Radiative Cooling in New York/New Jersey Metropolitan Areas by Wildfire Particulate Matter

GEORGIOS A. KELESIDIS, Constantinos Moularas, Hooman Parhizkar, Leonardo Calderón, Irini Tsiodra, Nikolaos Mihalopoulos, Ilias Kavouras, Panos G. Georgopoulos, Jose Guillermo Cedeno Laurent, Philip Demokritou, Rutgers, The State University of New Jersey

     Abstract Number: 224
     Working Group: Aerosol Physics

Abstract
Wildfire particulate matter (WFPM) from Canadian forest fires significantly impacted air quality in the northeastern United States during the summer of 2023, raising concerns about potential public health implications. Here, we used state-of-the-art real time and time integrated instrumentation to characterize the physicochemical properties and radiative effects of WFPM reaching the highly populated metropolitan areas of New Jersey/ New York during this extreme wildfire incident. The major finding of this study is the light absorption and scattering of the WFPM measured during the peak of the event that were three and two times higher than those obtained for normal traffic-related particulate matter sampled five days later, respectively. The direct radiative forcing, RF, of WFPM during the peak of the event ranged from -9 to -18.7 W/m2, corresponding to a potential air temperature reduction of 2.3-4.7 K. Such negative RF in densely populated megacities may limit natural ventilation, increase the residence time of WFPM and other background air pollutants, exacerbating public health risks. This study highlights the importance of radiative effects from WFPM in densely populated areas and their potential implications for air quality and public health, in line with emerging epidemiological evidence in the area affected by the wildfire event.