External Funding (left) Internal Funding (above)
Our research focuses on improving our understanding of the impacts atmospheric aerosols and engineered nanoparticles on climate and health effects at a fundamental molecular level and connecting to observations from the ambient environment. By integrating field measurements, laboratory measurements on field samples, and laboratory measurements on proxies, this integrated approach is allowing us to tackle important atmospheric processes:
- Aerosol acidity: Developing new methods for measuring acidity in individual particles and determining impacts on heterogeneous and multiphase chemistry for particles ranging from secondary organic aerosol (SOA) to sea spray aerosol (SSA) and more
- Aerosol phase state (liquid, viscous, or glassy particles) and liquid-liquid phase separations in the laboratory, chamber studies and field.
- Lake spray aerosol (LSA): aerosols emitted from freshwater lakes are a recently identified source of aerosols. The Ault Laboratory is focused on understanding how these particles impact health during harmful algal blooms (HABs) and climate by acting as cloud condensation nuclei or ice nuclei.
- Impact of engineered nanoparticles on human health
- Aerosol sources impacting urban mega-cities on the neighborhood scale (such as lead-acid battery recycling in India)
- The impact of long range transported aerosols on remote locations (Rockies, Caribbean, etc.)
To determine their physicochemical properties, continuing chemical evolution in the atmosphere, and their subsequent deposition/inhalation at the earth's surface on global to neighborhood scales, we use a wide of array of analytical/physical measurement techniques, including:
- Raman Microspectroscopy - detailed analysis of vibrational spectra at the single particle level for atmospherically relevant sizes, providing functional group information and morphological information at ambient pressure
- Scanning Electron Microscopy/Transmission Electron Microscopy - particle imaging, along with elemental information from energy dispersive X-ray (EDX) analysis and chemical speciation from electron energy loss spectroscopy (EELS)
- Atomic Force Microscopy with Infrared Spectroscopy (AFM-IR) - ambient temperature and pressure imaging and photothermal vibrational spectra.
- Single Particle Mass Spectrometry - real-time measurement of the size and chemistry of individual particles through light scattering and time-of-flight mass spectrometry of positive and negative ions generated through laser desorption/ionization
This interdisciplinary research involves collaborating with researchers in many fields, including atmospheric science, industrial hygiene, civil and environmental engineering, epidemiology, and oceanography. The broad aim of our group is to provide chemical information that can be used to reduce aerosol uncertainties by improving representation in climate models and increasing understanding of the chemistry behind negative health effects.