The dust cloud currently cloaking the Caribbean and the southern US is one of the largest in recent memory.
A monstrous cloud of Saharan dust arriving from North Africa has enveloped the Caribbean and some southern US states still grappling with the COVID-19 pandemic.
Saharan dust plumes, or what meteorologists refer to as Saharan Air Layer (SAL), are a regular occurrence in the summer months.
Strong wind storms crossing the desert whip up dust and sand into clouds that travel west through the Cape Verde islands and enter the Atlantic Ocean’s Intertropical Convergence Zone, where tropical storms typically form. The dust clouds follow trade winds near the equator and can hover as high as thousands of feet above the ocean.
The Saharan dust plumes usually become diluted before reaching the Caribbean, but this year, the clouds have stayed intact.
We flew over this Saharan dust plume today in the west central Atlantic. Amazing how large an area it covers! pic.twitter.com/JVGyo8LAXI
— Col. Doug Hurley (@Astro_Doug) June 21, 2020
The dust cloud currently cloaking the Caribbean and the southern US is one of the largest in recent memory, making it especially hazardous to those who suffer from respiratory illnesses or allergies, causing difficulty breathing, asthma attacks, and swelling of the throat and eyes.
“This is the most significant event in the past 50 years. Conditions are dangerous in many Caribbean islands,” Pablo Mendez Lazaro, an environmental health specialist at the University of Puerto Rico’s School of Public Health, told the Associated Press on June 22.
NASA satellites measure the intensity of dust clouds with the Aerosol Optical Thickness (AOT) metric, which indicates the degree to which aerosols prevent the transmission of light through the atmosphere. A measurement of 0.01 indicates clear skies, 0.4 corresponds with very hazy conditions, and 4 means the pollution is so dense the sun cannot be seen in the middle of the day.
In the thickest area of the “Godzilla dust cloud” near the islands of Hispaniola and Jamaica, AOT measured 1.5, or “very dense.” The density restricts visibility to less than a mile in some parts of the region and creates an unhealthy air quality.
While those with pre-existing conditions are most vulnerable to adverse health effects from the Saharan plume, airborne dust can also cause pulmonary disease or cause an inflammatory immune response when inhaled. Dust can even be harmful to people without any respiratory sensitivity after prolonged exposure.
The massive dust cloud is taking hold at a particularly precarious time as cases of COVID-19 are still on the rise in the US states of Florida and Texas, where the plume has already arrived.
While the dust plume spells trouble for people in its path, the meteorological phenomenon does have some benefits. Studies show the dust is packed with nutrients and minerals essential for sustaining vegetation in subtropical and tropical soils.
Some researchers also theorize that Saharan dust helped grow coral reefs in the Caribbean for millions of years, but recent severe dust storms have adversely impacted coral, perhaps due to agricultural practices in the region where the dust originates.
The dust does, however, quell hazardous tropical occurrences such as hurricanes by stifling the moisture needed for these storms. Meteorologists are predicting an active hurricane season, which means the historic dust cloud may be worth the short-term repercussions if it can suppress the severity of some upcoming tropical storms. At the same time, the threat of it exacerbating the destructive force of COVID-19 merits additional concern.