The paper in PNAS is one of the earliest published results from this experiment, and one of its findings is that biology -- the "critters" -- does affect the ability of sea spray to seed clouds. In particular, the researchers found that adding bacteria cultures to the ocean led to a reduction in the spray's ability to form clouds.
Big question, little existing data
For climate models, understanding how clouds form over the ocean, which covers 71 percent of the Earth's surface, and which droplets reflect radiation back out to space is important, because clouds have an overall cooling effect on the planet.
Right now, said Vicki Grassian, chemistry professor at the University of Iowa and another author on the study, models represent the influence of sea spray on cloud formation incredibly poorly, because they treat it as just one thing: sodium chloride -- salt.
"It's pretty clear that sea spray aerosol is not just sodium chloride and there is actually a different range of different chemical compositions in sea spray aerosol and in different particle types," she said.
So while a lot of sodium chloride does come off the ocean, there are also a number of other particles that might behave exactly opposite of salt particles in terms of how they form clouds or reflect light, she said.
Grassian likened the simplicity of this approach, in the climate models, to modeling the human body, which is made up primarily of water, as a shapeless blob of H2O. "There's so much you would miss!" she exclaimed.
As for climate modelers, whose simplified system she is breaking apart, she says their response to the nuance she and others are finding in how sea spray behaves has been positive. "They love it."
Stephen Schwartz, a senior scientist at Brookhaven National Laboratory and an expert on sea spray aerosols who was not involved with the research, called the new laboratory approach "a great way to go," especially because guest researchers can come and use the setup to do more work on sea spray aerosols.
"It's an impressive first study coming out of this facility, and I expect a lot more really good science to come out of it," he added.
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500