Climate change accelerated by anthropogenic activities has led to the shrinkage and eventually disappearance of salt lakes all over the world. Gradual desiccation of Lake Urmia (LU) in northwestern Iran, as one example of desiccating lakes, has led to the exposure of the lakebed sediment with enormous dust emission potential in some parts. Sand sheets of western LU are identified as one of the major contributors to aerosols in this region. Yet, dust blown from this area is not well characterized. The aims of the current study were, therefore, to comprehensively investigate the origin of dust from sand sheets; the characteristics of dust and temporal variability of the aerosol and to test the effectiveness of the application of sodium alginate (SA) on soil crusting and stabilization. Soil samples were collected from the two prevailing soil types from sand sheets in August 2020. Dust samples were also collected during four time periods: July and August (the beginning of the dry season); October and November (the beginning of the wet season). Using SA with varying concentrations and different methods of application, the effectiveness of the induced crusts was investigated. Authigenic aragonite minerals with elongated needle shapes were found to be the major constituent of the soil and dust samples. Temporal variability of the dust characteristics and their elemental correlation to dust sources revealed that while dust source 1 (DS1) with higher clay, salt, and silt contents contribute more to the dust composition from July to August (R2 > 0.75 for DS1 versus R2 > 0.58 for DS2), dust source 2 (DS2) with less salinity and higher sand content becomes the major contributor to dust composition from October to November (R2 > 0.91 for DS2 versus R2 > 0.75 for DS1). Results of stabilizing both DS1 and DS2 showed that SA-induced crusts on DS1 are more stable than DS2 due to the presence of higher clay, silt, salt, organic matter, and lower aragonite minerals. SA-induced crusts
