Aircraft measurements have revealed that super coarse dust (diameter > 10 mm) is surprisingly abundant in Earth’s atmosphere. However, most current models either neglect or greatly underestimate the abundance of super coarse dust. In this seminar, I explore the causes of this model underestimation of super coarse dust. I derive a new parameterization for the size distribution of emitted dust aerosols that matches measurements of super coarse dust close to source regions. Despite this improvement in the accuracy of coarse dust emissions, models still greatly underestimate super coarse dust in dust outflow regions. Thus, the model underestimation of super coarse atmospheric dust is in part due to the underestimation of super coarse dust emission and likely in part due to errors in deposition processes.

Dust carries consequences for public health, visibility, trade and transportation, and water insecurity, yet dust largely remains inscrutable to regulatory science. I examine the politics of how we measure, monitor, and manage dust in the United States and particularly the consequences of lacking regulatory data on dust and the ensuing uncertainty. This becomes even more of an issue in the Anthropocene, an era of environmental change that complicates our ability to see emerging environmental issues and understand anticipated future conditions. Current data practices can mislead efforts to better adapt to new environmental conditions. These include the designation and dismissal of outliers, particularly in changing systems, spatial gaps in monitoring systems, and even ambiguity about what counts as dust.

I focus specifically on a case study of the Exceptional Events Rule (EER) of the Clean Air Act that excludes data, resulting in air quality events—and dust storms in particular—going unregulated. Using a mixed-methods approach including interviews, participant observation, document analysis, and spatial analysis, I trace the data exclusions and their consequences for air quality knowledge and regulation.  This research identifies recursive process of distortion at play where constructing categories of abnormal–normal allows for the exclusion of “outliers” from data sets, which ultimately produces a false rarity and hides environmental changes. The result is regular and repeated surprises, unnoticed hazards, undetected exposures, and ultimately deregulation.

Dust storms appear to be a growing health hazard in the United States.  However, only a limited number of population-based health studies of dust storms have been published, and many of those use dust storm data sources known to have limitations.  In this talk we present dust storm epidemiology research covering 4 southwestern U.S. states conducted under an ongoing NIH R21 grant. First, we explore and evaluate alternative dust storm data sources to determine which are potentially better-suited to dust storm health research than those used previously, and second we quantify associations between dust storms and Emergency Department visits in a limited data set.  Future work will combine these lines of research.

Dust storms appear to be a growing health hazard in the United States.  However, only a limited number of population-based health studies of dust storms have been published, and many of those use dust storm data sources known to have limitations.  In this talk we present dust storm epidemiology research covering 4 southwestern U.S. states conducted under an ongoing NIH R21 grant. First, we explore and evaluate alternative dust storm data sources to determine which are potentially better-suited to dust storm health research than those used previously, and second we quantify associations between dust storms and Emergency Department visits in a limited data set.  Future work will combine these lines of research.

Dust storms appear to be a growing health hazard in the United States.  However, only a limited number of population-based health studies of dust storms have been published, and many of those use dust storm data sources known to have limitations.  In this talk we present dust storm epidemiology research covering 4 southwestern U.S. states conducted under an ongoing NIH R21 grant. First, we explore and evaluate alternative dust storm data sources to determine which are potentially better-suited to dust storm health research than those used previously, and second we quantify associations between dust storms and Emergency Department visits in a limited data set.  Future work will combine these lines of research.

As emerging environmental risks continue to challenge scientists, the need to enhance research designs and apply innovative technology and data products to basic epidemiology questions is at the forefront of global dialogue. For example, increased frequency of exposure to poor air quality (including dust), extreme heat temperatures, and mosquitoes or ticks can lead to detrimental health effects and influence the global burden of disease. To examine the impact of these potential environmental exposures on human health, Earth-observing satellite data provide real-time information about temporal and spatial changes within the global ecosystems. By forming cross-cutting research collaborations with multidisciplinary teams, experts can focus scientific inquiries to examine trends on how the Earth’s systems are changing. This presentation will provide an overview of the use of NASA Earth-observing satellite data, including the forthcoming TEMPO and MAIA missions, to examine risk associated with air quality management and infectious disease prevention and control. This valuable information can enhance public health surveillance programs and ultimately strengthen current efforts to meet national and international health goals, like the Sustainable Development Goals. Audience members will gain insight on these advanced approaches and learn about existing and upcoming capacity building activities in the program.

The Plankton, Aerosol, Cloud, and Ocean Ecosystem (PACE) mission is NASA’s next great investment in Earth Science, continuing NASA’s legacy of over forty years of satellite ocean color and atmospheric measurements. PACE, expected to launch in early 2024, will advance our Earth-observing and monitoring capabilities through hyperspectral imaging and multi-angle polarimetric observations of ocean, atmosphere, and land ecosystems. PACE will give us an unprecedented view of our home planet and will support user-driven environmental applications through research and applied science to address societal challenges and inform decision-making. Among other applications, PACE could enable dust-related research through the development of data products such as dust optical depth or dust speciation, as well as inform aerosol transport models for more accurate air quality or atmospheric management. This presentation will highlight PACE’s novel hyperspectral and polarimetric capabilities, future directions for dust-related research and applications, and how the PACE Applications program strengthens ties between science and decision-making.

Ozone pollution has long been recognized as an important air quality issue in the summer; however, it has recently been shown that ozone pollution is a major problem in the western United States during the winter that cannot be explained by traditional chemical pathways. A possibly explanation for this phenomenon is the production of chlorine radicals that can produce tropospheric ozone. In winter under low light and cold conditions, these radicals are thought to originate from the photolysis of nitryl chloride (ClNO2), formed when dinitrogen pentoxide (N2O5) reacts with chloride-containing aerosol. One aspect of this hypothesis that has puzzled the atmospheric chemistry community is, where does the aerosol chloride come from especially in regions far from the ocean? In this talk, I will provide evidence that a likely explanation is that ClNO2 is produced in large quantities from saline playas (e.g., dried lakebeds), which emit large quantities of dust that can interact with N2O5. By performing detailed bulk and single-particle analysis on different playa dust samples using ion chromatography, X-ray Diffraction (XRD), single-particle mass spectrometry, and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDS), we found that playa dust mineralogy, particularly at the particle surface determines the reactivity of these dusts with N2O5,  the production of ClNO2 from this reaction, and the overall impact of reactions between pollutant gases and saline playa dusts on ozone pollution and air quality. Because water use practices are predicted to increase the geographic extent of playas worldwide, this work has implications for current and future air quality considerations.

Iron oxide minerals in atmospheric dust have outsized effects on the Earth System relative to their low amounts and small sizes.  These minerals have large capacity to absorb solar radiation and can thereby contribute to heating the atmosphere as well as surfaces of snow and ice thereby inducing rapid melting.  After undergoing alterations during atmospheric transport, the iron in some oxide minerals serves as an essential nutrient for marine organisms, such as phytoplankton, consequently drawing down atmospheric carbon dioxide.  Respired iron oxide minerals can affect human health in many ways, such as by disrupting iron metabolism.  The key iron oxide minerals possess particular spectral, magnetic, and optical properties enabling their characterization using reflectance and Mössbauer spectroscopic, magnetic, chemical, and microscopic techniques.  Better assessments of iron-oxide effects on the Earth System await the resolution of key uncertainties, among them: (1) Refractive indices of hematite and goethite remain poorly quantified; (2) radiative forcing roles of Dark Rock Particles (DRPs), indicated by the presence of magnetite, lack systematic study and must be more thoroughly examined according to types, amounts, origins, sources, and associations with contaminants; efficient ways to recognize DRPs in global dust sources are needed; (3) mechanisms of iron uptake by many different marine phytoplankton remain undocumented; (4) pathways for biological responses to iron oxides in humans—considering oxidant generation and metal mobilization/complexation with resultant disruption of iron homeostasis—remain to be discovered.

Join us for an opportunity to learn more about DANA, a new partnership of scientists and practitioners with the purpose to accelerate the transition of dust-related research into service.  We will introduce the vision, organizational structure, and some future activities of DANA.