It’s no secret that massive dust storms in the Saharan Desert occasionally shroud the North Atlantic Ocean with iron, but it turns out these natural blankets aren’t the only things to sneeze at. Iron released by human activities contributes as much as 80 percent of the iron falling on the ocean surface, even in the dusty North Atlantic Ocean, and is likely underestimated worldwide, according to a new study in Nature Communications.
“People don’t even realize it,” said lead author Dr. Tim Conway, Assistant Professor at the USF College of Marine Science, “but we’ve already been doing an iron fertilization experiment of sorts for many decades.”
Burning fossil fuels, biofuels, and forests all release iron, which can be transported as an aerosol over large distances from land into the guts of the North Atlantic and beyond. But human-derived iron aerosols have been nearly impossible to see in the data – until now. The team used the isotope ratios of iron in the atmosphere to ‘fingerprint’ whether the iron came from Saharan desert dust or human sources such as cars, combustion, or fires.
Read more at University of South Florida
Image: The R/V Knorr was operated by Woods Hole Oceanographic Institution from 1970-2016. It was used on the GEOTRACES expeditions in 2010-2011 during which iron aerosol samples were collected for the study led by the USF College of Marine Science. CREDIT: University of South Florida