Oceans Suck Atmospheric Nitrogen Oxide at Night

 New measurements made on the coast of southern California reveal that the surface of sea sucks in the atmospheric nitrogen oxide present in the polluted air at night.

The study reported in the Proceedings of the National Academy of Sciences, discovered that at night the surface of the sea not just absorbs about 15 percent of the photochemical smog that is generated by Nitrogen oxide.

Nitrogen oxide is found in vehicle exhaust, cigarette smoke and smog. Formed by the burning of the fossil fuels, nitrogen oxide is known to produce photochemical smog. Though emitted in the night, the study researcher claims that this process triggers several other chemical reactions.

"One often neglected path is reaction at the surface of the sea," Tim Bertram, an assistant professor of chemistry at the University of California, San Diego, who led the research, said in a news release. "The sea has a salty, rich, organic surface with the potential for a variety of chemical reactions."

To prove the hypothesis, the researchers tracked the cycle of nitrogen in the atmosphere on the coast of southern California. They deployed scientific instruments at the Scripps Institution of Oceanography in the year 2013 to measure the flux of the molecules.

One night in February, the atmospheric conditions met the required conditions. The winds blew a polluted mass of air right from the Los Angeles Basin along the coast towards the sea. This event allowed the researchers to accurately track the changes occurring to the nitrogen oxide gases as they travelled across the sea surface, Los Angeles Times reports.

This finding helped solve the long lying mystery of the extent to which the sea surface expels the contents of the smog.

The study researchers initially expected the pollutants would undergo a chemical reaction at the surface level to give rise to other compounds. But they were taken aback in seeing that the ocean water acted like a sponge for the atmospheric oxide by simply absorbing them.

"We knew from previous work that nitrogen oxides are lost to various surfaces - sea spray and other aerosols, even snowpack," she said. "This study shows - for the first time - that the ocean is a terminal sink for nocturnal nitrogen oxides, and not a source for nitryl chloride under these sampling conditions."

The finding was documented in the Proceedings of the National Academy of Sciences.