Assessment of Smoke Plume Transport and Impact on Air Quality with a Synergistic Ground-Based and Satellite Observation in New York City

Wildfires across western North America and Canada have increased in number and size over the past three decades, and this trend will continue in response to further warming (Schoennagel, et al., PNAS, 2017). Consequently, large amount of smoke aerosols or particulate matters (PM) are injected into atmosphere, which can be transported over long-distance and affect air quality in regional and continental scales. In this study, we present observation of aerosol plumes transport and their interaction with the planetary-boundary-layer (PBL) in New York City (NYC) for June and July 2017. The impacts on the local air quality are evaluated with the ground in-situ measurements of PM_2.5 (PM with a diameter less than 2.5 µm) and carbon monoxide (CO) at the urban and upwind rural sites of NYC. Combined lidar-ceilometer measurements show the time-height evolution of the aerosols and indicate the plume intrusion, deposit and mixing process into the PBL. The PM_2.5 concentration in the urban and upwind rural areas show coincident increase from 5- to 20~30 μg/m³ along with a consistent enhancement of CO concentration at the upwind rural site. The wildfires sources and smoke transport paths are determined from the NOAA-HMS (hazard mapping system), satellites product and NOAA-HYSPLIT backward trajectories, as well as chemical transport model data. Based on the multi-year observations, we present a cluster analysis of plume transport paths and frequency of occurrence of transported aerosol layers in NYC area. Finally, with the lidar-identified events of plumes mixing into the PBL, we construct the statistics of increase in ground PM_2.5 and CO, to quantify the impacts of the plumes transport on the regional air quality.