Scientists from the National Oceanic and Atmospheric Administration (NOAA) are flying over the Texas oil and gas fields to gather data to measure air pollution in the Eagle Ford.

Related: Eagle Ford Study Shows Significant Increase in Pollution Through 2018

The research in Texas is  part of a larger project that includes over 15 research flights out of Colorado and Texas between March and May to measure air pollution from America’s biggest shale fields. The project tracks things like the excessive production of ozone and methane, a greenhouse gas far more potent than even carbon dioxide.

A nationwide study published in early April showed that methane emissions across the United States have dropped significantly in the past two decades and are much lower than current Environmental Protection Agency  estimates. But the scientists from NOAA are focused on understanding the variability between the leaks from one field to another. Lead research, Joost de Gouw cites many factors that cause a variability, such as what is being pumped from the ground, the techniques, equipment and the amount of regulation in each state.

Related: Methane Emissions Drop | Bakken Shale

The research takes place high above the ground in “Miss Piggy”, an airplane that has been customized as a flying lab. Once airborne, teams in the air and on the ground measure readings upwind and downwind of oil and gas activity. The researchers are using aircraft equipped with chemical instruments, and say that once their data is collected, it will take more than a year to synthesize.

Read more at npr.org