Seminar: Exploring Complex Relationships Between Meteorology and Air Quality in Urban Environments

Abstract

Recent decades have seen an increase in the quantity and density of urban air quality and meteorology measurements to address key questions related to the role that the urban boundary layer plays in pollution transport and dispersion. Much of the work conducted at the NOAA Chemical Sciences Laboratory focuses on addressing urban air quality, which is often done in coordination with other research institutions, thus leading to a convergence of instrumentation and a wealth of data at a high spatiotemporal resolution. In this presentation, we explore two recent examples featuring instruments deployed to survey the evolving air quality conditions in an urban environment: 1) a non-local transport event from the Canadian wildfires during June 2023 into the Baltimore-Washington region, and 2) some highlights from a recent study exploring the impact of complex mesoscale flows on ozone, NOx, and VOCs within the Los Angeles basin during the 2021 Southwest Urban NOx and VOCs Experiment (SUNVEx). The smoke transported into the Mid-Atlantic region in the former example led to health hazardous conditions that made national headlines. A Doppler lidar, a regional network of air quality stations, backscatter measurements from ceilometers, and the High Resolution Rapid Refresh (HRRR) model are used to interrogate the transport event and diagnose the meteorological conditions that led to high concentrations of fine particulate matter (PM2.5) and low visibility. The latter example focuses on relationships between dynamics and chemistry measurements in Pasadena, California during a Seabreeze event that also featured northerly flows from the San Gabriel Mountains that occurred simultaneously at the measurement site.