Comparison of the mesospheric gravity waves observed with the MU Radar (35°N) and the Adelaide MF Radar (35°S)

1993 ◽  
Vol 20 (9) ◽  
pp. 803-806 ◽  
Author(s):  
T. Nakamura ◽  
T. Tsuda ◽  
S. Fukao ◽  
S. Kato ◽  
R. A. Vincent
Keyword(s):  
Gravity Waves ◽  
Mu Radar ◽  
Mf Radar

Comparative observations of short-period gravity waves (10-100 min) in the mesosphere in 1989 by Saskatoon MF radar (52°N), Canada and the MU radar (35°N), Japan

Radio Science ◽  
1993 ◽  
Vol 28 (5) ◽  
pp. 729-746 ◽  
Author(s):  
T. Nakamura ◽  
T. Tsuda ◽  
S. Fukao ◽  
S. Kato ◽  
A. H. Manson ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Mu Radar ◽  
Short Period ◽  
Mf Radar

scholarly journals VHF volume-imaging radar observation of aspect-sensitive scatterers tilted in mountain waves above a convective boundary layer

2005 ◽  
Vol 23 (4) ◽  
pp. 1139-1145 ◽  
Author(s):  
R. M. Worthington
Keyword(s):  
Gravity Waves ◽  
Air Flow ◽  
Horizontal Wind ◽  
Convective Boundary ◽  
Mountain Waves ◽  
Imaging Radar ◽  
Mu Radar ◽  
Volume Imaging ◽  
Wind Measurements ◽  
To Receive

Abstract. Thin stable atmospheric layers cause VHF radars to receive increased echo power from near zenith. Layers can be tilted from horizontal, for instance by gravity waves, and the direction of VHF "glinting" is measurable by spatial domain interferometry or many-beam Doppler beam swinging (DBS). This paper uses the Middle and Upper atmosphere (MU) radar, Shigaraki, Japan as a volume-imaging radar with 64-beam DBS, to show tilting of layers and air flow in mountain waves. Tilt of aspect-sensitive echo power from horizontal is nearly parallel to air flow, as assumed in earlier measurements of mountain-wave alignment. Vertical-wind measurements are self-consistent from different beam zenith angles, despite the combined effects of aspect sensitivity and horizontal-wind gradients.

scholarly journals Numerical and the MU radar estimations of gravity wave enhancement and turbulent ozone fluxes near the tropopause

2004 ◽  
Vol 22 (11) ◽  
pp. 3889-3898 ◽  
Author(s):  
N. M. Gavrilov ◽  
S. Fukao
Keyword(s):  
Gravity Waves ◽  
Wave Breaking ◽  
Internal Gravity Waves ◽  
Vertical Temperature ◽  
Turbulent Diffusion Coefficient ◽  
Middle Latitudes ◽  
Mu Radar ◽  
Different Seasons ◽  
Ozone Fluxes ◽  
Vertical Ozone

Abstract. It is shown with a numerical simulation that a sharp increase in the vertical temperature gradient and Brunt-Väisälä frequency near the tropopause may produce an increase in the amplitudes of internal gravity waves (IGWs) propagating upward from the troposphere, wave breaking and generation of stronger turbulence. This may enhance the transport of admixtures between the troposphere and stratosphere in the middle latitudes. Turbulent diffusion coefficient calculated numerically and measured with the MU radar are of 1-10m2/s in different seasons in Shigaraki, Japan (35° N, 136° E). These values lead to the estimation of vertical ozone flux from the stratosphere to the troposphere of (1-10)x1014, which may substantially add to the usually supposed ozone downward transport with the general atmospheric circulation. Therefore, local enhancements of IGW intensity and turbulence at tropospheric altitudes over mountains due to their orographic excitation and due to other wave sources may lead to the changes in tropospheric and total ozone over different regions.

Dominant vertical scales of gravity waves in the middle atmosphere observed with the MU radar and rocketsondes

1992 ◽  
Vol 54 (3-4) ◽  
pp. 339-346 ◽  
Author(s):  
Y Murayama ◽  
T Tsuda ◽  
M Yamamoto ◽  
T Nakamura ◽  
T Sato ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Middle Atmosphere ◽  
Mu Radar ◽  
Vertical Scales

scholarly journals Evidence for tropospheric wind shear excitation of high-phase-speed gravity waves reaching the mesosphere using the ray-tracing technique

2015 ◽  
Vol 15 (5) ◽  
pp. 2709-2721 ◽  
Author(s):  
M. Pramitha ◽  
M. Venkat Ratnam ◽  
A. Taori ◽  
B. V. Krishna Murthy ◽  
D. Pallamraju ◽  
...  
Keyword(s):  
Ray Tracing ◽  
Gravity Waves ◽  
High Frequency ◽  
Phase Speed ◽  
Horizontal Wind ◽  
Climatological Model ◽  
Background Temperature ◽  
The Waves ◽  
High Phase ◽  
Mf Radar

Abstract. Sources and propagation characteristics of high-frequency gravity waves observed in the mesosphere using airglow emissions from Gadanki (13.5° N, 79.2° E) and Hyderabad (17.5° N, 78.5° E) are investigated using reverse ray tracing. Wave amplitudes are also traced back, including both radiative and diffusive damping. The ray tracing is performed using background temperature and wind data obtained from the MSISE-90 and HWM-07 models, respectively. For the Gadanki region, the suitability of these models is tested. Further, a climatological model of the background atmosphere for the Gadanki region has been developed using nearly 30 years of observations available from a variety of ground-based (MST radar, radiosondes, MF radar) and rocket- and satellite-borne measurements. ERA-Interim products are utilized for constructing background parameters corresponding to the meteorological conditions of the observations. With the reverse ray-tracing method, the source locations for nine wave events could be identified to be in the upper troposphere, whereas for five other events the waves terminated in the mesosphere itself. Uncertainty in locating the terminal points of wave events in the horizontal direction is estimated to be within 50–100 km and 150–300 km for Gadanki and Hyderabad wave events, respectively. This uncertainty arises mainly due to non-consideration of the day-to-day variability in the tidal amplitudes. Prevailing conditions at the terminal points for each of the 14 events are provided. As no convection in and around the terminal points is noticed, convection is unlikely to be the source. Interestingly, large (~9 m s−1km−1) vertical shears in the horizontal wind are noticed near the ray terminal points (at 10–12 km altitude) and are thus identified to be the source for generating the observed high-phase-speed, high-frequency gravity waves.

scholarly journals A case study of gravity waves in noctilucent clouds

2004 ◽  
Vol 22 (6) ◽  
pp. 1875-1884 ◽  
Author(s):  
P. Dalin ◽  
S. Kirkwood ◽  
A. Moström ◽  
K. Stebel ◽  
P. Hoffmann ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Time Lapse ◽  
Radar Data ◽  
Noctilucent Cloud ◽  
Wave Dynamics ◽  
Complex Wave ◽  
Radar Measurements ◽  
Time Lapse Photography ◽  
Mf Radar

Abstract. We present a case study of a noctilucent cloud (NLC) display appearing on 10-11 August 2000 over Northern Sweden. Clear wave structures were visible in the clouds and time-lapse photography was used to derive the parameters characterising the gravity waves which could account for the observed NLC modulation. Using two nearby atmospheric radars, the Esrange MST Radar data and Andoya MF radar, we have identified gravity waves propagating upward from the upper stratosphere to NLC altitudes. The wave parameters derived from the radar measurements support the suggestion that gravity waves are responsible for the observed complex wave dynamics in the NLC.

Simultaneous observations of mesospheric gravity waves with the MU radar and a sodium lidar

1996 ◽  
Vol 101 (D2) ◽  
pp. 4057-4063 ◽  
Author(s):  
S. P. Namboothiri ◽  
T. Tsuda ◽  
M. Tsutsumi ◽  
T. Nakamura ◽  
C. Nagasawa ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Mu Radar
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