Publikasjoner

Deployment and Evaluation of a Network of Open Low-Cost Air Quality Sensor Systems

Schneider, Philipp; Vogt, Matthias; Haugen, Rolf; Hassani, Amirhossein; Castell, Nuria; Dauge, Franck Rene; Bartonova, Alena

Low-cost air quality sensors have the potential to complement the regulatory network of air quality monitoring stations, with respect to increased spatial density of observations, however, their data quality continues to be of concern. Here we report on our experience with a small network of open low-cost sensor systems for air quality, which was deployed in the region of Stavanger, Norway, under Nordic winter conditions. The network consisted of AirSensEUR sensor systems, equipped with sensors for, among others, nitrogen dioxide and fine particulate matter. The systems were co-located at an air quality monitoring station, for a period of approximately six weeks. A subset of the systems was subsequently deployed at various roadside locations for half a year, and finally co-located at the same air quality monitoring station again, for a post-deployment evaluation. For fine particulate matter, the co-location results indicate a good inter-unit consistency, but poor average out-of-the-box performance (R2 = 0.25, RMSE = 9.6 μ
g m−3). While Köhler correction did not significantly improve the accuracy in our study, filtering for high relative humidity conditions improved the results (R2 = 0.63, RMSE = 7.09 μg m−3). For nitrogen dioxide, the inter-unit consistency was found to be excellent, and calibration models were developed which showed good performance during the testing period (on average R2 = 0.98, RMSE = 5.73 μg m−3), however, due to the short training period, the calibration models are likely not able to capture the full annual variability in environmental conditions. A post-deployment co-location showed, respectively, a slight and significant decrease in inter-sensor consistency for fine particulate matter and nitrogen dioxide. We further demonstrate, how observations from even such a small network can be exploited by assimilation in a high-resolution air quality model, thus adding value to both the observations and the model, and ultimately providing a more comprehensive perspective of air quality than is possible from either of the two input datasets alone. Our study provides valuable insights on the operation and performance of an open sensor system for air quality, particularly under challenging Nordic environmental conditions.

Deployment and Evaluation of Networks of Open Air Quality Sensor Systems - Experiences from deployments in Stavanger and Oslo

Schneider, Philipp; Vogt, Matthias; Haugen, Rolf; Hassani, Amirhossein; Castell, Nuria; Peters, Jan; Yatkin, Sinan; Gerboles, Michel; Matheeussen, Christina; Davila, Silvije; Signorini, Marco; Dauge, Franck Rene; Skaar, Jøran Solnes; Bartonova, Alena

Deposition of air pollutants around the North Sea and the North-East Atlantic in 2008. NILU OR

Barrett, K.

This reports summarises the observations of the deposition of pollutants from the atmosphere to the North Sea area during 2008. Priority is given to the metals arsenic, cadmium, chromium, copper, lead, mercury, nickel, and zinc, the organic pollutant lindane, and to oxidised and reduced forms of nitrogen. A number of voluntarily monitored pollutants are also reported by North Sea countries. As well as providing rates of deposition observed in 2008, the report summarises the temporal trends in deposition of lead, cadmium, mercury and PCB's.

Deposition of air pollutants around the North Sea and the North-East Atlantic in 2010. OSPAR monitoring and assessment, 564/2012

Newton, A.

Deposition of air pollutants around the North Sea and the North-East Atlantic in 2012. OSPAR monitoring and assessment, 632/2014

Aas, W.

Deposition of air pollutants around the North Sea and the North-East Atlantic in 2014. OSPAR monitoring and assessment, 680/2016

Aas, W.

Deposition of ionic species and black carbon to the Arctic snowpack: combining snow pit observations with modeling

Jacobi, Hans-Werner; Obleitner, Friedrich; Costa, Sophie Da; Ginot, Patrick; Eleftheriadis, Konstantinos; Aas, Wenche; Zanatta, Marco

Although aerosols in the Arctic have multiple and complex impacts on the regional climate, their removal due to deposition is still not well quantified. We combined meteorological, aerosol, precipitation, and snowpack observations with simulations to derive information about the deposition of sea salt components and black carbon (BC) from November 2011 to April 2012 to the Arctic snowpack at two locations close to Ny-Ålesund, Svalbard. The dominating role of sea salt and the contribution of dust for the composition of atmospheric aerosols were reflected in the seasonal composition of the snowpack. The strong alignment of the concentrations of the major sea salt components in the aerosols, the precipitation, and the snowpack is linked to the importance of wet deposition for transfer from the atmosphere to the snowpack. This agreement was less strong for monthly snow budgets and deposition, indicating important relocation of the impurities inside the snowpack after deposition. Wet deposition was less important for the transfer of nitrate, non-sea-salt sulfate, and BC to the snow during the winter period. The average BC concentration in the snowpack remains small, with a limited impact on snow albedo and melting. Nevertheless, the observations also indicate an important redistribution of BC in the snowpack, leading to layers with enhanced concentrations. The complex behavior of bromide due to modifications during sea salt aerosol formation and remobilization in the atmosphere and in the snow were not resolved because of the lack of bromide measurements in aerosols and precipitation.

Deposition of major inorganic compounds in Norway 2002-2006. NILU OR

Aas, W.; Hjellbrekke, A.-G.; Hole, L.R.; Tørseth, K.

Deposition of major inorganic compounds in Norway 2012-2016. NILU report

Aas, W.; Hjellbrekke, A.-G.; Fagerli, H.; Benedictov, A.

Avsetning av svovel og nitrogenforbindelser i Norge for perioden 2012 til 2016 er beregnet ved bruk av to forskjellige metoder, en observasjonsbasert metode, mens den andre kombinerer atmosfærisk transportmodell med observasjoner. Begge metodene viser en tydelig gradient med høyest avsetning i sør og sørvest. Den kombinerte metoden har bedre romlig informasjon, spesielt for våtavsetning. For tørravsetning er det ganske store usikkerheter i estimerte verdier for begge metodene. Sammenlignet med forrige periode 2007-2011 er det en nedgang i total svovelavsetning i Norge på 9%. For totalt nitrogen er det små endringer. Sammenlignet med 1978-1982 er det henholdsvis 75% og 20% reduksjon i svovel- og nitrogenavsetningen.

Derfor er det så mye metan i atmosfæren nå

Platt, Stephen Matthew (intervjuobjekt); Aukrust, Øyvind (journalist)

Derivation of a model for the calculation of impact loads of air pollutants to paintings in microclimate frames.

Grøntoft, T.

Deriving phytoplankton biomass in the marginal ice zone from satellite observable parameters

Engelsen, O.; Hop, H.; Hegseth, E.N.; Hansen, E.; Falk-Petersen, S.

Descent from the polar mesosphere and anomalously high stratopause observed in 8 years of water vapor and temperature satellite observations by the Odin Sub-Millimetre Radiometer.

Orsolini, Y. J.; Urban, J.; Murtagh, D.; Lossow, S.; Limpasuvan, V.