Research jets return with wealth of data on greenhouse gases

Black carbon particles in the Western Pacific are at levels comparable to megacities like Houston and Los Angeles because they are floating widely throughout the atmosphere. These dark colored particles, which form from incomplete combustion, are one of the major contributors to climate change by absorbing solar radiation and by causing snow and ice to melt faster.

The discovery is just one of a number that’s expected to come out of the far-reaching expedition called HIPPO (HAIPER Pole-to-Pole Observations), which ends this week. A project of a number of federal government agencies and universities, HIPPO involved a three-year series of research flights from the Arctic to the Antarctic that measured greenhouse gases and particles in the atmosphere that affect the Earth’s climate.

The goal was to sample a broad range of molecules in the atmosphere to better understand where they are most common and how they are spreading around the world. Tracking these molecules with surface measurements, which are often separated by thousands of miles, has been “like snorkeling with a really foggy mask,” says Britton Stephens, a scientist with the National Center for Atmospheric Research (NCAR) and one of the project’s principal investigators in a press release. “Finally, HIPPO is giving us a clear view of what’s really out there,” he says.

The scientists say that the data they have gathered is “extraordinary in detail.” More than 80 gases and particles were sampled were gathered at various latitudes, during different seasons, and from different altitudes. The hope is to use the data to understand how activities like logging and regrowth of forests are affecting CO2 levels in the atmosphere. It may also provide a baseline to evaluate the success of efforts to curb CO2 emissions and the uptake and storage of greenhouse gases through natural systems.

“Carbon markets and emission offset projects are moving ahead, but we still have imperfect knowledge of where human-emitted carbon dioxide is ending up,” Stephens says.

Among the other questions that need answers: Why are methane levels increasing again, after leveling off in the 1990s?

Besides NCAR, participants included Harvard University, the National Oceanic and Atmospheric Administration (NOAA),  the Scripps Institution of Oceanography, the University of Miami and Princeton University.