scholarly journals Comparison of Spheroidal Carbonaceous Particle Data with Modelled Atmospheric Black Carbon Concentration and Deposition and Air Mass Sources in Northern Europe, 1850–2010

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Meri Ruppel ◽  
Marianne T. Lund ◽  
Henrik Grythe ◽  
Neil L. Rose ◽  
Jan Weckström ◽  
...  
Keyword(s):  
Black Carbon ◽  
Fossil Fuels ◽  
Transport Model ◽  
Northern Europe ◽  
Spheroidal Carbonaceous Particles ◽  
Carbonaceous Particle ◽  
Carbonaceous Particles ◽  
Air Mass ◽  
Back Trajectories ◽  
Transport Patterns

Spheroidal carbonaceous particles (SCP) are a well-defined fraction of black carbon (BC), produced only by the incomplete combustion of fossil fuels such as coal and oil. Their past concentrations have been studied using environmental archives, but, additionally, historical trends of BC concentration and deposition can be estimated by modelling. These models are based on BC emission inventories, but actual measurements of BC concentration and deposition play an essential role in their evaluation and validation. We use the chemistry transport model OsloCTM2 to model historical time series of BC concentration and deposition from energy and industrial sources and compare these to sedimentary measurements of SCPs obtained from lake sediments in Northern Europe from 1850 to 2010. To determine the origin of SCPs we generated back trajectories of air masses to the study sites. Generally, trends of SCP deposition and modelled results agree reasonably well, showing rapidly increasing values from 1950, to a peak in 1980, and a decrease towards the present. Empirical SCP data show differences in deposition magnitude between the sites that are not captured by the model but which may be explained by different air mass transport patterns. The results highlight the need for numerous observational records to reliably validate model results.

The study of atmospherically deposited Spheroidal Carbonaceous Particles (SCP) from the Kongsfjorden, Svalbard

2017 ◽  
Vol 7 (2) ◽  
pp. 206-215
Author(s):  
Neelu Singh ◽  
Vartika Singh ◽  
Chikkamadaiah Krishnaiah
Keyword(s):  
Fossil Fuels ◽  
Size Range ◽  
Spheroidal Carbonaceous Particles ◽  
Carbonaceous Particles ◽  
X Ray ◽  
Remote Areas ◽  
Inland Lakes ◽  
Large Particles ◽  
Source Of Pollution

The surface sediment samples of Kongsfjorden were analyzed for the Spheroidal Carbonaceous Particles (SCP) in an attempt to document the SCP in the environment other than previously studied inland lakes and snow and also to understand the probable source of industrial atmospheric pollution. The SCP are derived from the combustion of fossil fuels at high temperatures and are not produced naturally. They are chemically inert in both sediment and water and thus provide the indestructible record of atmospherically deposited pollutants in remote areas and anthropogenic impact on pristine environments. The SCP were recovered from different locations of the fjord and were classified according to their size range (small particles, 5-10 µm – large particles, 20-50 µm). The characterization of the spherical carbonaceous particles (shape, size, morphology, color etc.) was done under the light microscope. The detailed morphological features and chemical composition of SCP were studied using Scanning Electron Microscope equipped with Energy Dispersive X-Ray (SEM-EDX). The result shows that in term of a source of pollution in the area, long-range transportation is the major source of pollution but local sources cannot be ignored. This is a first attempt to study the SCP from the Kongsfjorden.

scholarly journals Identification of the Aerosol Types over Athens, Greece: The Influence of Air-Mass Transport

2010 ◽  
Vol 2010 ◽  
pp. 1-15 ◽  
Author(s):  
D. G. Kaskaoutis ◽  
P. G. Kosmopoulos ◽  
H. D. Kambezidis ◽  
P. T. Nastos
Keyword(s):  
Winter Season ◽  
Saharan Dust ◽  
Dust Particles ◽  
Hysplit Model ◽  
Air Mass ◽  
Back Trajectories ◽  
Air Masses ◽  
Local Pollution ◽  
Coarse Mode ◽  
Aerosol Types

Aerosol optical depth at 550 nm () and fine-mode (FM) fraction data from Terra-MODIS were obtained over the Greater Athens Area covering the period February 2000–December 2005. Based on both and FM values three main aerosol types have been discriminated corresponding to urban/industrial aerosols, clean maritime conditions, and coarse-mode, probably desert dust, particles. Five main sectors were identified for the classification of the air-mass trajectories, which were further used in the analysis of the ( and FM data for the three aerosol types). The HYSPLIT model was used to compute back trajectories at three altitudes to investigate the relation between -FM and wind sector depending on the altitude. The accumulation of local pollution is favored in spring and corresponds to air masses at lower altitudes originating from Eastern Europe and the Balkan. Clean maritime conditions are rare over Athens, limited in the winter season and associated with air masses from the Western or Northwestern sector. The coarse-mode particles origin seems to be more complicated proportionally to the season. Thus, in summer the Northern sector dominates, while in the other seasons, and especially in spring, the air masses belong to the Southern sector enriched with Saharan dust aerosols.

scholarly journals Wintertime direct radiative effects due to black carbon (BC) over the Indo-Gangetic Plain as modelled with new BC emission inventories in CHIMERE

2021 ◽  
Vol 21 (10) ◽  
pp. 7671-7694
Author(s):  
Sanhita Ghosh ◽  
Shubha Verma ◽  
Jayanarayanan Kuttippurath ◽  
Laurent Menut
Keyword(s):  
Black Carbon ◽  
Transport Model ◽  
Eastern Coast ◽  
Emission Inventories ◽  
Surface Cooling ◽  
Gangetic Plain ◽  
Bottom Up ◽  
Bc Aerosols ◽  
Radiative Perturbation ◽  
Indo Gangetic Plain

Abstract. To reduce the uncertainty in climatic impacts induced by black carbon (BC) from global and regional aerosol–climate model simulations, it is a foremost requirement to improve the prediction of modelled BC distribution, specifically over the regions where the atmosphere is loaded with a large amount of BC, e.g. the Indo-Gangetic Plain (IGP) in the Indian subcontinent. Here we examine the wintertime direct radiative perturbation due to BC with an efficiently modelled BC distribution over the IGP in a high-resolution (0.1∘ × 0.1∘) chemical transport model, CHIMERE, implementing new BC emission inventories. The model efficiency in simulating the observed BC distribution was assessed by executing five simulations: Constrained and bottomup (bottomup includes Smog, Cmip, Edgar, and Pku). These simulations respectively implement the recently estimated India-based observationally constrained BC emissions (Constrainedemiss) and the latest bottom-up BC emissions (India-based: Smog-India; global: Coupled Model Intercomparison Project phase 6 – CMIP6, Emission Database for Global Atmospheric Research-V4 – EDGAR-V4, and Peking University BC Inventory – PKU). The mean BC emission flux from the five BC emission inventory databases was found to be considerably high (450–1000 kg km−2 yr−1) over most of the IGP, with this being the highest (> 2500 kg km−2 yr−1) over megacities (Kolkata and Delhi). A low estimated value of the normalised mean bias (NMB) and root mean square error (RMSE) from the Constrained estimated BC concentration (NMB: < 17 %) and aerosol optical depth due to BC (BC-AOD) (NMB: 11 %) indicated that simulations with Constrainedemiss BC emissions in CHIMERE could simulate the distribution of BC pollution over the IGP more efficiently than with bottom-up emissions. The high BC pollution covering the IGP region comprised a wintertime all-day (daytime) mean BC concentration and BC-AOD respectively in the range 14–25 µg m−3 (6–8 µg m−3) and 0.04–0.08 µg m−3 from the Constrained simulation. The simulated BC concentration and BC-AOD were inferred to be primarily sensitive to the change in BC emission strength over most of the IGP (including the megacity of Kolkata), but also to the transport of BC aerosols over megacity Delhi. Five main hotspot locations were identified in and around Delhi (northern IGP), Prayagraj–Allahabad–Varanasi (central IGP), Patna–Palamu (upper, lower, and mideastern IGP), and Kolkata (eastern IGP). The wintertime direct radiative perturbation due to BC aerosols from the Constrained simulation estimated the atmospheric radiative warming (+30 to +50 W m−2) to be about 50 %–70 % larger than the surface cooling. A widespread enhancement in atmospheric radiative warming due to BC by 2–3 times and a reduction in surface cooling by 10 %–20 %, with net warming at the top of the atmosphere (TOA) of 10–15 W m−2, were noticed compared to the atmosphere without BC, for which a net cooling at the TOA was exhibited. These perturbations were the strongest around megacities (Kolkata and Delhi), extended to the eastern coast, and were inferred to be 30 %–50% lower from the bottomup than the Constrained simulation.

scholarly journals Chemical mass balance of refractory particles (<i>T</i>=300 °C) at the tropospheric research site Melpitz, Germany

2013 ◽  
Vol 13 (10) ◽  
pp. 26981-27018
Author(s):  
L. Poulain ◽  
W. Birmili ◽  
F. Canonaco ◽  
M. Crippa ◽  
Z. J. Wu ◽  
...  
Keyword(s):  
Black Carbon ◽  
Mass Fraction ◽  
Field Experiments ◽  
Basic Result ◽  
Particle Mass ◽  
Heating Process ◽  
Research Station ◽  
Particle Volume ◽  
Carbonaceous Particles ◽  
Refractory Particle

Abstract. In the fine particle mode (aerodynamic diameter <1 μm) refractory material has been associated with black carbon (BC) and low-volatile organics and, to a lesser extent, with sea salt and mineral dust. This work analyses refractory particles at the tropospheric research station Melpitz (Germany), combining experimental methods such as a mobility particle size spectrometer (3–800 nm), a thermodenuder operating at 300 °C, a multi-angle absorption photometer (MAAP), and an aerosol mass spectrometer (AMS). The data were collected during two atmospheric field experiments in May/June 2008 as well as February/March 2009. As a basic result, we detected average refractory particle volume fractions of 11±3% (2008) and 17±8% (2009). In both periods, BC was in close linear correlation with the refractory fraction, but not sufficient to quantitatively explain the refractory particle mass concentration. Based on the assumption that BC is not altered by the heating process, the refractory particle mass fraction could be explained by the sum of black carbon BC (47% in summer, 59% in winter) and a refractory organic contribution estimated as part of the Low-Volatility Oxygenated Organic Aerosol (LV-OOA) (53% in summer, 41% in winter); the latter was identified from AMS data by factor analysis. Our results suggest that organics were more volatile in summer (May–June 2008) than in winter (February/March 2009). Although carbonaceous compounds dominated the sub-μm refractory particle mass fraction most of the time, a cross-sensitivity to partially volatile aerosol particles of maritime origin could be seen. These marine particles could be distinguished, however, from the carbonaceous particles by a characteristic particle volume size distribution. The paper discusses the uncertainty of the volatility measurements and outlines the possible merits of volatility analysis as part of continuous atmospheric aerosol measurements.

Resonance-stabilized hydrocarbon-radical chain reactions may explain soot inception and growth

Science ◽  
2018 ◽  
Vol 361 (6406) ◽  
pp. 997-1000 ◽  
Author(s):  
K. O. Johansson ◽  
M. P. Head-Gordon ◽  
P. E. Schrader ◽  
K. R. Wilson ◽  
H. A. Michelsen
Keyword(s):  
Interstellar Dust ◽  
Hydrogen Abstraction ◽  
Particle Formation ◽  
Reaction Pathways ◽  
Radical Chain ◽  
Carbonaceous Particle ◽  
Carbonaceous Particles ◽  
Chain Reactions ◽  
Polycyclic Aromatic ◽  
Covalently Bound

Mystery surrounds the transition from gas-phase hydrocarbon precursors to terrestrial soot and interstellar dust, which are carbonaceous particles formed under similar conditions. Although polycyclic aromatic hydrocarbons (PAHs) are known precursors to high-temperature carbonaceous-particle formation, the molecular pathways that initiate particle formation are unknown. We present experimental and theoretical evidence for rapid molecular clustering–reaction pathways involving radicals with extended conjugation. These radicals react with other hydrocarbon species to form covalently bound complexes that promote further growth and clustering by regenerating resonance-stabilized radicals through low-barrier hydrogen-abstraction and hydrogen-ejection reactions. Such radical–chain reaction pathways may lead to covalently bound clusters of PAHs and other hydrocarbons that would otherwise be too small to condense at high temperatures, thus providing the key mechanistic steps for rapid particle formation and surface growth by hydrocarbon chemisorption.

Tracing the sources of PCDD/Fs in Baltic Sea air by using metals as source markers

2018 ◽  
Vol 20 (3) ◽  
pp. 544-552 ◽  
Author(s):  
Anteneh Assefa ◽  
Mats Tysklind ◽  
Jana Klanova ◽  
Karin Wiberg
Keyword(s):  
Baltic Sea ◽  
Ambient Air ◽  
Air Mass ◽  
Back Trajectories ◽  
Air Samples ◽  
Metal Source ◽  
Source Markers

A combination of PCDD/F patterns and metal source markers in ambient air samples together with stable air mass back trajectories can reveal the most significant atmospheric sources of PCDD/Fs.

Quantifying the contribution of regional methane emissions to the global methane budget between 2008 and 2018 using the TOMCAT chemical transport model

2021 ◽  
Author(s):  
Emily Dowd ◽  
Christopher Wilson ◽  
Martyn Chipperfield ◽  
Manuel Gloor
Keyword(s):  
Carbon Dioxide ◽  
Land Surface ◽  
Fossil Fuels ◽  
Fossil Fuel ◽  
Transport Model ◽  
Chemical Transport ◽  
Methane Emissions ◽  
Anthropogenic Sources ◽  
Chemical Transport Model ◽  
Methane Budget

&lt;p&gt;Methane (CH&lt;sub&gt;4&lt;/sub&gt;) is the second most important atmospheric greenhouse gas after carbon dioxide. Global concentrations of CH&lt;sub&gt;4&lt;/sub&gt; have been rising in the last decade and our understanding of what is driving the increase remains incomplete. Natural sources, such as wetlands, contribute to the uncertainty of the methane budget. However, anthropogenic sources, such as fossil fuels, present an opportunity to mitigate the human contribution to climate change on a relatively short timescale, since CH&lt;sub&gt;4&lt;/sub&gt; has a much shorter lifetime than carbon dioxide. Therefore, it is important to know the relative contributions of these sources in different regions.&lt;/p&gt;&lt;p&gt;We have investigated the inter-annual variation (IAV) and rising trend of CH&lt;sub&gt;4&lt;/sub&gt; concentrations using a global 3-D chemical transport model, TOMCAT. We independently tagged several regional natural and anthropogenic CH&lt;sub&gt;4&lt;/sub&gt; tracers in TOMCAT to identify their contribution to the atmospheric CH&lt;sub&gt;4&lt;/sub&gt; concentrations over the period 2009 &amp;#8211; 2018. The tagged regions were selected based on the land surface types and the predominant flux sector within each region and include subcontinental regions, such as tropical South America, boreal regions and anthropogenic regions such as Europe. We used surface CH&lt;sub&gt;4&lt;/sub&gt; fluxes derived from a previous TOMCAT-based atmospheric inversion study (Wilson et al., 2020). These atmospheric inversions were constrained by satellite and surface flask observations of CH&lt;sub&gt;4&lt;/sub&gt;, giving optimised monthly estimates for fossil fuel and non-fossil fuel emissions on a 5.6&amp;#176; horizontal grid. During the study period, the total optimised CH&lt;sub&gt;4&lt;/sub&gt; flux grew from 552 Tg/yr to 593 Tg/yr. This increase in emissions, particularly in the tropics, contributed to the increase in atmospheric CH&lt;sub&gt;4 &lt;/sub&gt;concentrations and added to the imbalance in the CH&lt;sub&gt;4&lt;/sub&gt; budget. We will use the results of the regional tagged tracers to quantify the contribution of regional methane emissions at surface observation sites, and to quantify the contributions of the natural and anthropogenic emissions from the tagged regions to the IAV and the rising methane concentrations.&lt;/p&gt;&lt;p&gt;Wilson, C., Chipperfield, M. P., Gloor, M., Parker, R. J., Boesch, H., McNorton, J., Gatti, L. V., Miller, J. B., Basso, L. S., and Monks, S. A.: Large and increasing methane emissions from Eastern Amazonia derived from satellite data, 2010&amp;#8211;2018, Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-1136, in review, 2020.&lt;/p&gt;

Opening the black box: soil microcosm experiments reveal soot-black carbon short-term oxidation and influence on organic carbon mineralisation

2021 ◽  
Author(s):  
Marta Crispo ◽  
Duncan D. Cameron ◽  
Will Meredith ◽  
Aaron Eveleigh ◽  
Nicos Ladommatos ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Black Carbon ◽  
Fossil Fuels ◽  
Isotope Ratio Mass Spectrometry ◽  
Soil Microcosm ◽  
Short Term ◽  
Carbon Mineralisation ◽  
Significant Difference ◽  
Global Carbon ◽  
Over Time

&lt;p&gt;Black carbon (BC), the product of the incomplete combustion of fossil fuels and biomass, is ubiquitous in soils globally. Although BC is a major soil carbon pool, its effects on the global carbon cycle have not yet been resolved. It is deemed to represent a large stable pool in soils turning over on geological timescales, but research suggests it can alter soil biogeochemical cycling including that of ecosystem-derived organic carbon. Here, we established two soil microcosm chamber experiments: experiment one added &lt;sup&gt;13&lt;/sup&gt;C organic carbon to soil with and without added BC (soot and biochar) to investigate whether it suppressed organic carbon mineralisation; experiment two added &lt;sup&gt;13&lt;/sup&gt;C BC (soot) to soil to establish whether it is mineralised in soil over a short timescale. Gases were sampled over six-months and analysed using isotope ratio mass spectrometry. In experiment one we found that the efflux of &lt;sup&gt;13&lt;/sup&gt;C organic carbon from the soil decreased over time, but the addition of soot to soil significantly reduced the mineralisation of organic carbon from 32% of the total supplied without soot to 14% of the total supplied with soot. In contrast, there was not a significant difference after the addition of biochar in the flux of &amp;#948; &lt;sup&gt;13&lt;/sup&gt;CO&lt;sub&gt;2 &lt;/sub&gt;from the organic carbon added to the soil. In experiment two, we found that the efflux &lt;sup&gt;13&lt;/sup&gt;C from soil with added &lt;sup&gt;13&lt;/sup&gt;C labelled soot significantly differed from the control, but this efflux declined over time. There was a cumulative loss of 0.17% &lt;sup&gt;13&lt;/sup&gt;C from soot over the experiment.These experimental results represent a step-change in understanding the influence of BC continuum on carbon dynamics, which has major consequences for the way we measure, monitor and manage soils for carbon storage and sequestration in the future.&lt;/p&gt;

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