AUSTIN, Texas — A cloud of dust blowing through the Gulf of Mexico may not sound like an encouraging forecast, but it might be just what we need to keep tropical storms at bay and enjoy some gorgeous sunsets.
During the summer months, a large plume of dust can appear in the atmosphere over the Sahara Desert in northern Africa, kicked up by strong winds on the earth’s surface. This mass of dust combines with warm, dry air to form the Saharan Air Layer.
Riding trade winds westward from Africa to North America, the dust drifts across the Atlantic Ocean, reaching as far west as the Gulf. This week, conditions lined up perfectly for a cloud of dust to be swept out with the Saharan Air Layer.
“There’s a lot of dust with this one,” said University of Texas meteorology lecturer Troy Kimmel. “A lot of it is suspended at mid- and high levels of the atmosphere.”
Forecasters at the National Oceanic and Atmospheric Administration predict that the dust cloud reached the eastern edge of the Caribbean over the weekend, potentially making its way to the Texas Gulf Coast this week.
Aaron Treadway, a meteorologist with the National Weather Service said “impacts on air quality and tropical systems” are the two biggest things that will come from the presence of Saharan dust.
“For us and a lot of the other southern U.S. states where this dust is supposed to end up, it’s going to impact the air quality for a couple of days,” Treadway said.
However, the Texas Commission on Environmental Quality forecasts that “the intensity and duration of the dust is not expected to be enough to raise the daily (particulate matter in the atmosphere) beyond the 'Good' range throughout the impacted regions.”
Although some people may be more sensitive to the dust than others, Kimmel thinks that there may be a silver lining because of the timing of the cloud’s arrival: “The good news with that is we’re all wearing masks.”
“Tropical storms need a lot of moist air and relatively calm upper level winds to form,” Treadway said. “The lack of moisture and increased winds are not conducive for tropical storm development.”
Another benefit of dust from the Sahara Desert: more vivid sunsets and sunrises. As the sun passes the curve of the earth, its rays shine through a thicker layer of atmosphere.
Dust and water particles in the atmosphere are responsible for scattering sunlight, creating the rich colors of sunsets and sunrises. With the added dust in the atmosphere, a greater number of particles can refract sunlight into a beautiful range of purples, pinks, oranges and yellows.