The Piura radar is part of the University of Colorado/NOAA Pacific profiler network, and is partially funded by the National Science Foundation under ATM-96/46/3. Data from final (FNL) runs of the NCEP GDAS model were provided by the NOAA Air Resources Laboratory. The Aberystwyth MST radar is a U.K. national facility of the Natural Environment Research Council (NERC). Radiosonde data are by the U.K. Meteorological Office. U.K. radar and radiosonde data are supplied by the NERC British Atmospheric Data Centre, and NOAA satellite images by the University of Strasbourg, France. Topographic data from the Global Land One-kilometer Base Elevation (GLOBE) database are supplied by the NOAA National Geophysical Data Center. Programs to extract Piura radar data were provided by J. L. Chau of Jicamarca Radio Observatory, Perú, and Australian data in Table 1 by D. A. Holdsworth of ATRAD.
Angevine, W. M., 1997: Errors in mean vertical velocities measured by boundary layer wind profilers. J. Atmos. Oceanic Technol.,14, 565–569.
Asimakopoulos, D. N., D. G. Deligiorgi, and D. P. Lalas, 1980: Acoustic sounder observations of the atmospheric boundary layer from the top of a steep mountain. J. Appl. Meteor.,19, 109–112.
Balsley, B. B., and D. A. Carter, 1989: Mountain waves in the tropical Pacific atmosphere: A comparison of vertical wind fluctuations over Pohnpei and Christmas Island using VHF wind profilers. J. Atmos. Sci.,46, 2698–2715.
——, W. L. Ecklund, D. A. Carter, A. C. Riddle, and K. S. Gage, 1988: Average vertical motions in the tropical atmosphere observed by a radar wind profiler on Pohnpei (7°N lat, 157°E long). J. Atmos. Sci.,45, 396–405.
Bishop, B. B., 1968: Lee waves over the Welsh mountains. Sailplane Gliding,19, 94–95.
Bougeault, P., B. Benech, P. Bessemoulin, B. Carissimo, A. Jansa Clar, J. Pelon, M. Petitdidier, and E. Richard, 1997: PYREX: A summary of findings. Bull. Amer. Meteor. Soc.,78, 637–650.
Bradbury, T. A. M., 1965: Wave clouds over Berkshire. Weather,20, 16–17.
Brown, P. R. A., 1983: Aircraft measurements of mountain waves and their associated momentum flux over the British Isles. Quart. J. Roy. Meteor. Soc.,109, 849–865.
Caccia, J.-L., B. Benech, and V. Klaus, 1997a: Space–time description of nonstationary trapped lee waves using ST radars, aircraft, and constant volume balloons during the PYREX experiment. J. Atmos. Sci.,54, 1821–1833.
——, M. Crochet, and K. Saada, 1997b: ST radar evaluation of the standard deviation of the air vertical velocity perturbed by the local orography. J. Atmos. Solar-Terr. Phys.,59, 1127–1131.
Chau, J. L., and B. B. Balsley, 1998: A statistical comparison of VHF techniques to study clear-air vertical velocities in the lower atmosphere using the Jicamarca radar. Radio Sci.,33, 1565–1583.
Faust, H., 1962: The dynamical signifance of null layers; layers of zero or vanishing vertical motion. Weather,17, 285–295.
Fukao, S., M. F. Larsen, M. D. Yamanaka, H. Furukawa, T. Tsuda, and S. Kato, 1991: Observations of a reversal in long-term average vertical velocities near the jet stream wind maximum. Mon. Wea. Rev.,119, 1479–1489.
Gage, K. S., 1986: Implications of tilting of stable layers on atmospheric measurements by clear-air Doppler radars. Preprints, 23d Conf. on Radar Meteorology, Snowmass, CO, Amer. Meteor. Soc., 30–33.
——, J. R. McAfee, D. A. Carter, W. L. Ecklund, A. C. Riddle, G. C. Reid, and B. B. Balsley, 1991: Long-term mean vertical motion over the tropical Pacific: Wind-profiling Doppler radar measurements. Science,254, 1771–1773.
——, ——, and G. C. Reid, 1992: Diurnal variation in vertical motion over the central equatorial Pacific from VHF wind-profiling Doppler radar observations at Christmas Island (2°N, 157°W). Geophys. Res. Lett.,19, 1827–1830.
Gardiner, B. A., and M. K. Hill, 1986: Acoustic sounder observations from an elevated location. Bound.-Layer Meteor.,36, 307–316.
Gedzelman, S. D., 1977: Mountain wave weather in New York City. Weatherwise,30, 202–206.
George, D. J., 1959: A persistent wave cloud over north Breconshire, 13 April 1958. Weather,14, 233–236.
Gill, A. E., 1982: Atmosphere–Ocean Dynamics. Academic Press, 662 pp.
Green, J. L., and K. S. Gage, 1980: Observations of stable layers in the troposphere and stratosphere using VHF radar. Radio Sci.,15, 395–405.
Hensman, G. W. J., 1971: Wave in a fog top. Weather,26, 58–60.
Hines, C. O., 1989: Tropopausal mountain waves over Arecibo: A case study. J. Atmos. Sci.,46, 476–488.
Hoppe, U.-P., and D. C. Fritts, 1995: On the downward bias in vertical velocity measurements by VHF radars. Geophys. Res. Lett.,22, 619–622.
Huaman, M. M., and B. B. Balsley, 1996: Long-term average vertical motions observed by VHF wind profilers: The effect of slight antenna-pointing inaccuracies. J. Atmos. Oceanic Technol.,13, 560–569.
Huff, F. A., S. A. Changnon, and D. M. A. Jones, 1975: Precipitation increases in the low hills of southern Illinois. Part 1: Climatic and network studies. Mon. Wea. Rev.,103, 823–329.
Kuettner, J. P., P. A. Hildebrand, and T. L. Clark, 1987: Convection waves: Observations of gravity wave systems over convectively active boundary layers. Quart. J. Roy. Meteor. Soc.,113, 445–467.
Larsen, M. F., and J. Röttger, 1991: VHF radar measurements of in-beam incidence angles and associated vertical-beam radial velocity corrections. J. Atmos. Oceanic Technol.,8, 477–490.
——, S. Fukao, O. Aruga, M. D. Yamanaka, T. Tsuda, and S. Kato, 1991: A comparison of VHF radar vertical-velocity measurements by a direct vertical-beam method and by a VAD technique. J. Atmos. Oceanic Technol.,8, 766–776.
Lee, G. H., and O. W. Neumark, 1952: A standing wave at Dunstable. Meteor. Mag.,81, 307–310.
Lenschow, D. H., S. F. Zhang, and B. B. Stankov, 1988: The stably stratified boundary layer over the Great Plains. Bound.-Layer Meteor.,42, 123–135.
Liziola, L. E., and B. B. Balsley, 1998: Studies of quasi horizontally propagating gravity waves in the troposphere using the Piura ST wind profiler. J. Geophys. Res.,103, 8641–8650.
Luce, H., M. Crochet, C. Hanuise, M. Yamamoto, and S. Fukao, 1999:On the interpretation of the layered structures detected by mesosphere–stratosphere–troposphere radars in dual frequency domain interferometry mode. Radio Sci.,34, 1077–1083.
Manley, G., 1945: The Helm wind of Crossfell, 1937–1939. Quart. J. Roy. Meteor. Soc.,71, 197–220.
May, P. T., 1993: Comments on “VHF radar measurements of in-beam incidence angles and associated vertical-beam radial velocity corrections.” J. Atmos. Oceanic Technol.,10, 432–434.
McAfee, J. R., B. B. Balsley, and K. S. Gage, 1989: Momentum flux measurements over mountains: Problems associated with the symmetrical two-beam radar technique. J. Atmos. Oceanic Technol.,6, 500–508.
——, K. S. Gage, and R. G. Strauch, 1994: Examples of vertical velocity comparison from collocated VHF and UHF profilers. Radio Sci.,29, 879–880.
——, ——, and ——, 1995: Vertical velocities at Platteville, Colorado: An intercomparison of simultaneous measurements by the VHF and UHF profilers. Radio Sci.,34, 1027–1042.
Muschinski, A., 1996: Possible effect of Kelvin–Helmholtz instability on VHF radar observations of the mean vertical wind. J. Appl. Meteor.,35, 2210–2217.
——, P. B. Chilson, S. Kern, J. Nielinger, G. Schmidt, and T. Prenosil, 1999: First frequency-domain interferometry observations of large-scale vertical motion in the atmosphere. J. Atmos. Sci.,56, 1248–1258.
Nance, L. B., and D. R. Durran, 1997: A modeling study of nonstationary trapped mountain lee waves. Part I: Mean-flow variability. J. Atmos. Sci.,54, 2275–2291.
Nastrom, G. D., 1984: Detection of synoptic-scale vertical velocities using an MST radar. Geophys. Res. Lett.,11, 57–60.
——, and T. E. VanZandt, 1994: Mean vertical motions seen by radar wind profilers. J. Appl. Meteor.,33, 984–995.
——, and F. D. Eaton, 1995: Variations of winds and turbulence seen by the 50-MHz radar at White Sands Missile Range, New Mexico. J. Appl. Meteor.,34, 2135–2148.
——, and T. E. VanZandt, 1996: Biases due to gravity waves in wind profiler measurements of winds. J. Appl. Meteor.,35, 243–257.
——, W. L. Ecklund, and K. S. Gage, 1985: Direct measurement of large-scale vertical velocities using clear-air Doppler radars. Mon. Wea. Rev.,113, 708–718.
——, M. R. Peterson, J. L. Green, K. S. Gage, and T. E. VanZandt, 1990: Sources of gravity wave activity seen in the vertical velocities observed by the Flatland VHF radar. J. Appl. Meteor.,29, 783–1792.
——, R. Rüster, and G. Schmidt, 1998: The coupling of vertical velocity and signal power observed with the SOUSY VHF radar. J. Appl. Meteor.,37, 114–119.
Nicholls, J. M., 1973: Aircraft measurements of disturbed airflow over mountains. Weather,28, 141–152.
Palmer, R. D., M. F. Larsen, R. F. Woodman, S. Fukao, M. Yamamoto, T. Tsuda, and S. Kato, 1991: VHF radar interferometry measurements of vertical velocity and the effect of tilted refractivity surfaces on standard Doppler measurements Radio Sci.,26, 417–427.
Pitts, R. O., and T. J. Lyons, 1988: The influence of topography on Perth radiosonde observations. Aust. Meteor. Mag.,36, 17–23.
Prichard, I. T., L. Thomas, and R. M. Worthington, 1995: The characteristics of mountain waves observed by radar near the west coast of Wales. Ann. Geophys.,13, 757–767.
Rao, D. N., S. Thulasiraman, S. V. B. Rao, T. N. Rao, P. Kishore, M. V. Ratnam, and K. K. Reddy, 2000: VHF radar observations of tropical easterly jet stream over Gadanki. Adv. Space Res.,26, 943–946.
Röttger, J., C. H. Liu, J. K. Chen, A. J. Chen, C. J. Pan, and I. J. Fu, 1990: Spatial interferometer measurements with the Chung-Li VHF radar. Radio Sci.,25, 503–515.
Slater, K., and Coauthors, 1992: (Overview of the MST radar system at Aberystwyth. Proc. Fifth Workshop on Technical and Scientific Aspects of MST radar, Aberystwyth, Wales, Scientific Committee on Solar Terrestrial Physics, 479–482.
Takayabu, I., M. D. Yamanaka, and S. Fukao, 2000: A mechanism for the reversal of long-term average vertical velocities around East Asia during the cold season. J. Meteor. Soc. Japan,78, 13–23.
Thomas, L., I. Astin, and R. M. Worthington, 1997: A statistical study of underestimates of wind speeds by VHF radar. Ann. Geophys.,15, 805–812.
United States Geological Survey, 1957a: Mahomet quadrangle Illinois, 1:62500 scale topographic map. United States Geological Survey.
——, 1957b: Urbana quadrangle, Illinois-Champaign Co., 1:62500 scale topographic map. United States Geological Survey.
VanBaelen, J. S., A. D. Richmond, T. Tsuda, S. K. Avery, S. Kato, S. Fukao, and M. Yamamoto, 1991: Radar interferometry technique and anisotropy of the echo power distribution: First results. Radio Sci.,26, 1315–1326.
Van den Dool, H. M., 1990: Time-mean precipitation and vertical motion patterns over the United States. Tellus,42A, 51–64.
VanValin, C. C., R. F. Pueschel, E. W. Barrett, and G. M. Williams, 1982: Field observations of stratified atmospheric flow above an obstacle. Bound.-Layer Meteor.,24, 331–343.
Wallington, C. E., 1961: Airflow over broad mountain ranges—A study of five flights across the Welsh mountains. Meteor. Mag.,90, 213–222.
Warnock, J. M., T. E. VanZandt, W. L. Clark, S. J. Franke, H. S. Kim, G. D. Nastrom, and P. E. Johnston, 1994: Measurements of synoptic-scale vertical velocities by two nearby VHF Doppler radars in very flat terrain. J. Atmos. Oceanic Technol.,11, 5–13.
Worthington, R. M., 1998: Tropopausal turbulence caused by the breaking of mountain waves. J. Atmos. Solar-Terr. Phys.,60, 1543–1547.
——, 1999a: Calculating the azimuth of mountain waves, using the effect of tilted finescale stable layers on VHF radar echoes. Ann. Geophys.,17, 257–272.
——, 1999b: Alignment of mountain wave patterns above Wales: A VHF radar study during 1990–1998. J. Geophys. Res.,104, 9199–9212.
——, 1999b: Alignment of mountain wave patterns above Wales: A VHF radar study during 1990–1998. J. Geophys. Res.,104, 9199–9212.
——, and L. Thomas, 1996a: Radar measurements of critical-layer absorption in mountain waves. Quart. J. Roy. Meteor. Soc.,122, 1263–1282.
——, and ——, 1996b: The measurement of gravity wave momentum flux in the lower atmosphere using VHF radar. Radio Sci.,31, 1501–1517.
——, and ——, 1997a: Long-period unstable gravity-waves and associated VHF radar echoes. Ann. Geophys.,15, 813–822.
——, and ——, 1997b: Impact of the tropopause on upward propagation of mountain waves. Geophys. Res. Lett.,24, 1071–1074.
——, and ——, 1998: The frequency spectrum of mountain waves. Quart. J. Roy. Meteor. Soc.,124, 687–703.
Yoe, J. G., and R. Rüster, 1992: VHF Doppler radar observations of vertical velocities in the vicinity of the jet stream. Mon. Wea. Rev.,120, 2378–2382.
——, P. Czechowsky, R. Rüster, and G. Schmidt, 1994: Spatial variability of the aspect sensitivity of VHF radar echoes in the troposphere and lower stratosphere during jet stream passages. Ann. Geophys.,12, 733–745.