Fant 9758 publikasjoner. Viser side 66 av 391:
2017
State of the environment in the Norwegian, Finnish and Russian border area. The Finnish environment 6/2007
2007
State of the Climate in 2023: The Arctic
American Meteorological Society (AMS)
2024
State of the Climate in 2023 : Global Climate
American Meteorological Society (AMS)
2024
State of the Climate in 2022: The Arctic
American Meteorological Society
2023
State of the Climate in 2021: The Arctic
American Meteorological Society
2022
State of the Climate in 2021: 5. The Arctic
American Meteorological Society
2022
American Meteorological Society
2023
2021
2015
2016
Stad Skipstunnel. Vurdering av luftforureining ved tunnelportalar. NILU OR
Det er berekna produksjon og spreiing frå skipstunnelsamband mellom Moldefjorden og Kjødepollen ved Stad. Berekningane gjev utstrekning verdiar av nitrogendioksid som timemiddel og svevestøv som døgnmiddel tilsvarande Nasjonale mål ved tunnelportalar. Ved ventilering av tunnelen må det takast omsyn til bustadar ved tunnelportal i aust.
2000
2017
Svalbard is a remote and scarcely populated Arctic archipelago and is considered to be mostly influenced by long-range-transported air pollution. However, there are also local emission sources such as coal and diesel power plants, snowmobiles and ships, but their influence on the background concentrations of trace gases has not been thoroughly assessed. This study is based on data of tropospheric ozone (O3) and nitrogen oxides (NOx) collected in three main Svalbard settlements in spring 2017. In addition to these ground-based observations and radiosonde and O3 sonde soundings, ERA5 reanalysis and BrO satellite data have been applied in order to distinguish the impact of local and synoptic-scale conditions on the NOx and O3 chemistry. The measurement campaign was divided into several sub-periods based on the prevailing large-scale weather regimes. The local wind direction at the stations depended on the large-scale conditions but was modified due to complex topography. The NOx concentration showed weak correlation for the different stations and depended strongly on the wind direction and atmospheric stability. Conversely, the O3 concentration was highly correlated among the different measurement sites and was controlled by the long-range atmospheric transport to Svalbard. Lagrangian backward trajectories have been used to examine the origin and path of the air masses during the campaign.
2022
Svalbard is a near pristine Arctic environment, where long-range transport from mid-latitudes is an
important air pollution source. Thus, several previous studies investigated the background
nitrogen oxides (NO x ) and tropospheric ozone (O 3 ) springtime chemistry in the region. However,
there are also local anthropogenic emission sources on the archipelago such as coal power plants,
ships and snowmobiles, which may significantly alter in situ atmospheric composition.
Measurement results from three independent research projects were combined to identify the
effect of emissions from various local sources on the background concentration of NO x and O 3 in
Svalbard. The hourly meteorological and chemical data from the ground-based stations in
Adventdalen, Ny-Ålesund and Barentsburg were analysed along with daily radiosonde soundings
and weekly data from O 3 sondes. The data from the ERA5 reanalysis were used to evaluate the
prevailing synoptic conditions during the fieldwork. Although the correlation between the NO x
concentrations in the three settlements was low due to dominant influence of the local
atmospheric circulation, cases with common large-scale meteorological conditions increasing the
local pollutant concentration at all sites were identified. In colder and calmer days and days with
temperature inversions, the concentrations of NO x were higher. In contrast to NO x values, O 3
concentrations in Barentsburg and at the Zeppelin station in Ny-Ålesund correlated strongly, and
hence the prevailing synoptic situation and long-range transport of air masses were controlling
factors for them. The Lagrangian models HYSPLIT and FLEXPART have been used to investigate air
mass transport and transformations during the large scale O 3 depletion and enrichment events.
The factors affecting Arctic springtime photochemistry of O 3 have been investigated thoroughly
using Lagrangian and Eulerian numerical weather prediction model data and Metop GOME-2
satellite observations.
2021
2009
2007
2003
2013