A Colossal Cloud of Sahara Dust

Introduction to the Phenomenon

A massive cloud of dust from the Sahara Desert blanketed most of the Caribbean on Monday in the biggest event of its kind this year as it heads toward the United States. The cloud extended some 2,000 miles (3,200 kilometers) from Jamaica to well past Barbados in the eastern Caribbean, and some 750 miles (1,200 kilometers) from the Turks and Caicos Islands in the northern Caribbean down south to Trinidad and Tobago.

Impact on the Caribbean

The hazy skies unleashed sneezes, coughs and watery eyes across the Caribbean, with local forecasters warning that those with allergies, asthma and other conditions should remain indoors or wear face masks if outdoors. The dust concentration was high, at .55 aerosol optical depth, the highest amount so far this year, said Yidiana Zayas, a forecaster with the National Weather Service in San Juan, Puerto Rico.

By DÁNICA COTO
SAN JUAN, Puerto Rico (AP) —

Effects on Health and Environment

The aerosol optical depth measures how much direct sunlight is prevented from reaching the ground by particles, according to the U.S. National Oceanic and Atmospheric Administration. This not only affects the health of individuals with respiratory issues but also impacts the environment by reducing sunlight, which can affect photosynthesis and overall ecosystem health.

Movement and Concentration of the Dust Cloud

The plume is expected to hit Florida, Louisiana, Alabama and Mississippi late this week and into the weekend, DaSilva said. However, plumes usually lose most of their concentration in the eastern Caribbean, he noted. “Those islands tend to see more of an impact, more of a concentration where it can actually block out the sun a little bit at times,” he said.

Formation of the Saharan Air Layer

The dry and dusty air known as the Saharan Air Layer forms over the Sahara Desert in Africa and moves west across the Atlantic Ocean starting around April until about October, according to NOAA. It also prevents tropical waves from forming during the Atlantic hurricane season, which runs June 1 to Nov. 30.

Historical Context and Seasonal Patterns

June and July usually have the highest dust concentration on average, with plumes traveling anywhere from 5,000 feet to 20,000 feet above the ground, DaSilva said. In June 2020, a record-breaking cloud of Sahara dust smothered the Caribbean. The size and concentration of the plume hadn’t been seen in half a century, prompting forecasters to nickname it the “Godzilla dust cloud.”

Conclusion

The colossal cloud of Sahara dust smothering the Caribbean is a significant event, both in terms of its size and potential impact on health and the environment. As it moves towards the United States, it’s essential for individuals, especially those with allergies or respiratory conditions, to take necessary precautions. Understanding the formation and movement of such dust clouds can also provide valuable insights into global climate patterns and the interconnectedness of our planet’s ecosystems.

FAQs

• Q: What is the Saharan Air Layer?
  • A: The Saharan Air Layer is a layer of dry and dusty air that forms over the Sahara Desert in Africa and moves west across the Atlantic Ocean.
• Q: How often do these dust clouds occur?
  • A: These dust clouds are seasonal, typically occurring from April to October, with June and July having the highest dust concentration on average.
• Q: What health precautions should be taken?
  • A: Individuals, especially those with allergies, asthma, or other respiratory conditions, should remain indoors or wear face masks when outdoors to minimize exposure to the dust.
• Q: Will the dust cloud affect the United States?
  • A: Yes, the plume is expected to hit parts of the United States, including Florida, Louisiana, Alabama, and Mississippi, though its concentration is likely to decrease by then.
    Originally Published: June 2, 2025 at 10:29 AM EDT