What's the difference between sandstorms and regular storms? Are they more than just strong wind within deserts?
-
1$\begingroup$ It is also important to think about wind speed and how this influences which grain sizes (sand is a grain size in geology) can be picked up: Bagnold, R.A. 1937. The transport of sand by wind. The Geographical Journal 89(5):409-438. en.wikipedia.org/wiki/Ralph_Alger_Bagnold $\endgroup$– tobias47n9eApr 16, 2014 at 11:11
1 Answer
There are two types of dust storms.
The first, a dust storm or "sandstorm", is associated with a synoptic scale feature (like a low pressure system). Strong winds along air mass boundaries (i.e. cold front) create clouds of dust as sand, dust, or other particulates become suspended by turbulent eddies near the surface and aloft.
The second, the infamous "haboob" is associated with the cold pool of thunderstorms. In the American desert southwest, during the summer monsoon, numerous thunderstorms develop. These thunderstorms produce rain or virga that cools the atmosphere beneath the thunderstorm as it evaporates. Cool air sinks into what is known as a 'cold pool'. Cold pools generally strengthen as a thunderstorm decays. Cold pools are air masses of cooler than environment air that spreads out like a pancake in all directions from beneath the thunderstorm. These cold pools can create wind gust fronts between 40 and 70mph. Similar to larger dust storms, sand, dust or other particulates become suspended in the air and create the wall of dust.