By Rasheeda Hamidu
A NASA-backed study reported that 27.7 million tons of Saharan dust crossed the Atlantic annually to the Amazon rainforest, replenishing phosphorus lost through rainfall and sustaining forest productivity through long-range atmospheric transport.
According to the United States National Aeronautics and Space Administration (NASA), researchers used data from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite to quantify how much African dust reached the Amazon Basin between 2007 and 2013.
Hongbin Yu, an atmospheric scientist at the University of Maryland working with NASA’s Goddard Space Flight Center, said the transported dust played a critical ecological role in maintaining soil nutrients within the rainforest ecosystem.
Yu stated: “The phosphorus that reaches Amazon soils from Saharan dust, an estimated 22,000 tons per year, is about the same amount as that lost from rain and flooding.”
NASA reported that the dust originated largely from the Bodélé Depression in Chad, an ancient lake bed rich in phosphorus-containing mineral deposits formed from dead microorganisms.
According to the study published in Geophysical Research Letters, approximately 182 million tons of dust leave the Sahara annually, with about 15% eventually settling over the Amazon Basin.
Richard Thompson, founder of the University of Plymouth’s international marine litter research unit, was not involved in the NASA study but separately described atmospheric dust transport as one of several interconnected Earth systems influencing climate and ecosystems globally.
NASA explained that CALIPSO used laser-based lidar technology to measure the vertical distribution of aerosols and dust particles travelling across the Atlantic Ocean.
The agency further reported that variations in rainfall across the Sahel region could influence how much dust reaches South America by altering vegetation cover and wind circulation patterns.
According to NASA, researchers observed that dust transport fluctuated by as much as 86% between 2007 and 2011, highlighting the sensitivity of the process to changing climatic conditions.
Yu explained that understanding the relationship between climate change and dust transport remained important because atmospheric dust influences both regional weather systems and global climate processes.
NatureNews reports on transboundary environmental systems, including atmospheric transport, desertification and rainforest resilience, as part of its coverage of climate-linked ecological interactions affecting Africa and the wider world.
