Date of Award

2012-01-01

Degree Name

Doctor of Philosophy

Department

Environmental Science and Engineering

Advisor(s)

Thomas E. Gill

Abstract

Wind erosion is a dynamic physical process that leads to environmental degradation when strong winds blow on loose, dry, bare soils, creating dust events that can impact human health, visibility and air quality. Since 1932, more than two thousand dust event days were recorded at El Paso, averaging 25 per year. This research analyzes and models data on dust events in the El Paso/Juarez metropolitan area for better understanding of their effects. The meteorological characteristics of these events are analyzed for variables such as the frequency, visibility, and average wind speeds associated with convective and non-convective events. These variables are further correlated with other parameters including particulate matter concentrations, relative humidity and associated precipitation to determine their relationships. Air transport pathways into El Paso during days with dust events (classified as convective and non-convective in nature), as well as days in which dust was not reported, were created with the HYSPLIT model and statistically analyzed. During 2001- 2005, dust events were recorded on 12% of all days; 55% of the events were synoptically-driven, while 45% of the events were convectively-driven. Analyses showed different airflow patterns during dusty days as compared to overall trajectories into El Paso. For synoptically-driven dust events, arriving air masses were strongly associated with a zone of known dust source areas west-southwest of the city, and trajectories were consistent with air parcels moving toward cyclones crossing or developing NE of the Chihuahuan Desert. For convective dust events, trajectories were correlated with air masses arriving from the south and southeast, consistent with monsoon moisture surges bringing thunderstorms. Finally, numerical modeling of weather on a dust event day was performed and analyzed using the Weather Research and Forecasting (WRF)-Chem model. The case study selected was Feb. 4, 2008, where very strong gusty winds across much of northern Mexico, eastern New Mexico and Northwest Texas generated widespread dense blowing dust in the afternoon on. WRF-Chem model results were correlated with TCEQ station data to evaluate the model's performance for dust storms. The results of these analyses improve the knowledge of how dust storms and airborne particulate matter behave in the El Paso, Texas/ Ciudad Juarez, Chihuahua region and can aid in improving the forecasts of these phenomena.

Language

en

Provenance

Received from ProQuest

File Size

202 pages

File Format

application/pdf

Rights Holder

Nancy Ivette Rivera Rivera

Download

Share

COinS