Found 9746 publications. Showing page 7 of 390:
2013
2006
Volatile and persistent emissions from traffic and power production on Svalbard. VETAPOS. NILU OR
Volatile organic compounds (VOC) including Benzene-Toluene-Xylene (BTX) related compounds were monitored in ambient air samples during Spring (April-Mai) and Autumn (October) 2010 as a follow-up of an earlier BTX ambient air monitoring program in 2007 (Reimann et al 2007) at the Research park in Longyearbyen (Forskningsparken). In addition, BTX related compounds were measured in 18 ¿headspace¿ samples above collected surface soil along snowmobile tracks in Longyeardalen, Adventdalen, Todalen as well as Sassendalen (Fredheim). In addition, during the 2010 VETAPOS in a parallel surface soil sampling campaign 18 samples were analysed for 15 priority PAH compounds.
2011
VOC measurements by PTR-ToF-MS at the Birkenes Observatory. A summary report. NILU OR
A high resolution proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF- MS) was used for on-line and real-time measurements of volatile organic compounds (VOCs) at the Birkenes Observatory in Southern Norway. Measurements were carried out during late spring and summer 2012 and in January and early February 2013. Here we present the obtained PTR-MS standard data product which includes volume mixing ratios of methanol, acetonitrile, acetaldehyde, acetone, dimethyl sulphide, isoprene, methacrolein plus methylvinylketone, methylethylketone, benzene, toluene, C8-alkylbenzenes, C9-alkylbenzenes and the sum of the monoterpene isomers. Exploratory data of formic acid, acetic acid, pinonaldehyde and three unidentified signals (m/z 87.080, m/z 89.060 and m/z 101.098) are also shown. PTR-ToF-MS mass spectra were dominated by oxygenated VOCs both in summer and in winter. Pure hydrocarbons were mostly aromatic hydrocarbons (benzene, toluene, C8-alkylbenzenes) in winter and biogenic hydrocarbons (monoterpenes and isoprene) in summer. The summertime data confirm that the Birkenes Observatory is an interesting site in the boreo-nemoral vegetation zone where it is possible to observe both monoterpene and isoprene emissions and their photochemical processing in the atmosphere.
2014
This report documents the EMEP VOC monitoring carried out in 2022. The levels of the measured in 2022 are presented as well as the 2022-status and history of the VOC programme. The geographical pattern of the species in Europe is discussed as well as the long-term trend during the last 20 years.
NILU
2024
This report presents VOC (volatile organic compound) measurements carried out during 2018 at EMEP monitoring sites. In total, 20 sites reported VOC-data from EMEP VOC sites this year. Some of the data-sets are considered preliminary and are not included in the report.
The monitoring of NMHC (non-methane hydrocarbons) has become more diverse with time in terms of instrumentation. Starting in the early 1990s with standardized methods based on manual sampling in steel canisters with subsequent analyses at the lab, the methods now consist of a variety of instruments and measurement principles, including automated continuous monitors and manual flask samples. For oxygenated VOCs (OVOCs), sampling in DNPH-tubes with subsequent lab-analyses is still the only method in use at EMEP sites.
Within the EU infrastructure project ACTRIS-2, data quality issues related to measurements of VOC have been an important topic. Many of the institutions providing VOC-data to EMEP have participated in the ACTRIS-2 project, either as formal partners or on a voluntary basis. Participation in ACTRIS-2 has meant an extensive effort with data-checking including detailed discussions between the ACTRIS community and individual participants. There is no doubt that this extensive effort has benefited the EMEP-program and has led to improved data quality in general.
Comparison between median levels in 2018 and the medians of the previous 10-years period, revealed a similar north-to-south pattern for several species.
Changes in instrumentation, procedures, station network etc. during the last two decades make it difficult to provide a rigorous and pan-European assessment of long-term trends of the observed VOCs. In this report, we have estimated the long-term trends in NMHC over the 2000-2018 period at six sites by two independent statistical methods. These estimates indicate marked differences in the trends for the individual species. Small or non-significant trends were found for ethane over this period followed by propane which also showed fairly small reductions. On the other hand, components linked to road traffic (ethene, ethyne and benzene) showed the strongest drop in mean concentrations, up to 60-80% at some stations.
The persistent heatwave in summer 2018 in northern and central Europe lead to higher isoprene-levels than normal. The data indicate a clear relationship between isoprene and afternoon temperature at the sites. An exponential fit is seen to be well suited for the relationship between isoprene and temperature.
NILU
2020
This report presents VOC measurements carried out during 2016 at EMEP monitoring sites. In total, 19 sites reported VOC data from EMEP VOC sites this year. Some of the data sets are considered preliminary and are not included in the report.
The monitoring of NMHC (non-methane hydrocarbons) has become more diverse with time in terms of instrumentation. Starting in the early 1990s with standardized methods based on manual sampling in steel canisters with subsequent analyses at the lab, the methods now consist of a variety of instruments and measurement principles, including automated continuous monitors and manual flask samples. For oxygenated VOCs (OVOCs), sampling in DNPH-tubes with subsequent lab-analyses is still the only method in use at EMEP sites.
Within the EU infrastructure project ACTRIS-2, data quality issues related to measurements of VOC have been an important topic. Many of the institutions providing VOC data to EMEP have participated in the ACTRIS-2 project, either as formal partners or on a voluntary basis. Participation in ACTRIS-2 has meant an extensive effort with data checking including detailed discussions between the ACTRIS community and individual participants. There is no doubt that this extensive effort has benefited the EMEP program and has led to improved data quality in general.
Comparison between median levels in 2016 compared to the medians of the previous 10-years period, revealed a similar north-to-south pattern for several species.
Changes in instrumentation, procedures, station network etc. during the last two decades make it difficult to provide a rigorous and pan-European assessment of long-term trends of the observed VOCs. In this report we have estimated the long-term trends in NMHC over the 2000-2016 period at six selected sites by two independent statistical methods. These estimates indicate marked differences in the trends for the individual species. Small or non-significant trends were found for ethane over this period followed by propane which also showed fairly small reductions. On the other hand, components linked to road traffic (ethene, ethyne and toluene) showed the strongest drop in mean concentrations, up to 60-80% at some stations. The trend in n-butane was between these two groups of species with an estimated drop in the annual mean concentration of 20-40% over the 2000-2016 period
NILU
2018