Flight Performance of Super-Pressure Balloons for LODEWAVE

抄録

The LOng-Duration balloon Experiment of gravity WAVE over Antarctica (LODEWAVE) was conducted in 2022 to observe gravity waves using the Mesosphere-Stratosphere-Troposphere (MST)/ Incoherent Scatter (IS) radar, PANSY, at Syowa Station and using newly developed super-pressure balloons. The observation system was comprised of a super-pressure balloon and a gondola containing the Iridium communication board and data acquisition board to collect and transfer data from GPS receivers, pressure sensors, and temperature sensors. The super-pressure balloon had a volume of 186 m³ and was characterized by a net of high tensile fibers covering the envelope of 20 μm polyethylene film for pressure resistance and a double-layer structure with a rubber balloon inside the envelope for airtightness. In January and February 2022, three super-pressure balloons were launched from Syowa Station. The flight durations were 24 hours and 50 minutes, 34 hours and 50 minutes, and 67 hours and 30 minutes. The highest altitudes for LODEWAVE 1, 2, and 3 were 18.3, 17.9, and 18.5 km respectively, as expected. The ascent velocities of the balloons were consistent with the predicted velocities based on an empirical relation derived from zero-pressure balloon experiments. The differential pressure inside the balloon and the atmospheric pressure were also as expected. The temperature of the pressure gauge inside balloons varied widely, ranging from −50 ◦C to 40 ◦C. This campaign marked the first scientific experiment using Japanese super-pressure balloons.