People in coastal towns along the west coast of southern Africa watched skies turn red on September 25, 2019. Fierce wind picked up and carried huge plumes of sand and dust westward toward the Atlantic Ocean.
The plumes were observed that day at 2:25 p.m. South Africa Standard Time (12:25 Universal Time) with the Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-NASA Suomi NPP satellite. The event covered a wide area north and south of the Orange River, which forms part of the border between Namibia and South Africa.
The South African Weather Service reported that the winds lofted enough particles into the air to produce moderate to poor visibility. Indeed, photographs from people in Alexander Bay show dark, hazy skies and streets that are barely visible. According to news reports, aircraft were unable to land at nearby airports.
The amount of dust lofted from land in the Southern Hemisphere is negligible compared to that of the Northern Hemisphere. Africa’s Sahara Desert, for example, is one of the world’s major dust sources. Still, when winds blow over dry areas of the Southern Hemisphere, dust storms can be fierce. A similar scene unfolded in October 2018, when a thick, narrow plume streamed from the same area.
References & Resources
- News24 (2019, September 25) âPeople canât see the white line in the street!â: Alexander Bay hit by red sand storm. Accessed September 25, 2019.
- Shao, Y. et al. (2013) Recent global dust trend and connections to climate forcing. JGR Atmospheres, 118 (19), 107â111.
NASA Earth Observatory image by Lauren Dauphin, using VIIRS data from NASA EOSDIS/LANCE and GIBS/Worldview, and the Suomi National Polar-orbiting Partnership. Story by Kathryn Hansen.
