Read more about each poster below
Dust, Weather, and Climate
P.1 The Impacts of Saharan Dust on the Track and Intensity of Tropical Storm Hermine (2022)
Allan Lee, UC Davis and Shu-Hua Chen
During the Convective Processes Experiment-Cabo Verde in 2022, Tropical Storm Hermine formed between Cabo Verde and West Africa. Hermine developed from a tropical wave over West Africa with a dust rich Saharan air layer (SAL) to its north. As the wave moved offshore, the SAL wrapped around the western and southern side of the storm. Two experiments are conducted with the Weather Research and Forecasting Dust model to evaluate the effects of dust on the development and forecast of Hermine, one with dust effects and the other without. The differences between the experiments reveal dust initially strengthen Hermine at a faster rate but later decreased its intensity for the remainder of its life. Radiative heating of dust led to warming of the SAL and later developed a mid-level clockwise circulation due to the thermal wind relationship. The wind change helped to steer Hermine slightly southwest compared to the experiment without dust.
P.2 Observationally Constraining the Direct Radiative Effect of North African Dust
Olivia Salaben, UCLA and Jasper Kok, Adeyemi Adebiyi, and Qianqian Song
The uncertainty in dust direct radiative effect (DRE) is due to regional variations in dust loading and particle size distribution, and because regional dust refractive index are ignored in climate models. Accounting for regional variations in DRE by integrating observational constraints on dust loading and optical properties is necessary to determine the net effect of dust on climate. We focus on North African dust which accounts for ~50% of global dust and has increased by 46% since preindustrial times. We calculate our North African DRE estimates using new North African dust refractive index data with the regionally-resolved DustCOMM model. Despite North Africa dust accounting for ~50% of global dust, we find a smaller shortwave (SW) DRE than suggested by its contribution to the global dust loading, due to the high surface albedo over North Africa. This implies that other major dust source regions have a larger SW DRE than suggested by their contribution to the global dust loading.
P.3 Mining unconventional data sources: creating a social media-based catalogue of dust events in the Western US
Stuart Evans, University at Buffalo and Festus Adegbola and Andrew Crooks
Complete observations of dust events in the are difficult, as dust’s spatial and temporal variability means satellites may miss dust due to overpass time or cloud coverage, while ground stations may miss dust simply due to not being in the plume. Dust’s importance both for atmospheric processes and as a health and travel hazard makes detecting dust events whenever possible important. In recent years, social media platforms have provided an opportunity to access vast user-generated data. This research utilizes geotagged Flickr and Twitter posts referencing dust in the western US, and compares it to traditional datasets. Results show that this unconventional dataset broadly recreates the observed spatial and seasonal distributions of dust. Daily analysis of the locations of the social media creates a novel catalogue of dust events in the western US. While this catalogue is also incomplete it nonetheless provides a complementary list of events to those detected by traditional means.
P.4 Holographic Sensor Prospects in Atmospheric Dust Measurement
Gavin McMeeking, CloudSci LLC and Matthew Berg, Matthew Freer, and Nicholas Good
The measurement of atmospheric dust presents unique challenges due to the complexity of aerosol and the limitations of current measurement techniques. Addressing this, CloudSci LLC is developing holographic sensor technology aimed at enhancing the accuracy and detail in dust characterization. This proposed technology utilizes the principles of digital inline holography (DIH) to capture three-dimensional representations of dust particles, offering insights into their size, shape, and spatial distribution. The sensor seeks to overcome some of the constraints of traditional aerosol measurement methods by providing non-contact, high-resolution particle imaging. We focus on outlining the theoretical framework of the holographic sensor, discussing its potential advantages, and showing initial measurements of different aerosol types.
P.5 Quantifying the Size-Resolved Dust Concentration at Cirrus-Forming Heights based on In Situ Measurements
Flor Maciel, UCLA and Jasper Kok
Cirrus clouds are abundant in the atmosphere and have a net warming effect on the climate. Changes in dust can impact the microphysics of cirrus depending on the mechanism the ice crystals formed by – homogeneous freezing or heterogeneous nucleation. Here, we determined how accurately models represent both the concentration and the size distribution of dust at cirrus-forming heights using data from the Atmospheric Tomography Mission (Atom). By comparing the dust size distributions of these measurements to that from a dust reanalysis product, DustCOMM, we found that it overestimated the dust concentration more at finer diameters in contrast to coarse diameters. We established that the dust size distributions are similar but have statistically significant differences. Thus, we plan to extend this work once we can compile more suitable data with the aim of producing a dust number concentration climatology in the cirrus regime for use in climate models.
Dust, Agriculture, Renewable Energy
P.6 Linking fallowed agricultural lands to dust in California's Central Valley
Md Minhazul Kibria, UC Merced and Adeyemi A. Adebiyi, Satyendra Pandey, John Abatoglu, and Shu-Hua Chen
Fallowed croplands, where sections remain unplanted, pose a potentially substantial source of anthropogenic dust aerosols. However, the extent of their contribution to wind-blown dust and associated meteorological factors in semi-arid regions like California remains uncertain. Here, we used over 15 years (2008-2022) of the U.S. Department of Agriculture's Cropland Data Layer and satellite-based dust measurements to reveal the abundant fallowed agricultural lands in California's Central Valley, with some linked to increased downstream dust concentrations. Specifically, our study finds that there is a considerable association between the surface area fallowed and increased dust levels eastward of their locations, especially during southwesterly wind anomalies, which facilitate dust transport. Our result also suggests that severe drought, decreased soil moisture, and precipitation all increase the vulnerability of fallowed agricultural lands to dust emission.
Dust impact on air quality and disease/health/epidemiology
P.7 Dust size assumption in aerosol simulation and its impact on public health impact estimate.
Qian Tan, Bay Area Environmental Research Institute and Hongbin Yu and Mian Chin
Aerosol particles, especially those with diameter that is smaller than 2.5um, i.e. PM2.5, have detrimental impact on public health. As a regulated criteria air pollutant, PM2.5 is monitored by ground networks using various instruments. At the same time aerosol assimilation modeling system is developed to simulate the aerosol distribution with continuous global coverage. In this study we compared the PM2.5 simulated by NASA’s MERRA-2 modeling system with the measurements made at US Embassy sites around the globe on diurnal cycle, monthly average, and interannual variabilities. We focused the comparison in the places that are significantly impacted by the desert dust. Simulations based on both aerodynamic and geometric diameters are compared with available measurements. Aerodynamic diameter assumption shows better model-observation agreements over several dust belt stations.
P.8 UC Irvine's Dust Montitoring Network in Borrego Springs, CA
Charlie Zender, UC Irvine and Morgan Gorris, Wenshan Wang, and Sicco Rood
UC Irvine established a dust monitoring network in 2016 to monitor and assess particulate matter air quality (PMAQ) in Borrego Springs, CA, surrounded by the Anza-Borrego Desert and California's largest State Park. The network comprises five Automatic Weather Stations (AWS) that measure the environment and PMAQ every 10-minutes. Satellite-retrieved estimates local PMAQ increasing since the early 1980s. Seasonal PMAQ variations correlate well with windspeed, although windspeed shows no interannual trend. Factors that could explain the observed interannual PMAQ trend include increased soil disturbance, drier soils, and/or other new sources of primary aerosol. The measurements show no PMAQ exceedances of EPA or California standards since 2016, although exceedance levels are occasionally within the measurment uncertainty range. Efforts to improve intercalibration of UCI's optical-based air quality measurements with filter-based methods used by the EPA are ongoing.
P.9 The Core Aeolian Microbiome and its Pathogenic Potential
Linton Freund, UC Riverside and Talyssa Topacio, Yaning Miao, Will Porter, Jon Bothoff, and Emma Aronson
The Salton Sea is a hypersaline lake in Southern California that is shrinking, exposing its playa, and increasing local dust emissions. Nearby residents are burdened with high rates of respiratory illness, yet the cause of this distress is unknown. Here we aim to understand how the aeolian dust microbiome can impact public health. Dust samples were collected from four sites around the Salton Sea in Summer and Fall of 2020 and 2021. 16S rRNA sequencing found that dust microbial composition did not vary between sites (p = 0.528), with few bacteria genera dominating the samples. Furthermore, dust metagenomes revealed that these microbes contain a variety of lipopolysaccharide (LPS) biosynthesis genes (i.e., LpxL, kdta) and endospore-formation genes (i.e., spoIVCA), which support airborne microbial survival and are commonly found in pathogens. Our results demonstrate the potential of aeolian microbes to survive widespread dispersal, thus posing a health risk to exposed communities.
P.10 Pulmonary inflammation due to chronic dust exposure influences host lung microbiome diversity
Talyssa M. Topacio, UC Riverside and Linton Freund, Dr. Mia Maltz, Marina Zaza, and Dr. Emma Aronson
Among permanent residents of California’s Imperial Valley, the dust coming off of the desiccating Salton Sea and its surrounding playa has been made a primary suspect for the high burden of chronic respiratory disease observed in the region. In a collaborating immunological study by Biddle, et al.(2023) mice exposed to dust collected around the Salton Sea exhibited a “chronic-innate” pulmonary response characterized by neutrophil inflammation in host lung tissue. In this study, we examined the lung microbiomes from these same mice cohorts via 16s V3-V4 rRNA amplicon sequencing to compare microbial community composition in dust-exposed vs. ambient air control mice. Our preliminary results show that among mice exposed to Salton Sea dust, shifts in abundance and beta diversity may be relative to host pulmonary inflammation. This suggests that the relationship between the host lung microbiome and disease expression is ostensibly influenced by the aeolian environment.
P.11 Estimating surface-specific health impacts from windblown particulates around the Salton Sea
William Porter, UC Riverside and Yaning Miao, Tim Lyons, Caroline Hung, Charlie Diamond, Catherine Lowe, and Mara Freilich
Windblown dust has long been an air quality and public health concern among residents living around California’s Salton Sea, a region characterized by serious socioeconomic and health outcome disparities. Dropping water levels and unique biogeochemistry within the Salton Sea water itself have raised concerns regarding the human health impacts of drying sediments exposed on shrinking shorelines, as well as potential lake spray emissions from the water surface. As particles emitted from different surface types can differ greatly in terms of composition, size distribution, and other properties, variability in the resulting health impacts of windblown dust reaching communities in the region may likewise be source dependent. Here I will share work being done in my group to analyze surface-specific health outcomes associated with windblown coarse PM around the region, as well as attempts to better understand and mitigate the unique issues linked to these emissions across the basin.
P.12 Impact of Dust on climate, Health, and Disease Transmission in the California San Joaquin Valley
Adeola Fagbayibo, UC Merced and Estrella Herrera, Asa Bradman, and Katrina Hoyer
Coccidioides is the causative agent of the fungal infection known as Valley fever. This disease is caused by inhaling arthroconidia fungal spores that are aerosolized from the soil upon events such as dust storms. Dust refers to fine particles of matter found on the earth’s surface made up of pollen, ash, bacteria, and infectious components. Our collaborative research seeks to understand how dust impacts climate, and health outcomes across the California San Joaquin valley. The fungal composition in aerosolized dust across the season within this region is unknown and this knowledge could allow strategies to mitigate the spread of diseases. We aim to understand this by sampling dust, collecting air filter and sedimentation samples, isolating DNA, and sequencing the filtrates to determine bacterial and fungal diversity across different locations. we will correlate this data with wind pattern and hospitalization data from the region.
P.13 PM2.5, PM10, and Dust Patterns and Determinants in the Salton Sea Air Basin of California
Ian Faloona, UC Davis/Air Quality Research Center, and Heather Lieb and Mohammad Astaneh
The Salton Sea Air Basin (SSAB) is comprised of the Coachella and Imperial Valleys, part of a tectonic rift that runs nearly 200 km from the San Gorgonio (Banning) Pass at the east end of the Los Angeles basin on its north end to the Gulf of California in the south. Despite having a population less than one million residents, the SSAB has not attained the California Ambient Air Quality Standards for three regulated air pollutants: ozone, PM2.5, and PM10. We present 12 years of meteorology and air quality data across the air basin to show that while the highest PM2.5 occurrences in the south happen mostly in winter during stagnation events, there are several sites closer to the Salton Sea where exceedences of PM2.5 and PM10 occur during exceptionally strong winds events (primarily during the spring). We then turn to collocated measurements by sonic anemometry and a backscatter lidar along the west side of the Salton Sea, showing that the highest values of PM10 typically occur during the late afternoons (15:00-20:00 LT) when the friction velocity rises above ~0.4 m/s. The synoptic setting that gives rise to these afternoon wind and PM10 events are associated with strong heating and intensficiation of the Southwestern US thermal low.