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Continuous radar observations have been used to obtain the zonal, meridional andvertical velocities [Anandan et al., 1997]. The time series data of zonal, meridional andvertical velocity perturbations are further subjected to Fourier analysis to get the powerspectra of the velocity perturbations. Figure 3 (b) shows the power spectra of zonal windperturbations on September 25, 2002. From this figure it can be noticed that the oscillationwith a time period of ~82.4 min is dominant at most of the heights, especially in the lowerstratosphere. Moreover, it shows peak amplitudes in the lower stratosphere. But, it has beenobserved that the wave amplitudes are relatively weaker in the meridional and verticalvelocities (figures are not shown). The direction of horizontal propagation of gravity waves inthe troposphere are uniform in all directions whereas it will be eastward in the lowerstratosphere. This may be the reason for observed enhancement in the zonal windperturbations in the lower stratosphere [Tsuda et al., 1994].Generally, the gravity waves transport energy and momentum from lower atmosphereto middle atmosphere. Often, these waves break wherever it encounters the dynamic andconvective instabilities. When these waves break they deposit the momentum and energy inthat region, which are very crucial for understanding the wave interaction with the large-scaleenvironment. In the present study the temperature and wind field observations clearly showsthe modulation of respective fields by the gravity waves. A thorough study is underway toreveal the gravity wave breaking and their consequences in the lower stratosphere.(a)Figure 3. (a) Height profile of temperature derived from GPS-sonde measurement and (b)the spectra at different height levels for zonal wind perturbations on September 25, 2002which shows the dominant time period of 82.4 min (period =412/5) corresponding to 5 thharmonic number. The total period of observations corresponds to ~412 min.3. Concluding remarks:The existence of layered structures in the stratospheric-tropospheric height regionusing VHF radar observations are presented in this paper. The enhanced radar reflectivitylayers associated with high aspect sensitivity are observed in the same height region, whichare attributed to the presence of temperature gradients. The spectral analysis revealed thevertical wavelength of ~1.6 km indicating the perturbation of temperature by the propagatinggravity waves. For the same kind of structure, on the other day, the periodicity of thepropagating waves is found to be 82.4 min. These wave oscillations are more prominentlyseen in the zonal winds, which have shown the peak amplitudes in the lower stratosphere.(b)72
The present observations thus emphasize the gravity waves as an important source for theobserved temperature sheets in the lower stratosphere. However, further observations andevidences are required to shed more light on to this aspect.Acknowledgement:The authorities of Hydrospheric-Atmospheric Research Center, Nagoya University,Nagoya, Japan and S. V. University, Tirupati, India are acknowledge for their cooperation forlaunching GPS sondes from Tirupati, India during September 2000. We are also thankful toProf. G.S. Bhatt (Indian institute of Sciences, Bangalore) for his support in conducting theGPS sonde campaign from NMRF, Gadanki during September-October 2002. One of theauthors, SSD, is thankful to Indian Space Research Organisation (ISRO) for proving thefellowship and facility during the study.References:Anandan, V.K., P. Balmuralidhar, P.B. Rao and A. R. Jain, A method for adaptive momentsestimation technique applied to MST radar echoes, Progress in electromagnetic researchsymposium, Telecommunication research center, City University of Hongkong, Vol.2,pp. 670, 1997.Dalaudier, Francis, Claude Sidi, Michel Crochet and Jean Vernin, Direct Evidence of“Sheets” in the Atmosphere Temperature Field, J. Atmos. Sciences, 51, 237, 1994.Fritts,D.C. and P.K.Rastogi, Convection and dynamical instabilities due to gravity wavesmotions in the lower and middle atmosphere : theory and observations, Radio Sci.,20,1247-1277, 1985.Hocking, W.K., Fukao, S., M.Yamamoto., T. Tsuda and S. Kato., Viscosity waves andthermal-conduction waves as a cause of “specular” reflectors in radar studies of theatmosphere, Radio Sci., 26, 1281-1303, 1991.Jain, A.R., Jaya Rao Y., P.B.Rao., G. Viswanathan., S.H.Damle., P. Balamuralidharan andAnil Kulakarni, Preliminary observations using ST mode of Indian MST Radar :Detection of the signature of Tropopause, J. Atoms. and Terr. Phy, 56, 1157-1162, 1994.Jain. A.R., Y.Jaya Rao, and N.S. Mydhili, Height-time-structure of VHF backscatter fromstable and turbulently mixed atmosphere layers at tropical latitudes, J.Atmos. Solar-Terr.Phys., 63,1455-1463, 2001.Jayarao, Y., A.R.Jain., V.K.Anandan., P.B.Rao., G.Viswanathan and R. Aravindan, Someobservations of tropical tropopause using ST mode of the Indian MST radar : Multiplestable layer structure, Indian J Radio and Space Phy, 23, 75-85, 1994.Luce, H., M.Crochet and F. Dalaudier, Temperature sheets and aspect sensitive radar echoes,Annales Geophysicae, 19, 899-920, 2001.Muschinski Andreas and Wode Christian., First In situ evidence for Coexisting Submetertemperature and humidity Sheets in the Lower free Troposphere., J. Atmos. Sciences., 55,2893-2906, 1998.Tsuda Toshitaka, Yasuhiro Murayama, Harsono Wiryosumarto., Radiosonde observations ofequatorial atmosphere dynamics over Indonesia. 2. Characteristics of gravity waves., J.Geophy. Res, 99, 10507-10516, 1994.73
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MST10Tenth InternationalWORKSHOPOn
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MST 10 Group PictureMay 15 th , 200
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TENTH INTERNATIONAL WORKSHOP ON TEC
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Table of ContentsPREFACE ..........
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I.2.18 FURTHER OBSERVATIONS OF PMSE
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I.3.27 NEW MST RADAR METHODS FOR ME
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I.4.19 STUDY OF A MESOSCALE LAND-TO
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I.5.502 AN ATTEMPT TO CALIBRATE THE
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PrefaceMST10The Tenth International
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and the local organizing committee,
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The operational aspects and recent
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To improve the understanding of dyn
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Improving MST radar resolution by u
Page 27 and 28: latitudes, arguing that the former
Page 29 and 30: Report on Session I.3 “Winds, Wav
Page 31 and 32: Turbulence.The session then moved i
Page 33 and 34: Report on Session I.4 “Meteorolog
Page 35 and 36: Multiple Antenna Profiling Radar (M
Page 37 and 38: Report on Session II “Novel Persp
Page 39 and 40: synchronized by GPS and connected v
Page 41 and 42: The highly positive response of the
Page 43 and 44: 10th International Workshop on Tech
Page 45 and 46: 10th International Workshop on Tech
Page 47 and 48: Session I.1: Radar scattering proce
Page 49 and 50: ⎡7800 ∂q⎤(3)⎢ 15500q⎥M =
Page 51 and 52: Figure 2 compares profiles of ω B
Page 53 and 54: Figure 1: Data from the MST radar a
Page 55 and 56: Ri =shear2ωB22⎛ ∂u⎞ ⎛ ∂v
Page 57 and 58: Meridional (deg)1050−5−10Echo P
Page 59 and 60: Subarray Configuration, Capon Metho
Page 61 and 62: Fig. 2 PMSE plot (SOUSY Svalbard Ra
Page 63 and 64: VHF radar interferometry had shown
Page 65 and 66: turbulence. From Figures 1 and 2, i
Page 67 and 68: SummaryFrom the aspect sensitivity
Page 69 and 70: a specific range. In this work, syn
Page 71 and 72: P C(dB)(a) Echo Power60504030200.70
Page 73 and 74: most occidental area of South Ameri
Page 75 and 76: Quegan, 1992). It should be useful
Page 77: measurements, is shown in figure 1(
Page 82 and 83: RECENT OBSERVATIONS OF E REGION FIE
Page 84 and 85: measured spectra in order to separa
Page 86 and 87: drifts at E and F regions heights b
Page 88 and 89: • Are characterized by type II ec
Page 90 and 91: The main parameters that could be o
Page 92 and 93: THE ROLE OF UNSTABLE SPORADIC-E LAY
Page 94 and 95: (σ H / σ P )E y (where σ H and
Page 96: STUDY OF A LOW E-REGION QUASI-PERIO
Page 99 and 100: 100 m/syrFigure 4: Geometry of the
Page 101 and 102: Where the notations carry same mean
Page 103 and 104: Where dx/dt and dy/dt are the veloc
Page 105 and 106: non-negativity of the image is prio
Page 107 and 108: spectrum corresponding to the backs
Page 109 and 110: The Artigas and Machu-Picchu Statio
Page 111 and 112: Arguments against the second altern
Page 113 and 114: Extension of the Kolmogorov spectru
Page 115 and 116: volumeESRvolumeSSRSSR SSRESR ESRSSR
Page 117 and 118: individual particles in a statistic
Page 119 and 120: Anomalous spectraTalkner [4] studie
Page 121 and 122: To observe the E region FAI echoes,
Page 123 and 124: matter daytime or nighttime and are
Page 125 and 126: two sub-arrays, each sub-array made
Page 127 and 128: 4. SummaryHere we describe a radio
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Figure 1. E-region DPS4 spectra, ri
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effects. It is therefore plausible
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1996 and high in 2002). The electri
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electric fields map along the geoma
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SNR condition is always difficult a
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Figure-4 Power spectrum plots of a
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As we show below, Jicamarca offers
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particularly during daytime counter
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where ˆδ nm = (δ l − δ m )
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PMSE is more easily interpreted as
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ResultsTemperature climatology• s
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Simultaneous PMSE and NLC observati
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ResultsSeasonal variationMSE are no
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Figure 2: MSE parameters as functio
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Session I.3: Winds, waves and turbu
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poor. It was shown that poor perfor
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The use of diffraction pattern simi
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F 13 (ξ x ′) = (1 − cos 2ψ N)
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Figure 3: (a) Baseline length depen
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3. ResultsFigure 1 shows the amplit
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variability.Figure 4 shows the aver
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Figure 1. Period-time amplitude wav
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the 12-h and 24-h periodicities in
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winds and variances at altitudes 70
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similar correlation with larger mag
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of the refraction index are not equ
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Fig. 8. Zonal wind (top) and temper
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STUDIES ON ATMOSPHERIC GRAVITY WAVE
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1100-1200 hours. From this plot 6.3
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STUDIES ON WINDS AND MOMENTUM FLUXE
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3.4 Monthly variation of momentum f
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DEEP PENETRATIVE CONVECTION AND GEN
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ly changes direction with time with
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189
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191
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193
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These two last relations are the on
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3.2.1 From v ′2 to ɛ kThe questi
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5.2 Frequency distributionsSeveral
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ReferencesAlisse J.-R. and C. Sidi.
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Röttger J. and C.H. Liu. Partial r
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Specular reflection is negligible f
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−0.5C n2 Distribution (PROUST & S
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the beamwidth, α is the zenith ang
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this latitude in late April). Surfa
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Fig. 1. Median (upper) winds and (l
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Fig.1. Lines of constant radial vel
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which have not yet been considered
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is calculated from the radiosonde t
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Figure 3: Time-altitude cross-secti
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Absorption of cosmic noise is cause
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Incoherent scatter spectracompared
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variations of spectral widths, refr
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Figure 1. Diurnal variation of Turb
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further experimental test of the ST
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waves can be observed more clearly
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winter and a minimum in summer near
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The main recently assumed mechanism
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Figure 2. Statistics of numbers of
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LIDAR OBSERVATIONS OF MIDDLE ATMOSP
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latitudinal dependence of the seaso
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APPLICATION OF THE DUAL-BEAMWIDTH M
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Figure 2: Mean zonal and meridional
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JLKLLK/ILIL6II/G/II/G/LEODFLK/LO/DD
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The monthly diurnal mean of horizon
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Session I.4: Meteorological Phenome
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Integration of the VHF wind profile
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Figure 1 : Map of the Lago Maggiore
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precipitating clouds, the cyclonic
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Eyewall(a)(b)(c)(d)Fig. 3: Radius-h
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as low as 0.55. The Piura 50-MHz ra
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place features in the profile with
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• Period 1 (June 1-10): SCCs exis
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Sumatera occurs by stratiform cloud
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very interesting to note the double
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20(a) Convective Region(b) Transiti
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Typhoon LekimaFig. 2 Typhoon Lekima
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Fig. 5 Passage of typhoon Hayan on
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the 50 cm 2 sensor head, enabling t
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22 June 2000 23:22:23 - 23:24:20 at
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the time-height section of a convec
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Thurai, M., T.Iguchi,T. Kozu, J.D.E
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There are two main mechanisms which
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Horel, J.D. and Cornejo-Garrido, A.
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estimating two independent and redu
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RASS THETA (K) RASS v-component (m/
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Surface winds usually range from 10
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weak (maximum of 5 m s -1 ) and the
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The vertical component from the VTB
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Figure 8 shows the profile of virtu
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2 3D ( , ) ( ) ( ) ˆ ( ) ˆp∆ xm
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presented in Praskovsky et al. (200
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In Fig. 2 a sketch of a mountain le
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In Fig. 8 the lamina is aligned on
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Figure 1: composite day (13 days) o
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virtual sensible heat fluxes ( Wm-2
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3. Characteristics of precipitation
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Fig. 3: Horizontal distribution of
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3. Results and discussionUHF profil
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Figure 4. Monthly variation of slop
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system with two receiving antennae,
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cycle of precipitation. Figure 3(a)
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Histogram of Zonal Velocityh=5.13 K
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5. Summary of results and concludin
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the two nearby major cities, Chenna
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Boundary layer height, km32.521.5(a
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Figure 1:Data from the MST radar at
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spectral processing. In this partic
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3. Results and discussionIn the pre
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4. SummaryAn attempt has been made
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The purpose of this study is to exa
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Figure1. Three-day average of momen
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3. The improved method to estimate
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But in case of period until 1800 UT
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Session I.5: Operational Aspects an
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The profilers of WINDAS weredesigne
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NOAA, 1994 : Wind profiler assessme
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FIRST RESULTS OF THE BOUNDARY LAYER
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Figure 3. Pulse Design Diagram to s
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MOVEABLE UHF/S-BAND PROFILER/DISDRO
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one-minute Z values determined from
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TOWARD A MULTISENSOR GROUND BASED R
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3. Cloud Evolution Case StudyOn the
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DEVELOPMENT OF A DIGITAL RECEIVER F
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Experiment 1 Experiment 2IPP 999Km
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ELECTRONIC DIGITAL BEAMFORMING IMPL
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The main element of the unit (figur
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.ON-LINE ADAPTIVE DC-GROUND-CLUTTER
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esulting in a widening of the bandw
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ON THE RADIATION EFFICIENCY OF COCO
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Table 2: Experiment #1 results, Tra
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A NEW NARROW BEAM MF RADAR AT 3 MHZ
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Off-zenith beams towards N, S, E, W
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95ALWIN VHF radar: signal powerdB80
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ANTENNA BEAM VERIFICATION USING COS
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Figure 2: A 45 MHz reference sky te
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AN ATTEMPT TO CALIBRATE THE UHF STR
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is at 4.7 km, but in the first 4-ga
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QUALITY CONTROL FOR DOPPLER WIND PR
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The resulting moments are subjected
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SOUSY RADAR AT JICAMARCA: SYSTEM DE
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NEControl andcomputer roomCompCoute
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THE EQUATORIAL ATMOSPHERE RADAR:SYS
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Table 1: Specifications of the EAR
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VHF ATMOSPHERIC AND METEOR RADAR IN
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ased upon a geotechnical engineerin
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VORTICAL MOTIONS OBSERVED WITH THE
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interpolation from the original gri
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A NEW MINIRADAR TO INVESTIGATE URBA
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e eliminated to analyze correctly t
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Session PWG 1: System Calibrations
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Session PWG 2: Data Analysis, Valid
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• the time series vectors x(k) of
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Fig. 4: reflectivity of the hydrome
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Session PWG 3: Accuracies and Requi
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Session PWG 4: International Collab
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Session II.E: NOVEL PERSPECTIVES AN
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2 Proposed AlgorithmReceived signal
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N#4E-1-16E1A1#1#2A-1-1C1#3C-1-19Fig
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of conventional DCMP, with which th
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applying the directional constraint
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while for a beam of finite width, t
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In order to make the process more q
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WHAT IS TURBULENCE SEEN BY VHF RADA
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Enhanced resolution applyingpulse s
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Beckmann, Spizichino, 1964Fig. 8 Po
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Fig. 11 Plots of temporal variation
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Fig. 14 Distributions of phase cent
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Hocking, W.K., Radar studies of sma
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THE STRUCTURE FUNCTION-BASED APPROA
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{ Ui( t), Vi( t), Wi( t)} = { Ui ,
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161). Assumption 2H: the instantane
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Only the second order SF are consid
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fluctuations umk( t ) along the bas
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VHF PARASITIC RADAR INTERFEROMETRYF
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• All the costs of transmitter pr
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Figure 2: Example of range-azimuth
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Target Altitude, km1009080706050403
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ReferencesGriffiths, H. D., A. J. G
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Participants ListAvery, James P.Uni
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Hysell, David L.EAS/Cornell Univers
Page 491 and 492:
Silva, Robert R.ATRADAustraliarsilv
Page 493 and 494:
AAdachi, A. .......................
Page 495:
TTabary, P. .......................
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