The abbreviation "DU" in aviation weather reporting stands for what?

The abbreviation "DU" in aviation weather reporting specifically refers to "Widespread Dust." This terminology is used to describe significant dust conditions that can affect visibility and therefore impact flight safety. When reported, it indicates that a considerable amount of dust is suspended in the atmosphere, often resulting from weather phenomena such as strong winds or dry conditions in the vicinity. Such reports are crucial for pilots and air traffic controllers to ensure they are aware of potential hazards that could affect aircraft operations. The other options do not accurately represent what DU stands for in the context of aviation weather reporting.