Photograph by Matt Henry Gunther, The Image Bank, Getty Images
Published March 10, 2010
Sea spray has been detected in the middle of the United States, some 900 miles (1,400 kilometers) from any ocean, a new study says.
Scientists discovered chlorine—a key element in sodium chloride, or the type of salt found in seawater—in Boulder, Colorado's (see map) mountain air.
Boulder's sea spray is too sparse to taste or even smell. But it's still much more abundant than previously thought—and it may be contributing to air pollution, said study team member Joel Thornton, an atmospheric chemist at Seattle's University of Washington.
"We discovered chlorine chemistry happening in a region that we didn't expect it to be happening," Thornton said.
(Related: "Pollution From U.S., Europe, Others Speeding Arctic Warming, Study Says.")
Accidental Discovery
The chlorine discovery above Boulder was accidental, Thornton said.
Thornton and his team were testing out a custom-built chemical ionization mass spectrometer that they intended to use later, during a research cruise across the Atlantic Ocean.
"In preparation for that, we put our tubes out a window to do some tests, and we made the first observations of this compound," Thornton recalled.
When the team shifted their focus to study chlorine, they found that, worldwide, as much as ten billion metric tons of chlorine enters the atmosphere from sea spray annually, but only a tiny fraction—perhaps a third of a percent—does not fall back to the surface.
Yet not all, or even most, of the United States' inland chlorine comes from the ocean. Other sources include coal burning, the burning of biomass such as trees, the application of chemicals on icy winter roads, and even the release of dust from salt flats, the study said.
Salty Smog
While sea spray may be a pleasant beach experience, its presence so far inland may worsen air pollution in cities, added Thornton, whose research is detailed in this week's issue of the journal Nature.
That's because chlorine can react with other molecules to create smog. (Find out how much you know about the dangers of pollution.)
In the absence of chlorine, for example, haze-forming pollutants such as nitrogen oxide become bound to other molecules at night and are "cleaned" from the atmosphere. During the daytime, sunlight plays a role in keeping pollutants in the atmosphere.
If chlorine is present, this nighttime removal process doesn't occur, and the nitrogen oxides can be regenerated in the morning, when the sun rises and rush hour traffic adds more pollutants to the air.
Atmospheric chlorine may also enhance the production of ozone, a key ingredient of smog that is potentially toxic to animal and plant life, Thornton said. But chlorine may also reduce the concentration of certain global warming-causing greenhouse gases, such as methane.
However, he added, the chemical reactions associated with chlorine are so numerous and interconnected that it will take time for scientists to parse them all out.
Most Popular News
-
Black Hole Seen Eating Asteroids?
An ongoing rocky buffet would explain bright x-ray flares seen around our galaxy's supermassive black hole since 1999, astronomers say.
-
Zebra Stripes Are Bug Repellant?
Stripes may do more than help zebras hide in tall grass—the pattern may scramble the vision of bloodsucking horseflies
-
Lake Vostok Breached
Russian scientists have confirmed that they have breached the subglacial Lake Vostok in Antarctica—a first.
Advertisement
News Blogs
-
Ireland to Charge for Water for the First Time
New plan aims to boost water conservation.
-
Texas Moves to Save Critical Groundwater
Ogallala Aquifer has dropped as much as 150 feet.
-
Good News, Bad News on U.S. Energy Outlook
The "all of the above" energy approach Obama championed in his State of the Union speech is at odds with U.S. climate goals.
ScienceBlogs Picks
Connect With Nat Geo
Got Something to Share?
Special Ad Section
Great Energy Challenge Blog
Green Living Hot Topics
-
Organic Air Fresheners
Avoid toxic chemicals and create a calming space.
-
Surprising Recyclable Household Items
With a little know-how, you can recycle more than you think.
-
Side Effects of Vegetarianism
Find out how to stay healthy and eat lower on the food chain.
