scholarly journals Constraining the atmospheric limb of the plastic cycle

2021 ◽  
Author(s):  
Natalie Mahowald ◽  
Janice Brahney ◽  
Marje Prank ◽  
Gavin Cornwell ◽  
Zbigniew Klimont ◽  
...  
Keyword(s):  
Biodegradable Polymers ◽  
Social Issues ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Optimal Estimation ◽  
Future Research ◽  
Emission Sources ◽  
Source Attribution ◽  
Plastic Pollution ◽  
Transport Pathways

<p>Plastic pollution is one of the most pressing environmental and social issues of the 21<sup>st</sup> century. Recent work has highlighted the atmosphere’s role in transporting microplastics to remote locations. Here we use in situ observations of microplastic deposition combined with an atmospheric transport model and optimal estimation techniques to test hypotheses of the most likely sources of atmospheric plastic. Results suggest that atmospheric microplastics in the western USA are primarily derived from secondary re-emission sources including roads, the ocean and agricultural soil dust. Using our best estimate of plastic sources and modeled transport pathways, most continents were net importers of plastics from the marine environment, underscoring the cumulative role of legacy pollution in the atmospheric burden of plastic. This effort is the first to use high resolution spatial and temporal deposition data along with several hypothesized emission sources to constrain atmospheric plastic. Akin to global biogeochemical cycles, plastics now spiral around the globe with distinct atmospheric, oceanic, cryospheric, and terrestrial lifetimes. Though advancements have been made in the manufacture of biodegradable polymers, our data suggest that extant non-biodegradable polymers will continue to cycle through the Earth’s systems. Due to limited observations and understanding of the source processes, there remain large uncertainties in the, transport, deposition, and source attribution of microplastics. Thus, we prioritize future research directions for understanding the plastic cycle.</p>

scholarly journals Constraining the atmospheric limb of the plastic cycle

2021 ◽  
Vol 118 (16) ◽  
pp. e2020719118
Author(s):  
Janice Brahney ◽  
Natalie Mahowald ◽  
Marje Prank ◽  
Gavin Cornwell ◽  
Zbigniew Klimont ◽  
...  
Keyword(s):  
Social Issues ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Optimal Estimation ◽  
Future Research ◽  
Emission Sources ◽  
Source Attribution ◽  
Plastic Pollution ◽  
Transport Pathways ◽  
Global Biogeochemical Cycles

Plastic pollution is one of the most pressing environmental and social issues of the 21st century. Recent work has highlighted the atmosphere’s role in transporting microplastics to remote locations [S. Allen et al., Nat. Geosci. 12, 339 (2019) and J. Brahney, M. Hallerud, E. Heim, M. Hahnenberger, S. Sukumaran, Science 368, 1257–1260 (2020)]. Here, we use in situ observations of microplastic deposition combined with an atmospheric transport model and optimal estimation techniques to test hypotheses of the most likely sources of atmospheric plastic. Results suggest that atmospheric microplastics in the western United States are primarily derived from secondary re-emission sources including roads (84%), the ocean (11%), and agricultural soil dust (5%). Using our best estimate of plastic sources and modeled transport pathways, most continents were net importers of plastics from the marine environment, underscoring the cumulative role of legacy pollution in the atmospheric burden of plastic. This effort uses high-resolution spatial and temporal deposition data along with several hypothesized emission sources to constrain atmospheric plastic. Akin to global biogeochemical cycles, plastics now spiral around the globe with distinct atmospheric, oceanic, cryospheric, and terrestrial residence times. Though advancements have been made in the manufacture of biodegradable polymers, our data suggest that extant nonbiodegradable polymers will continue to cycle through the earth’s systems. Due to limited observations and understanding of the source processes, there remain large uncertainties in the transport, deposition, and source attribution of microplastics. Thus, we prioritize future research directions for understanding the plastic cycle.

Global age of air spectrum from the earth surface to the upper troposphere and tropopause: a model study

2020 ◽  
Author(s):  
Aurelien Podglajen ◽  
Edward Charlesworth ◽  
Felix Ploeger
Keyword(s):  
Time Scales ◽  
Atmospheric Chemistry ◽  
Large Scale ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Convective Transport ◽  
Transport Pathways ◽  
Upper Troposphere ◽  
Major Player ◽  
Interhemispheric Transport

<p>Transport of air masses from the surface into the atmosphere occurs via a variety of processes (including clear-air turbulence, atmospheric convection and large-scale circulations), which entails a multitude of transport time scales. This complexity can be characterized in an atmospheric transport model by calculating the age of air spectrum (transit time distribution from the surface). Up to now, mainly the slow time scales of stratospheric and interhemispheric transport (>10 days) have thus been studied. Vertical transport through the troposphere, for which convection is the major player, has only been evaluated using a handful of measured compounds (Radon, CO2 and SF6). However, a wealth of chemically relevant species are affected by the detailed structure of the age spectrum. Recent work (Luo et al., 2018) have used this sensitivity in order to gain observational insights into the tropospheric age spectrum, calling for a comparison with models.</p><p>To that end, we derive upper tropospheric and tropopause age spectra in the EMAC (ECHAM/MESSy Atmospheric Chemistry) model using the Boundary Impulse Response (BIR) method. Because of the large range of time scales involved in tropospheric transport, which extend from tens of minutes (convective transport) to years (stratospheric intrusions), we rely on a suite of pulses with variable durations providing hourly resolution for short time scales (< 12 hours) and monthly for long ones (> 1 month). We first describe the age spectra obtained and their diurnal and seasonal variability. Then, we examine the transport properties from a few specific surface regions to the upper troposphere and stratosphere, with an emphasis on fast pathways from the tropical Western Pacific and on interhemispheric transport. Finally, we investigate the sensitivity of different transport pathways to changes in some of the available model parameterizations (convection) and to different set-ups (using nudging or not).</p>

scholarly journals Quantifying missing annual emission sources of heavy metals in the United Kingdom with an atmospheric transport model

2014 ◽  
Vol 479-480 ◽  
pp. 171-180 ◽  
Author(s):  
Anthony J. Dore ◽  
Stephen Hallsworth ◽  
Alan G. McDonald ◽  
Małgorzata Werner ◽  
Maciej Kryza ◽  
...  
Keyword(s):  
Heavy Metals ◽  
United Kingdom ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Emission Sources ◽  
The United Kingdom ◽  
Atmospheric Transport Model

Atmospheric transport and deposition of trace elements to lake erie from Urban areas

1996 ◽  
Vol 33 (4-5) ◽  
pp. 259-265
Author(s):  
Gerald J. Keeler ◽  
Nicola Pirrone
Keyword(s):  
Trace Elements ◽  
Urban Areas ◽  
Lake Erie ◽  
Atmospheric Transport ◽  
Spatial And Temporal Variation ◽  
Deposition Flux ◽  
Emission Sources ◽  
Dry Deposition Flux ◽  
Ambient Concentration ◽  
Ambient Concentrations

A hybrid receptor-deposition (HRD) modeling approach was used to determine the spatial and temporal variation in the ambient concentration and dry deposition flux of trace elements on fine (< 2.5 mm) and coarse (> 2.5 mm) particulate matter over Lake Erie. Upper-air observations from the National Weather Service (NWS) and ambient concentrations measured at two sampling sites downwind of major emission sources in the Lake Erie basin were input to the model. An evaluation of the deposition flux of size-segregated trace elements to the lake during the over-water transport was performed. The average total (fine + coarse) deposition flux was 9.6 ng/m2-h for V, 70 ng/m2-h for Mn, 3.2 ng/m2-h for As, 4.2 ng/m2-h for Se, 10 ng/m2-h for Cd, and 43.3 ng/m2-h for Pb.

scholarly journals The Environmental Effects of the April 2020 Wildfires and the Cs-137 Re-Suspension in the Chernobyl Exclusion Zone: A Multi-Hazard Threat

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 467
Author(s):  
Rocío Baró ◽  
Christian Maurer ◽  
Jerome Brioude ◽  
Delia Arnold ◽  
Marcus Hirtl
Keyword(s):  
Air Quality ◽  
Nuclear Power ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Point Of View ◽  
Plume Dispersion ◽  
Exclusion Zone ◽  
Fire Plume ◽  
Mean Values ◽  
The Impact

This paper demonstrates the environmental impacts of the wildfires occurring at the beginning of April 2020 in and around the highly contaminated Chernobyl Exclusion Zone (CEZ). Due to the critical fire location, concerns arose about secondary radioactive contamination potentially spreading over Europe. The impact of the fire was assessed through the evaluation of fire plume dispersion and re-suspension of the radionuclide Cs-137, whereas, to assess the smoke plume effect, a WRF-Chem simulation was performed and compared to Tropospheric Monitoring Instrument (TROPOMI) satellite columns. The results show agreement of the simulated black carbon and carbon monoxide plumes with the plumes as observed by TROPOMI, where pollutants were also transported to Belarus. From an air quality and health perspective, the wildfires caused extremely bad air quality over Kiev, where the WRF-Chem model simulated mean values of PM2.5 up to 300 µg/m3 (during the first fire outbreak) over CEZ. The re-suspension of Cs-137 was assessed by a Bayesian inverse modelling approach using FLEXPART as the atmospheric transport model and Ukraine observations, yielding a total release of 600 ± 200 GBq. The increase in both smoke and Cs-137 emissions was only well correlated on the 9 April, likely related to a shift of the focus area of the fires. From a radiological point of view even the highest Cs-137 values (average measured or modelled air concentrations and modelled deposition) at the measurement site closest to the Chernobyl Nuclear Power Plant, i.e., Kiev, posed no health risk.

Biodegradable polymers: A real opportunity to solve marine plastic pollution?

2021 ◽  
Vol 416 ◽  
pp. 125763
Author(s):  
Loredana Manfra ◽  
Vincenzo Marengo ◽  
Giovanni Libralato ◽  
Maria Costantini ◽  
Francesca De Falco ◽  
...  
Keyword(s):  
Biodegradable Polymers ◽  
Plastic Pollution

scholarly journals Rediscovering the Cooperative Enterprise: A Systematic Review of Current Topics and Avenues for Future Research

2021 ◽  
Author(s):  
Andres Felipe Camargo Benavides ◽  
Michel Ehrenhard
Keyword(s):  
Social Impact ◽  
Social Issues ◽  
Social Enterprises ◽  
Future Research ◽  
Generation Process ◽  
Managerial Practices ◽  
Organizational Perspective ◽  
Multilevel Studies ◽  
Cooperative Enterprise ◽  
Organizational Literature

AbstractFor decades, the cooperative enterprise (CE) produces market goods and/or provides services in the interest to its members, such as communities, customers, and suppliers. The upsurge of interest in social enterprises, and their balancing of social and economic interests, has also led to a renewed interest in CEs, often seen as a specific type of social enterprise. However, from an organizational perspective, this renewed interest has been both limited and scattered over a variety of fields. In this paper, we systematically review papers on CE in the mainstream organizational literature, defined as literature in the fields of economics, business, management and sociology. Our review integrates and synthesizes the current topics in the mainstream organizational literature and provides a number of avenues for future research. In addition, we compare our findings in the organizational literature to the social issues literature as these appeared to be quite complimentary. We found multilevel studies, determination of social impact—in particular measurable impact, managerial practices for sustainable (organisational) development, and the entrepreneurial opportunity generation process as the four key avenues for future research.

CEO statements on racial inequity – (how) do they matter to shareholders?

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Pyemo Afego ◽  
Imhotep Alagidede
Keyword(s):  
Chief Executive Officers ◽  
Social Issues ◽  
Chief Executive ◽  
Future Research ◽  
Research Approach ◽  
Content Type ◽  
Racial Injustice ◽  
Communication Decisions ◽  
Executive Officers ◽  
The Impact

Purpose The purpose of this study is to explore how citizen protests against perceived acts of racial injustice impact on share prices of companies who weigh in on the protests. In particular, corporate statements that directly address the issues around the protests are identified and possible mechanisms underlying how these may impact shareholder value are discussed. Design/methodology/approach The authors first use a qualitative research approach of content and sentiment analysis to track how companies or their chief executive officers (CEOs) present their stance against racial injustice, as represented by their use of linguistic markers. Then, the authors use an event study methodology to assess the response from stock market participants. Findings The findings suggest that CEOs primarily convey their stance using language that is emotive and empathic. In addition, shareholders earn a significant abnormal return of 2.13%, on average, in the three days following the release of the statements. Research limitations/implications This study considered only US-listed companies. The sample size, also, is relatively small. Institutional and cultural differences across countries may also vary. Thus, future research could explore the extent to which the findings generalize to other contexts. Practical implications Results provide insights to top managers who communicate with various stakeholders on emotionally charged social issues. Findings also offer insights on the timing of trades for investors and arbitrageurs. Social implications Findings contribute to the understanding of corporate behaviour in times of social upheaval. Insights from the study may also be used to inform corporate communication decisions about important social issues. Originality/value This study brings into focus the role that affective appeal and moral emotion can play in evoking motivation for corporate activism, and the impact that this has on investor opinions’ formation process.

Modelling nitrogen transport across compartments over northern Europe

2021 ◽  
Author(s):  
Stefan Hagemann ◽  
Ute Daewel ◽  
Volker Matthias ◽  
Tobias Stacke
Keyword(s):  
Baltic Sea ◽  
Land Surface ◽  
Climate Model ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Regional Climate ◽  
Marine Ecosystem ◽  
Coupled System ◽  
Nutrient Concentrations ◽  
Nutrient Loads

<p>River discharge and the associated nutrient loads are important factors that influence the functioning of the marine ecosystem. Lateral inflows from land carrying fresh, nutrient-rich water determine coastal physical conditions and nutrient concentration and, hence, dominantly influence primary production in the system. Since this forms the basis of the trophic food web, riverine nutrient concentrations impact the variability of the whole coastal ecosystem. This process becomes even more relevant in systems like the Baltic Sea, which is almost decoupled from the open ocean and land-borne nutrients play a major role for ecosystem productivity on seasonal up to decadal time scales.</p><p> </p><p>In order to represent the effects of climate or land use change on nutrient availability, a coupled system approach is required to simulate the transport of nutrients across Earth system compartments. This comprises their transport within the atmosphere, the deposition and human application at the surface, the lateral transport over the land surface into the ocean and their dynamics and transformation in the marine ecosystem. In our study, we combine these processes in a modelling chain within the GCOAST (Geesthacht Coupled cOAstal model SysTem) framework for the northern European region. This modelling chain comprises:</p><p> </p><ul><li>Simulation of emissions, atmospheric transport and deposition with the chemistry transport model CMAQ at 36 km grid resolution using atmospheric forcing from the coastDat3 data that have been generated with the regional climate model COSMO-CLM over Europe at 0.11° resolution using ERA-Interim re-analyses as boundary conditions</li> <li>Simulation of inert processes at the land surface with the global hydrology model HydroPy (former MPI-HM), i.e. considering total nitrogen without any chemical reactions</li> <li>Riverine transport with the Hydrological Discharge (HD) model at 0.0833° spatial resolution</li> <li>Simulation of the North Sea and Baltic Sea ecosystems with 3D coupled physical-biogeochemical NPZD-model ECOSMO II at about 10 km resolution</li> </ul><p> </p><p>We will present first results and their validation from this exercise.</p><p> </p>

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