Where Does Dust In The Atmosphere Come From?

By Antonia Čirjak on May 4 2020 in Environment

Atmospheric dust is quite important for the climate of our planet.
Atmospheric dust is quite important for the climate of our planet.
  • Atmospheric dust affects many aspects of our planet and it's ecosystems.
  • Even though it is not impossible to capture the image of dust via satellites, it is still extremely difficult.
  • Lake Chad located in the Sahara is one of the most important surces of atmospheric dust.

Atmospheric dust is actually quite important for the climate of our planet. For the most part, it consists of small pieces of clays, carbonates, and metal oxides. It is the most prevalent component of aerosols in our planet’s atmosphere. It can also affect an extremely wide range of phenomena ranging from how much snow melts in the United States to how high the temperatures will be in the Atlantic Ocean.

Dust is also an extremely important factor in the Earth’s ecosystem. It can affect hurricanes as well, as shown by research that explored the relationship between the dust in the tropical North Atlantic and the appearances of hurricanes throughout the Atlantic over the course of several decades.

Detecting Dust

Dust is extremely hard to detect through satellite imagery; however, it is not impossible. It can seem strange that satellites that are traveling on heights 22,000 miles above the planet’s surface are able to detect something as tiny as dust particles. The reason for that is the fact that dust can reflect or absorb light, just like all other aerosols that can be found in our atmosphere. The sensors on the majority of satellites orbiting through space are able to detect the areas of absorption and reflection, which makes it able to measure the amounts of aerosols in the atmosphere.

Despite the fact that satellites can detect dust in our planet’s atmosphere, scientists are still not able to always detect it in satellite imagery. The most important reason for that is color. Satellite imagery is grayscale, which makes it extremely difficult to see dust clouds or to separate them from other clouds. However, with the technological advancements being made in satellites, difficulties like these can be overcome to an extent. There are still some caveats, for example, certain satellites allow a clearer detection of dust clouds but only during daytime.

Where Does It Come From

It is important to improve our ability to detect dust since the amounts of it that enter our atmosphere are extremely large. The exact amount is not exactly known, but the projections range anywhere from 200 to 5,000 teragrams per year. It is believed that 20 teragrams of dust are present in the atmosphere at all times. To make things a bit clearer, a teragram equals one trillion grams. Many weather phenomena that are closely tied to the ocean are also connected to dust and the ways it gets transported across the oceans and deserts.

One of the sources of atmospheric dust is a lake in Sahara called Lake Chad. It is considered to be the single largest source of dust on our planet. That lake can be found in the northern part of the African continent. This is interesting because almost half of the dust that is suspended in the atmosphere comes from North Africa.

The reason for that is the large number of sources of dust that can be found there, as well as the position of that region. It is placed just under the subtropical jet stream. This stream is capable of carrying dust all over our planet. The rest of the dust in the atmosphere comes from other regions, including the Taklimakan Desert in China, Iran, the shore of the Caspian Sea, and some parts of Arabia. Of course, there are many more places that are capable of producing dust, but these are some of the biggest ones.

More in Environment