The impact of Saharan dust on hurricane season: what it is and how it works

And when it’s in our sky, it can create a picturesque landscape for sunrises and sunsets, while simultaneously triggering some discomfort for those with upper respiratory sensitivity. But what exactly is it?

We often discuss Saharan dust during hurricane season, but do you really understand what it is and its effects? You might be surprised by its many impacts.

Dr. Kirt Knobelspiesse, a NASA research oceanographer, notes that understanding Saharan dust's impacts has been challenging due to historically limited measurements.

Thanks to NASA's PACE satellite, launched in February to gather more data on plankton, aerosols, clouds, and ocean ecosystems, we might soon gain detailed insights.

“With PACE, we’ve designed sensors that excel at measuring particulate matter, aerosols like dust, and clouds,” Knobelspiesse said. “This will help us understand the relationship between dust and hurricanes, which remains quite uncertain.”

Saharan dust, visible in dramatic skies such as South Florida's in July 2023, often limits tropical development. But how does it work?

Saharan dust consists of particulate matter from the Sahara Desert, traveling across the Atlantic from June through August. Thunderstorms in the Sahel region lift the dust into the atmosphere, where trade winds carry it across the Atlantic.

“You can see that dust traveling long distances, reaching the Caribbean and the Amazon basin. It interacts with cloud formation,” Knobelspiesse explained.

Abundant dust inhibits tropical wave strengthening. If a hurricane encounters dust, the dry air weakens the storm. Additionally, Saharan dust impacts local environments by creating atmospheric caps that hinder storm formation and reflecting sunlight, which cools the air and ocean surface.

Beyond hurricane season, Saharan dust also acts as a fertilizer, promoting phytoplankton growth in oceans and affecting the Amazon basin's ecology. Visually, it creates picturesque sunrises and sunsets, but can also cause discomfort for those with respiratory sensitivities.