Title: Characterization of International and Domestic Sources of Windblown Dust and Contribution to Fine and Coarse Particulate Matter in Texas
Institution(s) Represented: George Mason University (Tong, Ma)
Lead PI: Daniel Tong
AQRP Project Manager: David Sullivan
TCEQ Project Liaison: Ari Brandt
Awarded Budget: $160,470
Abstract
Windblown dust poses increasing challenges to air quality, public health, and transportation safety. In 2025, for instance, Texas experienced the dustiest spring since the Dust Bowl era, with 42 vehicle crashes and four fatalities caused by a single dust storm on March 14, 2025. Another critical issue in Texas is that crustal materials originating from Mexico and overseas sources such as the Saharan Desert can be transported by winds into Texas. The Clean Air Act section 179B states that pollution that originates outside of US borders is not to affect National Ambient Air Quality Standards (NAAQS) compliance. Given the high stakes associated with dust risks and complexity of dust source attribution, it is important to investigate the trends of dust storms and understand their sources and contributions to fine and coarse particulate matter (PM2.5 and PM10) in this region.
The objective of this study is to understand the trends in windblown dust and its effects on PM2.5 and PM10 in Texas. More specifically, we aim to 1) investigate the long-term trends in windblown dust activity in Texas and three “upwind” states (New Mexico, Oklahoma and Colorado); 2) analyze the environmental drivers of the dust trends; 3) improve dust emission model by integrating satellite-detected dust sources and updating other model inputs, and 4) quantify contributions from in-state and out-of-state dust sources to PM2.5 and PM10 in Texas.
The proposed project consists of four major activities:
- Reconstructing long-term dust trends from three ground networks. We will assemble windblown dust event records from three ground networks, including the Interagency Monitoring to PROtect Visual Environments (IMPROVE), the Texas Commission on Environmental Quality (TCEQ) air quality monitors, and National Oceanographic and Atmospheric Administration (NOAA) Integrated Surface Database (ISD). An intercomparison of these datasets will be performed to examine if there is a trend in the observed dust activity, and to identify high-dust and low-dust years for subsequent analyses and model simulations.
- Analyzing and diagnosing environmental drivers of dust trends. Built on the lessons learned from prior studies, several environmental factors will be selected for this analysis, including both single variables such as wind speed, vegetation cover (Normalized Difference Vegetation Index (NDVI), precipitation, and soil moisture, and composite indices such as drought index and El-Nino Southern Oscillation (ENSO). Identified key factors will be used to guide model optimization.
- Improving windblown dust emission modeling. To address the large uncertainties existing in windblown dust modeling, this task will: i) update soil texture in Mexico and the US based on a hybrid State Soil Geographic database Version 2 (STATSGO2)/Food and Agriculture Organization (FAO) derived map; ii) improve Mexico dust sources using a newly available Geostationary Operational Environmental Satellites (GOES) dust initiation map; iii) improve domestic cropland dust sources with George Mason University (GMU)/U.S. Department of Agriculture (USDA) CropScape data; and iv) conduct sensitivity tests with other key inputs, including winds, vegetation cover, surface roughness, and soil moisture.
- Quantifying windblown dust effects on PM5 and PM10. We will use the optimized modeling system to quantify the effect of windblown dust emissions on PM2.5 and PM10 in Texas. We choose a high-dust period and a low-dust one and use the updated model to reproduce the “relative trend”, and to assess windblown dust contributions in both periods. For each selected period, we will conduct two simulations: without and with windblown dust emissions. The dust contribution is calculated from the difference between the two simulations.
This work directly addresses the Research Priority area “Trends in wind-blown dust (PM2.5 and PM10) in Texas”. Leveraging prior work, this project will reconstruct long-term dust trends from ground stations and design a suite of dust emission improvements to reduce dust modeling uncertainties. This project also directly aims at “better characterization of the multiple sources of windblown dust and their contribution to PM10 and PM2.5”. Although the FENGSHA is currently implemented as a module in Community Multiscale Air Quality (CMAQ), a standalone version will be made available to the community so that it can be easily incorporated in other models such as Comprehensive Air Quality Model with Extensions (CAMx).
Technical Reports:
