|Van Pelt, Robert - Scott|
|GILL, THOMAS - University Of Texas - El Paso|
|CHANG, CHUNPING - Hebei University|
|EIBEDINGIL, IYASU - University Of Texas - El Paso|
|MENDEZ, MARCOS - University Of Texas - El Paso|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/28/2020
Publication Date: 3/3/2020
Citation: Van Pelt, R.S., Tatarko, J., Gill, T.E., Chang, C., Eibedingil, I.G., Mendez, M.P. 2020. Dust source characterization on and near Lordsburg Playa, Hidalgo county, New Mexico. Meeting Abstract. Presentation. Coolidge, AZ, March 3, 2020.
Technical Abstract: Closed drainage basins with playas, ephemeral lakes, are a common feature of inland semi-arid and arid regions. These ephemeral lakes have received sediment from the surrounding upland for several millenia and throughout history many levels of water in the lake often result in a complex landscape and pattern of surface sediments. When dry, the playa-formed landscapes can be local sources of dust and PM10, particles with diameters less than 10 µm. One such ephemeral lake, Lordsburg Playa, in southwestern New Mexico is bisected by Interstate Highway 10. Dust storms emanating from the landscapes have been responsible for numerous visibility-related accidents and the loss of 55 lives in the last 53 years. We investigated the critical wind friction velocity thresholds and the emissivities of surfaces representing areas typical of the stream deltas, the shorelines, and the ephemerally flooded lakebed using a Portable In-Situ Wind ERosion Laboratory with stepped hybrid tests of increasing friction velocities and resulting shear stress. Mean threshold friction velocities for PM10 entrainment ranged from less than 0.30 m s-1 for areas in the delta and shoreline to greater than 0.55 m s-1 for ephemerally flooded areas of the lakebed. Similarly, we quantified mean PM10 vertical flux rates ranging from less than 500 µg m-2 s-1 for ephemerally flooded areas of lakebed to nearly 25,000 µg m-2 s-1 for disturbed surfaces in the delta, a 50 fold difference. The lack of PM10 supply limitation indicates that the shoreline and delta may be the dominant source areas.