A thermal index from modis data for dust detection

With increasing land degradation and deforestation, dust storms have been an essential factor of air pollution and global climate and biogeochemical cycle. A new index, Thermal Infrared Integrated Dust Index (TIIDI), has been developed to detect dust over land and ocean. This dust detection algorithm is based on brightness temperature difference of four thermal infrared channels, including BTD3.7-11, BTD8.6-11 and BTD12-11. BTD12-11 is mainly used to identify cloud, BTD8.6-11 is used as an indicator of airborne dust and surface sand, and BTD3.7-11 is used to separate dark surface and represent the intensity of dust storm. The algorithm is applied to monitor atmospheric dust storms over various landcover types, including ocean, dark object (vegetation), and bright surface such as desert by using MODIS data. The results show that the TIIDI could distinguish mineral dust from cloud and land surface over bright surface and ocean. The index provides a dust indicator both day and night for global apply.