Black Carbon Involved Photochemistry Enhances the Formation of Sulfate in the Ambient Atmosphere: Evidence from in‐situ Individual Particle Investigation

2021 ◽  
Author(s):  
Guohua Zhang ◽  
Yuzhen Fu ◽  
Xiaocong Peng ◽  
Wei Sun ◽  
Zongbo Shi ◽  
...  
Keyword(s):  
Black Carbon ◽  
Individual Particle ◽  
Ambient Atmosphere

scholarly journals Estimation of Surface Concentrations of Black Carbon from Long-Term Measurements at Aeronet Sites over Korea

2020 ◽  
Vol 12 (23) ◽  
pp. 3904
Author(s):  
Yongjoo Choi ◽  
Young Sung Ghim ◽  
Ying Zhang ◽  
Seung-Myung Park ◽  
In-ho Song
Keyword(s):  
Black Carbon ◽  
Measurement Data ◽  
Water Soluble ◽  
Mixing Rule ◽  
Range Transport ◽  
Urban Rural ◽  
Fine Mode ◽  
The Difference ◽  
Mlr Model

We estimated fine-mode black carbon (BC) concentrations at the surface using AERONET data from five AERONET sites in Korea, representing urban, rural, and background. We first obtained the columnar BC concentrations by separating the refractive index (RI) for fine-mode aerosols from AERONET data and minimizing the difference between separated RIs and calculated RIs using a mixing rule that can represent a real aerosol mixture (Maxwell Garnett for water-insoluble components and volume average for water-soluble components). Next, we acquired the surface BC concentrations by establishing a multiple linear regression (MLR) between in-situ BC concentrations from co-located or adjacent measurement sites, and columnar BC concentrations, by linearly adding meteorological parameters, month, and land-use type as the independent variables. The columnar BC concentrations estimated from AERONET data using a mixing rule well reproduced site-specific monthly variations of the in-situ measurement data, such as increases due to heating and/or biomass burning and long-range transport associated with prevailing westerlies in the spring and winter, and decreases due to wet scavenging in the summer. The MLR model exhibited a better correlation between measured and predicted BC concentrations than those based on columnar concentrations only, with a correlation coefficient of 0.64. The performance of our MLR model for BC was comparable to that reported in previous studies on the relationship between aerosol optical depth and particulate matter concentration in Korea. This study suggests that the MLR model with properly selected parameters is useful for estimating the surface BC concentration from AERONET data during the daytime, at sites where BC monitoring is not available.

Photoacoustic soot sensor for in-situ black carbon monitoring

1996 ◽  
Vol 63 (2) ◽  
pp. 191-197 ◽  
Author(s):  
A. Petzold ◽  
R. Niessner
Keyword(s):  
Black Carbon

scholarly journals In situ observations of black carbon in snow and the corresponding spectral surface albedo reduction

2015 ◽  
Vol 120 (4) ◽  
pp. 1476-1489 ◽  
Author(s):  
C. A. Pedersen ◽  
J.-C. Gallet ◽  
J. Ström ◽  
S. Gerland ◽  
S. R. Hudson ◽  
...  
Keyword(s):  
Black Carbon ◽  
Surface Albedo ◽  
In Situ Observations

Novel bisimidazolium pincers as low loading ligands for in situ palladium-catalyzed Suzuki–Miyaura reaction in the ambient atmosphere

2013 ◽  
Vol 49 (11) ◽  
pp. 1127 ◽  
Author(s):  
Chao Gao ◽  
Hongjun Zhou ◽  
Siping Wei ◽  
Yinsong Zhao ◽  
Jingsong You ◽  
...  
Keyword(s):  
Ambient Atmosphere ◽  
Palladium Catalyzed

Controlled Environment Specimen Transfer

2014 ◽  
Vol 20 (4) ◽  
pp. 1038-1045 ◽  
Author(s):  
Christian D. Damsgaard ◽  
Henny Zandbergen ◽  
Thomas W. Hansen ◽  
Ib Chorkendorff ◽  
Jakob B. Wagner
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Elevated Temperatures ◽  
Controlled Environment ◽  
Ambient Atmosphere ◽  
Air Exposure ◽  
X Ray ◽  
Environmental Transmission ◽  
Transmission Electron

AbstractSpecimen transfer under controlled environment conditions, such as temperature, pressure, and gas composition, is necessary to conduct successive complementary in situ characterization of materials sensitive to ambient conditions. The in situ transfer concept is introduced by linking an environmental transmission electron microscope to an in situ X-ray diffractometer through a dedicated transmission electron microscope specimen transfer holder, capable of sealing the specimen in a gaseous environment at elevated temperatures. Two catalyst material systems have been investigated; Cu/ZnO/Al2O3 catalyst for methanol synthesis and a Co/Al2O3 catalyst for Fischer–Tropsch synthesis. Both systems are sensitive to ambient atmosphere as they will oxidize after relatively short air exposure. The Cu/ZnO/Al2O3 catalyst, was reduced in the in situ X-ray diffractometer set-up, and subsequently, successfully transferred in a reactive environment to the environmental transmission electron microscope where further analysis on the local scale were conducted. The Co/Al2O3 catalyst was reduced in the environmental microscope and successfully kept reduced outside the microscope in a reactive environment. The in situ transfer holder facilitates complimentary in situ experiments of the same specimen without changing the specimen state during transfer.

Non-Isothermal Devitrification Study of Wollastonite-Tricalcium Phosphate Bioeutectic® Glass

2008 ◽  
Vol 396-398 ◽  
pp. 127-130 ◽  
Author(s):  
M. Magallanes-Perdomo ◽  
R. García Carrodeguas ◽  
P. Pena ◽  
P.N. De Aza ◽  
S. De Aza ◽  
...  
Keyword(s):  
Tricalcium Phosphate ◽  
Eutectic Composition ◽  
Rietveld Method ◽  
Glass Ceramics ◽  
Ambient Atmosphere ◽  
X Ray ◽  
Amorphous Content ◽  
Wide Range ◽  
Devitrification Process

This document describes and discusses the non-isothermal devitrification process of the wollastonite-tricalcium phosphate (W-TCP) eutectic glass. This eutectic glass has been studied in situ, from room temperature up to 1375 °C, by Neutron Diffractometry (ND) in vacuum. The data obtained were complemented and compared with those performed on ambient atmosphere by Differential Thermal Analysis (DTA) and with those of samples fired in air, at selected temperatures, and then cooled down and subsequently studied by laboratory X-ray Powder Diffraction (LXRD) and Field Emission Scanning Electron Microscopy (FE-SEM) fitted with Energy X-Ray Dispersive Spectroscopy (EDS). Selected samples have been investigated by quantitative full-phase analysis (including the amorphous content) using the Rietveld method. The experimental evidence indicates that the devitrification of W-TCP eutectic glass, begins at ~870°C, with the crystallization of a Ca-deficient apatite phase (Ca9.92(P5.85O23.54)(OH)2.03 (H2O)2.194) followed by wollastonite-2M (-CaSiO3) crystallization at 1006°C. At 1375°C the bio glassceramic is comprised of quasi-rounded colonies formed by a homogeneous mixture of pseudowollastonite (-CaSiO3) and -tricalcium phosphate (-Ca3(PO4)2). This microstructure corresponds to irregular eutectic structures and is similar to that of Bioeutectic® W-TCP material obtained previously, via controlled slow solidification of the eutectic composition, by some of the present authors. It has also been found that from the eutectic composition of the wollastonite – tricalcium phosphate binary system is possible to obtain a wide range of bio glass-ceramics through appropriate design of thermal treatments.

Algorithm for Determining the Statistical Properties of Cloud Particles through In Situ Ensemble Measurements

2016 ◽  
Vol 33 (9) ◽  
pp. 1985-2000
Author(s):  
Matthew Hayman
Keyword(s):  
Cross Sections ◽  
Fundamental Principle ◽  
Individual Particle ◽  
Analytical Relationship ◽  
Particle Properties ◽  
Network Bandwidth ◽  
Single Detector ◽  
The Relationship ◽  
Aircraft Data

AbstractAn algorithm is described for inverting individual particle properties from statistics of ensemble observations, thereby dispelling the notion that coincident particles create inherently erroneous data in particle probes. The algorithm assumes that the observed property obeys superposition, that the particles are independently randomly distributed in space, and that the particle distribution is stationary over the accumulation distance. The fundamental principle of the algorithm is based on a derived analytical relationship between ensemble and individual particle statistics with fully defined derivatives. This enables rapid convergence of forward inversions. Furthermore, this relationship has no dependence on the particular instrument realization, so the accuracy of the relationship is not fundamentally constrained by the accuracy to which a measurement system can be characterized or modeled. This algorithm is presented in terms of a single observed property, but the derivation is valid for correlated multiparameter retrievals. Because data are collected in histograms, this technique would require relatively little storage and network bandwidth on an aircraft data system. This statistical analysis is derived here for measuring particle geometric extinction cross sections, but it could also be applied to other particle properties, such as scattering cross-section and phase matrix elements. In this example application, a simulated beam passes through a sampled environment onto a single detector to periodically measure beam extinction. This measured extinction may be the result of one or more particles, but it is shown that the probability distribution function of the ensemble (multiparticle) extinction measurement can be used to obtain the distribution of individual particle extinction cross sections (used here as a proxy for particle size distribution).

scholarly journals Characteristics of an aged organic "brown" aerosol in the urban Po Valley atmosphere

2016 ◽  
Author(s):  
F. Costabile ◽  
S. Gilardoni ◽  
F. Barnaba ◽  
A. Di Ianni ◽  
L. Di Liberto ◽  
...  
Keyword(s):  
Spectral Dependence ◽  
Organic Aerosol ◽  
Ambient Atmosphere ◽  
Size Distributions ◽  
Po Valley ◽  
Optical Signature ◽  
Physico Chemical ◽  
Fine Size ◽  
Visible Wavelengths

Abstract. We characterize the atmospheric nondust aerosol having the strongest spectral dependence of light absorption (as indicated by the Absorption Angstrom Exponent, AAE) at visible wavelengths in the urban Po Valley. In situ ground measurements of aerosol spectral optical properties, PM1 chemical composition (HR-ToF-AMS), and coarse and fine size distributions, were carried out in Bologna, and data statistically analysed. Findings prove that a "brown" aerosol (AAE from 2.5 to 6) in the ambient atmosphere is composed by "droplet" mode particles enriched in aged organic aerosol (OA) and nitrate. We provide a comprehensive physico-chemical characterisation of this brown aerosol, including its spectral optical signature, and possible sources. To our knowledge, no previous work has considered these issues in the ambient atmosphere. We compared to literature to put findings in a broader perspective. There is consistency with recent "diluted" urban observations (airborne, and AERONET), and combustion chamber observations. Our study adds to these previous ones that the high AAE values featuring the "brown" aerosol depend on the OA to Black Carbon (BC) ratio more than on OA, and that the link between AAE and OA-to-BC (already observed for freshly emitted primary aerosols from biomass burning) does exist in the ambient atmosphere for this aged "brown" aerosol, as well. The comparison with studies on the composition evolution of OA in the atmosphere strengthens the result that this "brown" aerosol is an aged OA, and provides experimental evidence for the aged "brown" OA formation in the ambient atmosphere. Findings will have important atmospheric implications for modeling studies, and remote sensing observations, as regards the parametrization and identification of Brown OA, and Brown Carbon in the atmosphere.

Constraining direct aerosol radiative forcing using remote sensing and in-situ constraints

2020 ◽  
Author(s):  
Lucia Timea Deaconu ◽  
Duncan Watson-Parris ◽  
Philip Stier ◽  
Lindsay Lee
Keyword(s):  
Remote Sensing ◽  
Black Carbon ◽  
Optical Depth ◽  
Radiative Forcing ◽  
Removal Rates ◽  
Aerosol Radiative Forcing ◽  
Aerosol Absorption ◽  
Direct Radiative Forcing ◽  
Aerosol Radiative

<p>Absorbing aerosols affect the climate system (radiative forcing, cloud formation, precipitation and more) by strongly absorbing solar radiation, particularly at ultraviolet and visible wavelengths. The environmental impacts of an absorbing aerosol layer are influenced by its single scattering albedo (SSA), the albedo of the underlying surface, and also by the atmospheric residence time and column concentration of the aerosols.</p><p>Black-carbon (BC), the collective term used for strongly absorbing, carbonaceous aerosols, emitted by incomplete combustion of fossil fuel, biofuel and biomass, is a significant contributor to atmospheric absorption and probably a main-driver in inter-model differences and large uncertainties in estimating the aerosol radiative forcing due to aerosol-radiation interaction (RFari). Estimates of BC direct radiative forcing suggest a positive effect of +0.71 Wm<sup>-2</sup> (Bond and Bergstrom (2006)) with large uncertainties [+0.08, +1.27] Wm<sup>-2</sup>. These uncertainties result from poor estimates of BC atmospheric burden (emissions and removal rates) and its radiative properties. The uncertainty in the burden is due to the uncertainty in emissions (7.5 [2, 29] Tg yr<sup>-1</sup>) and lifetime (removal rates). In comparison with the available observations, global climate models (GCMs) tend to under-predict absorption near source (e.g. at AERONET stations), and over-predict concentrations in remote regions (e.g. as measured by aircraft campaigns). This may be due to GCM’s weak emissions at the source, but longer lifetime of aerosols in the atmosphere.</p><p>This study aims to address the parametric uncertainty of GCMs and constrain the direct radiative forcing using a perturbed parameter ensemble (PPE) and a collection of observations, from remote sensing to in-situ measurements. Total atmospheric aerosol extinction is quantified using satellite observations that provide aerosol optical depth (AOD), while the SSA is constrained by the use of high-temporal resolution aerosol absorption optical depth (AAOD) measured with AERONET sun-photometers (for near-source columnar information of aerosol absorption) and airborne black-carbon in-situ measurements collected and synthesised in the Global Aerosol Synthesis and Science Project (GASSP) (for properties of long-range transported aerosols). Measurements from the airborne campaigns ATOM and HIPPO are valuable for constraining aerosol absorption in remote areas, while CLARIFY and ORACLES, that were employed over Southeast Atlantic, are considered in our study for near source observations of biomass burning aerosols transported over the bright surface of stratocumulus clouds.</p><p>Using the PPE to explore the uncertainties in the aerosol absorption as well as the dominant emission and removal processes, and by comparing with a variety of observations we have confidence to better constrain the aerosol direct radiative forcing.</p>

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