scholarly journals Frequency spectra and vertical profiles of wind fluctuations in the summer Antarctic mesosphere revealed by MST radar observations

2017 ◽  
Vol 122 (1) ◽  
pp. 3-19 ◽  
Author(s):  
Kaoru Sato ◽  
Masashi Kohma ◽  
Masaki Tsutsumi ◽  
Toru Sato
Keyword(s):  
Vertical Profiles ◽  
Frequency Spectra ◽  
Radar Observations ◽  
Mst Radar

scholarly journals Estimation of temperature and humidity from MST radar observations

2001 ◽  
Vol 19 (8) ◽  
pp. 855-861 ◽  
Author(s):  
K. Mohan ◽  
D. Narayana Rao ◽  
T. Narayana Rao ◽  
S. Raghavan
Keyword(s):  
Refractive Index ◽  
Dissipation Rate ◽  
Radiosonde Data ◽  
Refractive Index Gradient ◽  
Measured Temperature ◽  
Vertical Profiles ◽  
Radar Observations ◽  
Mst Radar ◽  
Temperature And Humidity ◽  
Index Gradient

Abstract. Retrieval of vertical profiles of temperature and humidity parameters using a VHF radar is described in this paper. For this, Indian MST radar located at Gadanki (13.5° N, 79.2° E) has been operated in a special mode. First, vertical velocities are collected continuously using the radar and are subjected to Fast Fourier Transform (FFT) analysis to obtain Brunt-Väisälä oscillations. From the measured Brunt-Väisälä  oscillations, temperature profile is obtained from the radar observations following Revathy et al. (1996). The various terms required for the retrieval of vertical profiles of humidity are the eddy dissipation rate, ε, the volume reflectivity, η, and the potential refractive index gradient, M. The eddy dissipation rate, ε, is calculated from the spectral width after removing the effects due to non-turbulence. The volume reflectivity, η, of the turbulence scattering is calculated using the signal-to-noise ratio as a function of height. The potential refractive index gradient, M, is evaluated using the measured Brunt-Väisälä  oscillations, the eddy dissipation rate and the volume reflectivity, η. Vertical profiles of humidity are retrieved following Tsuda (1997) using the radar derived temperature as well as the balloon measured temperature and are compared with the humidity as measured by the radiosonde. The sign of the potential refractive index gradient, M, is taken from the simultaneous measurements of balloon soundings. The retrieved vertical profiles of temperature and humidity have been compared with the radiosonde data, which are released simultaneously with the radar observations at the radar site. A fairly good comparison is seen between the two measurements on some days and there are some discrepancies on some other days. The strengths and limitations in estimating the vertical profiles of temperature and humidity from the radar observations are discussed.Key words. Atmospheric composition and structure (pressure, density and temperature; enhancements and techniques)

Deduction of temperature profile from MST radar observations of vertical wind

1996 ◽  
Vol 23 (3) ◽  
pp. 285-288 ◽  
Author(s):  
K. Revathy ◽  
S. R. Prabhakaran Nair ◽  
B. V. Krisha Murthy
Keyword(s):  
Temperature Profile ◽  
Vertical Wind ◽  
Radar Observations ◽  
Mst Radar

MST radar observations of short-period gravity wave during overhead tropical cyclone

Radio Science ◽  
2012 ◽  
Vol 47 (2) ◽  
pp. n/a-n/a ◽  
Author(s):  
Siddarth Shankar Das ◽  
K. N. Uma ◽  
Subrata Kumar Das
Keyword(s):  
Tropical Cyclone ◽  
Gravity Wave ◽  
Radar Observations ◽  
Short Period ◽  
Mst Radar

scholarly journals Gadanki radar observations of daytime E region echoes and structures extending down to 87 km

2006 ◽  
Vol 24 (7) ◽  
pp. 1861-1869 ◽  
Author(s):  
A. K. Patra ◽  
S. Sripathi ◽  
P. B. Rao ◽  
R. K. Choudhary
Keyword(s):  
Spectral Width ◽  
Plasma Waves ◽  
Observational Period ◽  
Low Velocity ◽  
Radar Observations ◽  
Mst Radar ◽  
Collisional Damping ◽  
E Region ◽  
Low Altitude

Abstract. Observations of daytime E region echoes extending to altitudes as low as 87 km made using the Gadanki MST radar are presented. The echoing regions display descending layer resembling the characteristics of tidal winds and show structures with periods 2–4 min having both positive and negative slopes. At the center of the layer where strongest SNR is observed, the velocity is maximum and spectral width is minimum. At altitudes slightly above and below, where SNR is relatively low, velocity is low but spectral width is maximum. Daytime observations of echoes extending to such a low altitude and associated structures akin to nighttime quasi-periodic echoes throughout the observational period are the most significant results, not reported earlier from Gadanki and other locations. Other notable results are large SNR (as high as 15 dB) and spectral width (as high as 70 m/s) at the bottommost altitudes, where collisional damping of the plasma waves is significant

Indian MST radar observations of gravity wave activities associated with tropical convection

2001 ◽  
Vol 63 (15) ◽  
pp. 1631-1642 ◽  
Author(s):  
S.K Dhaka ◽  
P.K Devrajan ◽  
Y Shibagaki ◽  
R.K Choudhary ◽  
S Fukao
Keyword(s):  
Gravity Wave ◽  
Tropical Convection ◽  
Radar Observations ◽  
Mst Radar
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