Saharan dust heads towards the USA
An annual ‘rain of dust’
It is the middle of June in 2020, and the dust is starting to fall. Not just any dust, but Saharan dust that journeyed up to 7,000 miles from the deserts of North Africa. High in the atmosphere, this dust blew across the Atlantic Ocean before landing on the USA Gulf Coast in Texas, Louisiana, Mississippi, and Florida. But this dust may go unnoticed except for colorful sunsets and the onset of asthma in those with respiratory problems.
This ‘rain of dust’ is not an anomaly because every year, unbeknownst to most people, somewhere between 400 million and 2.2 billion tons of tiny soil and mineral particles blow out of the North African deserts and head for the Caribbean, USA, and South America. The Sahara is the largest supplier of atmospheric dust on the planet. It accounts for half the world’s supply.
Winds sweep the dust particles from the Sahara’s surface between late spring and early fall, and they collect in a hot, dry air mass called the Saharan Air Layer. This air layer extends from 5,000 to 20,000 feet above the desert, and strong winds blow the dusty air westward across the Atlantic Ocean. So, the summer months of June and July are usually the time of peak transport.
The image below shows the density of atmospheric particles during a 2018 dust storm. The brown…
