Airborne aerosols and volatile organic compounds (VOCs) constitute significant air quality challenges. They come from diverse emission sources. Once released into the atmosphere, these pollutants undergo complex chemical and physical transformations during their transport. These complexities render their measurement and source identification very challenging.

We conduct multi-tiered field measurements using stationary monitoring stations, ground-based mobile laboratories, and airborne platforms. Employing cutting-edge techniques such as mass spectrometry and infrared spectroscopy, we examine the chemical composition of aerosols and VOCs in both ambient and indoor air. To pinpoint their sources, we employ advanced statistical models. Furthermore, we investigate the intricate mechanisms governing their formation and transformation as they age in the air. 

Air quality and climate change are intricately linked. Key air pollutants, such as aerosols and ozone, influence climate by interacting with radiation. Aerosols can directly warm (e.g. black carbon) or cool (e.g., sulfates) the atmosphere through sunlight absorption or scattering. They can also impact cloud dynamics, precipitation, and regional circulation patterns. Climate change, in turn, can exacerbate air quality by altering air pollution meteorology (e.g. dilution) and initiating amplifying responses in emissions and atmospheric chemistry. This complex interaction highlights the need for comprehensive understanding.

We quantify the climate-relevant characteristics of aerosols, such as absorption and scattering, and investigate how atmospheric processes can alter these properties that potentially affect climate. Through observations, we validate and inform climate models to enhance their predictive capabilities. Additionally, our research explores the reciprocal relationship: how climate change, such as temperature increases, impacts air quality.

Air pollution disproportionately impacts individuals in lower socioeconomic positions, including those with low incomes, people of color, and residents near pollution sources. Often, these communities lack the necessary resources and information to address this issue. 

In pursuit of equity, we develop innovative platforms, such as mobile laboratories, capable of high-resolution measurements of various air pollutants, including speciated aerosols, VOCs, and criteria air pollutants at a community scale. These tools enable us to identify hyperlocal pollution hotspots, enhance fine-scale emission inventories and modeling accuracy, and offer actionable insights for policymakers to enhance urban resilience.