Gravity wave saturation in the middle atmosphere: A review of theory and observations

This paper provides a review of recent advances in our understanding of gravity wave saturation in the middle atmosphere. A brief discussion of those studies leading to the identification of gravity wave effects and their role in middle atmosphere dynamics is presented first. This is followed by a simple development of the linear saturation theory to illustrate the principal effects. Recent extensions to the linear saturation theory, including quasi-linear, nonlinear, and transient effects, are then described. Those studies addressing the role of gravity wave saturation in the mean circulation of the middle atmosphere are also discussed. Finally, observations of gravity wave motions, distribution, and variability and those measurements specifically addressing gravity wave saturation are reviewed.

[1]  Hiroshi L. Tanaka,et al.  Atmospheric Circulation in the Lower Stratosphere Induced by the Mesoscale Mountain Wave Breakdown , 1985 .

[2]  T. Dunkerton,et al.  A Quasi-Linear Study of Gravity-Wave Saturation and Self-Acceleration , 1984 .

[3]  I. Hirota.  Climatology of gravity waves in the middle atmosphere , 1984 .

[4]  W. Chao,et al.  On the linear approximation of gravity wave saturation in the mesosphere , 1984 .

[5]  T. Dunkerton,et al.  Propagation and selective transmission of internal gravity waves in a sudden warming , 1984 .

[6]  T. Dunkerton,et al.  Transient gravity wave-critical layer interaction. I Convective adjustment and the mean zonal acceleration , 1984 .

[7]  R. Walterscheid,et al.  A simple model of the transient response of the thermosphere to impulsive forcing , 1984 .

[8]  R. Vincent,et al.  Gravity-wave motions in the mesosphere , 1984 .

[9]  J. Holton,et al.  Research status and recommendations from the Alaska Workshop on gravity waves and turbulence in the middle atmosphere, Fairbanks, Alaska, 18-22 July 1983 , 1984 .

[10]  M. Geller,et al.  Research Status and Recommendations from the Alaska Workshop on Gravity Waves and Turbulence in the Middle Atmosphere. , 1984 .

[11]  Hiroshi L. Tanaka,et al.  Multiple "gust-layers" observed in the middle stratosphere , 1984 .

[12]  R. Walterscheid.  Gravity wave attenuation and the evolution of the mean state following wave breakdown , 1984 .

[13]  D. Fritts,et al.  VHF Echoes from the Arctic Mesosphere and Lower Thermosphere, Part II: Interpretations , 1984 .

[14]  R. Lindzen.  Gravity waves in the mesosphere , 1984 .

[15]  D. Strobel,et al.  Nonzonal gravity wave breaking in the winter mesosphere , 1984 .

[16]  S. Miyahara.  A Numerical Simulation of the Zonal Mean Circulation of the Middle Atmosphere Including Effects of Solar Diurnal Tidal Waves and Internal Gravity Waves; Solstice Condition , 1984 .

[17]  J. Holton.  The Influence of Gravity Wave Breaking on the General Circulation of the Middle Atmosphere , 1983 .

[18]  G. D. Nastrom,et al.  A first look at wavenumber spectra from GASP data , 1983 .

[19]  D. Fritts,et al.  VHF Echoes from the High-Latitude Mesosphere and Lower Thermosphere: Observations and Interpretations , 1983 .

[20]  Erik Lundtang Petersen,et al.  Aircraft measurements of atmospheric kinetic energy spectra , 1983 .

[21]  J. Forbes,et al.  Turbulence originating from convectively stable internal waves , 1983 .

[22]  J. Barat.  The fine structure of the stratospheric flow revealed by differential sounding , 1983 .

[23]  D. Strobel,et al.  A numerical model of gravity wave breaking and stress in the mesosphere , 1983 .

[24]  Iain M. Reid,et al.  HF Doppler Measurements of Mesospheric Gravity Wave Momentum Fluxes , 1983 .

[25]  G. Loriot,et al.  Fine Doppler resolution observations of thin turbulence structures in the tropostratosphere at Millstone Hill , 1983 .

[26]  J. Weinstock.  Heat flux induced by gravity waves , 1983 .

[27]  T. Dunkerton.  Theory of the Mesopause Semiannual Oscillation , 1982 .

[28]  D. A. Carter,et al.  The Summer Wind Field Between 80 and 93 km Observed by the MST Radar at Poker Flat, Alaska (65°N) , 1982 .

[29]  D. Broutman.  The Interaction of Short-Wavelength Internal Waves with a Background Current, , 1982 .

[30]  Toru Sato,et al.  Fine Altitude Resolution Observations of Stratospheric Turbulent Layers by the Arecibo 430 MHz Radar , 1982 .

[31]  Jean Barat,et al.  Some Characteristics of Clear-Air Turbulence in the Middle Stratosphere , 1982 .

[32]  Toru Sato,et al.  Fine Altitude Resolution Radar Observations of Upper-Tropospheric and Lower-Stratospheric Winds and Waves , 1982 .

[33]  D. Strobel,et al.  Parameterization of IR cooling in a middle atmosphere dynamics model: 1. Effects on the zonally averaged circulation , 1982 .

[34]  D. Fritts.  The transient critical‐level interaction in a Boussinesq fluid , 1982 .

[35]  T. Dunkerton.  Stochastic Parameterization of Gravity Wave Stresses , 1982 .

[36]  J. Weinstock.  Nonlinear Theory of Gravity Waves: Momentum Deposition, Generalized Rayleigh Friction, and Diffusion , 1982 .

[37]  C. Leovy,et al.  An accurate radiative heating and cooling algorithm for use in a dynamical model of the middle atmosphere , 1982 .

[38]  T. VanZandt,et al.  A universal spectrum of buoyancy waves in the atmosphere , 1982 .

[39]  T. Dunkerton.  Wave Transience in a Compressible Atmosphere. Part III: The Saturation of Internal Gravity Waves in the Mesophere , 1982 .

[40]  O. Røyrvik,et al.  VHF power scattered from the mesosphere at mid‐latitudes , 1982 .

[41]  J. Holton,et al.  The Role of Gravity Wave Induced Drag and Diffusion in the Momentum Budget of the Mesosphere , 1982 .

[42]  E. B. Armstrong.  The association of visible airglow features with a gravity wave , 1982 .

[43]  G. D. Nastrom,et al.  Mean meridional winds in the mid‐ and high‐latitude summer mesosphere , 1982 .

[44]  Hiroshi L. Tanaka.  Application of WKB Theory to Turbulence Layers in the Vicinity of Critical Levels , 1982 .

[45]  T. Matsuno.  A Quasi One-Dimensional Model of the Middle Atmosphere Circulation Interacting with Internal Gravity Waves , 1982 .

[46]  C. R. Philbrick,et al.  Vertical density and temperature structure over Northern Europe , 1982 .

[47]  C. Koop.  A preliminary investigation of the interaction of internal gravity waves with a steady shearing motion , 1981, Journal of Fluid Mechanics.

[48]  R. Walterscheid.  Dynamical cooling induced by dissipating internal gravity waves , 1981 .

[49]  R. Wand,et al.  Observations of clear air turbulence and winds with the Millstone Hill radar , 1981 .

[50]  Alain Hauchecorne,et al.  Lidar observation of gravity and tidal waves in the stratosphere and mesosphere , 1981 .

[51]  R. Lindzen.  Turbulence and stress owing to gravity wave and tidal breakdown , 1981 .

[52]  S. M. Ball,et al.  Mesospheric winds at low‐ and mid‐latitudes in the southern hemisphere , 1981 .

[53]  W. Ecklund,et al.  Long‐term observations of the Arctic mesosphere with the MST radar at Poker Flat, Alaska , 1981 .

[54]  C. H. McComas,et al.  The dynamic balance of internal waves , 1981 .

[55]  J. Fellous,et al.  Simultaneous meteor radar observations at Monpazier (France, 44°N) and Punta Borinqnen (Puerto Rico, 18°N). III—The latitudinal variations of the energy of gravity waves (2–8 h) in the high mesosphere , 1981 .

[56]  R. Bernard,et al.  Simultaneous meteor radar observations at Monpazier (France, 44°N) and Punta Borinquen (Puerto Rico, 18°N). II—Mean zonal wind and long period waves , 1981 .

[57]  M. McIntyre,et al.  On the ‘wave momentum’ myth , 1981, Journal of Fluid Mechanics.

[58]  T. Dunkerton.  Wave Transience in a Compressible Atmosphere. Part I: Transient Internal Wave, Mean-Flow Interaction , 1981 .

[59]  C. H. McComas,et al.  Time Scales of Resonant Interactions Among Oceanic Internal Waves , 1981 .

[60]  J. Röttger.  Wind variability in the stratosphere deduced from spaced antenna VHF radar measurements , 1981 .

[61]  A. Manson,et al.  Gravity waves of short period (5–90 min), in the lower thermosphere at 52°N (Saskatoon, Canada); 1978/1979 , 1981 .

[62]  J. D. Mahlman,et al.  Stratospheric Sensitivity to Perturbations in Ozone and Carbon Dioxide: Radiative and Dynamical Response. , 1980 .

[63]  G. Holloway.  Oceanic Internal Waves Are Not Weak Waves , 1980 .

[64]  T. Dunkerton.  A Lagrangian Mean Theory of Wave, Mean-Flow Interaction With Applications to Nonacceleration and Its Breakdown (Paper 9R1575) , 1980 .

[65]  J. Röttger.  Structure and dynamics of the stratosphere and mesosphere revealed by VHF radar investigations , 1980 .

[66]  K. S. Gage,et al.  The MST radar technique: Potential for middle atmospheric studies , 1980 .

[67]  M. McIntyre,et al.  An introduction to the generalized Lagrangian-mean description of wave, mean-flow interaction , 1980 .

[68]  K. S. Gage,et al.  Use of Doppler radar for the measurement of atmospheric turbulence parameters from the intensity of clear‐air echoes , 1980 .

[69]  M. Herse,et al.  Waves in the OH emissive layer: photogrammetry and topography. , 1980, Applied optics.

[70]  J. Holton,et al.  A numerical model of the zonal mean circulation of the middle atmosphere , 1980 .

[71]  D. Strobel,et al.  Numerical Simulation of Sudden Stratospheric Warmings , 1980 .

[72]  K. S. Gage,et al.  Evidence far a k−5/3 Law Inertial Range in Mesoscale Two-Dimensional Turbulence , 1979 .

[73]  D. C. Allen,et al.  Radiative cooling near the mesopause , 1979, Nature.

[74]  W. Gordon,et al.  Mesospheric winds and waves over Jicamarca on May 23–24, 1974 , 1979 .

[75]  J. Röttger,et al.  High‐resolution VHF radar observations of turbulence structures in the mesosphere , 1979 .

[76]  M. Geller.  Dynamics of the middle atmosphere , 1979 .

[77]  Peter Czechowsky,et al.  Variations of Mesospheric Structures in Different Seasons , 1979 .

[78]  H. Teitelbaum,et al.  Observational Evidence of Internal Inertia-Gravity Waves in the Tropical Stratosphere , 1979 .

[79]  T. Matsuno,et al.  The Eulerian-and Lagrangian-Mean Meridional Circulations in the Stratosphere at the Time of a Sudden Warming , 1979 .

[80]  A. Manson,et al.  The role of atmospheric waves (1.5 h-10 days) in the dynamics of the mesosphere and lower thermosphere at Saskatoon (52°N, 107°W) during four seasons of 1976 , 1979 .

[81]  D. G. Andrews,et al.  On wave-action and its relatives , 1978, Journal of Fluid Mechanics.

[82]  D. G. Andrews,et al.  An exact theory of nonlinear waves on a Lagrangian-mean flow , 1978, Journal of Fluid Mechanics.

[83]  D. G. Stephenson,et al.  Winds and Wave Motions to 110 km at Midlatitudes. VI. Tidal, Gravity and Planetary Waves, 1976 , 1978 .

[84]  A. Mcewan,et al.  The Instability of a Forced Standing Wave in a Viscous Stratified Fluid: A Laboratory Analogue of .the Quasi-Biennial Oscillation , 1978 .

[85]  D. Lalas,et al.  The role of gravity waves in tropospheric processes , 1978 .

[86]  J. Röttger,et al.  Radar measurements of waves in the lower stratosphere , 1978 .

[87]  M. McIntyre,et al.  Generalized Eliassen-Palm and Charney-Drazin Theorems for Waves on Axismmetric Mean Flows in Compressible Atmospheres , 1978 .

[88]  J. Houghton.  The stratosphere and mesosphere , 1978 .

[89]  R. A. Plumb.  The Interaction of Two Internal Waves with the Mean Flow: Implications for the Theory of the Quasi-Biennial Oscillation , 1977 .

[90]  C. H. McComas.  Equilibrium Mechanisms within the Oceanic Internal Wave Field , 1977 .

[91]  D. Strobel,et al.  The Zonally Averaged Circulation of the Middle Atmosphere , 1977 .

[92]  S. M. Ball,et al.  Tides and gravity waves in the mesosphere at mid- and low-altitudes , 1977 .

[93]  R. Woodman,et al.  Preliminary multiheight radar observations of waves and winds in the mesosphere over Jicamarca , 1977 .

[94]  J. Barnett,et al.  Planetary waves in the winter mesosphere ‐ preliminary analysis of nimbus 6 PMR results , 1977 .

[95]  R. Vincent,et al.  A study of motions in the winter mesosphere using the partial reflection drift technique , 1977 .

[96]  F. Bretherton,et al.  Resonant interaction of oceanic internal waves , 1977 .

[97]  D. Cadet.  Energy Dissipation Within Intermittent Clear Air Turbulence Patches , 1977 .

[98]  John P. Boyd,et al.  The Noninteraction of Waves with the Zonally Averaged Flow on a Spherical Earth and the Interrelationships on Eddy Fluxes of Energy, Heat and Momentum , 1976 .

[99]  D. G. Andrews,et al.  Planetary Waves in Horizontal and Vertical Shear: The Generalized Eliassen-Palm Relation and the Mean Zonal Acceleration , 1976 .

[100]  I. Hirota.  Seasonal variation of planetary waves in the stratosphere observed by the Nimbus 5 SCR (Selective Ch , 1976 .

[101]  P. Rastogi,et al.  Scattering of radio waves from the mesosphere—2. Evidence for intermittent mesospheric turbulence , 1976 .

[102]  J. Weinstock.  Nonlinear theory of acoustic‐gravity waves 1. Saturation and enhanced diffusion , 1976 .

[103]  P. Rastogi,et al.  Gravity waves in the equatorial mesosphere , 1976 .

[104]  D. Cunnold.  Vertical Transport Coefficients in the Mesosphere Obtained from Radar Observations , 1975 .

[105]  M. Geller,et al.  Production of Turbulence in the Vicinity of Critical Levels for Internal Gravity Waves , 1975 .

[106]  E. Dewan,et al.  Stratospheric turbulence and vertical effective diffusion coefficients , 1975 .

[107]  D. Olbers,et al.  On the dynamics of internal waves in the deep ocean , 1975 .

[108]  D. G. Stephenson,et al.  Winds and Wave Motions to 110 km at Mid-Latitudes. IV. Coupling Between Internal Gravity Waves and the Mean Flow , 1975 .

[109]  R. Grimshaw.  Nonlinear Internal Gravity Waves and Their Interaction with the Mean Wind , 1975 .

[110]  I. Orlanski,et al.  On the role of density jumps in the reflexion and breaking of internal gravity waves , 1975, Journal of Fluid Mechanics.

[111]  S. A. Thorpe,et al.  The excitation, dissipation, and interaction of internal waves in the deep ocean , 1975 .

[112]  Chris Garrett,et al.  Space-Time Scales of Internal Waves' A Progress Report , 1975 .

[113]  I. Hirota.  Spectral Analysis of Planetary Waves in the Summer Stratosphere and Mesosphere , 1975 .

[114]  D. G. Stephenson,et al.  Winds and Wave Motions to 110 km at Mid–Latitudes I. Partial Reflection Radiowave Soundings, 1972–73 , 1974 .

[115]  D. Lilly,et al.  Stratospheric Mixing Estimated from High-Altitude Turbulence Measurements , 1974 .

[116]  K. Yeh,et al.  Acoustic‐gravity waves in the upper atmosphere , 1974 .

[117]  John Theodore Houghton,et al.  Remote sounding of atmospheric temperature from satellites V. The pressure modulator radiometer for Nimbus F , 1974, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[118]  S. P. Zimmerman.  The effective vertical turbulent viscosity as measured from radio meteor trails , 1974 .

[119]  Ronald F. Woodman,et al.  Radar Observations of Winds and Turbulence in the Stratosphere and Mesosphere. , 1974 .

[120]  D. G. Stephenson,et al.  Winds and wave motions (70–100 km) as measured by a partial reflection radiowave system , 1973 .

[121]  M. McIntyre.  Mean motions and impulse of a guided internal gravity wave packet , 1973, Journal of Fluid Mechanics.

[122]  D. Lilly,et al.  Observations of a Stationary Mountain Wave and its Associated Momentum Flux and Energy Dissipation , 1973 .

[123]  A. Mcewan.  Interactions between internal gravity waves and their traumatic effect on a continuous stratification , 1973 .

[124]  R. Lindzen.  Wave-mean flow interactions in the upper atmosphere , 1973 .

[125]  J. Holton,et al.  An Updated Theory for the Quasi-Biennial Cycle of the Tropical Stratosphere , 1972 .

[126]  I. Orlanski.  On the breaking of standing internal gravity waves , 1972, Journal of Fluid Mechanics.

[127]  W. L. Jones,et al.  The Self-Destructing Internal Gravity Wave , 1972 .

[128]  R. Breeding.  A nonlinear model of the break-up of internal gravity waves due to their exponential growth with height , 1972 .

[129]  K. Labitzke.  Temperature Changes in the Mesosphere and Stratosphere Connected with Circulation Changes in Winter , 1972 .

[130]  Chris Garrett,et al.  Space-Time scales of internal waves , 1972 .

[131]  K. H. Lloyd,et al.  Determination of the structure of the atmosphere between 90 and 250 km by means of contaminant releases at Woomera, May 1968 , 1972, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[132]  D. Lilly.  Wave Momentum Flux—A GARP Problem , 1972 .

[133]  A. Mcewan.  Degeneration of resonantly-excited standing internal gravity waves , 1971, Journal of Fluid Mechanics.

[134]  T. Matsuno,et al.  A Dynamical Model of the Stratospheric Sudden Warming , 1971 .

[135]  W. L. Jones,et al.  The Coupling of Momentum Between Internal Gravity Waves and Mean Flow: A Numerical Study , 1971 .

[136]  R. Hodges.  Vertical transport of minor constituents in the lower thermosphere by nonlinear processes of gravity waves , 1970 .

[137]  C. Hines.  Eddy diffusion coefficients due to instabilities in internal gravity waves , 1970 .

[138]  R. Lindzen.  Internal gravity waves in atmospheres with realistic dissipation and temperature part I. Mathematical development and propagation of waves into the thermosphere , 1970 .

[139]  K. Bryan,et al.  Formation of the thermocline step structure by large‐amplitude internal gravity waves , 1969 .

[140]  F. Bretherton.  Waves and Turbulence in Stably Stratified Fluids , 1969 .

[141]  R. Hodges.  Eddy diffusion coefficients due to instabilities in internal gravity waves. , 1969 .

[142]  R. S. Quiroz.  The Warming of the Upper Stratosphere in February 1966 and the Associated Structure of the Mesosphere , 1969 .

[143]  F. Bretherton.  On the mean motion induced by internal gravity waves , 1969, Journal of Fluid Mechanics.

[144]  F. Bretherton.  Momentum transport by gravity waves , 1969 .

[145]  J. London,et al.  Infrared Radiative Cooling in the Middle Atmosphere (30–110 km) , 1969 .

[146]  C. Justus,et al.  Measurement of the magnitude of the irregular winds in the altitude region near 100 kilometers. , 1968 .

[147]  J. Holton,et al.  A Theory of the Quasi-Biennial Oscillation , 1968 .

[148]  R. Lindzen,et al.  The application of classical atmospheric tidal theory , 1968, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[149]  R. Lindzen.  Lower Atmospheric Energy Sources for the Upper Atmosphere , 1968 .

[150]  R. Hodges,et al.  GENERATION OF TURBULENCE IN THE UPPER ATMOSPHERE BY INTERNAL GRAVITY WAVES. , 1967 .

[151]  W. Nordberg,et al.  Some observations on the thermal behavior of the mesosphere , 1967 .

[152]  Francis P. Bretherton,et al.  The critical layer for internal gravity waves in a shear flow , 1967, Journal of Fluid Mechanics.

[153]  C. Hines,et al.  On the propagation of atmospheric gravity waves through regions of wind shear , 1967 .

[154]  R. Lindzen.  Thermally driven diurnal tide in the atmosphere , 1967 .

[155]  F. Bretherton.  The propagation of groups of internal gravity waves in a shear flow , 1966 .

[156]  J. Midgley,et al.  Gravity waves in a realistic atmosphere , 1966 .

[157]  F. S. Johnson,et al.  Atmospheric composition in the lower thermosphere. , 1966 .

[158]  J. P. Friedman.  Propagation of Internal Gravity Waves in a Thermally Stratified Atmosphere , 1966 .

[159]  J. R. Scoggins,et al.  Mesoscale Structure of 11-20 km Winds. , 1966 .

[160]  C. Hines,et al.  Dynamical heating of the upper atmosphere , 2013 .

[161]  F. S. Johnson,et al.  Thermal upper limit on eddy diffusion in the mesosphere and lower thermosphere , 1965 .

[162]  G. W. Sharp,et al.  EVIDENCE FOR TEMPERATURE STRATIFICATION IN THE E REGION , 1965 .

[163]  A. Kochanski.  Atmospheric motions from sodium cloud drifts , 1964 .

[164]  H. Edwards,et al.  Observations of ionospheric wind patterns through the night , 1964 .

[165]  C. Leovy.  Simple Models of Thermally Driven Mesopheric Circulation , 1964 .

[166]  C. Leovy.  Radiative Equilibrium of the Mesosphere , 1964 .

[167]  S. P. Zimmerman,et al.  Transport processes in the upper atmosphere , 1963 .

[168]  I. Tolstoy.  The Theory of Waves in Stratified Fluids Including the Effects of Gravity and Rotation , 1963 .

[169]  C. Hines.  The Upper Atmosphere in Motion , 1963 .

[170]  E. Gossard.  Vertical flux of energy into the lower ionosphere from internal gravity waves generated in the troposphere , 1962 .

[171]  G. Witt.  Height, structure and displacements of noctilucent clouds , 1962 .

[172]  F. Singleton,et al.  Possible meridional circulations in the stratosphere and mesosphere , 1961 .

[173]  J. G. Charney,et al.  Propagation of planetary‐scale disturbances from the lower into the upper atmosphere , 1961 .

[174]  J. Blamont,et al.  Upper atmospheric turbulence near the 100 km level , 1961 .

[175]  C. Hines.  INTERNAL ATMOSPHERIC GRAVITY WAVES AT IONOSPHERIC HEIGHTS , 1960 .

[176]  C. Eckart,et al.  Hydrodynamics of oceans and atmospheres , 1960 .

[177]  J. S. Greenhow.  Eddy diffusion and its effect on meteor trails , 1959 .

[178]  J. S. Greenhow,et al.  Measurements of turbulence in the 80‐ to 100‐km region from the radio echo observations of meteors , 1959 .

[179]  C. Moore,et al.  Some wind determinations in the upper atmosphere using artificially generated sodium clouds , 1959 .

[180]  R. Goody,et al.  Sources and sinks of radiative energy from 30 to 90 km , 1958 .

[181]  G. Munro.  Travelling Ionospheric Disturbances in the F Region , 1958 .

[182]  L. Heisler.  Anomalies in Ionosonde Records due to Travelling Ionospheric Disturbances , 1958 .

[183]  C. Hines.  Hydromagnetic Resonance in Ionospheric Waves , 1955 .

[184]  F. Whipple,et al.  High-altitude winds by meteor-train photography , 1954 .

[185]  G. Munro.  Reflexions from irregularities in the ionosphere , 1953, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[186]  G. Munro.  Travelling disturbances in the ionosphere , 1950, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[187]  D. F. Martyn.  Cellular atmospheric waves in the ionosphere and troposphere , 1950, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[188]  W. Beynon.  Evidence of Horizontal Motion in Region F2 Ionization , 1948, Nature.

[189]  G. H. Munro.  Short-Period Changes in the F Region of the Ionosphere , 1948, Nature.