Heavy dust blew across Afghanistan in late July, 2014, especially along its borders between Iran and Pakistan. When rain is plentiful, shallow lakes and wetlands along the Afghanistan-Iran border fill with water. When precipitation is scarce, the Sistan Wetlands and, further south, the Hamoun Wetlands (a former oasis) become rich sources of fine dust which is easily raised aloft and carried by the wind.
The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra satellite captured this true color image on July 24 as it passed over the region. Iran is in the west, Afghanistan in the east, and Pakistan in the south. The northern stream of dust is darker than the more southerly one, indicating they arise from different soil types.