(WFLA) – Dust from the Sahara Desert in Africa is currently making a 5,000 mile trek west across the Atlantic Ocean and is expected arrive in the Gulf of Mexico later this week.
Every year, these Saharan dust plumes are generated from strong winds over the Sahara. These winds and updrafts kick up the dry top layer of soil and raise it high into the atmosphere. Easterly trade winds can then carry the dust into the Atlantic. Sometimes, when the dust plume is large enough and the easterly winds are strong enough, the plume travels all the way to the Caribbean and even the United States.
To avoid confusion, this isn’t a typical dust storm. When the dust arrives, it is suspended high up in the atmosphere, between 5,000 feet and 20,000 feet or about one to four miles.
Even though the individual dust particles are very small, when the plume arrives, skies will become much hazier.
Hazier skies will lead to exceptionally colorful sunrises and sunsets as the light bends around and through the particulate.
Allergy sufferers may notice an increase in irritation from the dust as some of it does mix in closer to the surface.
As the dust begins to settle, large portions of it drop into the Gulf of Mexico. NASA is currently studying a link between these dust plumes and red tide. Studies have shown after large plumes arrive, there is an increase in the harmful algae.
Mixed in with the dust is iron from the topsoil in Africa. When the iron ends up in the Gulf, it actually fertilizes the water which can begin the process of the toxic algae bloom.
As explained on last week’s episode of Tracking the Tropics, these dust plumes also seem to inhibit tropical development thanks to the embedded dry air, strong 25-55 mph mid-level winds along with a few other factors. However, research is on-going on this topic.
Dust plumes coming off the coast of Africa are quite normal this time of year. The plumes typically begin in mid-June and run through mid-August, peaking somewhere in the middle. According to NOAA, the plumes of dust seem to rapidly subside after mid-August, which is also why we see an uptick in tropical activity in August and September.
This particular plume seen on visible satellite over the Atlantic is rather large and dense and could linger over the southern US for several days.