The Marine Cloud Brightening Project is run by volunteer scientists with extensive experience in engineering, chemistry and physical sciences — with specific expertise in the particle creation needed for ink jet printing.

But cloud brightening demands much smaller particles than are used for ink jet printing, said atmospheric science expert Robert Wood of the University of Washington.

“That has been the challenge,” Wood said.

To understand the fundamental principals of cloud creation, the team studied cloud physics, radiation balance and climate science. Project member Lee Galbraith, famed for inventing a way to find flaws on semi-conductor wafers, read two textbooks on fluid mechanics and two on physical chemistry.

For instrumentation, they’ve gotten help from University of Washington’s David Covert, who loaned them a tool to measure the larger particles. But many of their other instruments come from NASA Ames, Stanford and their own garages.

Many key components must be designed from scratch. There are no off-the-shelf tools, they found, that fit their needs.

For the past seven years, they’ve tried about 10 different approaches. Of these, four have been seriously investigated. One holds the most promise.

“Aerosols are weird beasts,” Cooper said. “To get the correct particles size and distribution of an aerosol is not a simple matter.”

The team has to identify the perfect mix of compressed air and water.

For droplets to be effervescent — lifting and suspending properly — they must be “barely big enough to function,” said project leader Armand Neukermans.

So far, their research has led to publication of four papers in scientific journals.

Now — while also fundraising and seeking more volunteers — they are refining their “effervescent spray” technique.

Lab instrumentation provides “real time” results — in a matter of minutes, as salt water flows and air pressure is adjusted, it’s possible to see exactly what aerosol size and concentration is being produced, Covert said. “This rapid feedback lets them home in on the optimum parameters.”

Success is within reach, he said. “The latest results suggest that they have developed a scalable method for making a spray system that could be used to conduct controlled perturbation experiments in marine low clouds,” he said.

For now, it remains a labor of love, run by volunteers.

But to scale up and take the tool out into the field, they need paid staff and more financial support, they said.

“It sits in the crux between traditional cloud physics research and geoengineering,” said project director Kelly Wanser, CEO of Luminus Networks, which provides intelligence software to data networks.

“The traditional channels of government support don’t exist in this category,” she said. “There’s no funding for geoengineering innovation.”

Contact Lisa M. Krieger at 650-492-4098. Follow her at Twitter.com/Lisa M. Krieger.