UNIVERSITY Park, Pa. — A beautiful sunset over the Atlantic off the Florida coast, or an orangey glow in the Texas sky at dusk may be caused by dust from West Africa, according to researchers who are looking at the paths of particulate matter in the skies over the Sahara desert and the semi-arid Sahel.
"We are looking at how much dust is being transported into West Africa in the winter and across the Atlantic in the summer," said Gregory S. Jenkins, professor of meteorology and atmospheric science, geography, and African studies, Penn State. "In the winter, it is low in the atmosphere and in the summer, it is higher in the atmosphere. Dust has an impact, especially on health."
Jenkins and Moussa Gueye, research professor, University of SIne Saloum El-Hȃdj Ibrahima NIASS, Dakar, Sénégal, modeled annual particulates less than 10 microns (PM10) from 1960 to 2016.
"We showed that there is a simulated annual downward trend in surface PM10 concentrations in Senegal and Cabo Verde after the 1980s, which is similar to earlier findings," the researcher report in Atmospheric Environment. However, the data for summers suggests that there was an increase in dust over the Western Sahara that was transported to Cabo Verde suggesting that this Eastern Atlantic dust continued on toward the U.S. and the Caribbean.
The researchers can measure the amounts of dust that reach the Western Atlantic near Miami, Barbados and Puerto Rico for example, because there are ample meteorological and other measurement stations in those areas, but in West Africa and places like Cabo Verde, there are few ground-based measurement facilities to measure the dust reaching there.