2017 Academic High Altitude Conference

Balloon-borne methane and radiation measurements

The BalloonSAT program is a high altitude research and education outreach program at Arkansas State University. Weather balloons carried a Geiger counter that measured X-ray, β, and γ radiation profiles together and a methane sensor (Arduino and MQ-6 detector) in payload boxes to 30 km (90,000 ft) over the past five years. Payload boxes were foam containers for water resistant and floating abilities in possible water landings, no modifications beyond securing sensors to the payload box were made. Methane and radiation measurements are not directly related, but collected independently and flown on many flights together and therefore presented together. A radiation peak related to decreasing cosmic radiation and increased secondary radiation, or Pfotzer maximum at 10-15 km was found. Lower tropopause temperatures were related to higher radiation counts at the Pfotzer maximum. Methane is 30 times more potent as a greenhouse gas than carbon dioxide. A linear calibration curve was made with known concentrations of methane at various temperatures to convert voltage readings into concentrations. The low temperatures and pressure were not found to significantly impact concentration measurements. Methane concentration was found to decrease with altitude similar to satellite and Unmanned Aerial Vehicle (UAV) measurements. BalloonSAT does not collect data that can replace satellites, but proves to be an effective instrument in identifying radiation and methane profiles in the troposphere and lower stratosphere comparable to other balloon-borne, UAV and satellite studies.