Gå til innhold
  • Send

  • Kategori

  • Sorter etter

  • Antall per side

Fant 648 publikasjoner. Viser side 1 av 27:

Publikasjon  
År  
Kategori

Effect of Long-Range Transported Fire Aerosols on Cloud Condensation Nuclei Concentrations and Cloud Properties at High Latitudes

Kommula, Snehitha M.; Buchholz, Angela; Gramlich, Yvette; Mielonen, Tero; Hao, L.; Pullinen, Iida; Vettikkat, Lejish; Ylisirniö, A.; Joutsensaari, J.; Schobesberger, Siegfried; Tiitta, P; Leskinen, Ari; Heslin-Rees, Dominic; Haslett, S. L.; Siegel, Karolina; Lunder, Chris Rene; Zieger, Paul; Krejci, Radovan; Romakkaniemi, Sami; Mohr, C.; Virtanen, Annele

Active vegetation fires in south-eastern (SE) Europe resulted in a notable increase in the number concentration of aerosols and cloud condensation nuclei (CCN) particles at two high latitude locations—the SMEAR IV station in Kuopio, Finland, and the Zeppelin Observatory in Svalbard, high Arctic. During the fire episode aerosol hygroscopicity κ slightly increased at SMEAR IV and at the Zeppelin Observatory κ decreased. Despite increased κ in high CCN conditions at SMEAR IV, the aerosol activation diameter increased due to the decreased supersaturation with an increase in aerosol loading. In addition, at SMEAR IV during the fire episode, in situ measured cloud droplet number concentration (CDNC) increased by a factor of ∼7 as compared to non-fire periods which was in good agreement with the satellite observations (MODIS, Terra). Results from this study show the importance of SE European fires for cloud properties and radiative forcing in high latitudes.

American Geophysical Union (AGU)

2024

The Greenhouse Gas Budget of Terrestrial Ecosystems in East Asia Since 2000

Wang, Xuhui; Gao, Yuanyi; Jeong, Sujong; Ito, Akihiko; Bastos, Ana; Poulter, Benjamin; Wang, Yilong; Ciais, Philippe; Tian, Hanqin; Yuan, Wenping; Chandra, Naveen; Chevallier, Frédéric; Fan, Lei; Hong, Songbai; Lauerwald, Ronny; Li, Wei; Lin, Zhengyang; Pan, Naiqing; Patra, Prabir K.; Peng, Shushi; Ran, Lishan; Sang, Yuxing; Sitch, Stephen; Takashi, Maki; Thompson, Rona Louise; Wang, Chenzhi; Wang, Kai; Wang, Tao; Xi, Yi; Xu, Liang; Yan, Yanzi; Yun, Jeongmin; Zhang, Yao; Zhang, Yuzhong; Zhang, Zhen; Zheng, Bo; Zhou, Feng; Tao, Shu; Canadell, Josep G.; Piao, Shilong

American Geophysical Union (AGU)

2024

Modelled sources of airborne microplastics collected at a remote Southern Hemisphere site

Aves, Alex; Ruffell, Helena; Evangeliou, Nikolaos; Gaw, Sally; Revell, Laura E.

Airborne microplastics have emerged in recent years as ubiquitous atmospheric pollutants. However, data from the Southern Hemisphere, and remote regions in particular, are sparse. Here, we report airborne microplastic deposition fluxes measured during a five-week sampling campaign at a remote site in the foothills of the Southern Alps of New Zealand. Samples were collected over 24-hour periods for the first week and for 7-day periods thereafter. On average, atmospheric microplastic (MP) deposition fluxes were six times larger during the 24-hour sampling periods (150 MP m−2 day−1) than during the 7-day sampling periods (26 MP m−2 day−1), highlighting the importance of sampling frequency and deposition collector design to limit particle resuspension. Previous studies, many of which used weekly sampling frequencies or longer, may have substantially underestimated atmospheric microplastic deposition fluxes, depending on the study design. To identify likely sources of deposited microplastics, we performed simulations with a global dispersion model coupled with an emissions inventory of airborne microplastics. Modelled deposition fluxes are in good agreement with observations, highlighting the potential for this method in tracing sources of deposited microplastics globally. Modelling indicates that sea-spray was the dominant source when microplastics underwent long-range atmospheric transport, with a small contribution from road dust.

Elsevier

2024

Can plastic related chemicals be indicators of plastic ingestion in an Arctic seabird?

Collard, France; Tulatz, Felix; Harju, Mikael; Herzke, Dorte; Bourgeon, Sophie; Gabrielsen, Geir Wing

For decades, the northern fulmar (Fulmarus glacialis) has been found to ingest and accumulate high loads of plastic due to its feeding ecology and digestive tract morphology. Plastic ingestion can lead to both physical and toxicological effects as ingested plastics can be a pathway for hazardous chemicals into seabirds' tissues. Many of these contaminants are ubiquitous in the environment and the contribution of plastic ingestion to the uptake of those contaminants in seabirds’ tissues is poorly known. In this study we aimed at quantifying several plastic-related chemicals (PRCs) -PBDE209, several dechloranes and several phthalate metabolites- and assessing their relationship with plastic burdens (both mass and number) to further investigate their potential use as proxies for plastic ingestion. Blood samples from fulmar fledglings and liver samples from both fledgling and non-fledgling fulmars were collected for PRC quantification. PBDE209 and dechloranes were quantified in 39 and 33 livers, respectively while phthalates were quantified in plasma. Plastic ingestion in these birds has been investigated previously and showed a higher prevalence in fledglings. PBDE209 was detected in 28.2 % of the liver samples. Dechlorane 602 was detected in all samples while Dechloranes 601 and 604 were not detected in any sample. Dechlorane 603 was detected in 11 individuals (33%). Phthalates were detected in one third of the analysed blood samples. Overall, no significant positive correlation was found between plastic burdens and PRC concentrations. However, a significant positive relationship between PBDE209 and plastic number was found in fledglings, although likely driven by one outlier. Our study shows the complexity of PRC exposure, the timeline of plastic ingestion and subsequent uptake of PRCs into the tissues in birds, the additional exposure of these chemicals via their prey, even in a species ingesting high loads of plastic.

Elsevier

2024

Air pollution emission inventory using national high-resolution spatial parameters for the Nordic countries and analysis of PM2.5 spatial distribution for road transport and machinery and off-road sectors

Paunu, Ville-Veikko; Karvosenoja, Niko; Segersson, David; Lopez-Aparicio, Susana; Nielsen, Ole-Kenneth; Plejdrup, Marlene S.; Thorsteinsson, Throstur; Vo, Dam Thanh; Kuenen, Jeroen; van der Gon, Hugo Denier; Jalkanen, Jukka-Pekka; Brandt, Jørgen; Geels, Camilla

Air pollution is an important cause of adverse health effects, even in the Nordic countries, which have relatively good air quality. Modelling-based air quality assessment of the health impacts relies on reliable model estimates of ambient air pollution concentrations, which furthermore rely on good-quality spatially resolved emission data. While quantitative emission estimates are the cornerstone of good emission data, description of the spatial distribution of the emissions is especially important for local air quality modelling at high resolution. In this paper we present a new air pollution emission inventory for the Nordic countries with high-resolution spatial allocation (1 km × 1 km) covering the years 1990, 1995, 2000, 2005, 2010, 2012, and 2014. The inventory is available at https://doi.org/10.5281/zenodo.10571094 (Paunu et al., 2023). To study the impact of applying national data and methods to the spatial distribution of the emissions, we compared road transport and machinery and off-road sectors to CAMS-REGv4.2, which used a consistent spatial distribution method throughout Europe for each sector. Road transport is a sector with well-established proxies for spatial distribution, while for the machinery and off-road sector, the choice of proxies is not as straightforward as it includes a variety of different type of vehicles and machines operating in various environments. We found that CAMS-REGv4.2 was able to produce similar spatial patterns to our Nordic inventory for the selected sectors. However, the resolution of our Nordic inventory allows for more detailed impact assessment than CAMS-REGv4.2, which had a resolution of 0.1° × 0.05° (longitude–latitude, roughly 5.5 km × 3.5–6.5 km in the Nordic countries). The EMEP/EEA Guidebook chapter on spatial mapping of emissions has recommendations for the sectoral proxies. Based on our analysis we argue that the guidebook should have separate recommendations for proxies for several sub-categories of the machinery and off-road sectors, instead of including them within broader sectors. We suggest that land use data are the best starting point for proxies for many of the subsectors, and they can be combined with other suitable data to enhance the spatial distribution. For road transport, measured traffic flow data should be utilized where possible, to support modelled data in the proxies.

2024

New insights from an eight-year study on per- and polyfluoroalkyl substances in an urban terrestrial ecosystem

Heimstad, Eldbjørg Sofie; Nygård, Torgeir; Moe, Børge; Herzke, Dorte

Per- and polyfluoroalkyl substances (PFAS) were analysed in a high number of terrestrial samples of soil, earthworm, bird eggs and liver from red fox and brown rat in an urban area in Norway from 2013 to 2020. PFOS and the long chain PFCAs were the most dominating compounds in all samples, proving their ubiquitous distribution. Other less studied compounds such as 6:2 FTS were first and foremost detected in earthworm. 8:2 FTS was found in many samples of fieldfare egg, sparrowhawk egg and earthworm, where the eggs had highest concentrations. Highest concentrations for both 6:2 FTS and 8:2 FTS were detected at present and former industry areas. FOSA was detected in many samples of the species with highest concentrations in red fox liver and brown rat liver of 3.3 and 5.5 ng/g ww.

PFAS concentrations from the urban area were significantly higher than from background areas indicating that some of the species can be suitable as markers for PFAS emissions in an urban environment. Fieldfare eggs had surprisingly high concentrations of PFOS and PFCA concentrations from areas known to be or have been influenced by industry. Biota-soil-accumulation factor and magnification calculations indicate accumulation and magnification potential for several PFAS.

Earthworm and fieldfare egg had average concentrations above the Canadian and European thresholds in diet for avian wildlife and predators. For earthworms, 18 % of the samples exceeded the European threshold (33 ng/g ww) of PFOS in prey for predators, and for fieldfare eggs, 35 % of the samples were above the same threshold. None of the soil samples exceeded a proposed PNEC of PFOS for soil living organisms of 373 ng/g dw.

Elsevier

2024

Widespread Pesticide Distribution in the European Atmosphere Questions their Degradability in Air

Mayer, Ludovic; Degrendele, Celine; Senk, Petr; Kohoutek, Jiří; Přibylovác, Petra; Kukučka, Petr; Melymuk, Lisa; Durand, Amandine; Ravier, Sylvain; Alastuey, Andres; Baker, Alex R.; Baltensperger, Urs; Baumann-Stanzer, Kathrin; Biermann, Tobias; Bohlin-Nizzetto, Pernilla; Ceburnis, Darius; Conil, Sébastien; Couret, Cedric; Degorska, Anna; Diapouli, Evangelia; Eckhardt, Sabine; Eleftheriadis, Konstantinos; Forster, Grant L.; Freier, Korbinian; Gheusi, Francois; Gini, Maria; Hellén, Heidi; Henne, Stephan; Hermann, Hartmut; Šmejkalová, Adéla Holubová; Horrak, Urmas; Hüglin, Christoph; Junninen, Heikki; Kristensson, Adam; Langrene, Laurent; Levula, Janne; Lothon, Marie; Ludewig, Elke; Makkonen, Ulla; Matejovičová, Jana; Mihalopoulos, Nikolaos; Mináriková, Veronika; Moche, Wolfgang; Noe, Steffen M.; Perez, Noemi; Petäjä, Tuukka; Pont, Veronique; Poulain, Laurent; Quivet, Etienne; Ratz, Gabriela; Rehm, Till; Reimann, Stefan; Simmons, Ivan; Sonke, Jeroen E.; Sorribas, Mar; Spoor, Ronald; Swart, Daan P.J.; Vasilatou, Vasiliki; Wortham, Henri; Yela, Margarita; Zarmpas, Pavlos; Zellweger-Fäsi, Claudia; Tørseth, Kjetil; Laj, Paolo G.; Klanova, Jana; Lammel, Gerhard

Risk assessment of pesticide impacts on remote ecosystems makes use of model-estimated degradation in air. Recent studies suggest these degradation rates to be overestimated, questioning current pesticide regulation. Here, we investigated the concentrations of 76 pesticides in Europe at 29 rural, coastal, mountain, and polar sites during the agricultural application season. Overall, 58 pesticides were observed in the European atmosphere. Low spatial variation of 7 pesticides suggests continental-scale atmospheric dispersal. Based on concentrations in free tropospheric air and at Arctic sites, 22 pesticides were identified to be prone to long-range atmospheric transport, which included 15 substances approved for agricultural use in Europe and 7 banned ones. Comparison between concentrations at remote sites and those found at pesticide source areas suggests long atmospheric lifetimes of atrazine, cyprodinil, spiroxamine, tebuconazole, terbuthylazine, and thiacloprid. In general, our findings suggest that atmospheric transport and persistence of pesticides have been underestimated and that their risk assessment needs to be improved.

2024

Composition and sources of carbonaceous aerosol in the European Arctic at Zeppelin Observatory, Svalbard (2017 to 2020)

Yttri, Karl Espen; Bäcklund, Are; Conen, Franz; Eckhardt, Sabine; Evangeliou, Nikolaos; Fiebig, Markus; Kasper-Giebl, Anne; Gold, Avram; Gundersen, Hans; Myhre, Cathrine Lund; Platt, Stephen Matthew; Simpson, David; Surratt, Jason D.; Szidat, Sönke; Rauber, Martin; Tørseth, Kjetil; Ytre-Eide, Martin Album; Zhang, Zhenfa; Aas, Wenche

We analyzed long-term measurements of organic carbon, elemental carbon, and source-specific organic tracers from 2017 to 2020 to constrain carbonaceous aerosol sources in the rapidly changing Arctic. Additionally, we used absorption photometer (Aethalometer) measurements to constrain equivalent black carbon (eBC) from biomass burning and fossil fuel combustion, using positive matrix factorization (PMF).

Our analysis shows that organic tracers are essential for understanding Arctic carbonaceous aerosol sources. Throughout 2017 to 2020, levoglucosan exhibited bimodal seasonality, reflecting emissions from residential wood combustion (RWC) in the heating season (November to May) and from wildfires (WFs) in the non-heating season (June to October), demonstrating a pronounced interannual variability in the influence of WF. Biogenic secondary organic aerosol (BSOA) species (2-methyltetrols) from isoprene oxidation was only present in the non-heating season, peaking in July to August. Warm air masses from Siberia led to a substantial increase in 2-methyltetrols in 2019 and 2020 compared to 2017 to 2018. This highlights the need to investigate the contribution of local sources vs. long-range atmospheric transport (LRT), considering the temperature sensitivity of biogenic volatile organic compound emissions from Arctic vegetation. Tracers of primary biological aerosol particles (PBAPs), including various sugars and sugar alcohols, showed elevated levels in the non-heating season, although with different seasonal trends, whereas cellulose had no apparent seasonality. Most PBAP tracers and 2-methyltetrols peaked during influence of WF emissions, highlighting the importance of measuring a range of source-specific tracers to understand sources and dynamics of carbonaceous aerosol. The seasonality of carbonaceous aerosol was strongly influenced by LRT episodes, as background levels are extremely low. In the non-heating season, the organic aerosol peak was as influenced by LRT, as was elemental carbon during the Arctic haze period.

Source apportionment of carbonaceous aerosol by Latin hypercube sampling showed mixed contributions from RWC (46 %), fossil fuel (FF) sources (27 %), and BSOA (25 %) in the heating season. In contrast, the non-heating season was dominated by BSOA (56 %), with lower contributions from WF (26 %) and FF sources (15 %).

Source apportionment of eBC by PMF showed that FF combustion dominated eBC (70±2.7 %), whereas RWC (22±2.7 %) was more abundant than WF (8.0±2.9 %). Modeled BC concentrations from FLEXPART (FLEXible PARTicle dispersion model) attributed an almost equal share to FF sources (51±3.1 %) and to biomass burning. Both FLEXPART and the PMF analysis concluded that RWC is a more important source of (e)BC than WF. However, with a modeled RWC contribution of 30±4.1 % and WF of 19±2.8 %, FLEXPART suggests relatively higher contributions to eBC from these sources. Notably, the BB fraction of EC was twice as high as that of eBC, reflecting methodological differences between source apportionment by LHS and PMF. However, important conclusions drawn are unaffected, as both methods indicate the presence of RWC- and WF-sourced BC at Zeppelin, with a higher relative BB contribution during the non-heating season.

In summary, organic aerosol (281±106 ng m−3) constitutes a significant fraction of Arctic PM10, although surpassed by sea salt aerosol (682±46.9 ng m−3), mineral dust (613±368 ng m−3), and typically non-sea-salt sulfate SO (314±62.6 ng m−3), originating mainly from anthropogenic sources in winter and from natural sources in summer.

2024

Recommendations for reporting equivalent black carbon (eBC) mass concentrations based on long-term pan-European in-situ observations

Savadkoohi, Marjan; Pandolfi, Marco; Favez, Olivier; Putaud, Jean-Philippe; Eleftheriadis, Konstantinos; Fiebig, Markus; Hopke, Philip K.; Laj, Paolo G.; Wiedensohler, Alfred; Alados-Arboledas, Lucas; Bastian, Susanne; Chazeau, Benjamin; Maria, Alvaro Clemente; Colombi, Cristina; Costabile, Francesca; Green, David C.; Hueglin, Christoph; Liakakou, Eleni; Luoma, Krista; Listrani, Stefano; Mihalopoulos, Nikos; Marchand, Nicolas; Močnik, Griša; Niemi, Jarkko V; Ondráček, Jakub; Petit, Jean Eudes; Rattigan, Oliver V.; Reche, Cristina; Timonen, Hilkka; Titos, Gloria; Tremper, Anja H.; Vratolis, Stergios; Vodicka, Petr; Funes, Eduardo Yubero; Zíková, Naděžda; Harrison, Roy M.; Petäjä, Tuukka; Alastuey, Andrés; Querol, Xavier

A reliable determination of equivalent black carbon (eBC) mass concentrations derived from filter absorption photometers (FAPs) measurements depends on the appropriate quantification of the mass absorption cross-section (MAC) for converting the absorption coefficient (babs) to eBC. This study investigates the spatial–temporal variability of the MAC obtained from simultaneous elemental carbon (EC) and babs measurements performed at 22 sites. We compared different methodologies for retrieving eBC integrating different options for calculating MAC including: locally derived, median value calculated from 22 sites, and site-specific rolling MAC. The eBC concentrations that underwent correction using these methods were identified as LeBC (local MAC), MeBC (median MAC), and ReBC (Rolling MAC) respectively. Pronounced differences (up to more than 50 %) were observed between eBC as directly provided by FAPs (NeBC; Nominal instrumental MAC) and ReBC due to the differences observed between the experimental and nominal MAC values. The median MAC was 7.8 ± 3.4 m2 g-1 from 12 aethalometers at 880 nm, and 10.6 ± 4.7 m2 g-1 from 10 MAAPs at 637 nm. The experimental MAC showed significant site and seasonal dependencies, with heterogeneous patterns between summer and winter in different regions. In addition, long-term trend analysis revealed statistically significant (s.s.) decreasing trends in EC. Interestingly, we showed that the corresponding corrected eBC trends are not independent of the way eBC is calculated due to the variability of MAC. NeBC and EC decreasing trends were consistent at sites with no significant trend in experimental MAC. Conversely, where MAC showed s.s. trend, the NeBC and EC trends were not consistent while ReBC concentration followed the same pattern as EC. These results underscore the importance of accounting for MAC variations when deriving eBC measurements from FAPs and emphasize the necessity of incorporating EC observations to constrain the uncertainty associated with eBC.

Elsevier

2024

Aircraft-based mass balance estimate of methane emissions from offshore gas facilities in the southern North Sea

Pühl, Magdalena; Roiger, Anke; Fiehn, Alina; Gorchov Negron, Alan M.; Kort, Eric A.; Schwietzke, Stefan; Pisso, Ignacio; Foulds, Amy; Lee, James; France, James L.; Jones, Anna E.; Lowry, Dave; Fisher, Rebecca E.; Huang, Langwen; Shaw, Jacob; Bateson, Prudence; Andrews, Stephen; Young, Stuart; Dominutti, Pamela; Lachlan-Cope, Tom; Weiss, Alexandra; Allen, Grant

Atmospheric methane (CH4) concentrations have more than doubled since the beginning of the industrial age, making CH4 the second most important anthropogenic greenhouse gas after carbon dioxide (CO2). The oil and gas sector represents one of the major anthropogenic CH4 emitters as it is estimated to account for 22 % of global anthropogenic CH4 emissions. An airborne field campaign was conducted in April–May 2019 to study CH4 emissions from offshore gas facilities in the southern North Sea with the aim of deriving emission estimates using a top-down (measurement-led) approach. We present CH4 fluxes for six UK and five Dutch offshore platforms or platform complexes using the well-established mass balance flux method. We identify specific gas production emissions and emission processes (venting and fugitive or flaring and combustion) using observations of co-emitted ethane (C2H6) and CO2. We compare our top-down estimated fluxes with a ship-based top-down study in the Dutch sector and with bottom-up estimates from a globally gridded annual inventory, UK national annual point-source inventories, and operator-based reporting for individual Dutch facilities. In this study, we find that all the inventories, except for the operator-based facility-level reporting, underestimate measured emissions, with the largest discrepancy observed with the globally gridded inventory. Individual facility reporting, as available for Dutch sites for the specific survey date, shows better agreement with our measurement-based estimates. For all the sampled Dutch installations together, we find that our estimated flux of (122.9 ± 36.8) kg h−1 deviates by a factor of 0.64 (0.33–12) from reported values (192.8 kg h−1). Comparisons with aircraft observations in two other offshore regions (the Norwegian Sea and the Gulf of Mexico) show that measured, absolute facility-level emission rates agree with the general distribution found in other offshore basins despite different production types (oil, gas) and gas production rates, which vary by 2 orders of magnitude. Therefore, mitigation is warranted equally across geographies.

2024

Air-soil cycling of oxygenated, nitrated and parent polycyclic aromatic hydrocarbons in source and receptor areas

Mwangi, John K.; Degrendele, Celine; Bandowe, Benjamin A. M.; Bohlin-Nizzetto, Pernilla; Halse, Anne Karine; Šmejkalová, Adela Holubová; Kim, Jun-Tae; Kukučka, Petr; Martiník, Jakub; Nežiková, Barbora Palátová; Přibylová, Petra; Prokeš, Roman; Sáňka, Milan; Tannous, Mariam; Vinkler, Jakub; Lammel, Gerhard

Elsevier

2024

Trends in Air Pollution in Europe, 2000–2019

Aas, Wenche; Fagerli, Hilde; Alastuey, Andres; Cavalli, Fabrizia; Degorska, Anna; Feigenspan, Stefan; Brenna, Hans; Gliss, Jonas; Heinesen, Daniel; Hueglin, Christoph; Holubová, Adela; Jaffrezo, Jean-Luc; Mortier, Augustin; Murovec, Marijana; Putaud, Jean-Philippe; Rüdige, Julian; Simpson, David; Solberg, Sverre; Tsyro, Svetlana; Tørseth, Kjetil; Yttri, Karl Espen

This paper encompasses an assessment of air pollution trends in rural environments in Europe over the 2000–2019 period, benefiting from extensive long-term observational data from the EMEP monitoring network and EMEP MSC-W model computations. The trends in pollutant concentrations align with the decreasing emission patterns observed throughout Europe. Annual average concentrations of sulfur dioxide, particulate sulfate, and sulfur wet deposition have shown consistent declines of 3-4% annually since 2000. Similarly, oxidized nitrogen species have markedly decreased across Europe, with an annual reduction of 1.5-2% in nitrogen dioxide concentrations, total nitrate in the air, and oxidized nitrogen deposition. Notably, emission reductions and model predictions appear to slightly surpass the observed declines in sulfur and oxidized nitrogen, indicating a potential overestimation of reported emission reductions. Ammonia emissions have decreased less compared to other pollutants since 2000. Significant reductions in particulate ammonium have however, been achieved due to the impact of reductions in SOx and NOx emissions. For ground level ozone, both the observed and modelled peak levels in summer show declining trends, although the observed decline is smaller than modelled. There have been substantial annual reductions of 1.8% and 2.4% in the concentrations of PM10 and PM2.5, respectively. Elemental carbon has seen a reduction of approximately 4.5% per year since 2000. A similar reduction for organic carbon is only seen in winter when primary anthropogenic sources dominate. The observed improvements in European air quality emphasize the importance of comprehensive legislations to mitigate emissions.

2024

Optical and Microphysical Properties of the Aerosols during a Rare Event of Biomass-Burning Mixed with Polluted Dust

Gidarakou, Marilena; Papayannis, Alexandros; Kokkalis, Panagiotis; Evangeliou, Nikolaos; Vratolis, Stergios; Remoundaki, Emmanouella; Zwaaftink, Christine Groot; Eckhardt, Sabine; Veselovskii, Igor; Mylonaki, Maria; Argyrouli, Athina; Eleftheriadis, Konstantinos; Solomos, Stavros; Gini, Maria

A rare event of mixed biomass-burning and polluted dust aerosols was observed over Athens, Greece (37.9° N, 23.6° E), during 21–26 May 2014. This event was studied using a synergy of a 6-wavelength elastic-Raman-depolarization lidar measurements, a CIMEL sun photometer, and in situ instrumentation. The FLEXPART dispersion model was used to identify the aerosol sources and quantify the contribution of dust and black carbon particles to the mass concentration. The identified air masses were found to originate from Kazakhstan and Saharan deserts, under a rare atmospheric pressure system. The lidar ratio (LR) values retrieved from the Raman lidar ranged within 25–89 sr (355 nm) and 35–70 sr (532 nm). The particle linear depolarization ratio (δaer) ranged from 7 to 28% (532 nm), indicating mixing of dust with biomass-burning particles. The aerosol optical depth (AOD) values derived from the lidar ranged from 0.09–0.43 (355 nm) to 0.07–0.25 (532 nm). An inversion algorithm was used to derive the mean aerosol microphysical properties (mean effective radius (reff), single scattering albedo (SSA), and mean complex refractive index (m)) inside selected atmospheric layers. We found that reff was 0.12–0.51 (±0.04) µm, SSA was 0.94–0.98 (±0.19) (at 532 nm), while m ranged between 1.39 (±0.05) + 0.002 (±0.001)i and 1.63 (±0.05) + 0.008 (±0.004)i. The polarization lidar photometer networking (POLIPHON) algorithm was used to estimate the vertical profile of the mass concentration for the dust and non-dust components. A mean mass concentration of 15 ± 5 μg m−3 and 80 ± 29 μg m−3 for smoke and dust was estimated for selected days, respectively. Finally, the retrieved aerosol microphysical properties were compared with column-integrated sun photometer CIMEL data with good agreement

MDPI

2024

Holocene black carbon in New Zealand lake sediment records

Brugger, Sandra O.; McWethy, David B.; Chellman, Nathan J.; Prebble, Matiu; Courtney Mustaphi, Colin J.; Eckhardt, Sabine; Plach, Andreas; Stohl, Andreas; Wilmshurst, Janet M.; McConnell, Joseph R.; Whitlock, Cathy

Elsevier

2024

Hemispheric-scale heavy metal pollution from South American and Australian mining and metallurgy during the Common Era

McConnell, Joseph R.; Chellman, Nathan J.; Wensman, Sophia M.; Plach, Andreas; Stanish, Charles; Santibáñez, Pamela A.; Brugger, Sandra O.; Eckhardt, Sabine; Freitag, Johannes; Kipfstuhl, Sepp; Stohl, Andreas

Elsevier

2024

A scalable method for identifying key indicators to assess urban environmental sustainability: A case study in Norway

Liu, Hai Ying; Ebrahimi, Babak

Urbanization presents numerous societal challenges and exacerbates environmental issues. It is crucial to comprehend the current state and future direction of cities to formulate strategies and actions that mitigate negative consequences while ensuring a prosperous future for citizens. This study presents a universally applicable method for selecting indicators to gauge urban environmental sustainability. It aims to aid in structuring thinking for understanding and implementing Sustainable Development Goals (SDGs) within urban settings, using Norway as a case study but with a clear potential for broader applications. To achieve this, a comprehensive literature survey was conducted to gain insight into how urban environmental sustainability is conceptualized and operationalized in Norway. This involved assessing the key environmental challenges, as well as the strategies and action plans associated with them. Standardized sustainable cities' indicators served as references, which were then tailored to the municipal level to address the identified environmental challenges specific to Norwegian cities. Furthermore, the study discussed the proposed indicators for tracking the progress and state of these specific environmental challenges. In doing so, it establishes a foundation for comprehending environmental issues and establishing connections between indicators and environmental strategies and action plans in the urban sustainability context. Importantly, the methodologies and indicators we have unveiled in this study are designed to be applicable to cities beyond Norway, offering a scalable and adaptable approach for evaluating environmental challenges internationally. This work proposes a novel approach for evaluating the status and trends of environmental challenges by employing targeted indicators. These indicators can be expanded to include social and economic dimensions, enabling decision-makers and stakeholders to prioritize actions towards urban sustainability.

Elsevier

2024

Microfiber emissions from wastewater effluents: abundance, transport behavior and exposure risk for biota in an arctic fjord

Herzke, Dorte; Ghaffari, Peygham; Sundet, Jan Henry; Tranang, Caroline Aas; Halsband, Claudia

Microfibers (MF) are one of the major classes of microplastic found in the marine environment on a global scale. Very little is known about how they move and distribute from point sources such as wastewater effluents into the ocean. We chose Adventfjorden near the settlement of Longyearbyen on the Arctic Svalbard archipelago as a case study to investigate how microfibers emitted with untreated wastewater will distribute in the fjord, both on a spatial and temporal scale. Fiber abundance in the effluent was estimated from wastewater samples taken during two one-week periods in June and September 2017. Large emissions of MFs were detected, similar in scale to a modern WWTP serving 1.3 million people and providing evidence of the importance of untreated wastewater from small settlements as major local sources for MF emissions in the Arctic. Fiber movement and distribution in the fjord mapped using an online-coupled hydrodynamic-drift model (FVCOM-FABM). For parameterizing a wider spectrum of fibers from synthetic to wool, four different density classes of MFs, i.e., buoyant, neutral, sinking, and fast sinking fibers are introduced to the modeling framework. The results clearly show that fiber class has a large impact on the fiber distributions. Light fibers remained in the surface layers and left the fjord quickly with outgoing currents, while heavy fibers mostly sank to the bottom and deposited in the inner parts of the fjord and along the northern shore. A number of accumulation sites were identified within the fjord. The southern shore, in contrast, was much less affected, with low fiber concentrations throughout the modeling period. Fiber distributions were then compared with published pelagic and benthic fauna distributions in different seasons at selected stations around the fjord. The ratios of fibers to organisms showed a very wide range, indicating hot spots of encounter risk for pelagic and benthic biota. This approach, in combination with in-situ ground-truthing, can be instrumental in understanding microplastic pathways and fate in fjord systems and coastal areas and help authorities develop monitoring and mitigation strategies for microfiber and microplastic pollution in their local waters.

Frontiers Media S.A.

2021

Trends in polar ozone loss since 1989: potential sign of recovery in the Arctic ozone column

Pazmiño, Andrea; Goutail, Florence; Godin-Beekmann, Sophie; Hauchecorne, Alain; Pommereau, Jean-Pierre; Chipperfield, Martyn P.; Feng, Wuhu; Lefèvre, Franck; Lecouffe, Audrey; Van Roozendael, Michel; Jepsen, Nis; Hansen, Georg H.; Kivi, Rigel; Strong, Kimberly; Walker, Kaley A.

Ozone depletion over the polar regions is monitored each year by satellite- and ground-based instruments. In this study, the vortex-averaged ozone loss over the last 3 decades is evaluated for both polar regions using the passive ozone tracer of the chemical transport model TOMCAT/SLIMCAT and total ozone observations from Système d'Analyse par Observation Zénithale (SAOZ) ground-based instruments and Multi-Sensor Reanalysis (MSR2). The passive-tracer method allows us to determine the evolution of the daily rate of column ozone destruction and the magnitude of the cumulative column loss at the end of the winter. Three metrics are used in trend analyses that aim to assess the ozone recovery rate over both polar regions: (1) the maximum ozone loss at the end of the winter, (2) the onset day of ozone loss at a specific threshold, and (3) the ozone loss residuals computed from the differences between annual ozone loss and ozone loss values regressed with respect to sunlit volume of polar stratospheric clouds (VPSCs). This latter metric is based on linear and parabolic regressions for ozone loss in the Northern Hemisphere and Southern Hemisphere, respectively. In the Antarctic, metrics 1 and 3 yield trends of −2.3 % and −2.2 % per decade for the 2000–2021 period, significant at 1 and 2 standard deviations (σ), respectively. For metric 2, various thresholds were considered at the total ozone loss values of 20 %, 25 %, 30 %, 35 %, and 40 %, all of them showing a time delay as a function of year in terms of when the threshold is reached. The trends are significant at the 2σ level and vary from 3.5 to 4.2 d per decade between the various thresholds. In the Arctic, metric 1 exhibits large interannual variability, and no significant trend is detected; this result is highly influenced by the record ozone losses in 2011 and 2020. Metric 2 is not applied in the Northern Hemisphere due to the difficulty in finding a threshold value in enough of the winters. Metric 3 provides a negative trend in Arctic ozone loss residuals with respect to the sunlit VPSC fit of −2.00 ± 0.97 (1σ) % per decade, with limited significance at the 2σ level. With such a metric, a potential quantitative detection of ozone recovery in the Arctic springtime lower stratosphere can be made.

2023

Estimating volcanic ash emissions using retrieved satellite ash columns and inverse ash transport modelling using VolcanicAshInversion v1.2.1, within the operational eEMEP volcanic plume forecasting system (version rv4_17)

Brodtkorb, André R.; Benedictow, Anna Maria Katarina; Klein, Heiko; Kylling, Arve; Nyiri, Agnes; Valdebenito Bustamante, Alvaro Moises; Sollum, Espen; Kristiansen, Nina Iren

Accurate modeling of ash clouds from volcanic eruptions requires knowledge about the eruption source parameters including eruption onset, duration, mass eruption rates, particle size distribution, and vertical-emission profiles. However, most of these parameters are unknown and must be estimated somehow. Some are estimated based on observed correlations and known volcano parameters. However, a more accurate estimate is often needed to bring the model into closer agreement with observations.

This paper describes the inversion procedure implemented at the Norwegian Meteorological Institute for estimating ash emission rates from retrieved satellite ash column amounts and a priori knowledge. The overall procedure consists of five stages: (1) generate a priori emission estimates, (2) run forward simulations with a set of unit emission profiles, (3) collocate/match observations with emission simulations, (4) build system of linear equations, and (5) solve overdetermined systems. We go through the mathematical foundations for the inversion procedure, performance for synthetic cases, and performance for real-world cases. The novelties of this paper include a memory efficient formulation of the inversion problem, a detailed description and illustrations of the mathematical formulations, evaluation of the inversion method using synthetic known-truth data as well as real data, and inclusion of observations of ash cloud-top height. The source code used in this work is freely available under an open-source license and is able to be used for other similar applications.

2024

Reassessing the role of urban green space in air pollution control

Venter, Zander; Hassani, Amirhossein; Stange, Erik; Schneider, Philipp; Castell, Nuria

The assumption that vegetation improves air quality is prevalent in scientific, popular, and political discourse. However, experimental and modeling studies show the effect of green space on air pollutant concentrations in urban settings is highly variable and context specific. We revisited the link between vegetation and air quality using satellite- derived changes of urban green space and air pollutant concentrations from 2,615 established monitoring stations over Europe and the United States. Between 2010 and 2019, stations recorded declines in ambient NO2, (particulate matter) PM10, and PM2.5 (average of −3.14% y−1), but not O3 (+0.5% y−1), pointing to the general success of recent policy interventions to restrict anthropogenic emissions. The effect size of total green space on air pollution was weak and highly variable, particularly at the street scale (15 to 60 m radius) where vegetation can restrict ventilation. However, when isolating changes in tree cover, we found a negative association with air pollution at borough to city scales (120 to 16,000 m) particularly for O3 and PM. The effect of green space was smaller than the pollutant deposition and dispersion effects of meteorological drivers including precipitation, humidity, and wind speed. When averaged across spatial scales, a one SD increase in green space resulted in a 0.8% (95% CI: −3.5 to 2%) decline in air pollution. Our findings suggest that while urban greening may improve air quality at the borough- to- city scale, the impact is moderate and may have detrimental street- level effects depending on aerodynamic factors like vegetation type and urban form.
vegetation | urban planning | green infrastructure | ecosystem service | public health

2024

Query-driven Qualitative Constraint Acquisition

Belaid, Mohamed-Bachir; Belmecheri, Nassim; Gotlieb, Arnaud; Lazaar, Nadjib; Spieker, Helge

Many planning, scheduling or multi-dimensional packing problems involve the design of subtle logical combinations of temporal or spatial constraints. Recently, we introduced GEQCA-I, which stands for Generic Qualitative Constraint Acquisition, as a new active constraint acquisition method for learning qualitative constraints using qualitative queries. In this paper, we revise and extend GEQCA-I to GEQCA-II with a new type of query, universal query, for qualitative constraint acquisition, with a deeper query-driven acquisition algorithm. Our extended experimental evaluation shows the efficiency and usefulness of the concept of universal query in learning randomly-generated qualitative networks, including both temporal networks based on Allen’s algebra and spatial networks based on region connection calculus. We also show the effectiveness of GEQCA-II in learning the qualitative part of real scheduling problems.

2024

Design of multi-luminescent silica-based nanoparticles for the detection of liquid organic compounds

Delic, Asmira; Lindgren, Mikael; Psarrou, Maria; Economopoulos, Solon; Mariussen, Espen; Krivokapic, Alexander; Torsæter, Ole; Omran, Mohamed ; Einarsrud, Mari-Ann

Tracer testing in reservoir formations is utilised to determine residual oil saturation as part of optimum hydrocarbon production. Here, we present a novel detection method of liquid organic compounds by monodisperse SiO2 nanoparticles (NPs) containing two luminophores, a EuIII:EDTA complex and a newly synthesised fluorophore based on the organic boron-dipyrromethene (BODIPY)-moiety. The particles exhibited stable EuIII PL emission intensity with a long lifetime in aqueous dispersion. The fluorescence of the BODIPY was also preserved in the aqueous environment. The ratiometric PL detection technique was demonstrated by using toluene and 1-octanol as model compounds of crude oil. The optimal synthesis conditions were found to give NPs with a diameter of ~100 nm, which is suitable for transport through porous oil reservoir structures. The cytotoxicity of the NPs was confirmed to be very low for human lung cell and fish cell lines. These findings demonstrate the potential of the NPs to replace the hazardous chemicals used to estimate the residual oil saturation. Moreover, the ratiometric PL detection technique is anticipated to be of benefit in other fields, such as biotechnology, medical diagnostics, and environmental monitoring, where a reliable and safe detection of a liquid organic phase is needed.

Wiley-VCH

2024

The challenges of opportunistic sampling when comparing prevalence of plastics in diving seabirds: A multi-species example from Norway

Benjaminsen, Stine Charlotte; Dehnhard, Nina; Herzke, Dorte; Johnsen, Arild; Anker-Nilssen, Tycho; Bourgeon, Sophie; Collard, France; Langset, Magdalene; Christensen-Dalsgaard, Signe; Gabrielsen, Geir W.

There is a need for baseline information about how much plastics are ingested by wildlife and potential negative consequences thereof. We analysed the frequency of occurrence (FO) of plastics >1 mm in the stomachs of five pursuit-diving seabird species collected opportunistically.

Atlantic puffins (Fratercula arctica) found emaciated on beaches in SW Norway had the highest FO of plastics (58.8 %), followed by emaciated common guillemots (Uria aalge; 9.1 %) also found beached in either SW or SE Norway. No plastics were detected in razorbills (Alca torda), great cormorants (Phalacrocorax carbo), and European shags (Gulosus aristotelis) taken as bycatch in northern Norway. This is the first study to report on plastic ingestion of these five species in northern Europe, and it highlights both the usefulness and limitations of opportunistic sampling. Small sample sizes, as well as an unbalanced sample design, complicated the interpretation of the results.

Elsevier

2024

Phthalate contamination in marine mammals off the Norwegian coast

Andvik, Clare; Bories, Pierre; Harju, Mikael; Borgå, Katrine; Jourdain, Eve; Karoliussen, Richard; Rikardsen, Audun; Routti, Heli; Blévin, Pierre

Phthalates are used in plastics, found throughout the marine environment and have the potential to cause adverse health effects. In the present study, we quantified blubber concentrations of 11 phthalates in 16 samples from stranded and/or free-living marine mammals from the Norwegian coast: the killer whale (Orcinus orca), sperm whale (Physeter macrocephalus), long-finned pilot whale (Globicephala melas), white-beaked dolphin (Lagenorhynchus albirostris), harbour porpoise (Phocoena phocoena), and harbour seal (Phoca vitulina). Five compounds were detected across all samples: benzyl butyl phthalate (BBP; in 50 % of samples), bis(2-ethylhexyl) phthalate (DEHP; 33 %), diisononyl phthalate (DiNP; 33 %), diisobutyl phthalate (DiBP; 19 %), and dioctyl phthalate (DOP; 13 %). Overall, the most contaminated individual was the white-beaked dolphin, whilst the lowest concentrations were measured in the killer whale, sperm whale and long-finned pilot whale. We found no phthalates in the neonate killer whale. The present study is important for future monitoring and management of these toxic compounds.

Elsevier

2023

Publikasjon
År
Kategori