A giant plume of dust from the Saharan Desert has been traveling over the Gulf of Mexico, Central American, and into the United States. Satellite images from NASA show the plume’s progress over the last several weeks, providing yet another cause for concern for those suffering from respiratory conditions.
While this plume happens every year, as is becoming a pattern, 2020 is anything but a normal year. The expansive of this year’s plume is surprising atmospheric scientists, who say that the mix of desert dust, smoke, and volcanic ash pose a threat to an ever-expanding region.
"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 NASA atmospheric scientist Colin Seftor. Seftor works at NASA's Goddard Space Flight Center in Greenbelt, Maryland; he was responsible for tracking the plume using imagery from the Suomi NPP Ozone Mapping and Profiling Suite absorbing aerosol index and imagery from the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument. "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," he adds.
According to NASA's Earth Observatory, the plume grew significantly over the period from June 18-24, stretching from 1,500 miles at its widest range to 5,000 miles. According to Seftor, 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."
This mix of dust, smoke, and aerosol particles reduces visibility and impacts human health, weather, and climate. Aerosol particles can be dangerous when inhaled by people with respiratory conditions such as asthma or, of course, COVID-19. As Science Daily reports, “Aerosol particles also affect weather and climate by cooling or warming the earth as well as enhancing or preventing cloud formation.”
Yet, the Saharan Air Layer can have another impact, too: its dry, warm, windy conditions can stop tropical storms and hurricanes in their tracks. Scientists say it is too early to tell what long-term effects the dust plume will have on the climate in the coming months, so stay tuned!