PORTSMOUTH, N.H. – The second phase of a massive air quality study began Monday with the launch of a boat that will map and analyze air masses from the West Coast.

Using ships, balloons, planes and land-based laboratories, scientists are mapping pollution from sea level to 20,000 to 30,000 feet in the air as part of what they call the largest air quality study ever.

The study, which is using the New Hampshire seacoast as its hub, involves hundreds of scientists from six countries.

The project includes NASA, the National Oceanic and Atmospheric Administration, and the University of New Hampshire, which developed a low-cost solar-powered balloon that can measure ozone levels.

The Ronald H. Brown, a NOAA ship that left Portsmouth on Monday, will spend three weeks in the Gulf of Maine to track pollution moving across the country. Airborne laboratories aboard NASA airplanes will study the same air masses at higher altitudes.

Researchers said the International Consortium for Atmospheric Research on Transport and Transformation is the first attempt to map, track and analyze air pollution in such detail and at so many levels. The difference between older studies and the new effort is like the difference between a photograph and a movie, they said.

“For the first time we’re starting to understand the details of large-scale air pollution transportation from one continent to another,” said Robert Talbot, director of the AIRMAP Cooperative Institute at UNH. “What we’re learning is how the global community is affecting the air quality of our planet.”

U.S. Sen. Judd Gregg, R-N.H., who helped secure $5 million for the project, said the results will power atmospheric research for the next 10 years.