Modeling of Air Pollution at Airports

Although airports provide several benefits for our society, communities in the vicinity of airports are subjected to the deterioration of air quality. Currently, the basic objects of attention are NOx and ultrafine PM due to airport-related emissions. Considered environmental problems are intensified in connection with increasing air traffic, rising tensions of airports expansion and growing cities closer and closer each other, and accordingly growing public concern with air quality around the airport. Aircraft are the dominant and special source of emission and air pollution at airports in most cases under consideration. So, to evaluate the aircraft contribution in LAQ assessment of the airports accurately, it is important to take in mind few features of the aircraft during their landing-takeoff cycle (LTO), which define emission and dispersion parameters of the considered source. The complex model PolEmiCa allows the calculation of the inventory and dispersion parameters of the aircraft engine emissions during the LTO cycles of the aircraft in the airport area. But a clear quantification of aircraft emission contribution to total air pollution is the actual task for development of cost-effective strategies to improve local air quality according to the vicinity of the airport, and to meet regulatory requirements

Aircraft engine exhaust emissions and other airport-related contributions to ambient air pollution: A review

Civil aviation is fast-growing (about +5% every year), mainly driven by the developing economies and globalisation. Its impact on the environment is heavily debated, particularly in relation to climate forcing attributed to emissions at cruising altitudes and the noise and the deterioration of air quality at ground-level due to airport operations. This latter environmental issue is of particular interest to the scientific community and policymakers, especially in relation to the breach of limit and target values for many air pollutants, mainly nitrogen oxides and particulate matter, near the busiest airports and the resulting consequences for public health. Despite the increased attention given to aircraft emissions at ground-level and air pollution in the vicinity of airports, many research gaps remain. Sources relevant to air quality include not only engine exhaust and non-exhaust emissions from aircraft, but also emissions from the units providing power to the aircraft on the ground, the traffic due to the airport ground service, maintenance work, heating facilities, fugitive vapours from refuelling operations, kitchens and restaurants for passengers and operators, intermodal transportation systems, and road traffic for transporting people and goods in and out to the airport. Many of these sources have received inadequate attention, despite their high potential for impact on air quality. This review aims to summarise the state-of-the-art research on aircraft and airport emissions and attempts to synthesise the results of studies that have addressed this issue. It also aims to describe the key characteristics of pollution, the impacts upon global and local air quality and to address the future potential of research by highlighting research needs

A number-based inventory of size-resolved black carbon particle emissions by global civil aviation

With the rapidly growing global air traffic, the impacts of the black carbon (BC) in the aviation exhaust on climate, environment and public health are likely rising. The particle number and size distribution are crucial metrics for toxicological analysis and aerosol-cloud interactions. Here, a size-resolved BC particle number emission inventory was developed for the global civil aviation. The BC particle number emission is approximately (10.9 ± 2.1) × 1025 per year with an average emission index of (6.06 ± 1.18) × 1014 per kg of burned fuel, which is about 1.3% of the total ground anthropogenic emissions, and 3.6% of the road transport emission. The global aviation emitted BC particles follow a lognormal distribution with a geometric mean diameter (GMD) of 31.99 ± 0.8 nm and a geometric standard deviation (GSD) of 1.85 ± 0.016. The variabilities of GMDs and GSDs for all flights are about 4.8 and 0.08 nm, respectively. The inventory provides new data for assessing the aviation impacts. Size-resolved Black Carbon (BC) particle number emission inventory is not available for global civil aviation. Here the authors converted BC mass emission inventory into number emission inventory and found that aviation BC number emission contributes to 1.3% of total ground anthropogenic emissions and 3.6% on global average. Document type: Articl

Characterising Ultrafine Particles at Heathrow Airport

Exposure to ultrafine particles (UFP) is increasingly associated with adverse health outcomes. However, measurement of UFP in the ambient environment is generally not widespread, which limits both understanding and data for detailed assessment of the health impact. Of particular interest is the impact of airport and aircraft activities on UFP concentrations, as there are no abatement strategies for emissions from aircraft engines and jet fuel typically has a relatively high sulphur content, which can contribute to UFP formation during combustion. Three UFP measurement studies were undertaken between 2016 and 2019 to progressively understand the environment around Heathrow Airport: • The study in 2016 was carefully arranged to put airport measurements into context with representative traffic, residential and rural measurements in the south of England. As far as possible, the analysers, configurations and QA/QC used at the airport was the same as the analysers used in the UK regulatory monitoring network. The results clearly show that local airport activity has a very significant effect on local concentrations. The size distribution of airport-related UFP was seen to be different to other locations; particles smaller than 30 nm were observed in far higher numbers at the airport. Departing aircraft were associated with higher UFP concentrations than arriving aircraft. • The 2017 study was designed to just investigate particles smaller than 100 nm, at a faster time resolution than conventional analyser configurations. This study confirmed UFP measurements were greater in number concentration from departing aircraft and also from larger aircraft within that subset. • The 2019 study made use of a very fast UFP analyser, accurate aircraft location data and meteorology to uniquely associate UFP measurements with individual aircraft. The data were used to calculate emission rates for each aircraft type, which were found to be much higher than stated literature values. This is almost certainly due to measurement of condensable particles not accounted for in the published literature data. Larger and older aircraft were associated with higher measurements and emission rates, not necessarily mitigated by carrying more passengers. In 2021, the World Health Organization published guidance for recommended maximum hourly and daily exposure to UFP. The recorded measurements from all three studies exceeded these guide values; UFP exposure at large airports will be a key area of interest for future research and health assessments

Comparison of flow and dispersion properties of free and wall turbulent jets for source dynamics characterisation

The objective of this paper is to provide an investigation, using large eddy simulations, into the dispersion of aircraft jets in co-flowing take-off conditions. Before carrying out such study, simple turbulent plane free and wall jet simulations are carried out to validate the computational models and to assess the impact of the presence of the solid boundary on the flow and dispersion properties. The current study represents a step towards a better understanding of the source dynamics behind an airplane jet engine during the take-off and landing phases. The information provided from these simulations can be used for future improvements of existing dispersion models

Environmental impact assessment of commercial aircraft operations in the United States

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2009.Cataloged from PDF version of thesis.Includes bibliographical references (p. 313-365).The objective of this thesis was to evaluate the environmental trade-offs inherent in multi-criteria objectives of an integrated environmental policy. A probabilistic multi-attribute impact pathway analysis (MAIPA) was formulated to assess the environmental damages of US commercial aircraft operations from 1991-2003. The initial contribution of this work was demonstrating the feasibility of, and identifying requirements for, the FAA Aviation-environmental Portfolio Management Tool (APMT), an integrated assessment capability for US regulatory decision-making. Non-aircraft sources have been found to dictate marginal emissions costs. The implication is that aviation emissions reductions influence neither the magnitudes nor trends in per-unit marginal damages. In contrast, noise mitigation is the dominant influence on the value of per-unit marginal damages. Trends in sum damages were found to depend on the growth rates of air transport relative to other source emissions. Growth in air transport emissions outpaced non-aircraft sources from 1991-2003. Because growth in marginal costs is nonlinear over this period, aviation emissions damages grow faster than inventories. Applying methods similar to MAIPA to estimate damages for future scenarios suggests that stemming climate impacts is fast becoming the priority. A reassessment of the environmental benefits derived from mandated phase-outs of noisy aircraft during the 1990's has been carried out. Previous studies estimated a -80% reduction in population exposure. In contrast, the reassessment estimates a ~2% reduction, providing benefits 17-20 times lower than published estimates of abatement costs.(cont.) The primary environmental benefit of the noise phase-outs was found to be related to reductions in particulate matter inventories. One way to avoid trade-off inefficiencies is to identify options that bundle benefits. This action provides such an example, where the phase-outs led to reductions in both noise and air quality emissions. Other contributions in the thesis include the following: a treatment of air transport particulate matter emissions, environmental fate, and health impacts of particulate matter; identification that the major source of reducible uncertainty in emissions damages stems from the assumed extent of ozone and particulate matter production in the engine exhaust plume; and quantification of the environmental tradeoffs in decisions specifying aircraft performance for the technology in the US commercial fleet from 1991-2003.by Stephen P. Lukachko.Ph.D

Covid-19 grounding - Monitoring air pollution at Zurich Airport during the pandemic using trees as bio-indicators

When the world stayed at home at the time of the Covid-19 pandemic in 2020, it also suddenly became quiet around Zurich/Kloten Airport. The turbines stopped and aircraft remained on the ground. The movement restrictions had the effect that air traffic was reduced by 91%. In fact, you could call it a "Covid-19 grounding". In this thesis, the effects of the pandemic lockdown and the associated reduction in traffic-related emissions on air quality are studied using Norway spruce trees (Picea abies (L.) H.Karst) as bio-indicators at Zurich Airport. For this purpose, three sites were investigated, two of which were located at exposed locations to air (runway site) and road (carparking site) traffic and one control site further away from traffic-related emission sources. Using the radiocarbon method, spruce needles from four generations (pre-pandemic: 2018-2019 and pandemic: 2020-2021) were analyzed and a decreasing dilution effect (14 C enrichment) was detected in the lockdown needle generations (2020) at sites near traffic-related emission sources. This effect comes from reduced combustion of fossil fuels and release of 14 C free CO2. The mean decreases in -F14 C in needles from 2020 was 30% at the carparking site, like the decrease in local road traffic, and 52% at the runway site, which was thus additionally affected by the reduction of air traffic. In contrast, nitrogen isotope analysis at none of the three sites showed a significant change in the d15 N nor d13 C ratio in the 2020 needle generation compared to previous years. The method appeared less suitable than the radiocarbon method for examining shortterm reductions in air pollutants. Similarly, the mean tree-ring chronologies at the sites did not correlate with the mean annual NO2 concentrations measured at Zurich Airport, but rather with local climate factors such as precipitation and temperature. The results of the stable isotope and tree-ring analysis showed that the signals caused by pollution or climate are difficult to distinguish. The same applies to changes in measured concentrations of air pollutants during the pandemic, which are strongly dependent on meteorological conditions that influence the distribution and dilution of pollutants in the air. Determining which changes in air quality are actually caused by emissions and which are due to weather conditions is therefore one of the greatest challenges to date

On Enhancing Air Quality Model Predictions of Particulate Matter From Aircraft Emissions

Aviation is an important mode of transportation and usage is expected to continually grow. However, aircraft emit numerous pollutants that adversely impact air quality. The goal of this work is to provide additional certainty in air quality estimates of one of those pollutants, aircraft-attributable PM2.5, during landing and takeoff cycles using the Community Air Quality (CMAQ) Model and its enhancements. First, CMAQ's response to secondary organic aerosol (SOA) concentrations, a component of PM2.5, formed from aircraft emissions was examined. It was determined that at coarser model resolutions (36-km and 12-km), aircraft NOx emissions lowered free radical concentrations and thereby reduced SOA precursor oxidation. This directly resulted in the reduction of SOA concentrations, primarily biogenic SOA. At a finer grid resolution (4-km), aircraft primary organic aerosol (POA) emissions provided additional mass for SOA to partition onto, promoting semi-volatile organic carbon species to partition from the particle phase to the gas phase, increasing SOA concentrations. Secondly, a new formation pathway for modeled PM2.5 (based on recent sampling and smog chamber data) was incorporated into CMAQ to account for non-traditional SOA (NTSOA), SOA formed from aircraft emissions of semi and intermediate volatile organic compounds. This new pathway added 1.7% in January and 7.4% in July to aircraft-attributable PM2.5 at the Hartsfield-Jackson Atlanta International Airport. Downwind of the Atlanta airport, NTSOA averaged 4.6-17.9% of aircraft- attributable PM2.5. These contributions were generally low compared to smog chamber results due to considerably lower ambient organic aerosol concentrations in CMAQ versus those in the smog chamber experiments. Thirdly, alternative aircraft PM emission estimates based on a 1-D plume model were coupled with a plume in grid (PinG) treatment for aircraft in CMAQ. This treatment increased grid-based monthly and contiguous U.S. average aircraft-attributable PM2.5 by 40% (from 1.9 ng m-3 to 2.7 ng m-3) in a winter month and 12% (from 2.4 ng m-3 to 2.6 ng m-3) in a summer month. Maximum modeled hourly subgrid scale aircraft-attributable PM2.5 concentrations were 23.7 µg m-3 in a winter month and 59.3 µg m-3 in a summer month, considerably higher than typical grid-based aircraft contributions (~0.1 µg m-3).Doctor of Philosoph

Environmental Impact of Aviation and Sustainable Solutions

Environmental Impact of Aviation and Sustainable Solutions is a compilation of review and research articles in the broad field of aviation and the environment. Over three sections and thirteen chapters, this book covers topics such as aircraft design and materials, combustor modeling, atomization, airport pollution, sonic boom and street noise pollution, emission mitigation strategies, and environmentally friendly contributions from a Russian aviation pioneer. This volume is a useful reference for both researchers and students interested in learning about various aspects of aviation and the environmen

Quantifying the Impacts of Anthropogenic Emissions and Specific Infrastructures on Urban Air Quality

The interconnectivity between city infrastructure, energy and air quality is explored by evaluating the impact of environmental regulations, urban layout, and the transportation sector on air quality and energy use. Particular aspects of the research include assessing how controls have impacted aerosol acidity (which impacts health), linkages between energy, demographics, and how both airports and the use of autonomous and electric vehicles may impact on air quality. This research finds that while environmental regulations are effective in curbing pollution, as measured through decreases in fine particulate matter (PM2.5) emissions in the U.S., PM2.5 particles (aerosol) remain acidic. An implication of this is that it could be decades before changes in aerosol acidity, which is related to the toxicity and adverse health impacts of PM2.5, are seen. The research also found a strong statistical relationship between residential energy (electric and natural gas) consumption and socio-economic demographic (SED) factors for Zip Code Tabulated Areas (ZCTAs) in metropolitan Atlanta. However the electricity model exhibited high bias. Additional analyses found that electricity use is affected by the urban morphology of the roadways, with ZCTAs in high road density areas using more electricity The impacts of airports, mainly the Atlanta Hartsfield Jackson (ATL) on air quality, was examined using fine scale chemical transport modeling (CMAQ).CMAQ results are evaluated using ground-based and high resolution satellite-based observations from the TROPOspheric Monitoring Instrument (TROPOMI). TROPOMI's ability to provide consistent NO2 vertical column densities (VCDs) is assessed using the CMAQ results around two power plants. A 3D airport emission inventory from full flight operations is developed and compared against a base inventory with only surface airport operation emissions allocated to ATL. Results show that the magnitude and spatial extent of airport effects on air quality would be understated if only the base inventory is used for regulatory purposes. Lastly, we assess the efficacy of an electrified automated fleet of passenger cars on 2050 air quality in the US with a 2050 scenario where gasoline powered passenger cars emit lower levels of pollution than present day automobiles with CMAQ. We find that electric cars have advantages over future gasoline vehicles in terms of improving air quality, though the magnitude varies by species (O3, PM2.5). The overall implications of our findings is that policy, technology and urban infrastructure have a compounded effect on the efficacy of environmental regulations, air quality and energy use. Multiple factors should be considered when designing policies promoting equitable, sustainable cities.Ph.D