by Jaymi Heimbuch, San Francisco, California

Photo by mrpbps

We know that a significant portion of ocean pollution comes from particles in the air released by fossil fuel combustion, power plants and the like, and that rainfall is a primary way it moves from air to ocean. But just how much of the ocean’s pollution from from airborne chemicals? 

 Scientists at the University of Miami (UM) Rosenstiel School of Marine & Atmospheric Science have developed a new way to figure this out, and their findings could help us understand the real impact of atmospheric pollution on the ocean.

Science Daily points us to the news from U Miami. “By measuring Beryllium-7 (7Be) isotope concentrations in the ocean, which is found naturally throughout Earth’s atmosphere, Rosenstiel School scientists David Kadko and Joseph Prospero were able to provide a method to accurately estimate rainfall in remote regions of the ocean. The two-year study measured 7Be deposited in rain collectors at two sites in Bermuda and compared these estimates to those observed in the nearby Sargasso Sea.”

Usually, rainfall is measured with conventional rain collectors on islands, but these are not necessarily representative of the rainfall happening in the oceans. The new measurements help improve accuracy, as well as help determine the accuracy of the island-placed collectors.

Understanding of how the process by which airborne particles are captured in rain and make their way into the ocean can help researchers uncover more clues to the real impacts of land-based pollution on oceans. We usually think of carbon dioxide causing ocean acidification, agricultural runoff causing dead zones, or plastic bits creating a murky soup ingested by animals, but the story of pollutants making their way into the ocean is far more complex. But this new method of understanding rainfall over the ocean can shed some light.
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