Spectral analysis of salt clouds originated at Mar Chiquita lake using remote sensing

Abstract

Laguna Mar Chiquita, is a permanent saltwater lagoon located in theArgentine province of Cordoba. The extent of the water surface of the Mar Chiquita lagoon has experienced increases and decreases over the years. However, since 2003 the lagoon began a period of regression, exposing large areas of land covered with salt. Since 2006, observations from space with different satellites allowed to document the presence of very white salt clouds originated when fine sediments around the lake perimeter are easily lofted into the air by winds. In this study some examples of salt storms are documented using satellite images captured byMODISsensor on board ofAqua andTerra satellites andAVHRRsensor onNOAA18 and 19 satellites. The salt event on 8 July 2012 and 29 July 2012 were investigated with two reflective and two infrared thermalAVHRR bands. It is found that salt clouds are more reflective than the background soil, but less reflective than water or ice clouds, probably because salt clouds have less thickness. Other characteristics of these clouds are that the observed 11μm minus 12μm brightness temperature difference is always negative. Then it could be used for the identification of salt storm outbreak and for the estimation of the spatial extent developed. It can be used in both daytime and night time conditions for automatic identifying of the salt storm. The variation of the temperature difference is also associated with the dust concentration.