Aerosol time-of-flight mass spectrometry (ATOFMS) allows for simultaneous determination of the aerodynamic particle size and chemical composition of individual particles in real time. Polydisperse particles originating from July 4, 1995, fireworks displays were monitored using ATOFMS over a 4-day period. Fireworks particles were identified by ion combinations in the single-particle mass spectra of potassium, aluminum, magnesium, barium, and lead and grouped into chemically specific categories. The relative number of ambient fireworks particles peaked on the morning of July 5, 1995, with representative particles being detected as late as July 19, 1995. The mass spectra of the detected particles are indicative of the original chemical composition of typical fireworks mixtures. This study demonstrates the ability of ATOFMS to serve as a real-time monitor of aerosols in the atmosphere, capable of detecting and tracking aerosol particles of a specific size and chemical composition from a particular source over time.

Knowledge of black carbon (BC) emission factors from ships is important from human health and environmental perspectives. A study of instruments measuring BC and fuels typically used in marine operation was carried out on a small marine engine. Six analytical methods measured the BC emissions in the exhaust of the marine engine operated at two load points (25% and 75%) while burning one of three fuels: a distillate marine (DMA), a low sulfur, residual marine (RMB-30) and a high-sulfur residual marine (RMG-380). The average emission factors with all instruments increased from 0.08 to 1.88 gBC/kg fuel in going from 25 to 75% load. An analysis of variance (ANOVA) tested BC emissions against instrument, load, and combined fuel properties and showed that both engine load and fuels had a statistically significant impact on BC emission factors. While BC emissions were impacted by the fuels used, none of the fuel properties investigated (sulfur content, viscosity, carbon residue and CCAI) was a primary driver for BC emissions. Of the two residual fuels, RMB-30 with the lower sulfur content, lower viscosity and lower residual carbon, had the highest BC emission factors. BC emission factors determined with the different instruments showed a good correlation with the PAS values with correlation coefficients R2 > 0.95. A key finding of this research is the relative BC measured values were mostly independent of load and fuel, except for some instruments in certain fuel and load combinations.

Ship emissions contribute to air pollution, increasing the adverse health impacts on people living in coastal cities. We estimated the impacts caused by ship emissions, both on air quality and human health, in 2015 and future (2030) within the Pearl River Delta (PRD) region of China. In addition, we assessed the potential health benefits of implementing an Emission Control Area (ECA) in the region by predicting avoided premature mortality with and without an ECA. In 2015, ship emissions increased PM2.5 concentrations and O3 mixing ratios by 1.4 μg/m3 and 1.9 ppb, respectively, within the PRD region. This resulted in 466 and 346 excess premature acute deaths from PM2.5 and O3, respectively. Premature mortality from chronic exposures was even more significant, with 2,085 and 852 premature deaths from ship‐related PM2.5 and O3, respectively. In 2030, we projected the future ship emissions with and without an ECA, using two possible land scenarios. With an ECA, we predicted 76% reductions in SO2 and 13% reductions in NOx from the shipping sector. Assuming constant land emissions from 2015 in 2030 (2030 Constant scenario), we found that an ECA could avoid 811 PM2.5‐related and 108 O3‐related deaths from chronic exposures. Using 2030 Projected scenario for land emissions, we found that an ECA would avoid 1,194 PM2.5‐related and 160 O3‐related premature deaths in 2030. In both scenarios, implementing an ECA resulted in 30% fewer PM2.5‐related premature deaths and 10% fewer O3‐related premature deaths, illustrating the importance of reducing ship emissions.

Air carriers and aircraft manufacturers are investing in technologies and strategies to reduce fuel consumption and associated emissions. This chapter reviews related issues to assess airline fuel efficiency and offers various empirical evidences from our recent work that focuses on the U.S. domestic passenger air transportation system. We begin with a general presentation of four methods (ratio-based, deterministic frontier, stochastic frontier, and data envelopment analysis) and three perspectives for assessing airline fuel efficiencies, the latter covering consideration of only mainline carrier operations, mainline-subsidiary relations, and airline routing circuity. Airline fuel efficiency results in the short run, in particular the correlations of the results from using different methods and considering different perspectives, are discussed. For the long-term efficiency, we present the development of a stochastic frontier model to investigate individual airline fuel efficiency and system overall evolution between 1990 and 2012. Insight about the association of fuel efficiency with market entry, exit, and airline mergers are also obtained.

With the booming natural gas trade, liquefied natural gas (LNG) carriers—the primary transportation method for intercontinental trade on natural gas—have been experiencing enormous growth. This study offers a novel analysis that connects 2011's in-use LNG fleet characteristics, global satellite data on ship movement, and literature on LNG trade to assess the long-term prospects for increasing the energy efficiency of LNG carriers. This analysis also investigates how efficiency characteristics (such as age, size, technology, and operational practices) influence the efficiency of the LNG fleet and develops a ship stock model to independently track technical and operational efficiency practices in LNG carriers. The findings indicate that industry-leading LNG carriers are about 40% more efficient than industry laggards. This analysis indicates that by fully embracing the available technical and in-use practices of the low-carbon industry leaders of today, the fleet could reduce CO2 emissions by 30 million metric tons by 2040—about 8 million metric tons of natural gas, equivalent to $4 billion savings in the LNG supply chain. This study has important implications for the shipping industry and policy makers. The industry has to address split incentives to take advantage of energy-saving opportunities. Regulations that set targets for the energy efficiency of the in-use fleet may ultimately help the industry harvest the efficiency gains while mitigating climate impact from the industry.