A new study by scientists at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science provides a new way to estimate how much of the ocean’s pollution is raining down from the sky. These new findings can help improve scientific understanding of how toxic airborne chemicals, from industrial processes, are impacting the earth’s oceans.
RSMAS scientists David Kadko and Joseph Prospero measured Beryllium-7 isotope concentrations in the ocean to accurately estimate rainfall in remote regions of the ocean. Berrylium-7 is found naturally throughout the Earth’s atmosphere. The two-year study measured 7-Be deposited in rain collectors at two sites in Bermuda and compared these estimates to those observed in the nearby Sargasso Sea.
“Over vast areas of the oceans the only rainfall data available are those made by using conventional rain collectors placed on islands,” said Prospero, professor of marine and atmospheric chemistry at the UM Rosenstiel School. “However, rainfall on the island is not necessarily representative of that which falls in the surrounding ocean. Our paper shows that properly placed rain collectors on Bermuda do yield rainfall rates that agree with those determined through the 7Be measurements.”
Rainfall is a primary method of transporting pollution from the atmosphere into the oceans. Berrylium-7 attaches itself to atmospheric dust particles, just like other chemicals and pollutants, and enters the ocean during rain events. By understanding this process, scientists can establish new ways to quantify airborne pollutants deposited to the ocean.
“The accumulation of 7Be in the upper ocean provides a means of assessing 7Be deposition to the ocean on regional and global scales,” said Kadko, professor of marine and atmospheric chemistry at the Rosenstiel and lead author of the study. “This then can be used to assess the deposition of other chemical species.”
The paper, titled “Deposition of 7Be to Bermuda and the regional ocean: Environmental factors affecting estimates of atmospheric flux to the ocean” was published in the February 9 issue of the American Geophysical Union Journal of Geophysical Research.
Copyright © 2011 by Marine Science Today, a publication of OceanLines LLC