MU radar observations of the aspect sensitivity of backscattered VHF echo power in the troposphere and lower stratosphere

Radio Science ◽  
1986 ◽  
Vol 21 (6) ◽  
pp. 971-980 ◽  
Author(s):  
Toshitaka Tsuda ◽  
Toru Sato ◽  
Kazuo Hirose ◽  
Shoichiro Fukao ◽  
Susumu Kato
Keyword(s):  
Lower Stratosphere ◽  
Radar Observations ◽  
Mu Radar ◽  
Aspect Sensitivity

Internal gravity wave selection in the upper troposphere and lower stratosphere observed by the MU radar: Preliminary results

1989 ◽  
Vol 130 (2-3) ◽  
pp. 481-495 ◽  
Author(s):  
Manabu D. Yamanaka ◽  
Shoichiro Fukao ◽  
Hiromasa Matsumoto ◽  
Toru Sato ◽  
Toshitaka Tsuda ◽  
...  
Keyword(s):  
Gravity Wave ◽  
Lower Stratosphere ◽  
Internal Gravity Wave ◽  
Upper Troposphere ◽  
Preliminary Results ◽  
Mu Radar

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.

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

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 Comparisons of refractive index gradient and stability profiles measured by balloons and the MU radar at a high vertical resolution in the lower stratosphere

2007 ◽  
Vol 25 (1) ◽  
pp. 47-57 ◽  
Author(s):  
H. Luce ◽  
G. Hassenpflug ◽  
M. Yamamoto ◽  
S. Fukao
Keyword(s):  
Lower Stratosphere ◽  
Imaging Technique ◽  
Refractive Index Gradient ◽  
Vertical Resolution ◽  
Range Imaging ◽  
Range Resolution ◽  
Mu Radar ◽  
Resolution Improvement ◽  
Radar Echo ◽  
Index Gradient

Abstract. Many experimental studies have demonstrated that VHF Stratosphere-Troposphere (ST) radar echo power is proportional to the generalized refractive index gradient squared M2 when using a vertically oriented beam. Because humidity is generally negligible above the tropopause, VHF ST radars can thus provide information on the static stability (quantified by the squared Brunt-Väisälä frequency N2) at stratospheric heights and this capability is useful for many scientific applications. Most studies have been performed until now at a vertical resolution of 150 m or more. In the present paper, results of comparisons between radar- and (balloon borne) radiosonde-derived M2 and N2 are shown at a better vertical resolution of 50 m with the MU radar (34.85° N, 136.15° E; Japan) by benefiting from the range resolution improvement provided by the multi-frequency range imaging technique, using the Capon processing method. Owing to favorable winds in the troposphere, the radiosondes did not drift horizontally more than about 30 km from the MU radar site by the time they reached an altitude of 20 km. The measurements were thus simultaneous and almost collocated. Very good agreements have been obtained between both high resolution profiles of M2, as well as profiles of N2. It is also shown that this agreement can still be improved by taking into account a frozen-in advection of the air parcels by a horizontally uniform wind. Therefore, it can be concluded that 1) the range imaging technique with the Capon method really provides substantial range resolution improvement, despite the relatively weak Signal-to-Noise Ratios (SNR) over the analyzed region of the lower stratosphere, 2) the proportionality of the radar echo power to M2 at a vertical scale down to 50 m in the lower stratosphere is experimentally demonstrated, 3) the MU radar can provide stability profiles with a vertical resolution of 50 m at heights where humidity is negligible, 4) stable stratospheric layers as thin as 50 m or less have at least a horizontal extent of a few km to several tens of kilometers and can be considered as frozenly advected over scales of a few tens of minutes.

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