Submitted to: Journal of Geophysical Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/6/1997
Publication Date: N/A
Interpretive Summary: Dust from soil and sediment blown into the air by the wind is now suspected to have effects on the Earth's climate. Much more remains to be known about how different wind weather and land conditions affect the production of the finest grains of dust. This study took place on the dried bed of Owens Lake, California, the source of some of the most intense dust storms in North America. During dust storms on the dry lake bed, we measured how much very fine dust moved upward into the atmosphere, and compared it to the total amount of salty sediment blown along the surface of the ground by the wind. The ratio was similar to what was measured for agricultural fields in west Texas. Even though dry lake beds in the California desert and fields in Texas are very different types of land, at both locations the individual grains of soil are about the same size, and the amount of energy needed to break off fine particles of dust is similar. This may imply that simple descriptions of the texture of the soil are just as useful as complex descriptions of the type and use of the land in predicting the effect of dust on the atmosphere.
Technical Abstract: The vertical flux of particles smaller than 10 um for a saline playa surface, the mineral composition of which was classified as loam- textured, was estimated for a highly wind-erodible site on the playa of Owens (dry) Lake in California. The ratio of this vertical flux to the horizontal flux of total airborne material through a surface perpendicular to the soil and to the wind, Fa/qtot., is 2.75 X 10-4 m-1. This is consistent with that ratio for sand-textured soils, and suggests that the binding energy and size of saltating particles for the tested surface material at Owens Lake is of the same order as that for sandier soils. The horizontal mass flux of saltating grains, q, in the reported wind erosion event is 51.3% of the total horizontal mass flux qtot. Therefore, the ratio of Fa/q is 5.4 X 10-4.