Upper Atmosphere Pressure Measurements with Thermal Conductivity Gages

Abstract

Recent studies of meteorological rocket data have shown a significant diurnal variation of temperature, pressure and density in the stratopause region; however, some doubts have been expressed concerning possible effects on the head thermistor sensing system which may contribute to the large diurnal changes previously observed. While all known effects have been accounted for and no evidence to the contrary has been offered, it seemed worthwhile to investigate this possibility with an independent system which would not be subject to the external effects encountered by the exposed bead thermistor as employed with standard rocketsondes. Consequently, two pressure soundings between approximately 30 and 60 km were obtained with thermal conductivity gages which were incorporated with standard rocketsondes. The thermal conductivity gages were found to be very efficient and reliable in the low subsonic regime encountered with parachute-suspended sounding systems, and good agreement was obtained between the computed and measured pressure and also between the computed and measured temperature.