Dusts of Different Stripes

July 11, 2023

Easterly winds blew across Namibia in July 2023, lofting bands of dust across the coastal plains and out to sea. Streams of tan-colored dust jetted out from the entire length of Namibia’s coast and parts of the southern Angola coast when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this image on July 11. In addition, a streak of white salt dust from the Etosha Pan swept across the northern part of Namibia.

The pattern is not unusual for this time of year, when hot, dry squalls known as berg winds rush down from the interior highlands. In 2023, the warm east winds set in on July 6, picking up dust from the desert and salt pans and sending it toward the coast.

By the time this image was acquired, the dust and sand had created poor visibility and hazardous driving conditions in some coastal towns, including Walvis Bay. According to news reports, heavy machinery was needed to clear sand drifts from roadways.

The Etosha Pan, the distinct bright rectangular patch in the image, is an expansive salt flat roughly 130 kilometers (80 miles) long and 50 kilometers (30 miles) wide. It is typically dry except for brief periods in the summer months, when flamingos and other aquatic congregate there. At the time of the image, winds had carried the salty dust approximately 300 kilometers (180 miles) toward the Atlantic.

The windy conditions were forecast to persist in coastal and interior regions for several days, with the possibility for more sandstorms, according to the Namibia Meteorological Service. However, compared with Saharan dust storms that are large enough to influence hurricane formation and ultimately the weather on the opposite side of the Atlantic, the amount of dust in southern African storms is negligible.

 

NASA Earth Observatory images by Wanmei Liang, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview. Story by Lindsey Doermann.

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