A new scientific analysis has revealed that most dust rising from the Sahara Desert is not generated by strong surface winds alone, but by powerful “hidden thunderstorms” that occur high above the desert. The discovery is reshaping scientists’ understanding of how massive dust clouds form and travel thousands of kilometres across continents.
Dust from the Sahara regularly reaches regions such as Europe and the United Kingdom, sometimes turning skies orange and producing vivid sunsets. These dust particles scatter blue light while allowing red and orange wavelengths to pass through, creating dramatic atmospheric colours. However, scientists say these events also highlight the complex connections within the Earth’s atmosphere.
Dry Thunderstorms Drive Most Saharan Dust Emissions
Research led by climate scientist Richard Washington found that about 80 percent of Saharan dust emissions during summer originate from unusual thunderstorms forming high in the atmosphere above the desert.
Unlike typical storms, these desert thunderstorms occur in extremely dry air where rain rarely reaches the ground. Clouds can form more than five kilometres above the surface, but the rainfall often evaporates before touching the desert floor.
This evaporation cools the surrounding air, causing it to become dense and rapidly descend toward the ground. When the cool air hits the desert surface, it spreads out violently, creating powerful gusts that sweep across the sand and lift massive quantities of dust into the atmosphere.
Satellite observations have tracked more than 1,500 such storms, many of which travel hundreds of kilometres across the desert, particularly during nighttime, generating enormous dust plumes that can later be transported across continents.
Climate Models Struggle to Capture Dust Processes
Scientists say these discoveries present challenges for climate prediction models. Many global climate models currently used to estimate future dust emissions are unable to simulate individual thunderstorms or the cold air flows that generate the dust.
Previous projections suggested Saharan dust emissions could increase by up to 13 percent by the end of the century due to climate change. However, experts caution that such estimates remain uncertain because the models do not fully capture the processes responsible for most dust formation.
Future high-resolution climate models capable of simulating thunderstorms may offer more accurate predictions. Researchers also warn that changes in the West African Monsoon, possibly influenced by a warming Mediterranean Sea, could alter the frequency of dust-producing storms across the Sahara.
For now, scientists say the research highlights how distant environmental processes are interconnected. Dust particles seen in European skies may have rested on the Sahara’s surface for thousands of years before being lifted into the atmosphere by these powerful desert storms.