scholarly journals MU Radar observations of kilometer-scale waves in the midlatitude lower E-region

2000 ◽  
Vol 27 (22) ◽  
pp. 3667-3670 ◽  
Author(s):  
P. B. Rao ◽  
M. Yamamoto ◽  
A. Uchida ◽  
I. Hassenpflug ◽  
S. Fukao
Keyword(s):  
Radar Observations ◽  
Mu Radar ◽  
E Region

Extension of MF radar tidal measurements to E-region heights (95-125 km): Saskatoon (52°N, 107°W), Canada

1994 ◽  
Vol 12 (4) ◽  
pp. 333-341
Author(s):  
S. P. Namboothiri ◽  
A. H. Manson ◽  
C. E. Meek
Keyword(s):  
Radar Observations ◽  
Tidal Propagation ◽  
Radar Echoes ◽  
Tidal Data ◽  
E Region ◽  
Future Work ◽  
Mf Radar

Abstract. Efforts have been made to extend the MF radar tidal profiles to E-region heights. The totally reflected MF radar echoes from E-region heights during daytime are known to be group-retarded and the corresponding wind and tidal data will have associated height discrepancies. The estimation of the E-region real heights (Namboothiri et al., 1993), and the elimination of the data for which the group retardation is significant, are selected as the basic criteria to extend the tidal profiles to 100-125 km. The analysis of the quiet (Ap<19) days of the winter and summer seasons of 1988/89 shows that the tidal propagation continues to higher altitudes with some changes in their pattern, e.g. longer wavelengths, compared to that in the lower altitudes. Comparison with the model profiles shows some resemblance and some disagreements. The reliability of the MF radar tidal measurements of E-region heights and the propagation of tides in this region have been discussed in the light of existing theories and other experimental observations. It is concluded that, based on the initial studies with UHF and MF systems and within the limits of the available theories, the information on tides presented here for the 100-125 km region using the MF radar observations is useful. Suggestions for future work in this direction are also given.

scholarly journals Convective Instability Underneath Midlevel Clouds: Comparisons between Numerical Simulations and VHF Radar Observations

2015 ◽  
Vol 54 (11) ◽  
pp. 2217-2227 ◽  
Author(s):  
Atsushi Kudo ◽  
Hubert Luce ◽  
Hiroyuki Hashiguchi ◽  
Richard Wilson
Keyword(s):  
Numerical Simulations ◽  
Initial Conditions ◽  
Radiosonde Data ◽  
Cloud Base ◽  
Very High Frequency ◽  
Vhf Radar ◽  
Turbulent Layer ◽  
Radar Observations ◽  
Mu Radar ◽  
Upper Level

AbstractDeep turbulent layers can sometimes be observed on the underside of clouds that extend above upper-level frontal zones. In a recent study based on 3D numerical simulations with idealized initial conditions, it was found that midlevel cloud-base turbulence (MCT) can result from Rayleigh–Bénard-like convection as a result of cooling by sublimation of precipitating snow into dry and weakly stratified subcloud layers. In the present study, numerically simulated MCT was compared with a turbulent layer detected by the very high-frequency (VHF) middle- and upper-atmosphere (MU) radar during the passage of an upper-level front topped by clouds. The simulations were initialized with thermodynamic parameters derived from simultaneous radiosonde data. It was found that some important features of the simulated MCT (such as the scale of convection and vertical wind velocity perturbations) agreed quantitatively well with those reported in radar observations. Even if the possibility of other generation mechanisms cannot be ruled out, the good agreement strongly suggests that the MU radar actually detected MCT.

Evidence of kilometer-scale waves in the lower E region from high resolution VHF radar observations over Gadanki

2002 ◽  
Vol 29 (10) ◽  
pp. 137-1-137-4 ◽  
Author(s):  
A. K. Patra ◽  
S. Sripathi ◽  
V. Siva Kumar ◽  
P. B. Rao
Keyword(s):  
High Resolution ◽  
Vhf Radar ◽  
Radar Observations ◽  
E Region

scholarly journals MU radar observations of H+ions in the topside ionosphere

1998 ◽  
Vol 103 (A9) ◽  
pp. 20697-20704 ◽  
Author(s):  
S. Kawamura ◽  
Y. Otsuka ◽  
W. L. Oliver ◽  
N. Balan ◽  
S. Fukao
Keyword(s):  
Topside Ionosphere ◽  
Radar Observations ◽  
Mu Radar

scholarly journals LOW-LATITUDE E-REGION QUASI-PERIODIC ECHOES STUDIED USING LONG-TERM RADAR OBSERVATIONS OVER GADANKI

2009 ◽  
pp. 245-261
Author(s):  
N. VENKATESWARA RAO ◽  
A. K. PATRA ◽  
S. VIJAYA BHASKARA RAO
Keyword(s):  
Low Latitude ◽  
Radar Observations ◽  
E Region

scholarly journals A Review of MU Radar Observations of the Thermosphere and Ionosphere.

1995 ◽  
Vol 47 (7) ◽  
pp. 621-637 ◽  
Author(s):  
H. Rishbeth ◽  
S. Fukao
Keyword(s):  
Radar Observations ◽  
Mu 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

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