12th Conference on Middle Atmosphere

Tuesday, 5 November 2002
Turbulence and wind observation in the tropical tropopause region by the Equatorial Atmosphere Radar
Masayuki Yamamoto, Kyoto University, Kyoto, Japan; and T. Horinouchi, M. Fujiwara, H. Hashiguchi, S. Fukao, and M. D. Yamanaka
Equatorial Atmosphere Radar (EAR) was installed in Kototabang (100.32E, 0.20S), West Sumatra in the Republic of Indonesia in March 2001, and continuous observations including the tropical tropopause region (2-20 km) has been performed since the end of June 2001. EAR has a VHF frequency of 47.0 MHz, peak output power of 100 kW, and maximum resolution is 150 m in height and 1 min in time, respectively. EAR observe three-dimensional wind velocities by five-beam DBS (Doppler Beam Swinging) mode, and 3-m scale turbulence corresponding to a half of the radar wavelength. Through the continuous observation, we found an "Apparent updraft" seems to be caused by Kelvin-Helmholtz instability just above the tropopause continuously during November 2001. And radiosonde observation also showed that Richardson number is small (smaller than 0.5) in that term. We show a wind and turbulence observation results by the EAR, especially in November 2001.

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