Normal Methane Over Hutchinson

May 1, 2001 | Mike Key

MADISON, WI, May 4, 2001—According to a report from the University of Wisconsin-Madison’s Space Science and Engineering Center (SSEC), no indications of high methane, or natural gas, amounts over Hutchinson, Kansas were found on March 31 when test observations were conducted from a NASA aircraft.

To gain experience in using aircraft remote sensing to observe these types of natural hazards in the future, officials took advantage of an atmospheric science experiment already planned for the area. Lee Allison, Director of the Kansas Geological Survey at the University of Kansas, requested the observations to help determine whether methane levels were unusually high following explosions in January. The test observations, conducted from NASA’s high-altitude aircraft, the ER-2, indicated only normal levels of methane in the area.

One of the specialized instruments flown during the March experiment was SSEC’s Scanning High-resolution Interferometer Sounder. The sounder measures the atmosphere vertically in fine increments in infrared wavelengths, or, temperature. It is capable of sensing trace gasses, including methane.

Other instruments detected some low-lying clouds, but, in the clear areas, according to Henry Revercomb, principal investigator for the sounder, “the S-HIS data reveals no anomalously high methane amounts.” In other words, the amount of methane is about the same as it would have been before the leak. Revercomb added that “the observing technique is designed for climate applications and the sensitivity is limited for natural hazards. The technique is not expected to be capable of detecting seriously high levels of methane in thin isolated layers.”

The technique was developed for NASA to map carbon monoxide distribution from fires in southern Africa. In his report, Revercomb said, “The method makes use of high spectral resolution emission lines observed by the S-HIS spectrometer to derive an optical depth using weak absorption lines. It is less sophisticated than a full profile retrieval approach, but is very useful for a survey result of localized events.”

NASA funded the Texas MODIS Experiment 2001 during which the ER-2 flew over Kansas. The main purpose of the experiment was to improve calibration of the MODerate resolution Imaging Spectroradiometer, which flies on NASA’s Terra satellite, launched in late 1999.

Kansas officials will also use data from NASA’s Jet Propulsion Laboratory, who flew a 10-day mission over the Hutchinson area in late April to view smaller areas in greater detail.

For more information, contact Henry Revercomb, Director, Space Science and Engineering Center, UW-Madison, 608-263-6758; M. Lee Allison, State Geologist & Director, Kansas Geological Survey; or SSEC’s Public Information Officer, 608-263-3373.