Understand the ‘rain of blood’ that could hit the United Kingdom – 02/01/2024 – Environment

The United Kingdom could be hit this week by a very peculiar phenomenon called “blood rain”, according to weather forecasts.

But what is this?

The term “blood rain” refers to precipitation that carries sand particles from deserts.

Storms in the Sahara desert, located more than 3,000 kilometers away, often stir up dust, which is then transported towards the United Kingdom, as explained by the British national weather service, Met Office.

When rain falls, it has a reddish color and, when it dries, it leaves a thin layer of dust of the same color.

This dust is capable of covering houses, cars and objects that are outdoors, but for it to leave a residue, it needs to be a brief rain.

“Saharan dust is being transported north and will affect the UK in the coming days, following the recent dust storms in North Africa,” says Marco Petagna, meteorologist at the Met Office.

Rain and the thin layer of dust that remains after it can also have other colors.

“The different colors of sand in the Sahara cause the rain and the layer it leaves behind to vary in color,” climate expert Philip Eden told BBC News.

“It may have a reddish tint, but it is quite rare. It is more likely to be sand or brown in color. It is not as spectacular as it looks.”

How rare is the phenomenon?

The phenomenon is more common in southern Europe, such as Spain and southern France — which are closer to the Sahara. But sand rain can also travel long distances and happen in areas like Scandinavia.

“Blood rain” occurs a few times a year in the UK, experts say. However, the dust seen is usually yellow or brown and mixed in very low concentrations — which makes the rain appear ordinary.

“As in other parts of the world, the wind can blow strongly over deserts — lifting dust and sand high into the sky. If winds in the upper part of the atmosphere blow north, the dust can be transported as far as the UK.” , explains the Met Office.

A well-documented “blood rain” incident occurred in 2001 in the southern Indian state of Kerala.

In the middle of a monsoon season, red rains began to fall and continued, without stopping, for several weeks. The color was strong enough to stain clothes.

Investigations suggested that the rain was red because winds had raised dust from the Arabian Peninsula.