Rocket-grenade measurements of temperatures and winds in the mesosphere over Churchill, Canada

Abstract

Firing of ten Aerobee rockets, each carrying 18 to 19 high‐explosive grenades at Fort Churchill, Canada, have resulted in the accurate measurement of temperatures and winds in the atmosphere up to 95 km during November 1956, July, August, and December 1957, and January 1958. One hundred and fifty measurements of temperatures and of winds were made over the period. Each measurement represents the average temperature and wind of an atmospheric layer of about 3‐km thickness. The results show clearly a seasonal variation, with average summer temperatures of 275°K at the mesopeak (about 50 km) and 170°K at the mesopause (about 80 km); corresponding average winter temperatures are 260°K and 230°K. In summer, prevailing winds above 25 km were from the east, usually less than 50 m/sec. In winter these winds were from the west, usually between 50 and 100 m/sec but frequently exceeding 100 m/sec. A breakdown in circulation up to 80 km is indicated by the wind results of two firings on January 27, 1958, where strong northerly and southerly wind components were measured. This phenomenon coincides with the occurrence of sharp temperature increases at stratospheric levels over large parts of the northern hemisphere east of Churchill. Remarkable temperature inversions between 50 and 80 km were measured in all winter firings. These inversions resulted in secondary temperature peaks above 50 km. On December 11, 1957, the temperature at 72 km was about 290°K. In summer, temperatures at 50 km and below at Churchill (59°N) were higher than at White Sands (33°N); above 65 km the Churchill temperatures were lower. This picture is reversed in winter. Only minor diurnal temperature variations were detected. No sound energy from detonations of 4‐pound high‐explosive charges above 95 km was detected on the ground with microphones of 1‐dyne cm2 sensitivity in the frequency range 8 to 25 cycles/sec.

Review of U. S. Meteorological Rocket Network Activities and Results

“…TI'I G ammnia nc kctsnde for the A rcas rocket. [1]. Dr. Nordberg, in a subsequent paper in this symposium, discusses more extensively these conditions above 60 km.…”

In-situ Measurements of Acoustic Wave Propagation Characteristics in the Middle and Upper Atmosphere On-board S-310-41 Sounding Rocket

“…The attenuation of an acoustic wave in air can be found using 1) (1) where is distance and is the total attenuation coefficient, which can be calculated from 2) (2)…”

“…Observation methods using grenades, and middle and upper atmosphere radar (MU-radar) combined with a radio acoustic sounding system (RASS), have been used to study the stratosphere, mesosphere, and thermosphere. Explosions from multiple grenades can be measured using rocket-mounted generation systems located in the upper atmosphere at altitudes of 20-120 km from multiple sites on the ground 2) . This method can be used to calculate the temperature, wind speed, and direction of the wind based on the measured arrival time of the sound.…”

“…By Daiki KIHARA 1) , Masa-yuki YAMAMOTO 1) , Takatoshi MORINAGA 2) , Ayano HATAKEYAMA 1) , Yudai MANABE 1) , Jun-ichi FURUMOTO 3) , Yoshihiro KAKINAMI 1) and Takumi ABE 4) 1) Kochi University of Technology, Kami, Japan 2) Hokkaido University, Sapporo, Japan 3) Kyoto University, Uji, Japan 4) ISAS, JAXA, Sagamihara, Japan (Received June 17th, 2013) Sound measurements were carried out using rocket-based propagation diagnostics in the middle and upper atmosphere via infrasonic/acoustic waves to investigate their frequency dependence. The S-310-41 sounding rocket was used, equipped with one main microphone, two sub-microphones, and a loudspeaker, to examine the sound propagation in the payload section of the rocket as a function of the ambient atmospheric pressure.…”

Meteorological Rocketsonde Equipment and Techniques

“…The poor geographical distribution of stations. 4. The apparent disregard for a systematic schedule of observations.…”