In August and September 2015, a massive dust storm swirled across the Middle East. After reporting on the storm, I read a fair amount of speculation — but no clear answers — as to what kicked up such an unusually large amount of dust. Several reports made the case that the ongoing war in Syria was a contributing factor. The war, some scientists speculated, had increased the military traffic over unpaved roads and had led farmers to abandon their land.
Now a new study led by a researcher from Duke University argues that the war was not an important cause. By analyzing satellite data of vegetation cover before the war, the researchers concluded that the conflict did not have much effect on vegetation. (Vegetation helps hold sand and soil in place.) In fact, the satellites observed that agricultural activity was healthy in 2015 in comparison to earlier years.
Rather, the research team found that the key drivers of the dust storm were meteorological. The summer of 2015 was unusually hot and dry compared to the past 20 years, meaning more dust was available and in a condition that winds could easily lift. So when an unusual cyclonic wind pattern developed in late August and persisted for more than a week, a mega dust storm was born.
Read a press release about the study from Princeton University, and read the full study in Environmental Research Letters. To reach their conclusion, the researchers used Aerosol Optical Depth and Normalized Difference Vegetation Index (NDVI) observations from NASA’s Moderate Resolution Imaging Spectroadiomters (MODIS), and meteorological simulations from the Weather Research and Forecasting (WRF) model. You can view several types of satellite imagery of the storm, which began on August 31 and peaked on September 8, on NASA’s Worldview browser.