Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 107 for “"black carbon"”.
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Constraining black carbon emission inventories with observations
Black carbon (BC) is a tiny particle in the atmosphere that plays an important role in affecting the Earth’s energy balance. It can absorb solar radiation, interact with clouds, and reduce the albedo of snow. More accurate quantification of the long-term climatic influence of BC requires estimates …
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Laser-based method for black carbon determination in lake sediment cores and black carbon deposition in Greenland since 300 CE
Black carbon (BC) is a conservative tracer for industrial combustion and open biomass burning that has a significant contribution to Earth's radiative budget. Because BC is a dark, light-absorbing particle, BC is estimated by the Intergovernmental Panel on Climate Change (IPCC) to have a forcing of …
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Nature and origin of black carbon in Ireland
Black carbon (BC) particles are important atmospheric radiative forcing agents and also have a negative effect on human health. In this study, a seven wavelength, dual spot aethalometer, was used to determine the equivalent BC (eBC) concentrations at four locations in Ireland; Killarney, …
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Sensitivity of black carbon aging to modeling assumption in CAM-chem
Black carbon (BC) aerosol strongly absorbs visible light and therefore has a warming impact on climate. Quantifying this impact requires us to develop faithful model representations of its climate-relevant properties, such as CCN activity and optical properties. One key process that needs to be …
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Improving model representations of black carbon using a particle-resolved aerosol model
"Particles containing black carbon (BC) alter the Earth's energy balance by scattering and absorbing solar radiation, by interacting with clouds, and by decreasing the albedo of ice and snow. Each of these climate effects depends on the properties of individual BC-containing particles and their …
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Black Carbon Measurements of Snow and Ice Using the Single Particle Soot Photometer: Method Development and an AD 1852-1999 Record of Atmospheric Black Carbon from a Mount Logan Ice Core
<p>Black carbon (BC), produced by the combustion of fossil and biofuels, warms the climate by absorbing solar radiation when in the atmosphere and by reducing the albedo of snow and ice when deposited. Measuring BC in snow and ice is important for estimating albedo reduction and developing …
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Black carbon mixing state impacts on aerosol activation investigations using particle-resolved model simulations
Black carbon-containing aerosol particles (called BC particles hereafter) are a major particle type in the atmosphere. Their source is the incomplete combustion of carbon containing material, which means that except for natural biomass burning all sources of BC particles are anthropogenic. They …
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Constraining a historical black carbon emission inventory of the United States from 1960-2000
In order to improve the accuracy of the black carbon (BC) historical emission inventory of the United States over the period 1960-2000, I studied the transport of global BC emissions and ambient air concentrations using the Community Atmosphere Model. I formulated the relationship between emissions …
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Assessment of Black Carbon in Snow and Ice from the Tibetan Plateau and Pacific Northwest
… Mountains were analyzed for concentrations of black carbon (BC) using a Single Particle Soot Photometer (SP2). From the ice core, the high-resolution BC record displayed substantial variability, a 2-fold increase in peak concentrations from 1853-1930 to 1930-1983, and a 1.6-fold increase in …
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Black carbon in marine sediments : quantification and implications for the sorption of polycyclic aromatic hydrocarbons
… determining the fate of polycyclic aromatic hydrocarbons (PAHs) in the environment. Here, PAH sorption is proposed as the sum of two mechanisms: absorption into a biogenic, organic carbon (OC) fraction and adsorption onto a combustion-derived, black carbon (BC) fraction. To study BC adsorption, a …
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Black carbon mixing state in Paris during MEGAPOLI: Connecting particle resolved observation to particle resolved modeling
The composition and properties of black carbon aerosol particles change continuously after emission during transport in the atmosphere. Coagulation, condensation, and photochemistry are contributing processes, collectively termed aging. Understanding these processes is important for assessing the …
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Investigating the impacts of entrainment on nucleation scavenging of black carbon particles through particle-resolved simulations
… our climate by direct and indirect effects. Black carbon is a unique aerosol in that along with scattering, it can also absorb solar radiation, which heats the atmosphere and contributes to a positive radiative forcing. The optical and cloud condensation nuclei properties of the aerosol …
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Effects of incomplete combustion on atmospheric chemistry: Black carbon climate forcing and global carbon monoxide emissions
… chemistry. The first explores the sensitivity of black carbon (BC) forcing to aerosol vertical location since BC has an increased forcing per unit mass when it is located above reflective clouds. We used a column radiative transfer model to produce globally-averaged values of normalized direct …
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Sources and Transport of Black Carbon at the United States-Mexico Border near San Diego-Tijuana
… border in San Diego and Tijuana, we measured black carbon (BC) concentrations at three locations in Mexico and one in the United States. The measurements were intended to support the following objectives: to characterize the spatial and temporal variability in BC concentrations and emissions …
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Sub-grid process analysis of the sensitivity of black carbon aging to particle microphysical properties at emission
The microphysical properties of black carbon-containing particles change due to interaction with other aerosol components after emission, altering their radiative properties and cloud condensation nuclei activity. Understanding these aging processes is essential in assessing black carbon’s direct …
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Mobile Laboratory Measurement of Black Carbon, Particulate Polycyclic Aromatic Hydrocarbons and Other Exhaust Emissions in Mexico City
Black carbon (BC) and polycyclic aromatic hydrocarbons (PAHs) are two atmospheric pollutants produced by motor vehicles using carbonaceous fuels. As a part of the Mexico City Project, measurements of BC, PPAHs and many other gas- and particle-phase emissions were measured in Mexico City using a …
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AN APPROACH TO ESTIMATE GLOBAL BIOMASS BURNING EMISSIONS OF ORGANIC AND BLACK CARBON FROM MODIS FIRE RADIATIVE POWER
… fire is the main global source of fine primary carbonaceous aerosols in the form of organic carbon (OC) and black carbon (BC), but uncertainty in aerosol emission estimates from biomass burning is still rather large. Application of satellite based measures of fire radiative power (FRP) has been …
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Black carbon in the Gulf of Maine : new insights into inputs and cycling of combustion-derived organic carbon
Emissions of black carbon (BC), the soot and char formed during incomplete combustion of fossil and biomass fuels, have increased over the last century and are estimated to be between 8 and 270 Tg BC/yr. BC may affect problems as diverse as global warming, human health, carbon cycling in …
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Thermodynamics and kinetics of hydrophobic organic compound sorption in natural sorbents and quantification of black carbon by electron microscopy
… and literature data suggested logKoc (organic-carbon normalized partition coefficient) and logKBC (black-carbon normalized partition coefficient) values were fairly constant across different geosorbents (around 4.5-5.7 and 5.6-6.3, respectively), while the non-linearity exponent varied …
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