Assessing the relative importance of biogenic and anthropogenic sources to primary and secondary aerosols in the Fraser Valley during the summertime

Abstract. Aerosols act as cloud condensation nuclei (CCN) for cloud water droplets, and changes in aerosol concentrations have significant microphysical impacts on the corresponding cloud properties. Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol and cloud properties are combined with NCEP Reanalysis data for six different regions around the globe between March 2000 and December 2005 to study the effects of different aerosol, cloud, and atmospheric conditions on the aerosol indirect effect (AIE). Emphasis is placed in examining the relative importance of aerosol concentration, type, and atmospheric conditions (mainly vertical motion) to AIE from region to region. Results show that in most regions, AIE has a distinct seasonal cycle, though the cycle varies in significance and period from region to region. In the Arabian Sea (AS), the six-year mean anthropogenic + dust AIE is −0.27 Wm−2 and is greatest during the summer months (<−2.0 Wm−2) during which aerosol concentrations (from both dust and anthropogenic sources) are greatest. Comparing AIE as a function of thin (LWP<20 gm−2) vs. thick (LWP≥20 gm−2) clouds under conditions of large scale ascent or decent at 850 hPa showed that AIE is greatest for thick clouds during periods of upward vertical motion. In the Bay of Bengal, AIE is negligible owing to less favorable atmospheric conditions, a lower concentration of aerosols, and a non-alignment of aerosol and cloud layers. In the eastern North Atlantic, AIE is weakly positive (+0.1 Wm−2) with dust aerosol concentration being much greater than the anthropogenic or sea salt components. However, elevated dust in this region exists above the maritime cloud layers and does not have a hygroscopic coating, which occurs in AS, preventing the dust from acting as CCN and limiting AIE. The Western Atlantic has a large anthropogenic aerosol concentration transported from the eastern United States producing a modest anthropogenic AIE (−0.46 Wm−2). Anthropogenic AIE is also present off the West African coast corresponding to aerosols produced from seasonal biomass burning (both natural and man-made). Interestingly, atmospheric conditions are not particularly favorable for cloud formation compared to the other regions during the times where AIE is observed; however, clouds are generally thin (LWP<20 gm−2) and concentrated very near the surface. Overall, we conclude that vertical motion, aerosol type, and aerosol layer heights do make a significant contribution to AIE and that these factors are often more important than total aerosol concentration alone and that the relative importance of each differs significantly from region to region.

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Relative importance of nitrogen and phosphorus emissions from shrimp farming and other anthropogenic sources for six estuaries along the NE Brazilian coast

Aquaculture ◽

10.1016/j.aquaculture.2005.09.005 ◽

2006 ◽

Vol 253 (1-4) ◽

pp. 433-446 ◽

Cited By ~ 40

Author(s):

Luiz Drude de Lacerda ◽

Ariel Gustavo Vaisman ◽

Luís Parente Maia ◽

Carlos Augusto Ramos e Silva ◽

Eugênio Marcos Soares Cunha

Keyword(s):

Shrimp Farming ◽

Anthropogenic Sources ◽

Brazilian Coast ◽

Relative Importance ◽

Nitrogen And Phosphorus

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CO source contribution analysis for California during ARCTAS-CARB

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-3627-2011 ◽

2011 ◽

Vol 11 (2) ◽

pp. 3627-3661 ◽

Cited By ~ 3

Author(s):

G. G. Pfister ◽

J. Avise ◽

C. Wiedinmyer ◽

D. P. Edwards ◽

L. K. Emmons ◽

...

Keyword(s):

Transport Model ◽

Anthropogenic Sources ◽

Relative Importance ◽

Free Troposphere ◽

Chemical Transport Model ◽

Time Period ◽

The Pacific ◽

Aircraft Observations ◽

Satellite Retrievals ◽

Local Emissions

Abstract. Air pollution is of concern in many parts of California and is impacted by both local emissions and also by pollution inflow from the Pacific. In this study, we use the regional chemical transport model WRF-Chem V3.2 to examine the CO budget over California. We include model CO tracers for different emission sources in the model, which allow estimating the relative importance of local sources versus pollution inflow on the distribution of CO at the surface and in the free troposphere. The focus of our study is on the 15 June–15 July 2008 time period, which coincides with the aircraft deployment of the NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission over California. Model simulations are evaluated using these aircraft observations as well as satellite retrievals and surface observations of CO. Evaluation results show that the model overall predicts the observed CO fields well, but points towards an underestimate of CO from the fires in Northern California, which had a strong influence during the study period, and towards a slight overestimate of CO from pollution inflow and local anthropogenic sources. The analysis of the CO budget over California reveals that inflow of CO explains on average 53 ± 21% of surface CO during the study period, compared to 22 ± 18% for local anthropogenic sources and 18 ± 22% for fires. In the free troposphere, the average CO contributions are estimated as 78 ± 16% for CO inflow, 6 ± 4% for CO from local anthropogenic sources and 11 ± 13% for CO from fires.

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Sources and Geographical Origins of PM10 in Metz (France) Using Oxalate as a Marker of Secondary Organic Aerosols by Positive Matrix Factorization Analysis

Atmosphere ◽

10.3390/atmos10070370 ◽

2019 ◽

Vol 10 (7) ◽

pp. 370 ◽

Cited By ~ 2

Author(s):

Jean-Eudes Petit ◽

Cyril Pallarès ◽

Olivier Favez ◽

Laurent Y. Alleman ◽

Nicolas Bonnaire ◽

...

Keyword(s):

Matrix Factorization ◽

Positive Matrix Factorization ◽

Temporal Variations ◽

Anthropogenic Sources ◽

Positive Matrix ◽

Original Source ◽

Atmospheric Processing ◽

Balkan Region ◽

Secondary Aerosols

An original source apportionment study was conducted on atmospheric particles (PM10) collected in Metz, one of the largest cities of Eastern France. A Positive matrix factorization (PMF) analysis was applied to a sampling filter-based chemical dataset obtained for the April 2015 to January 2017 period. Nine factors were clearly identified, showing mainly contributions from anthropogenic sources of primary PM (19.2% and 16.1% for traffic and biomass burning, respectively) as well as secondary aerosols (12.3%, 14.5%, 21.8% for sulfate-, nitrate-, and oxalate-rich factors, respectively). Wood-burning aerosols exhibited strong temporal variations and contributed up to 30% of the PM mass fraction during winter, while primary traffic concentrations remained relatively constant throughout the year. These two sources are also the main contributors during observed PM10 pollution episodes. Furthermore, the dominance of the oxalate-rich factor among other secondary aerosol factors underlines the role of atmospheric processing to secondary organic aerosol loadings which are still poorly characterized in this region. Finally, Concentration-Weighted Trajectory (CWT) analysis were performed to investigate the geographical origins of the apportioned sources, notably illustrating a significant transport of both nitrate-rich and sulfate-rich factors from Northeastern Europe but also from the Balkan region.

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Contributions of foreign, domestic and natural emissions to US ozone estimated using the path-integral method in CAMx nested within GEOS-Chem

10.5194/acp-2017-366 ◽

2017 ◽

Author(s):

Alan M. Dunker ◽

Bonyoung Koo ◽

Greg Yarwood

Keyword(s):

Path Integral ◽

Integral Method ◽

Anthropogenic Sources ◽

Anthropogenic Emissions ◽

Base Case ◽

Relative Importance ◽

Natural Background ◽

Air Quality Model ◽

Ozone Concentrations ◽

Path Integral Method

Abstract. The Goddard Earth Observing System global chemical transport (GEOS-Chem) model was used at 2° × 2.5° resolution to simulate ozone formation for a base case representing year 2010 and a natural background case without worldwide anthropogenic emissions. These simulations provided boundary concentrations for base and natural background simulations with the Comprehensive Air Quality Model with Extensions (CAMx) on a North American domain at 12 km × 12 km resolution over March–September 2010. The predicted maximum daily average 8-hour (MDA8) background ozone for the US is largest in the mountainous areas of Colorado, New Mexico, Arizona, and California. The background MDA8 ozone in some of these locations exceeds 60 ppb, when averaged over the 10 days with the largest base-case ozone. The ozone difference between the base and background cases represents the increment to ozone from all anthropogenic sources. Using the Path-Integral Method, the anthropogenic ozone increment was allocated to US anthropogenic emissions, Canadian/Mexican anthropogenic emissions, and the anthropogenic components of the lateral and top boundary concentrations (BCs). For the larger MDA8 ozone concentrations in the base case, the relative importance of the sources is generally US emissions > anthropogenic lateral BCs > Canadian/Mexican emissions &gg; anthropogenic top BCs. The contributions of the lateral BCs are largest for the higher elevation US sites in the Intermountain West and sites closest to the boundaries. If the focus instead is on the larger ozone concentrations in the background case, the contribution from US emissions is reduced leading to a reduction in the anthropogenic ozone increment. The contribution of the Canadian/Mexican emissions remains about the same, and the contribution from the lateral BCs increases at lower elevation urban sites. The net effect is that the relative importance of the anthropogenic lateral BCs is significantly increased for the days with the largest background concentrations. In addition to the source apportionment, we also used surface and ozonesonde measurements to evaluate GEOS-Chem and CAMx performance.

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Contributions of foreign, domestic and natural emissions to US ozone estimated using the path-integral method in CAMx nested within GEOS-Chem

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-12553-2017 ◽

2017 ◽

Vol 17 (20) ◽

pp. 12553-12571 ◽

Cited By ~ 8

Author(s):

Alan M. Dunker ◽

Bonyoung Koo ◽

Greg Yarwood

Keyword(s):

Path Integral ◽

Integral Method ◽

Anthropogenic Sources ◽

Anthropogenic Emissions ◽

Base Case ◽

Relative Importance ◽

Natural Background ◽

Background Ozone ◽

Path Integral Method ◽

Urban Sites

Abstract. The Goddard Earth Observing System global chemical transport (GEOS-Chem) model was used at 2°  ×  2.5° resolution to simulate ozone formation for a base case representing year 2010 and a natural background case without worldwide anthropogenic emissions. These simulations provided boundary concentrations for base and natural background simulations with the Comprehensive Air Quality Model with Extensions (CAMx) on a North American domain (one-way nested) at 12 km  ×  12 km resolution over March–September 2010. The predicted maximum daily average 8 h (MDA8) background ozone for the US is largest in the mountainous areas of Colorado, New Mexico, Arizona, and California. The background MDA8 ozone in some of these locations exceeds 60 ppb, when averaged over the 10 days with the largest base-case ozone (T10base average). The background ozone generally becomes both a larger fraction of the base-case ozone in the western US and a smaller fraction in the eastern US when proceeding from spring to summer to the T10base average. The ozone difference between the base and background cases represents the increment to ozone from all anthropogenic sources. The path-integral method was applied to allocate this anthropogenic ozone increment to US anthropogenic emissions, Canadian/Mexican anthropogenic emissions, and the anthropogenic components of the lateral and top boundary concentrations (BCs). Using the T10base average MDA8 ozone, the relative importance of the sources is generally US emissions  >  anthropogenic lateral BCs  >  Canadian/Mexican emissions  ≫  anthropogenic top BCs. Specifically, for 10 US urban areas, the source contributions were 12–53 ppb for US emissions, 3–9 ppb for lateral BCs, 0.2–3 ppb for Canadian/Mexican emissions, and ≤  0.1 ppb for top BCs. The contributions of the lateral BCs are largest for the higher-elevation US sites in the Intermountain West and along the western boundary of the domain. In Denver, for example, the lateral BCs contribute 44 % to the T10base anthropogenic increment. Averaging over the 10 days in the background case with the largest MDA8 ozone (T10bkgd), the contribution from US emissions is reduced to 3–13 ppb at the 10 urban sites, leading to a reduction in the anthropogenic ozone increment. The contribution of the Canadian/Mexican emissions remains about the same (0.3–2 ppb), and the contribution from the lateral BCs increases (5–10 ppb), especially at the lower-elevation urban sites. The net effect at the urban sites is that the relative importance of the anthropogenic lateral BCs is significantly greater for the T10bkgd average than the T10base average. This is also true for rural sites studied, where the anthropogenic lateral BC contribution becomes as large as 68 % of the anthropogenic increment for the T10bkgd average. In addition to the source apportionment, we also used surface and ozonesonde measurements to evaluate GEOS-Chem and CAMx performance.

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MEDIDAS DE FLUXO DE DIÓXIDO DE CARBONO E METANO EM UM DEPÓSITO DE RESÍDUOS INSALUBRE NA AMAZÔNIA

Revista Brasileira de Ciências Ambientais (Online) ◽

10.5327/z2176-947820190021 ◽

2019 ◽

pp. 13-33

Author(s):

Layse Teixeira Pinheiro ◽

Jose Henrique Cattanio ◽

Breno Imbiriba ◽

Saul Edgardo Martinez Castellon ◽

Silvia Adriane Elesbão ◽

...

Keyword(s):

Metropolitan Region ◽

Anthropogenic Sources ◽

Emission Rates ◽

Relative Importance ◽

Flux Chamber ◽

Ch4 Flux ◽

Ch4 Production ◽

The Subject ◽

High Concentrations ◽

Chamber Technique

Dumps are important anthropogenic sources of greenhouse gas emissions into the atmosphere, mostly CH4. However, few studies on the subject have been carried out in the Amazon region. Several factors affect the production and emission of dumps gas. The objective of this study was to quantify the spatial variation of CO2 and CH4 production in an Amazon dump and try to associate the relative importance of some environmental factors with the fluxes. This study was carried out in an open-air dump in the metropolitan region of Belém, where approximately 11.0 million Mg of waste was deposited in 25 years, of which 6.4 million Mg was organic. The emission rates of CH4 and CO2 from the surface of the dump were determined using the closed dynamic flux chamber technique. The study was conducted in three cells of different ages, sampled in two moments between the Amazon rainy and dry season. The Aura dump has an area of 30 ha and emits a total of 51.49 Mg CO2 ha-1 month-1 and 3.16 Mg CH4 ha-1 month-1 to the atmosphere. This results in an expressive production of 1,359,961.04 Mg CO2-e year-1, being that 58.54% is due to CH4 flux. The spatial variability in CO2 and CH4 flux is very large, especially for CH4, forming hotspots of high concentrations, and perhaps because of this, the flow has not been correlated with micrometeorological variations.

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