Read more about each presentation below
A. Dust, Weather, and Climate
A.1 The Earth Surface Mineral Dust Source Investigation (EMIT) Arid Land Imaging Spectroscopy Observations, Analyses, and Initial Results Across Six Continents
Robert O. Green, NASA JPL and David R. Thompson, Natalie Mahowald, and Science and Engineering Team
NASA’s Earth Surface Mineral dust source Investigation (EMIT) is an Earth Venture Instrument mission located on the International Space Station (ISS). EMIT’s focus is to reduce uncertainty in the mineral dust radiative forcing and related impacts throughout the Earth System by providing improved mineral compositional information for the Earth’s arid lands. The EMIT imaging spectrometer measures spectra from the Visible to Short Wavelength Infrared (VSWIR where important dust minerals have diagnostic spectral absorptions. Surface mineral composition maps from these imaging spectroscopy observations are planned for use in state-of-the-art Earth System Models so that they can better estimate the resulting composition of mineral dust in the atmosphere. Mineral dust aerosol composition, and in particular the fraction of iron oxide, is a major source of uncertainty in the mineral dust-induced radiative forcing. By mapping the mineralogy of dust forming lands, EMIT aims to close this knowledge gap and support improved Earth System Modeling. The EMIT imaging spectrometer acquires spectra from 380 nm to 2500 nm at 7.5 nm sampling and a 75-kilometer swath width at 60 m ground sampling. From the ISS EMIT delivers high signal-to-noise ratio spectral image data sets with accurate radiometric calibration and excellent spectral uniformity. To date, EMIT has delivered more than 70,000 spectral image cube spanning the arid land regions of six continents. Calibration, atmospheric correction and initial mineral composition analyses have been completed for cloud free observations comprising 80% of the grid cells for EMIT’s arid land target regions. All EMIT measurements and products are available from the NASA Land Process Distributed Active Archive Center (LP DAAC). We present the background, current status, and future plans for EMIT.
A.2 Three-Dimensional Transport of Saharan Dust Aerosols by African Easterly Waves: Theory and Reanalysis
Terry Nathan, UC Davis and Dustin Grogan
Theory and reanalysis are combined to expose the physical and dynamical processes that control the three-dimensional (3D) transports of Saharan mineral dust aerosols by African easterly waves (AEWs). The 3D theory proves to be an important predictive and interpretive tool for the dust transports by AEWs, which are calculated from the 3D meteorological fields obtained from 37 summers of the Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA-2). The theory accurately predicts where the transports are largest over both land and ocean, which occurs where the eddy momentum fluxes acting on the mean dust gradients are large near a critical surface. The reanalysis results show a clear transition in the structure of the eddy dust transports from land to ocean. The zonal transports depend on their position relative to the AEJ axis, whereas the meridional and vertical transports depend on their position relative to the maximum in dust aerosol optical depth.
A.3 Impacts of Dust Radiative Effects on Tropical Easterly Waves
Farnaz Hosseinpour, Desert Research Institute and Eric Wilcox
The Sahara Desert in North Africa is the world's primary source of dust, where over sixty million tons of dust aerosols are lifted annually and transported within the Saharan Air Layer (SAL) across the Atlantic Ocean. The diabatic heating of dust aerosols in the SAL serves as an additional energy source, enhancing the growth of waves. The enhanced diabatic heating of dust leads to amplified meridional temperature gradients within the baroclinic zone, suggesting that diabatic heating of dust aerosols can increase the eddy kinetic energy of the African easterly waves and enhance the baroclinicity of the region. Our findings also show that dust outbreaks over the tropical Atlantic Ocean precede the development of baroclinic waves downstream of the African easterly jet. This suggests that the dust radiative effect has the capability to trigger the generation of the zonal and meridional transient eddies in the system comprising the African easterly jet and African easterly waves.
A.4 Do the height and thickness of Sahara air layer matter for dust semi-direct effect over North Atlantic Ocean?
Adeyemi Adebiyi, UC Merced and Satyendra K Pandey
Dust is an important component of the Earth system because, unlike other aerosols, it can scatter and absorb shortwave (SW) and longwave (LW) radiation. Dust can also interact with clouds, influencing the properties that shape their radiative effects. For this, previous studies have shown that above-cloud dust can increase low-level cloud cover (LLCC) through semi-direct effects, whereby dust-induced SW warming increases boundary-layer (BL) stability. However, exactly how dust interacts with SW and LW radiation and the roles of dust's physical properties in changing the LLCC have remained largely unclear. Here, we show that increases in LLCC when the dust is above depend sensitively on the geometrical thickness, optical depth, and proximity of the dust layer to the underlying clouds. We further show that these changes in LLCC are linked to dust-induced anomalous LW warming that modulates the mean cloud-top LW cooling, influencing the BL processes that drive cloud development.
A.5 Influence of CALIOP Backscatter Data Assimilation on Dust and Cloud Forecasts over North Africa and the East Atlantic
Shu-Hua Chen, UC Davis and Shu-Chih Yang, Chu-Chun Huang, Toshihisa Matsui, Clark Yu, Yuejian Zhu, Bing Fu, Xianwu Xue, and Chih-Ying Chen
This study investigates how assimilating aerosol backscatter profiles impacts dust and cloud forecasts over North Africa and the East Atlantic. Two numerical experiments are conducted: one assimilating AOD and the other additionally assimilating aerosol backscatter profiles. The assimilation of aerosol backscatter profiles tends to increase dust in the middle troposphere. The change in the dust amount and distribution modifies large-scale environmental temperatures and winds due to the dust-radiation interaction. The change in large-scale environment will have an impact on cloud activities, depending on how the dust distribution is altered and what types of clouds exist. Results show that after the assimilation of aerosol backscatter profiles, the increase of the dust concentration at the middle troposphere can suppress the marine boundary layer cloud development. The dust-induced mechanisms that cause the changes in these cloud activities will be presented as well.
A.6 Overview of dust emission forecasting research at the US Army Engineer Research and Development Center (ERDC)
Sandra LeGrand, US Army Engineer Research and Development Center and Gregory Okin
Airborne dust is an essential part of climatological and biogeochemical processes. Blowing dust can also create poor air quality conditions. As a result, accurate dust event characterization and forecasting is a priority for operational weather centers. While dust detection and prediction capabilities have evolved considerably over the previous decades, the modeling community must continue to improve the specific location and timing of individual dust event forecasts, especially for extreme dust outbreaks. Accordingly, US Army Engineer Research and Development Center researchers are working with university and federal partners to explore the sensitivity of dust modeling capabilities to emerging drag partition and surface erodibility treatments. Here, we provide a brief overview of ongoing efforts to 1) establish an inventory of dust case study events and 2) assess the sensitivity of community and operational dust transport modeling systems to new dust emission modeling approaches.
A.7 Wind erodibility and particulate matter emissions from of dry saline-sodic soils under diverse atmospheric humidity conditions.
Tobia Rinaldo, UC Berkeley and Paolo D'Odorico, Ganesh Khatei, Sujith Ravi, and Scott Van Pelt
Salt accumulation, particularly soil salinization and sodification, poses a significant challenge in agroecosystems worldwide. In our study, we performed laboratory experiments to explore how atmospheric humidity influences wind erodibility and the release of particulate matter from agricultural soils treated with salt-enriched water. Results show that, while threshold velocity for wind erosion increases with soil salinity, it does not exhibit a similar trend with sodicity. This is attributed to the effects of salt-induced aggregation and sodium-induced dispersion in the soil. Despite initial resistance to wind erosion, salt crusts were ruptured by saltating sand grains, leading to comparable emissions compared to non-saline soils. Interestingly, the salinity of the emitted dust was significantly higher than that of the parent soil. Understanding the role of atmospheric humidity is crucial for controlling accelerated wind erosion in salt-affected soils and mitigating dust emissions.
A.8 Insights from Dust Research at the Jornada Experimental Range
Saroj Dhital, USDA-ARS Jornada Experimental Range and Nicholas P. Webb, Brandon L. Edwards, Gregory S. Okin, Sarah E. McCord, and Brandon T. Bestelmeyer
The Jornada Experimental Range (JER) is a USDA Agricultural Research Service lab in Las Cruces, New Mexico and manages a 300 square-mile fenced research area in the Chihuahuan Desert. The JER is the most intensively studied and densely instrumented dryland research area in the world. Since its establishment, a large amount of aeolian dust-related research has been conducted by JER research scientists and collaborators from multiple research institutions. Here, we present highlights of our current research streams that include coordinating the National Wind Erosion Research Network, parameterizing the AERO model using a GLUE approach to explicitly represent dust model uncertainty, predicting fine-scale (<100 m) PM10 and PM2.5 emissions west-wide using standardized big data collected by ecological monitoring programs, and using WRF-Chem and the Rangeland Analysis Platform (RAP) to elucidate ecological and management controls on dust source area dynamics and predict dust-on-snow episodes.
A.9 Landscape topography and regional drought events alter dust microbiomes in California’s Sierra Nevada
Mia Maltz, UC Riverside and Chelsea J. Carey, H. Linton Freund, Talyssa Topacio, Jon Botthoff, Jason Stajich, Stephen C. Hart, Sarah Aarons, Sarah Aciego, Molly Blakowski, Nicholas Dove, Morgan Barnes, Nuttapon Pombubpa, and Emma L. Aronson
Dust supplies nutrients to slowly eroding ecosystems and serves as a vector for dispersing microorganisms. While little is known about dust-microbial dispersal, dust-driven inputs may influence recipient ecosystems. Using molecular analyses, we examined variation in dust microbiomes along an elevation gradient within California’s Sierra Nevada. These dust microbiomes differed by elevation across two dry seasons. Dust complexity and P content increased with elevation but were inversely proportional to dust microbial diversity. Early season dust microbiomes were more diverse than those found later, while microbial groups shifted over the dry season. Although mutualistic fungal diversity was related to elevation, fungal pathogens differed temporally, with potential implications for humans and wildlife. This research suggests that landscape topography and regional droughts may alter the composition and diversity of ecologically relevant dust-associated microorganisms.
A.10 Impacts of Long-range Transport of Dust and Mixing of Smoke from Crop Residue Burning on Air Quality, and Climate
Ramesh P Singh, Chapman University and Akshansha Chauhan
The local dust and long-range transport of dust mix with the aerosol emissions from the crop residue burning over the north-western parts of India affecting the air quality and aerosol properties. The dust and smoke influence the aerosol characteristics that affect the climate and weather conditions. The increased concentrations of the particulate matter depend upon the favorable meteorological conditions, dense haze, fog, and smog are formed over the Indo-Gangetic Plains (IGP), sometimes over the western and central parts of India. The dense, haze, smog, and fog move over the IGP depending on the wind velocity and directions and meteorological parameters. An overview of the dust interaction with the smoke impacts will be discussed in the changing atmospheric loading and health impacts. The contrasting differences in human health from the northern and southern parts of India and aerosol characteristics will be presented.
B. Dust, Agriculture, Renewable Energy
B.1 Health and safety effects and annual economic cost of dust
Scott Van Pelt, USDA and Karin Ardon-Dryer, Irene Feng, Thomas Gill, Jennifer Hand, Junran Li, Ling Ren, William Sprigg, and Daniel Tong
Mineral dust is the most visible evidence of the soil degrading process of wind erosion. In addition to degrading soils and limiting the sustainability of agriculture, it has many deleterious effects on human and environmental health, safety, commerce, recreation, and industry. Although mostly limited to semi-arid and arid regions of North America, dust can have deadly impacts in more humid regions, as witnessed by the dust-induced crash that took eight lives in the state of Illinois (United States) in May of 2023. As climate change increases the susceptibility of the land surface to erosive winds, atmospheric dust concentrations have continued to rise in the western and central areas of the United States. In sum, the direct and indirect costs of atmospheric dust cost the economy of the United States hundreds of billions of dollars annually.
C. Dust impact on air quality and disease/health/epidemiology
C.1 Management of Dust Emissions at the Oceano Dunes State Vehicular Recreation Area and the Salton Sea Shoreline
Jack Gillies, Desert Research Institute and E. Furtak-Cole, G. Nikolich, and V. Etyemezian
Dust from the Oceano Dunes and the Salton Sea shoreline can result in levels of PM10 that exceed federal and state standards. The Oceano Dunes are contained within the Oceano Dunes State Vehicular Recreation Area (ODSVRA). The Salton Sea in Imperial and Riverside counties has significant areas of shoreline with the potential to emit dust. Dust from the ODSVRA must be reduced to meet a Stipulated Order of Abatement (SOA). The State of California’s Salton Sea Management Plan (SSMP) involves suppression of dust emissions on areas of the exposed shoreline. This presentation will describe management strategies used to mitigate dust emissions at the ODSVRA and the Salton Sea. Data will be presented that demonstrates these strategies are lowering the PM10 levels downwind of the ODSVRA during periods of elevated wind speed and that for areas at the Salton Sea the mitigations are controlling emissions of PM10 from managed areas.
C.2 Detection of airborne Coccidioides spores using unmanned aircraft systems in the Carrizo Plain, California: A pilot study
Sarah Dobson, University of Michigan School of Public Health and Amanda K. Weaver, Molly Radosevich, Phinehas Lampman, Tim Wallace, Dr. John Taylor, Dr. Leda Kobziar, Dr. Justin Remais, Dr. James Markwiese, and Dr. Jennifer Head
Coccidioidomycosis is an emerging fungal infection caused by inhalation of airborne spores of the Coccidioides genus. Few studies have detected the spores in air, limiting understanding of environmental factors that give rise to dispersal. Here, we use a novel sampling strategy as a means of detecting C. immitis in aerosolized soil dust. We conducted a pilot study across 14 sites in Carrizo Plain National Monument, an area with confirmed C. immitis soil presence. We completed 41 20-minute flights using two unmanned aircraft systems (UAS) equipped with an 8 L/min aerosol sampler and Purple Air Monitor. We sampled air under ambient conditions and a simulated high-wind event. We concurrently collected soils (n=168) using an interrupted radial transect design. Coccidioides was detected in 32% of precinct soil and 21% of surface soil samples. At time of conference, we will present results of Coccidioides detection on filters and estimated associations between detection, PM, and wind.
C.3 Estimating the Impacts of Climate Variability and Dust Exposure on Valley Fever Risk in Arizona
Alexandra Heaney, UCSD and Amanda Weaver, Jennifer Head, Aidan Rosas, Thomas Williamson, and Irene Ruberto,
Valley Fever (VF) is an emerging fungal infection in the southwestern US caused by inhalation of airborne spores of Coccidioides spp. Though exposures to infectious spores are expected to co-occur with exposures to aerosolized soil, literature supporting the association between mineral dust exposures and VF incidence remains inconclusive. Our past work has demonstrated a positive association between dust concentrations and VF incidence—driven by C. immitis infection—in California. However, the relationships between dust and VF established in California cannot be extrapolated to Arizona—the state with the highest incidence rate of VF—where C. posadasii prevails and different dust regimes dominate. We will present work estimating the relationship between fine mineral dust concentration and VF incidence in Arizona. The results of this work will help to guide public health messaging in Arizona to both the general population and clinicians on VF transmission risks.
C.4 Associations between exposure to air pollution after a dust event and hospitalizations in dust prone areas
Estrella Herrera-Molina, UC Merced and Thomas E. Gill, Gabriel Ibarra-Mejia, Soyoung Jeon, and Karin Ardon-Dryer
The Southwestern USA has been identified as one of the most persistent dust-producing regions of North America, where exposure to dust events or their fine or coarse particulate matter can increase risks to human health. We investigated whether dust exposures (DE) in three dusty cities of Texas, El Paso, Lubbock, and Amarillo are associated with significant increases in hospitalizations on the day of the exposure and up to seven days afterward. Using a quasi-Poisson regression, it was found that relative risks of hospitalizations for multiple conditions were positively associated with DE in these cities between 2010 and 2014. As climate change increases water stresses on dryland agriculture and land cover, dust exposures are likely to increase for residents of dryland cities. Additional investigations are needed for other dust-prone cities to investigate the health effects of dust exposures.
C.5 Spatial Variability of Surface/Subsurface Geochemistry of the Exposed Playa of Great Salt Lake, Utah.
Kevin Perry, University of Utah
To determine the geochemistry of Great Salt Lake playa, a systematic survey of the entire exposed lakebed was completed using Incremental Sampling Methodology. 5,246 soil samples were collected from both the surface (1-2 cm) and subsurface (2-4 cm) layers and composited into 122 subunits. The composited samples were dried, sieved, resuspended, and analyzed using ICP-MS and SXRF to determine the elemental mass fractions of the respirable particles. The PM10 soil from the surface of the GSL playa is highly enriched in elements associated with evaporate minerals. 13 elements (i.e., Al, As, Co, Cu, Fe, La, Li, Mn, Sb, Th, U, V, and Zr) had some values that exceeded the Regional Screening Levels (RSLs) established by the USEPA for residential exposures. 4 elements (i.e., As, La, Li, and Zr) had some values that exceeded the RSLs for industrial exposures. Of these, As and La were the only elements for which every measurement exceeded the RSLs for both residential and industrial exposures.
C.6 LPS in playa dust generated from the Salton Sea microbiome drives neutrophilic pulmonary Inflammation and correlates with asthma incidence
Keziyah Yisrael, UCR and Diana del Castillo, Linton Freund, Malia Shapiro, Daniel Gonzalez, David Cocker, Emma Aronson, Chris Morin, Jenna LeComte-Hinely, and David D. Lo
California’s largest lake, the Salton Sea, situated at the Riverside-Imperial County border, is linked to rising asthma cases in nearby communities. In environmental chamber exposure studies, we found that mice exposed to material collected from across the region showed responses characteristic of innate immunity rather than allergic immunity, with a pattern suggesting LPS as the likely toxin. To confirm the toxin identity, wildtype (WT) C57BL/6J mice, Toll-like receptor 4 (TLR4) -/- mice, Toll-like receptor 2 (TLR2) -/- mice, and MYD88 -/- mice were exposed to Salton Sea dust for 48 hours. WT and TLR2 -/- mice exhibited similar inflammatory cell cellular recruitment, but TLR4 -/- and MYD88 -/- mice were unresponsive to the dust, suggesting that LPS is indeed the aerosol toxin. Quantification of LPS concentrations in dust samples gathered from across the region revealed surprisingly high concentrations of LPS, with a distinct gradient from the Northern to Southern end of the lake. To determine whether this was relevant to the incidence of clinical disease, we conducted an epidemiological study on immune-related symptoms and diagnoses. Strikingly, we found that asthma incidence followed a North to South gradient very similar to the LPS dust concentration gradient, peaking at upwards of 30+% in Imperial County. These results strongly implicate aerosolized LPS, likely entrained from the Salton Sea water microbiome into playa dust, as a key driver of the region’s pulmonary health issues.
C.7 Californian Haboobs: A Meteorological Analysis of Monsoonal Dust Storms in the Salton Basin
Amato Evan, UCSD
Dust storms are common in the Salton Basin, and several studies have described the meteorological aspects of outbreaks in the region occurring in the fall through spring seasons. However, dust storms that occur during the monsoon season, which typically spans July through September, are distinct in their meteorology, being driven by convective downdrafts from mesoscale convective systems. These convective centers and their radial outflow are observed to occur throughout the valley, such that the subsequent dust storms can propagate in any direction, rather than just the easterly or southerly directions that are common during other seasons. We highlight two cases of dust storms that produced unhealthy surface concentrations of dust stretching over 150 miles, from El Centro to Riverside. This work suggests that all communities in the Imperial and Coachella Valleys are at risk of exposure to dust emitted from the rapidly growing Salton Sea playa during the monsoon season.