Morphology of Atmospheric Aerosol and Some Implications

Description

The morphology of individual atmospheric particles, including their mixing state, shape and internal structure, can have important implications on cloud-aerosol interactions and on aerosol direct and indirect radiative forcing. Understanding the mechanisms leading to specific morphologies, the role of morphology in different atmospheric processes, and accounting for these details in models present considerable challenges. These challenges include a lack of fundamental understanding of the physical and chemical aerosol process, computational difficulties to account for morphological effects in transport, regional and global models, and technical and interpretative limitations of observational tools. Several approaches are currently underway to make progress toward the resolution of these difficulties; for example, development and deployment of improved single particle analytical and observational tools, use of accurate electromagnetic models to quantitatively predict the interactions of solar radiation with single complex particles, and particle resolved models. Currently, the single particle analytical and observational methods include single particle mass spectrometry, laser induced incandescence, optical and Raman spectroscopy, optical microscopy and electron microscopy. In addition, denuders are commonly used to study the effects of mixing on, for example, the optical properties of aerosols. In this poster, we will present single particles analyses of samples collected during several field campaigns co-sponsored by DOE, including ClearfLo (clear air for London), SAAS (soot aerosol and aging study), FLAME IV (fire laboratory at Missoula experiment), Whitewater Baldy fire (New Mexico), and PICO (Pico mountain observatory in the Azores). A particular focus will be on constraining discrete dipole approximation simulations with single particle morphological information obtained from electron microscopy. Implications of these results on the effects upon aerosol optical properties will be discussed.