Dust emission variability at the Salton Sea, California, USA

A field study conducted through a series of four field campaigns between 2005 and 2007 investigated the potential for dust emissions around the Salton Sea in California, USA. This paper explores the landform related controls on fugitive PM10 dust emissions from soil surfaces surrounding the Salton Sea by measuring soil properties combined with estimating the in situ PM10 dust emissions using a novel small portable field wind tunnel (PI-SWERL). The locations surrounding the Salton Sea were selected to encompass varying geomorphic landforms, including exposed shoreline areas with playa characteristics, barnacle covered beaches, dry washes, interdunes, and exposures of ancient Lake Cahuilla. The largest variation in potential dust emissions over the sampling period was from the playa-like surfaces that are near the open water and exhibited surface salt crusts, with the highest emissions measured from these surfaces during the winter. However, the largest emitting landform over the entire period were the dry washes that only exhibited a small degree of silt/clay crust, if any and were composed mainly of sand-sized particles. The highest emissions from all surfaces are compared with dust fluxes measured from Owens Lake and are within the same order of magnitude as those also measured with wind tunnels. Salt content did not show any statistically significant correlation with PM10 dust emissions during any sampling period for the soils tested, which is attributed to the complications associating soil salt contents with particular salt crystal habit. (C) 2011 Elsevier B.V. All rights reserved.