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Long-term changes of heavy metal transboundary pollution of the environment (1990-2010). EMEP contribution to the revision of the Heavy Metal Protocol. EMEP Status Report, 2/2012
2012
2013
2007
2001
2010
2023
This study investigates the impact of meteorological variations on the long-term patterns of PM2.5 in Delhi from 2007 to 2022 using the AirGAM 2022r1 model. Generalized Additive Modeling was employed to analyze meteorology-adjusted (removing the influence of inter-annual variations in meteorology) and unadjusted trends (trends without considering meteorology) while addressing auto-correlation. PM2.5 levels showed a modest decline of 14 μg m−3 unadjusted and 18 μg m−3 meteorology-adjusted over the study period. Meteorological conditions and time factors significantly influenced trends. Temperature, wind speed, wind direction, humidity, boundary layer height, medium-height cloud cover, precipitation, and time variables including day-of-week, day-of-year, and overall time, were used as GAM model inputs. The model accounted for 55% of PM2.5 variability (adjusted R-squared = 0.55). Day-of-week and medium-height cloud cover were non-significant, while other covariates were significant (p
Elsevier
2024
2010
2013
2013
2015
2004
2021
Aerosols are an important constituent of the atmosphere both influencing the climate system and contributing to increasing pollution of the Arctic. At the same time, their adequate monitoring is a big challenge, as instruments on the ground only can sample aerosols in the lowermost atmosphere. For this reason, these measurements are complemented with observations of aerosol optical depth (AOD) which quantify the total amount of aerosols throughout the atmosphere from the attenuation of direct sunlight (and moonlight). This procedure requires extremely careful instrument calibration and removal of cloud contaminated data. In Svalbard, such measurements have been performed by several research groups with different instruments, mostly in Ny-Ålesund and in Hornsund, but also on research vessels offshore. In the framework of the SSF Strategic Grant project ReHearsol, all AOD data from the Svalbard region since 2002 have been collected and made available to the SIOS research community. They indicate that number and intensity of Arctic haze episodes occurring in late winter and spring have decreased consistently and significantly in the last 20 years, while pollution events in summer/early autumn, caused by boreal biomass burning, are on the rise, though not as consistently. Comparison between in-situ measurements at Gruvebadet Atmosphere Laboratory in Ny-Ålesund and AOD measurements indicate that most (more than 65%) of the episodes with high aerosol load are not captured by surface measurements. This finding does not change when one includes in-situ measurements at Zeppelin Observatory (475 m a.s.l.). Studying extensive high-AOD episodes such as those in summer 2019 requires a multi-tool approach including in-situ and remote-sensing measurements combined with model tools.
2023
2016
2022
2017
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.
2018
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2008