Seeing Saharan Dust from Space
Last year, Godzilla made its way across the Atlantic Ocean. No, it wasn’t a giant lizard monster, but a cloud of dust so large it could be seen from a million miles away in space.
The plume of dust blowing from the Sahara Desert broke records and was nicknamed the “Godzilla plume.”
This year, another massive dust plume is traveling across the Atlantic.
The transport of dust from the Sahara to the Americas isn’t unusual: every year, winds pick up more than 180 million tons of dust particles from the Sahara Desert, move them over the African continent and carry them all the way across the Atlantic Ocean, depositing much of the dust along the way.
What’s remarkable about the past two years is the size of the plumes. Last year, the “Godzilla plume” was the largest dust storm in our two decades of observations.
Although this year’s plume has yet to complete its journey across the Atlantic, dust plumes from the Sahara often have important impacts on the Americas.
So, why do the dust plumes matter?
Before the Sahara was a desert, it was a lakebed, where nutrients like phosphorous and iron were deposited before the lake dried up. As a result, winds pick up these nutrients in the dust plumes. Some of these nutrients get deposited in the Atlantic Ocean, feeding marine life – iron, for example, is critical for marine life. Phosphorus is also a much-needed nutrient that fertilizes vegetation in the Amazon rainforest. The amount of phosphorus deposited by Saharan dust plumes into the Amazon every year – around 22,000 tons – is roughly equivalent to the amount that gets removed from the rainforest’s soil by weather conditions. In other words, long term, the dust plumes provide an essential nutrient to the Amazon’s vegetation.
Both the dust plumes themselves and the conditions associated with them can also influence the formation of tropical storms during hurricane season. As climate change appears to be strengthening the strongest storms, understanding the relationship between dust plumes and hurricanes has only grown more important.
The dust plumes can carry microbes that can be deadly and can worsen air quality, creating potentially dangerous conditions for sensitive populations. The iron in the plumes can also kick off blooms of toxic algae off the coast of Florida that result from the increase in nutrients in the ocean.
What comes next for Saharan dust? We’re still looking into it!
Some research suggests dust plumes will intensify with higher temperatures and dryer conditions, creating more loose dust to be picked up. However, other research shows that rising ocean temperatures and changing wind speeds would result in more rainfall and vegetation in the desert, reducing how much dust blows across the Atlantic.
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