Modeling dispersion of aircraft emissions is challenging because aircraft are mobile sources with varying emissions rates at different elevations depending on the operating mode. Aircraft emissions during landing and take-off cycle (LTO) influence air quality in and around the airport, and depending on the number of aircraft operations and location of the airport, this influence may be significant. AERMOD (v22112) incorporates a variety of conventional source types to characterize the intended emissions source, leaving the question of which conventional source type(s) best characterizes aircraft activities across the four modes of LTO cycle, unanswered. Currently, the publicly released version of FAA’s Aviation Environmental Design Tool (version 3e) models aircraft emissions as a set of AREA sources for all flight segments. A research version of AEDT allows users to model aircraft sources—both fixed wing and rotorcraft—as a series of VOLUME sources in AERMOD. However, both source treatments do not account for plume rise of aircraft jet exhaust. This paper compares AERMOD’s performance in describing SO₂ concentrations associated with airport sources by comparing model results from the two source options during the summer campaign of the Air Quality Source Apportionment study conducted at the Los Angeles International Airport. We conclude that both VOLUME source and AREA treatments overestimate the highest observed SO₂ concentrations despite not accounting for background sources. The VOLUME source option reduces this overestimation by using a higher initial plume spread than the AREA option does, and through the inclusion of meander. Our results suggest the need to include the plume rise of jet exhaust when using AERMOD for airport air quality studies.

对飞机排放分散进行建模具有挑战性，因为飞机是移动源，根据运行模式，在不同海拔高度的排放率也不同。着陆和起飞周期 (LTO) 期间的飞机排放会影响机场及其周围的空气质量，并且根据飞机运营的数量和机场的位置，这种影响可能会很大。 AERMOD (v22112) 结合了各种传统源类型来表征预期排放源，而哪种传统源类型最能表征 LTO 循环四种模式中的飞机活动的问题尚未得到解答。目前，FAA 航空环境设计工具的公开发布版本（版本 3e）将飞机排放建模为所有航段的一组 AREA 源。 AEDT 的研究版本允许用户将飞机源（固定翼飞机和旋翼机）建模为 AERMOD 中的一系列体积源。然而，两种源处理方法都没有考虑飞机喷气废气的羽流上升。本文通过比较在洛杉矶国际机场进行的空气质量源解析研究夏季活动期间两种源选项的模型结果，比较了 AERMOD 在描述与机场源相关的SO ₂浓度方面的性能。我们得出的结论是，尽管没有考虑背景源，但体积源和面积处理都高估了观察到的最高 SO ₂浓度。 VOLUME 源选项通过使用比 AREA 选项更高的初始羽流分布以及包含曲流来减少这种高估。我们的结果表明，在使用 AERMOD 进行机场空气质量研究时，需要考虑喷气机废气的羽流上升。