C-130 News: NASA Langley creates program to track greenhouse gases

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Carbon dioxide and methane are challenging gases to track, but scientists at NASA Langley aim to change that.

Starting Monday, a program called Atmospheric Carbon and Transport-America will use two aircraft, several instruments and lasers to measure the concentrations, movements, sources and sinks of these two powerful gases in the Earth’s atmosphere.

While carbon dioxide is somewhat easier to track because scientists can use data from fossil fuel sales to infer sources, methane sources are different. The troublesome gas is naturally produced by numerous sources, including landfills, wetlands, agriculture and enteric fermentation, which produces methane when carbohydrates are broken down for absorption by animals.

“These are all large sources and they don’t report to anybody,” said Ken Davis, principal investigator. “You know, cows don’t say, ‘Hey, I burped.’ ”

Though aircraft have been used to infer levels of greenhouse gases in the environment before, NASA Langley’s program is the first to study concentrations of carbon dioxide and methane in the environment in relation to weather systems in the eastern United States.

Flights are scheduled for three regions across the mid-latitudes of the United States. The first flights will take off from Wallops Island on the Eastern Shore on Monday morning.

“If we want to understand long-term patterns of these gases over the Earth, we have to know how storms transport greenhouse gases,” Davis said.

Using two aircraft, the C-130 Hercules and the B200 King Air, scientists will fly in “lawnmower-style” patterns across Virginia for two weeks. Instruments on board will measure concentrations of gases as well as wind direction, speed and mixing depth. The planes will fly through varying weather systems to study how they affect gas concentration levels.

The program will span the next several years, with two to three years for scheduled flights and one year to analyze collected data. The projected end date is sometime in 2019.

“We have summer, spring, winter and fall campaigns planned so we can cover different seasons when there are different fluxes and atmospheric conditions,” Davis said.

Onboard the C-130, an instrument called a remote laser absorption spectrometer will use lasers to measure carbon dioxide levels in the atmosphere between the aircraft and the ground.

“The lasers are reflected off of the ground and collected by a telescope,” said Jeremy Dobler, principal investigator and engineer with Harris Corporation. The signal is digitized, he said, and then a computer separates the wavelengths.

The C-130 was purchased from the Coast Guard specifically for the ACT-America campaign. It had to be completely redesigned by scientists before it could be used.

The much smaller B200 will complete the low-altitude air sampling using probes underneath the plane.

“We’ll fly the airplane at half of the atmospheric boundary layer, which is where the turbulent region of the air is close to the ground,” said Greg Slover, a Langley res

earch pilot. “It can vary between 1,000 and 10,000 feet.”

After flights out of Virginia are completed, scientists aboard the aircraft will repeat the processes with flights out of Lincoln, Neb., for two weeks before moving to Shreveport, La., for an additional two weeks.

“What we find in the eastern United States, we expect to be typical of the mid-latitudes of the Earth,” Davis said. “Ultimately, we should be able to better manage and predict the future climate.”

Source: http://pilotonline.com/news/nasa-langley-creates-program-to-track-greenhouse-gases/article_8297e542-3302-53c4-8f5c-51d4a04599a3.html

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