Browsing by Subject "Black carbon"
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Item Open Access Emission Trajectories of BC Compared to CO2 and SO2 Based on Global Country-level Emission Inventories(2016-04-29) Ru, MuyeBlack carbon (BC), as an essential component of particulate matters causing air pollution, has been recently recognized as the second largest contributor to global warming. The emission trajectory of BC with increase of income and the determinants of it are studied in this project, with analysis in different sectors and regions. It shows that BC developed a unique pattern of emission trajectories dominated by the mixture of fuel switch in residential sector and demand growth in transportation sector. This contrasts the typical understanding of Environmental Kuznets Curve (EKC) trajectories for air pollutants and greenhouse gases, which have been heavily studied in the forms of SO2 and CO2 respectively. Based on the same inventory, emission trajectories with income for CO2, SO2, and BC are compared, with CO2 and SO2 fitted with quadratic EKC. Based on the depicted emission trajectories of countries in power, industrial, residential, and transportation sectors, analysis are led on the effectiveness of regulation, influences of natural resources, and the relationship with different developmental patterns.Item Open Access Seasonal and Interannual Variations of Carbonaceous Aerosols over the Amazon(2020) Hu, AllenThis study examines the seasonal and interannual variabilities of carbonaceous aerosols, including black carbon (BC) and organic carbon (OC), over the years of 2005-2016 by using outputs from the NASA GISS ModelE simulations and observations from the OMI instrument aboard Aura, AERONET stations in Amazon region, and the GoAmazon aircraft campaigns.
Simulated seasonal variations and spatial distributions of surface concentrations of BC and OC in Amazon agree well with those of biomass burning emissions. The concentrations are the highest in the dry season (July-September) and lowest in the wet season (February-May), and the locations of high concentrations follow those of high emissions. ModelE is found to underestimate concentrations of OC and BC. Comparisons of the vertical profiles of OC from ModelE with GoAmazon observations in 2014 show that ModelE underestimates OC at all altitudes. In the dry season, when biomass burning dominates, ModelE captures 42%-86% of OMI AAOD in Amazon over 2005-2016, suggesting a low bias in simulated BC concentrations. Simulated seasonal variations in AOD and AAOD in ModelE differ from OMI observations; simulated AOD (AAOD) values are the highest in the dry season, while OMI observed AOD (AAOD) values are the highest in October-January.
Interannual variations in BC and OC are quantified by relative deviation from the mean (RDEVM). Interannual variations of BC and OC in dry season are much higher than those in wet season. RDEVM values are in the range of -63.2% to 127.2% (-70.8% to 143.8%) for BC (OC) in dry season and in the range of -17.8% to 32.7% (-26.3% to 53.4%) for BC (OC) in wet season. Simulated OC concentrations have larger interannual variability than simulated BC for both the dry and wet seasons. We also found that, compared with OMI observations, ModelE overestimates the interannual variability of AOD and AAOD in the Amazon region for both the dry and wet seasons.
Results from this study contribute to the understanding of aerosol distributions in the Amazon and have implications for the impact of carbonaceous aerosols on climate on an interannual timescale.