Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8140167 | Journal of Atmospheric and Solar-Terrestrial Physics | 2014 | 11 Pages |
Abstract
We present a comprehensive study on radar scattering cross section of mesospheric echoes and mesospheric turbulence parameters based on several days of observations made during two rocket-radar campaigns, one in July 2004 and another in April 2005, meant for studying mesospheric turbulence. Radar scattering cross section was found to have large local time and day-to-day variability and was found to be as low as 3.1Ã10â18Â mâ1 and as high as 1Ã10â14Â mâ1 and the median values were in the range of 4.4Ã10â18-4.7Ã10â16Â mâ1. Echoes connected with the low value of scattering cross section could be detected only when a long pulse width was used. Turbulence parameters were found to vary remarkably with time of the day and also from one day to another. In July, the turbulent kinetic energy (TKE) dissipation rate, outer scale and inner scale were in the range of 0.08-150Â mW/kg, 33-1500Â m, and 1.9-50Â m, respectively, and their median values were in the range of 5-52Â mW/kg, 293-977Â m, and 2-31Â m, respectively. In April, these estimates were in the range of 0.9-69Â mW/kg, 38-1081Â m, and 4-21Â m, respectively, and their median values were in the range of 1-12Â mW/kg, 140-378Â m, and 8-13Â m, respectively. These parameters are found to agree quite well with those estimated from rocket-borne observations, which were in the range of 4-117Â mW/kg, 220-1475Â m, and 15-31Â m, respectively, in July and 2-36Â mW/kg, 170-680Â m, and 17-37Â m, respectively, in April. Interestingly, the inner and outer scales estimated using both radar and rocket observations agree exceedingly well with model values. These results are compared in detail with those reported from low, middle and high latitudes including model and discussed in the light of current knowledge of mesospheric turbulence.
Keywords
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geophysics
Authors
D. Selvaraj, A.K. Patra, H. Chandra, H.S.S. Sinha, U. Das,