Lower thermospheric density fluctuations during the time period of Typhoon DinahHigh frequency Doppler sounder arrays were used to study the thermospheric density fluctuations caused by Typhoon Dinah in August, 1987. The results show that the maximum density fluctuations caused by the typhoon at altitudes of 150 to 350 km were close to + or - 30 percent deviation from the quiet background. The time-dependent density fluctuations were in phase with the horizontal phase velocity of major gravity waves excited by the storm. It is suggested that the study demonstrates the use of HF Doppler sounder measurement of gravity waves, horizontal wind velocity in the direction of gravity wave propagation, and density perturbations at thermospheric heights.
Document ID
19890038250
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Hung, R. J. (Alabama Univ. Huntsville, AL, United States)
Tsao, Y. D. (Alabama, University Huntsville, United States)
Johnson, D. L. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Chen, A. J. (National Central University Chung-Li, Republic of China, United States)
Liu, J. M. (Alabama Univ. Huntsville, AL, United States)