From Heaven to Hell – The Sandstorm

The desert may seem like a paradise in the sunshine, but it can also quickly turn into hell in a sandstorm.

Weather-related causes of a sandstorm

Scientifically speaking, there are two categories of phenomena that can lead to sandstorms.

1. The first phenomenon is linked to strong, violent winds or intense depressions. In the Moroccan Sahara, this type of so-called synoptic storm is often produced when there is a sirocco known as Chergui.
2. The second phenomenon concerns the so-called mesoscale effects, linked to the average winds blowing down to the ground, generating gust fronts. The so-called mesoscale storm, found in all desert areas in general, is linked to downbursts generated by a thunderstorm or a line of thunderstorms.

More broadly speaking, there are three types of sandstorm:

1. The wall or ‘Haboob’ in Arabic, a 2,000 metre high wall that moves at 80 km/h and usually lasts around three hours.
2. The column is more like a tornado, and is very common in the Sahara. Its nickname is ‘Dancing Djinns’.
3. The tablecloth, or sand fog, a thick mist.

Wind effects

The three actions that move sand or dust are known as ‘creeping’, “saltation” and ‘suspension diffusion’.

Reptation : movement takes place as close to the ground as possible, involving the largest grains of sand.
Saltation: the movement involves lighter particles that fly up into the atmosphere, fall back and bounce off the ground, ejecting other particles…
Suspension diffusion: concerns the finest and lightest grains, dispersed and carried by the wind.

How do you protect yourself in a desert sandstorm?

Obviously, if you’re in the middle of the desert, accompanied by Tuaregs, nomads and blue men, you don’t need to worry… If not, here are the instructions to follow if you get caught in a sandstorm.

First of all, you’ll need to try and find a slope, perhaps leaning against a dune, behind a rock, behind a tree or behind the camel.

You need to sit down and wrap up in your clothes, and it’s vital to protect your face, eyes and mouth. Obviously, you must avoid talking, as you risk swallowing sand, which could cause serious respiratory damage.

So you have to be patient and wait for the storm to calm down, getting up once there is no longer any risk and the sand is no longer flying through the atmosphere.

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