As I type this on Friday morning, there is a high likelihood that you have already seen social media posts of “African dust” sunrises or sunsets. You have also likely seen references to Godzilla or friends saying “wow, this has never happened before, right?” To be clear, this dust outbreak is certainly an anomaly event and poses potential health risks for people all along its pathway so it is important that the media and other stakeholders have picked up on it. Herein, I officially induct “African dust storms” into the “new” old weather phenomena Hall of Fame. Let me explain.
Dust interacting with cloud systems in the Gulf of Mexico
To illustrate just how extreme this current dust storm is, FEMA scientist Michael Lowry tweeted the following: “The ongoing Saharan #dust outbreak across the tropical Atlantic is *by far* the most extreme of the MODIS satellite record — our most detailed, continuous record of global dust back to 2002.” The graphic below shows a quantity called aerosol optical depth (AOD). AOD provides an indication of how much particulate matter or aerosols are in a column of the atmosphere. This event clearly exceeds other dust events of the past two decades.
Aerosol Optical Depth from the NASA Aqua satellite showing how anomalous this dust event is compared ... [+]
I wrote this piece because of the sheer volume of social media posts and questions from people saying, “I have never heard of dust storms like this making it to the U.S.” or “2020 strikes again, we now have dust coming from Africa.” Extreme events are newsworthy, and this event attracted the attention of the media. As an atmospheric scientist and professor at the University of Georgia, I am rather attentive to meteorological and climate phenomena on a daily basis. While certainly and dangerous from a respiratory ailment perspective, I knew that an African dust storm crossing the Atlantic Ocean was not, in itself, unusual. In fact, I discuss why it happens in a previous Forbes article.
African dust approaching the U.S. on June 25th, 2020
At times in meteorology, we experience the coronation of “new” old things. Many terms that have been well-studied and observed in my field often take on new novelty or significance within the media or social media. Other examples that I have observed in recent years include Polar Vortex, derecho, and bombogenesis. All of these are relatively common meteorological terms that have been around for decades. To be fair, most people are not sitting around reading atmospheric sciences journals or going to meteorology conferences so these terms would not be familiar to many people. I am sure there are many medical, business, or engineering terms that I am not familiar with too. Within the past decade, the rise of social media, weather - climate journalism, and 24/7 news cycles have injected these terms into the lexicon of the general public. For many people, they are certainly “new.”
Oh, there is one more thing to mention while we are talking terminology. My friend and colleague Dr. Tom Gill is one of the foremost experts on atmospheric dust events in the world. Gill, a professor at the University of Texas - El Paso, posted a reminder on Twitter about the current dust storm: “But... it's not a Haboob. Don't let anyone conflate the two! #NotAllDustStormsAreHaboobs.” According to the Glossary of the American Meteorological Society, a haboob is “An intense sandstorm or duststorm caused by strong winds, with sand and/or dust often lofted to heights as high as 1500 m (~5000 ft), resulting in a “wall of dust” along the leading edge of the haboob that can be visually stunning.” They are quite common in arid regions and or of much smaller scale than African dust storms.
If you would like to track the African dust in real-time, I highly recommend this link.
Saharan dust leaving the African continent
