Fant 9758 publikasjoner. Viser side 303 av 391:
2019
Monitoring of the atmospheric ozone layer and natural ultraviolet radiation. Annual Report 2018.
Denne rapporten presenterer resultatene fra det norske måleprogrammet for totalozon og UV-stråling. Ozonlaget har blitt målt ved tre stasjoner siden 1979: i Oslo, Tromsø/Andøya og Ny-Ålesund. UV-målinger startet i 1995. Resultatene viser at det var en signifikant ozonreduksjon over Norge i perioden 1979 til 1997. Deretter stanset reduksjonen og ozonverdiene stabiliserte seg på et nivå ~2% lavere pre-1980 nivået. Mest karakteristisk for 2018 var de lave totalozon-verdiene over Oslo i sommermånedene og den rekordhøye årlige integrerte UV-dosen.
NILU
2019
Supporting the improvement of air quality management practices: The “FAIRMODE pilot” activity
Academic Press
2019
2019
Monitoring Soil Moisture Drought over Northern High Latitudes from Space
Mapping drought from space using, e.g., surface soil moisture (SSM), has become viable in the last decade. However, state of the art SSM retrieval products suffer from very poor coverage over northern latitudes. In this study, we propose an innovative drought indicator with a wider spatial and temporal coverage than that obtained from satellite SSM retrievals. We evaluate passive microwave brightness temperature observations from the Soil Moisture and Ocean Salinity (SMOS) satellite as a surrogate drought metric, and introduce a Standardized Brightness Temperature Index (STBI). We compute the STBI by fitting a Gaussian distribution using monthly brightness temperature data from SMOS; the normal assumption is tested using the Shapior-Wilk test. Our results indicate that the assumption of normally distributed brightness temperature data is valid at the 0.05 significance level. The STBI is validated against drought indices from a land surface data assimilation system (LDAS-Monde), two satellite derived SSM indices, one from SMOS and one from the ESA CCI soil moisture project and a standardized precipitation index based on in situ data from the European Climate Assessment & Dataset (ECA&D) project. When comparing the temporal dynamics of the STBI to the LDAS-Monde drought index we find that it has equal correlation skill to that of the ESA CCI soil moisture product ( 0.71 ). However, in addition the STBI provides improved spatial coverage because no masking has been applied over regions with dense boreal forest. Finally, we evaluate the STBI in a case study of the 2018 Nordic drought. The STBI is found to provide improved spatial and temporal coverage when compared to the drought index created from satellite derived SSM over the Nordic region. Our results indicate that when compared to drought indices from precipitation data and a land data assimilation system, the STBI is qualitatively able to capture the 2018 drought onset, severity and spatial extent. We did see that the STBI was unable to detect the 2018 drought recovery for some areas in the Nordic countries. This false drought detection is likely linked to the recovery of vegetation after the drought, which causes an increase in the passive microwave brightness temperature, hence the STBI shows a dry anomaly instead of normal conditions, as seen for the other drought indices. We argue that the STBI could provide additional information for drought monitoring in regions where the SSM retrieval problem is not well defined. However, it then needs to be accompanied by a vegetation index to account for the recovery of the vegetation which could cause false drought detection.
MDPI
2019
2019
2019
2019
Plastic pollution is a global and increasing threat to ecosystems. Plastics in the oceans are unevenly distributed, are transported by currents and can now be found in the most remote environments, including Arctic sea ice. The entanglement of wildlife by large plastic debris such as ropes is an obvious and well documented threat. However, the risks associated with the ingestion of smaller plastic particles, including microplastics (< 5mm) have been largely overlooked. Recent studies show that microplastic accumulates in the food web. Even in the Arctic and the deep sea, fish frequently contain microplastics in their guts. This, together with the fact that small microplastic particles can pass from the gut into blood and organs and also leach associated toxic additives raises health concerns for wildlife that ingest microplastic.
Within the North Atlantic, plastic ingestion in seabirds has been studied systematically only in the northern fulmar (Fulmarus glacialis), for which plastic particles > 1mm found in the stomachs of dead (beached or bycaught) birds are quantified. With the origin of these birds being unknown, it is, however, impossible to assess how plastics affect populations even of this one monitored species, let alone for other seabird species that differ in their foraging behaviour and risk to ingest plastics.
This report sums up the results of a workshop which aimed to identify possibilities for long-term monitoring of (micro-) plastic ingestion by seabirds in the framework of SEAPOP, the basal programme monitoring the performance of Norwegian seabird populations (www.seapop.no). The key conclusions were: 1) There is a need for baseline information on plastic ingestion across all seabird species to identify which species and populations are most suitable for monitoring. To obtain this information, the best approach is to investigate the stomach contents of dead birds (i.e. comparable methodology across all species). For long-term monitoring, not only species with high plastic ingestion are of interest, but also those with low plastic prevalence. 2) In the absence of information from (1), eight species that are complementary in their foraging behaviour and have a wide distribution range were selected as preliminary species of interest to monitor plastic ingestion. 3) For minimally invasive monitoring, regurgitates, fresh prey items and faeces are most suitable; 4) More information on prevalence of plastic ingestion is needed to identify optimal sample sizes for long-term monitoring. We therefore highlight the need for several pilot studies before establishing a plastic monitoring protocol within SEAPOP.
Norsk institutt for naturforskning (NINA)
2019