A three-year series of research flights from the Arctic to the Antarctic has successfully produced an unprecedented¹ portrait of greenhouse gases and particles in the atmosphere, scientists announced. The far-reaching field project, known as HIPPO, is enabling researchers to generate the first detailed² mapping of the global distribution of gases and particles that affect Earth's climate. The series of flights, which come to an end next week, mark an important milestone³ as scientists work toward targeting both the sources of greenhouse gases and the natural processes that draw the gases back out of the atmosphere.

"Tracking carbon dioxide and other gases with only surface measurements has been like snorkeling（潜水） with a really foggy mask," says Britton Stephens, a scientist with the National Center for Atmospheric⁴ Research (NCAR) and one of the project's principal investigators⁶. "Finally, HIPPO is giving us a clear view of what's really out there."

"With HIPPO, we now have views of whole slices of the atmosphere," says Steven Wofsy, HIPPO principal investigator⁵ and atmospheric and environmental professor at Harvard University's School of Engineering and Applied⁷ Sciences. "We've been quite surprised by the abundance of certain atmospheric components⁸ and the locations where they are most common."

The three-year campaign has relied on the powerful capabilities⁹ of a specially¹⁰ equipped Gulfstream V aircraft, owned by the National Science Foundation (NSF) and operated by NCAR. The research jet, known as the High-performance Instrumented Airborne Platform for Environmental Research (HIAPER), has a range of about 7,000 miles (11,000 kilometers). It is outfitted¹¹ with a suite¹² of specially designed instruments to sample a broad range of atmospheric constituents¹³.

The flights have helped scientists compile extraordinary detail about the atmosphere. The research team has studied air samples at different latitudes¹⁴ during various seasons from altitudes of 500 feet (150 meters) above Earth's surface up to as high as 45,000 feet (13,750 meters), into the lower stratosphere（同温层） .

HIPPO, which stands for HIAPER Pole-to-Pole Observations, brings together scientists from organizations across the nation, including NCAR, Harvard University, the National Oceanic and Atmospheric Administration (NOAA), Scripps Institution of Oceanography, the University of Miami, and Princeton University. NSF, which is NCAR's sponsor, and NOAA are funding the project.