-the-art atmospheric and Earth system models by assessing their representation of Arctic and Northern Hemisphere atmospheric SLCF distributions, considering a wide range of different chemical species (methane, tropospheric ozone and its precursors, black carbon, sulfate, organic aerosol, and particulate matter) and multiple observational datasets. Model simulations over 4 years (2008–2009 and 2014–2015) conducted for the 2022 Arctic Monitoring and Assessment Programme (AMAP) SLCF assessment report are thoroughly evaluated against satellite, ground, ship, and aircraft-based observations. The annual means, seasonal cycles, and 3-D distributions of SLCFs were evaluated using several metrics, such as absolute and percent model biases and correlation coefficients. The results show a large range in model performance, with no one particular model or model type performing well for all regions and all SLCF species. The multi-model mean (mmm) was able to represent the general features of SLCFs in the Arctic and had the best overall performance. For the SLCFs with the greatest radiative impact (CH4, O3, BC, and SO), the mmm was within ±25 % of the measurements across the Northern Hemisphere. Therefore, we recommend a multi-model ensemble be used for simulating climate and health impacts of SLCFs.
Of the SLCFs in our study, model biases were smallest for CH4 and greatest for OA. For most SLCFs, model biases skewed from positive to negative with increasing latitude. Our analysis suggests that vertical mixing, long-range transport, deposition, and wildfires remain highly uncertain processes. These processes need better representation within atmospheric models to improve their simulation of SLCFs in the Arctic environment. As model development proceeds in these areas, we highly recommend that the vertical and 3-D distribution of SLCFs be evaluated, as that information is critical to improving the uncertain processes in models.
2022
Model estimates of SO2 and heavy metal depositions in the border areas of Norway and Russia. NILU OR
1994
Model development for high-resolution emissions from residential wood combustion
I denne rapporten beskriver vi MetVed-modellen. Denne modellen estimerer vedfyringsutslipp med høy oppløsning. Metved-modellen kombinerer nedskalering med bottom-up prinsipper for å estimere vedfyringspotensiale i modellgrid. Den baserer seg på boligtyper, størrelse, oppvarmingsteknologi, energibehov og utendørs temperatur. Modellen baserer seg på å kombinere flere databaser med høyt detaljert informasjon. Databasene inneholder boligtall og boligtyper med 250 meters romlig oppløsning, statistikk av energibruk i husholdninger, plassering av ildsteder som punktkilder, og geografisk posisjon av boliger med informasjon om boligtyper og tilgjengelige teknologier for oppvarming i husholdningene. Databasene blir i MetVed-modellen kombinert og forhold mellom ulike variabler analysert. MetVed-modellen inkluderer en tidsvarisjon av vedforbruket som baserer seg på oppvarmingsgradkonseptet kombinert med tidsvariasjon fra forbrukerstatistikk. Vertikalfordeling av utslippene baserer seg på vedforbruk fordelt på leiligheter og hus (enebolig, tomannsbolig og rekkehus). Resultater fra spredningsmodellberegninger viser at utslippsdata fra MetVed-modellen gir bedre samsvar med målinger enn spredningsberegninger basert på utslipp fra tidligere metoder for å estimere vedfyringsutslipp.
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Mobile technologies and services for supporting green mobility in Oslo: the Citi-Sense-MOB approach. NILU F
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