NASA satellites are monitoring the Sahara dust cloud

A massive dust plume from the Sahara desert has drifted 5,000 miles across the Atlantic Ocean and reached the Gulf Coast of the United States, covering the region in a thick haze. 

It is not unusual for Sahara dust to take flight and migrate west over long distances, but this year’s dust cloud is exceptionally large. NASA has been using satellites and other tools to track the dust plume. 

The Absorbing Aerosol Index is useful for identifying and tracking the long-range transport of smoke from wildfires, volcanic ash, and dust from desert storms. According to NASA, these aerosol particles can even be tracked over clouds and areas covered by snow and ice.

The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP satellite provides a visible image, while the Ozone Mapping and Profiling Suite (OMPS) Nadir-Mapper (NM) instrument calculates aerosol values. The OMPS index detects the presence of aerosol particles as they absorb and scatter sunlight.

Colin Seftor is an atmospheric scientist at NASA’s Goddard Space Flight Center. Based on satellite imagery, he said that on June 23 and 24 the dust plume had moved completely over Mexico’s Yucatan Peninsula, up through the Gulf of Mexico, and into southern Texas. 

“At that point, the situation becomes more complicated because the absorbing aerosol index signal seen further north into Texas, Oklahoma, Nebraska, etc., is probably a mix of dust and smoke from the numerous fires burning in the southwest U.S. You can also see that the dust traveled over Central America and out into the Eastern Pacific Ocean.”

Aerosol particles can impact human health, weather conditions, and the climate. The dust will not be harmful to most people, but may cause complications for people with respiratory issues. 

The African dust plays an important ecological role, such as helping to fertilize soils in the Amazon and build beaches in the Caribbean. In addition, the dry and windy conditions associated with Saharan dust outbreaks can inhibit the formation and intensification of tropical cyclones.

“While Saharan dust transport across the ocean to the Americas is not uncommon, the size and strength of this particular event is quite unusual,” said Seftor. “Also, if you look off the coast of Africa you can see yet another large cloud coming off the continent, continuing to feed the long chain of dust traveling across the Atlantic.”

The Sahara dust will continue to move north and east this weekend, making its way up to the Canadian border. 

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By Chrissy Sexton, Earth.com Staff Writer