PhD Proposal: Ansel Lavitz
Location
Physics : 401
Date & Time
May 5, 2025, 9:00 am – 11:00 am
Description
ADVISOR: Dr. Adriana Rocha Lima
TITLE: Angular scattering and extinction measurements toward improved characterization of global dust and its radiative effects
ABSTRACT: Dust aerosols are a major actor in Earth’s atmosphere, influencing its radiative balance, hydrological cycle, atmospheric chemistry, and cloud formation. However, there are many uncertainties surrounding dust aerosol’s microphysical and optical properties, particularly in the context of composition, size, and shape. Further still, the complexity of dust-radiation interactions is compounded more by regional variations in mineralogy, leading to significant discrepancies in climate models and remote sensing retrievals. Ultimately, this limits our ability to accurately quantify their radiative effects. The proposed research aims to address these uncertainties by exploring the impact of angular scattering measurements on phase function accuracy and improving constraints on key particle characteristics. Using a diverse set of dust samples from six arid regions—Chad, Chile, Afghanistan, Mali, Nevada (USA), and Iraq—we will integrate laboratory measurements and remote sensing measurements to derive highly resolved optical and microphysical properties. By analyzing both bulk and suspended particles with the University of Maryland, Baltimore County's (UMBC's) Polarized Imaging Nephelometer (PI-Neph), the Desert Research Institute's (DRI) multi-angle scattering setup with extreme forward- and back-scattering angles, and a Fourier Transform Infrared Spectrometer, we seek to assess the evolution of dust properties from parent soil to airborne aerosol and compare these findings with NASA’s Earth Surface Mineral Dust Source Investigation mission (EMIT) retrievals of soil reflectance and mineralogy. Ultimately, this work will reduce uncertainties in climate models, enhance remote sensing capabilities, and improve our understanding of dust’s role in modulating Earth’s radiative forcing.
TITLE: Angular scattering and extinction measurements toward improved characterization of global dust and its radiative effects
ABSTRACT: Dust aerosols are a major actor in Earth’s atmosphere, influencing its radiative balance, hydrological cycle, atmospheric chemistry, and cloud formation. However, there are many uncertainties surrounding dust aerosol’s microphysical and optical properties, particularly in the context of composition, size, and shape. Further still, the complexity of dust-radiation interactions is compounded more by regional variations in mineralogy, leading to significant discrepancies in climate models and remote sensing retrievals. Ultimately, this limits our ability to accurately quantify their radiative effects. The proposed research aims to address these uncertainties by exploring the impact of angular scattering measurements on phase function accuracy and improving constraints on key particle characteristics. Using a diverse set of dust samples from six arid regions—Chad, Chile, Afghanistan, Mali, Nevada (USA), and Iraq—we will integrate laboratory measurements and remote sensing measurements to derive highly resolved optical and microphysical properties. By analyzing both bulk and suspended particles with the University of Maryland, Baltimore County's (UMBC's) Polarized Imaging Nephelometer (PI-Neph), the Desert Research Institute's (DRI) multi-angle scattering setup with extreme forward- and back-scattering angles, and a Fourier Transform Infrared Spectrometer, we seek to assess the evolution of dust properties from parent soil to airborne aerosol and compare these findings with NASA’s Earth Surface Mineral Dust Source Investigation mission (EMIT) retrievals of soil reflectance and mineralogy. Ultimately, this work will reduce uncertainties in climate models, enhance remote sensing capabilities, and improve our understanding of dust’s role in modulating Earth’s radiative forcing.
