Found 9887 publications. Showing page 113 of 396:
Monitoring of the atmospheric ozone layer and natural ultraviolet radiation: Annual report 2017.
This report summarizes the results from the Norwegian monitoring programme on stratospheric ozone and UV radiation measurements. The ozone layer has been measured at three locations since 1979: in Oslo, Tromsø/Andøya and Ny-Ålesund. The UV measurements started in 1995. The results show that there was a significant decrease in stratospheric ozone above Norway between 1979 and 1997. After that the ozone layer stabilized at a level ~2% below pre-1980 level. There are large inter-annual variations and in 2017 there were relatively low values at all the three Norwegian stations during the winter. However, the ozone situation normalized towards the end of spring.
NILU
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The UK Toxic Organic Micro Pollutants (TOMPs) Network, which has operated since 1991, collects ambient air samples at six urban, rural, and semi-rural sites across England and Scotland, using high-volume active air samplers [1]. Furthermore, in 1994, a latitudinal sampling transect from the south of England to the north of Norway was established with eleven sampling sites, mainly in remote locations, using Semi-Permeable Membrane Devices (SPMDs) as passive air samplers [2]. Both networks provide continuous, long-term ambient air trend data for a range of Persistent Organic Pollutants (POPs), including PCBs and PBDEs, and have helped demonstrating a decline in POPs air concentrations over the last three decades. However, in recent years no further significant declines have been observed. SumPCB and SumPBDE levels in the UK are lowest at the rural sites and highest for the urban sites (TOMPs), and they generally decrease from the south of England to the north of Norway (UK/Norway) in line with expectations. Higher values at less remote sites and sites downwind from population centres show that POPs concentrations may still mainly be influenced by primary emissions. Concentrations at semi-rural sites lie between rural and urban sites; however, they can exceed the latter in some years. This can probably be attributed to short-term local effects. The data from the TOMPs network shows that concentrations of PCBs are higher in warmer than in colder months, while the seasonal patterns are less uniform for PBDEs.
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Seasonality of aerosol optical properties in the Arctic
Given the sensitivity of the Arctic climate to short-lived climate forcers, long-term in situ surface measurements of aerosol parameters are useful in gaining insight into the magnitude and variability of these climate forcings. Seasonality of aerosol optical properties – including the aerosol light-scattering coefficient, absorption coefficient, single-scattering albedo, scattering Ångström exponent, and asymmetry parameter – are presented for six monitoring sites throughout the Arctic: Alert, Canada; Barrow, USA; Pallas, Finland; Summit, Greenland; Tiksi, Russia; and Zeppelin Mountain, Ny-Ålesund, Svalbard, Norway. Results show annual variability in all parameters, though the seasonality of each aerosol optical property varies from site to site. There is a large diversity in magnitude and variability of scattering coefficient at all sites, reflecting differences in aerosol source, transport, and removal at different locations throughout the Arctic. Of the Arctic sites, the highest annual mean scattering coefficient is measured at Tiksi (12.47Mm−1), and the lowest annual mean scattering coefficient is measured at Summit (1.74Mm−1). At most sites, aerosol absorption peaks in the winter and spring, and has a minimum throughout the Arctic in the summer, indicative of the Arctic haze phenomenon; however, nuanced variations in seasonalities suggest that this phenomenon is not identically observed in all regions of the Arctic. The highest annual mean absorption coefficient is measured at Pallas (0.48Mm−1), and Summit has the lowest annual mean absorption coefficient (0.12Mm−1). At the Arctic monitoring stations analyzed here, mean annual single-scattering albedo ranges from 0.909 (at Pallas) to 0.960 (at Barrow), the mean annual scattering Ångström exponent ranges from 1.04 (at Barrow) to 1.80 (at Summit), and the mean asymmetry parameter ranges from 0.57 (at Alert) to 0.75 (at Summit). Systematic variability of aerosol optical properties in the Arctic supports the notion that the sites presented here measure a variety of aerosol populations, which also experience different removal mechanisms. A robust conclusion from the seasonal cycles presented is that the Arctic cannot be treated as one common and uniform environment but rather is a region with ample spatiotemporal variability in aerosols. This notion is important in considering the design or aerosol monitoring networks in the region and is important for informing climate models to better represent short-lived aerosol climate forcers in order to yield more accurate climate predictions for the Arctic.
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Grenseområdene Norge-Russland. Luft- og nedbørkvalitet, årsrapport 2017.
Smelteverkene i NV-Russland slipper ut store mengder svoveldioksid (SO2) og tungmetaller. Utslippene påvirker luft- og nedbørkvalitet i grenseområdene. Miljøovervåkingen viser at grenseverdier for SO2 er overholdt i kalenderåret
2017, samt sesongmiddel vinter 2016/17. Målsettingsverdier for Ni og As er overholdt.
NILU
2018
Ny-Ålesund is an international research settlement where the thermodynamics and chemical composition of the air are monitored. The present work investigates the effects of micrometeorological conditions, mesoscale dynamics and local air pollution on the data collected at two different locations around the village. Daily filter measurements of sulphur dioxide and non-sea salt sulphate from the temporary Ny-Ålesund station and permanent Zeppelin mountain station have been analysed along with meteorological data. The influence of different factors representing micrometeorological phenomena and local pollution from ships has been statistically investigated. Seasonal variation of the correlation between the data from Ny-Ålesund and Zeppelin stations is revealed, and the seasonal dependence of the relative contribution of different factors has been analysed. The median concentrations of SO42- measured in Ny-Ålesund increased significantly on days with temperature inversions in winter. In spring, concentrations of SO2 and SO42- were higher than normal at both stations on days with temperature inversions, but lower on days with strong humidity inversions. In summer, local ship traffic affects the SO2 data set from Ny-Ålesund, while no statistically significant influence on the Zeppelin data set has been observed. The pollution from ships has an effect on SO42- values at both stations; however, the concentrations in Ny-Ålesund were higher when local pollution accumulated close to the ground in days with strong humidity inversions.
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