Toward Standard Radiosonde Observations of Waves and the Mean State in the 30–40 km Altitude Range Using 3–kg Balloons

Abstract Observations of temperature and wind velocity in the 30–40 km altitude layer have been sparse since elimination of the standard rocketsonde sounding network in the 1990s. In an effort to extend the vertical range of radiosonde observations into the upper stratosphere, experiments were conducted with a 3–kg balloon at Tsukuba, Japan on November 5, 2019. Using this relatively inexpensive balloon technology, four radiosondes were launched, with two reaching above 40 km altitude. These profiles were compared with satellite and reanalysis data in the 30–40 km layer, which showed an overall good agreement and an ability of radiosondes to capture shorter vertical-scale variations. The ability to quantify gravity wave parameters from the data is described, with application to wave events detected near 38–40 km. This type of balloon will be deployed extensively in an upcoming intensive observation campaign over the Maritime Continent, which will contribute toward achieving standard radiosonde observations in the 30–40 km altitude range. This system extends the ability to provide information regarding gravity wave and planetary wave activity upward to ∼40 km.