Abstract View
Ultrafine Particle Ground-Level Impacts during Aircraft Approach and Climb Out Operations at a Major Cargo Hub
MARYSSA LOEHR, Jay R. Turner, Washington University in St. Louis
Abstract Number: 707
Working Group: Urban Aerosols
Abstract
Ultrafine particles (UFP) contribute to adverse health outcomes such as asthma, obstructive pulmonary disease, cardiovascular disease, and lung cancer. Recent studies have drawn attention to elevated ground-level UFP number concentrations from aircraft and airport operations emissions. In this study, we aim to quantify ground level impacts of individual aircraft during climb out and approach operations at a commercial airport with a large air cargo hub. Ground level UFP concentrations are measured along public roads near the airport at one-second resolution using mixing particle condensation counters (MCPC, Brechtel, Hayward, CA) on mobile platforms. Measurements are conducted during late evening and early morning hours corresponding to air cargo arrivals and departures, respectively. These times of day tend to have low atmospheric mixing layer heights which suppress the vertical dispersion of emissions and exacerbate ground level concentrations. Aircraft typically approach the airport into the wind and UFP during the arrivals period features contributions from individual approaching aircraft superposed on a rising baseline because of increased airport operations to process the cargo. UFP concentrations reaching 160,000 #/cc were observed ~0.7 km downwind of the airport at locations underneath or immediately downwind of the arrival flight path. In contrast, aircraft typically depart into the wind and UFP measurements upwind of the airport to characterize climb out emissions were not confounded by airport operations impacts. Ground-level UFP during climb out operations rarely exceed 50,000 #/cc at locations ~0.5 km from the airport even though the climb out phase uses more engine thrust, likely because the aircraft rapidly ascend above the mixed layer. Nighttime UFP in a low-income residential area ~1.3 km downwind of the airport consistently exceeded 50,000 #/cc during periods of peak flight activity and rose to >90,000 #/cc because of the corresponding increase in airport operations to support air cargo handling.