Sahara dust may make you cough, but it's a storm killer

Sahara Desert
Credit: CC0 Public Domain

The bad news: Dust from the Sahara Desert in Africa—totaling a staggering 2 to 9 trillion pounds worldwide—has been almost a biblical plague on Texas and much of the Southern United States in recent weeks. The good news: the same dust appears to be a severe storm killer.

Research from a team of scientists led by Texas A&M University has studied Saharan dust and their work is published in the current issue of the Journal of Climate of AMS (American Meteorological Society).

Texas A&M's Bowen Pan, Tim Logan, and Renyi Zhang in the Department of Atmospheric Sciences analyzed recent NASA satellite images and computer models and said the Saharan dust is composed of sand and other mineral particles that are swept up in air currents and pushed over the Atlantic Ocean to the Gulf of Mexico and other nearby regions.

As the dust-laden air moves, it creates a temperature inversion which in turn tends to prevent cloud—and eventually— formation.

It means fewer storms and even hurricanes are less likely to strike when the dust is present.

"The Saharan dust will reflect and absorb sunlight, therefore reduce the sunlight at the Earth's surface," said Pan.

"If we have more frequent and severe dust storms, it's likely that we have a cooler sea surface temperature and land surface temperature. The storms have less energy supply from the colder therefore will be less severe."

The study goes on to show that dust and storm formation don't mix.

"Our results show significant impacts of dust on the radiative budget, hydrological cycle, and large-scale environments relevant to tropical cyclone activity over the Atlantic," said Zhang.

"Dust may decrease the , leading to suppression of hurricanes. For the dust intrusion over the past few days, it was obvious that dust suppressed cloud formation in our area. Basically, we saw few cumulus clouds over the last few days. Dust particles reduce the radiation at the ground, but heats up in the atmosphere, both leading to more stable atmosphere. Such conditions are unfavorable for cloud formation."

Zhang said that the chances of a hurricane forming tended to be much less and "our results show that dust may reduce the occurrence of hurricanes over the Gulf of Mexico region."

Logan said that recent satellite images clearly show the Saharan dust moving into much of the Gulf of Mexico and southern Texas.

"The movement of the dust is there," Zhang said, "but predictions of storms can be very challenging."


Explore further

More category 5 hurricanes forecasted by scientists

More information: Bowen Pan et al, Impacts of Saharan Dust on Atlantic Regional Climate and Implications for Tropical Cyclones, Journal of Climate (2018). DOI: 10.1175/JCLI-D-16-0776.1
Journal information: Journal of Climate

Citation: Sahara dust may make you cough, but it's a storm killer (2018, July 20) retrieved 19 September 2019 from https://phys.org/news/2018-07-sahara-storm-killer.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
484 shares

Feedback to editors

User comments

Jul 20, 2018
Some air pollution good, some air pollution bad. If nature does it, it's good and part of the cycle of life. If mankind does it, it's bad and the people doing it must be imprisoned or killed.

Jul 20, 2018
Some air pollution is preventable, some you can't do anything about more like. Don't be an idiot. I could explain false equivalency to you but I would have to use very small words.

Jul 21, 2018
Small words, yes, the poor guy was born in 1357 you know.

Jul 21, 2018
How very amusing, that Texans are dependent upon African dust to p moderate dangerous weather events.

So much for 'self-reliance'...

And of course there is that whole 'lack of capacity for gratitude' thing the Texans got going on.

Oh, and all of you Texans dependent on strong petroleum prices? With pimp putin's whore trump selling out America's oil industry as one more kremlin action in the russians ongoing strategic economic warfare against the West?

How's that legalizing vote cheating working out for you in the late, grate state of taxless?

Jul 21, 2018
Africa exporting its deserts to Texan's completely unforeseen and unexpected Texan climate change

Good to see Africa sending the Sahara desert to Texas, it will feel at home with Texan temperature of 104 degrees Fahrenheit, may be it will encourage the Texans to get desert robes and trade their gas guzzlers for camels, there the only creature suited to this completely unforeseen and unexpected Texan climate change courtesy of the Bermuda high-pressure system. I can just see gas guzzlers sinking into the sand as Texans gracefully glide silently past aloft those ancient camels on their way to work or returning loaded down with groceries from Walmart passing those unused gas stations as all camels need is love and care and oasis in the desert for that thirsty well earned drink of clean mean H2O!

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more