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

 We consistently talk about the Saharan dust during hurricane season, but do you really know what it is and what it does? You may be surprised at its many impacts.

Dr. Kirt Knobelspiesse, a NASA research oceanographer, says it’s been difficult to fully understand the impacts of Saharan dust due to the lack of measurements in the pastBut thanks to the PACE satellite launched by NASA in February, with the objective of getting more data on plankton aerosol, clouds and the ocean ecosystem, we may soon have more detailed information.

”So with PACE, we've specifically designed sensors that will be very good at measuring particulate matter, aerosols, such as dust and clouds," Knobelspiesse said. "And so we'll have the ability to better understand that relationship and understand the role that dust might play in hurricanes. It's still quite uncertain.”. 

Saharan dust is exactly that--dust from the Sahara Desert, a particulate matter that moves across the Atlantic waters typically June through August. 

Just south of the desert, in the Sahel, is where the monsoon season begins and creates thunderstorms. Those storms either move into the Atlantic or fall apart. As they fall apart, outflow wind rushes out of the storms and into the desert, picking up the dust and sending it into the atmosphere. Once that happens, upper level trade winds can then pick it up and carry it all across the Atlantic basin.

"You can see that dust traveling very long distances. [It] makes it to the Caribbean, it makes it to the Amazon basin. That dust interacts with cloud formation,” Knobelspiesse said.

When there’s an abundance of dust, it makes it harder for tropical waves to strengthen. On the contrary, if a hurricane has already developed and moves into an environment with dust, the dust will start to weaken the storm as the dry air gets wrapped into the system.