An evaluation of satellite dust-detection algorithms in the Middle East region

ABSTRACT

In the last 15 years, the frequency, spatial extent, and intensity of dust storms have increased and it is one of the main continuously occurring environmental hazard in the Middle East region. Since dust storms generally cover a large spatial extent and are highly dynamic, satellite Earth Observation (EO) is a key tool for detecting their occurrence, identifying their origin, and monitoring their transport and state. A variety of satellite dust detection algorithms have been developed to identify dust emissions sources and dust plumes once entrained in the atmosphere. This paper evaluates the performance of five widely applied dust detection algorithms: the Brightness Temperature Difference (BTD), D-parameter, Normalized Difference Dust Index (NDDI), Thermal-Infrared Dust Index (TDI) and the Middle East Dust Index (MEDI). These algorithms are applied to Moderate Resolution Imaging Spectroradiometer (MODIS) data to detect dust-contaminated pixels during three significant dust events in 2007 in the Middle East region that originated from sources in Iraq, Syria and Saudi Arabia. The results indicate that all methods have a comparable performance in detecting dust-contaminated pixels during the three dust events with an average detection rate (between all algorithms) of 85%. However, substantial differences exist in their ability to distinguish dust from clouds and the land surface, which resulted in large errors of commission. Direct validation of these algorithms with observations from seven Aerosol Robotic Network (AERONET) stations in the region found an average false detection rate (between all algorithms) of 89.6%. Although the algorithms performed well in detecting the dust-contaminated pixels their high false detection rate means it is challenging to apply these algorithms in operational context.

Acknowledgments

The authors are grateful to the anonymous reviewers for their comments and suggestions that have helped to improve the manuscript. Authors gratefully acknowledge the NASA Land Processes Distributed Active Archive Center (LP DAAC) (https://lpdaac.usgs.gov/data_access) for providing free access to the MODIS data. We would also like to show our gratitude to AErosol RObotic NETwork (AERONET) site managers for provision of the AERONET data. We gratefully thank King Abdulaziz City for Science and Technology (KACST) for funding a studentship (Abdullah bin Abdulwahed).

Disclosure statement

No potential conflict of interest was reported by the authors.