Comprehensive assessment of air pollutant and noise emissions at airports across different altitudes

Abstract

<p>We utilized the International Civil Aviation Organization (ICAO) standard emission model, refined with adjustments for fuel flow, LTO cycle work mode time, and emission indices, to investigate the environmental footprint of airports at different altitudes. Airports categorized as high (above 5000 $ \mathrm{f}\mathrm{t} $), medium (1500–5000 $ \mathrm{f}\mathrm{t} $), and low (below 1500 $ \mathrm{f}\mathrm{t} $) altitudes were selected to provide a comprehensive representation of the altitude spectrum. The analysis was anchored over the period spanning 2016 to 2017. Emission inventories for air pollutants and noise were computed for these airports, focusing on the LTO (Landing and Take-Off) cycle. Our findings indicated that high altitude airports exhibit the highest $ {\mathrm{N}\mathrm{O}}_{\mathrm{x}} $ emissions, reaching 406.4 $ \mathrm{t} $, whereas low altitude airports record the highest noise levels at 73.1 $ \mathrm{d}\mathrm{B} $. Significant disparities in emission profiles were observed across different phases of the LTO cycle at airports of varying altitudes. Notably, during the climb phase, the types and proportion of $ {\mathrm{N}\mathrm{O}}_{\mathrm{x}} $ emissions at high altitude airports were as high as 71.8%, contrasting with the 45.6% at low altitude airports. Additionally, emissions of gaseous pollutants from major aircrafts, exemplified by the A320 model, escalated with altitude. Specifically, $ {\mathrm{N}\mathrm{O}}_{\mathrm{x}} $ emissions increased from 10.55 $ \mathrm{k}\mathrm{g}/\mathrm{c}\mathrm{y}\mathrm{c}\mathrm{l}\mathrm{e} $ at low altitude to 20.48 $ \mathrm{k}\mathrm{g}/\mathrm{c}\mathrm{y}\mathrm{c}\mathrm{l}\mathrm{e} $ at high altitude, and $ \mathrm{C}\mathrm{O} $ emissions from 10.88 $ \mathrm{k}\mathrm{g}/\mathrm{c}\mathrm{y}\mathrm{c}\mathrm{l}\mathrm{e} $ to 22.89 $ \mathrm{k}\mathrm{g}/\mathrm{c}\mathrm{y}\mathrm{c}\mathrm{l}\mathrm{e} $. A robust correlation between $ {\mathrm{N}\mathrm{O}}_{\mathrm{x}} $ emissions and $ {L}_{den} $ was identified among airports at different altitudes, with correlation coefficients of 0.96 for low altitude, 0.97 for medium altitude, and 0.93 for high altitude airports. This study delineates the distinct characteristics of air pollutant and noise emissions from airports across altitudes, offering novel insights for the environmental assessment of airport operations.</p>