HANDBOOK OF GEOPHYSICS

AND

SPACE ENVIRONMENTS

Scientific Editor

Shea L. Valley

Air Force Cambridge Research Laboratories

McGRAWHILL BOOK COMPANY, INC.New York San Francisco Toronto London Sydney

TABLE OF CONTENTS

CHAPTER 1. GEODESY1 AND GRAVITY

1.1 FIGURES OF THE EARTH AND REFERENCE SURFACES . . . . 1-11.1.1 The Geoid 1-11.1.2 The Reference Ellipsoid 1-21.2 HORIZONTAL GEODETIC SURVEYING 1-21.2.1 Reduction to the Geoid 1-21.2.2 Deflections of the Vertical 1-21.2.3 Projection to the Ellipsoid 1-3

1.2.3.1 The Development Method 1-31.2.3.2' The Translative Method 1-31.2.3.3 Pizzetti's Projection . 1-31.2.3.4 Projective Method of Astronomical Geodesy . 1-4

KL.2.4 Earth Ellipsoids 1-4- 1.2.4.1 Reference Ellipsoids 1-4

1.2.4.2 Best-Fitting Ellipsoids 1-41.2.4.3 Arc-Measuring Method . 1-41.2:4.4 Area Method 1-51.2.4.5 Partial Systems Method 1-51.2.4.6 Mean Earth Ellipsoid 1-5

1.3 VERTICAL GEODETIC SURVEYING 1-61.4^ GRAVITY . . . 1-61.4.1 The Spheroidal Earth and Normal Gravity 1-61.4.2 The International Gravity Formula 1-71.4.3 Disturbing Potential and Gravity Anomaly 1-71.4.4 Gravimetrical Geoid and Deflections of the Vertical 1-81.4.5 Applications of Gravity Anomalies for Geodesy 1-10

1.4.5.1 Existing'Gravity Material 1-101.4.5.2 Existing Geoids 1-101.4.5.3 World Geodetic System 1-10

1.4.6 Gravity Measurements 1-131.4.6.1 Absolute Measurements 1-131.4.6.2 Relative Measurements 1-14

1.4.7 Reduction of Gravity Observations 1-141.4.8 Isostatic Equilibrium and Reduction 1-14

1.4.8.1 Reduction Tables 1-161.4.8.2 Reduction Maps 1-16

1.4.9 New Reduction Methods 1-161.5 GRAVITY FIELD EXTENDED TO HIGH ALTITUDES 1-161.5.1 Normal Gravity or Gravitation 1-161.5.2 Continuation of Gravity Anomalies and Disturbance 1-171.6 ELECTRONIC DISTANCE MEASUREMENTS 1-171.7 LUNAR OBSERVATIONS 1-181.7.1 Solar Eclipse 1-181.7.2 Occultations 1-181.7.3 Lunar Camera 1-181.8 ROCKET7FLASH TRIANGULATION 1-181.9 SATELLITE GEODESY 1-191.9.1 Orbits 1-20

1.9.1.1 Geocentric Coordinate System 1-201.9.1.2 Computation of Orbital Elements 1-211.9.1.3 Kepler's Equation 1-21

1.9.2 Orbit Perturbations 1-211.9.3 Position Determination 1-221.9.4 Analysis of Satellite Motions to Determine Gravitational Potential . . 1-231.10 REFERENCES 1-27

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CHAPTER 2. MODEL ATMOSPHERES

2.1 ATMOSPHERIC STRUCTURE AND DEFINITIONS 2-12.2 U.S. STANDARD ATMOSPHERE, 1962 2-22.3 SUPPLEMENTAL ATMOSPHERES : 2-22.4 EXTREME ATMOSPHERES 2-62.5 REFERENCES 2-6

CHAPTER 3. ATMOSPHERIC TEMPERATURE, DENSITY,PRESSURE, AND MOISTURE

3.1 THERMAL PROPERTIES UP TO 90 KM 3-13.1.1 Energy Supply and Transformation 3-13.1.2 Station Temperatures 3-2

3.1.2.1 Probability Distributions . . ., 3-73.1.2.2 Highest and Lowest Temperatures 3-8

3.1.3 Upper Air Temperatures 3-113.1.3.1 Variability Below 30 Km 3-123.1.3.2 Variability Above 30 Km 3-12

3.1.4 Speed of Sound vs Temperature 3-143.1.5 The Lower Level Air Temperatures 3-143.1.6 Earth/Air Interface Temperatures w 3.193.1.7 Subsoil Temperatures * 3-203.1.8 Miscellaneous 3-233.2 ATMOSPHERIC DENSITY UP TO 90 KM 3-233.2.1 Distribution Below 30 Km 3-23

3.2.1.1 Statistical Applications to Reentry Problems 3-23' 3.2.1.2 Latitudinal Variations 3-23

3.2.1.3 Seasonal Variations 3-253.2.1.4 Interdiurnal and Diurnal Variations 3-253.2.1.5 Interlevel Correlations 3-263.2.1.6 Density-Wind Correlations 3-27

3.2.2 Distribution Between 30 and 90 Km 3-273.2.2.1 Latitudinal and Seasonal Variability 3-283.2.2.2 Interdiurnal and Diurnal Changes . 3-28

3.3 ATMOSPHERIC PRESSURE UP TO 90 KM 3-293.3.1 Sea-Level Pressure 3-293.3.2 Variations in Height of Constant Pressure Surfaces 3-30

3.3.2.1 Seasonal and Daily Variations 3-303.3.2.2 Diurnal and Semidiurnal Variations 3-31

3.4 ATMOSPHERIC WATER VAPOR 3-313.4.1 Polar Model 3-343.4.2 Midlatitude Model 3-343.4.3 Tropical Observations 3-343.5 TEMPERATURE, DENSITY, AND PRESSURE (90 TO 300 KM) 3-343.6 VARIATIONS ABOVE 200 KM 3-383.6.1 Diurnal Density Variations 3-393.6.2 Density as a Function of Solar Flux 3-393.6.3 Annual and Semiannual Density Variations 3-403.6.4 Effects of Magnetic Storms on Density 3-403.6.5 Latitude Effects 3-413.6.6 Diurnal Temperature Variations 3-413.6.7 Temperature as a Function of Solar Flux . 3-433.6.8 Effects of Magnetic Storms on Temperature 3-433.7 REFERENCES 3-43

CHAPTER 4. WINDS

4.1 MEAN WIND AS A FUNCTION OF HEIGHT 4-14.1.1 Variation of Mean Wind Speed (Lowest 300 Ft) 4-1

1.1.2 ( Wind Direction Shifts (Lower 10,000 Ft) 4-24.1.3 ' Diurnal Variation and Low-Level Jet Streams (Lower 6000 Ft) . . . . 4-44.2 LARGE-SCALE WIND STRUCTURE 4-64.2.1 Time Variability up to 30 Km 4-64.2.2 Spatial Variability up to 30 Km x, . 4-84.2.3 Variability Above 30 Km 4-8

4.2.3.1 Seasonal Variation 4-154.2.3.2 Diurnal Variation 4-17

4.3 WIND SHEAR 4-174.4 TROPOSPHERIC WIND PROFILES FOR VEHICLE DESIGN . 4-204.4.1 Synthetic or Discrete Wind Profiles for Preliminary Design 4-214.4.2 Other Methods of Predicting Winds for Design Purposes 4-274.4.3 Final Design Calculations 4-274.4.4 Ballistic Profiles 4-284.5 DESIGN DATA ON WINDS 4-294.5.1 Hourly Surface Wind Speeds 4-334.5.2 Extreme Surface Wind Speeds 4-334.5.3 Wind Direction, Speed, and Variability Below 100,000 Ft 4-384.5.4 Structure of Jet Streams : 4-444.5.5 Observed Winds Above 100,000 Ft 4-454.6 REFERENCES 4-45

CHAPTER 5. PRECIPITATION, CLOUDS, AND AEROSOLS

5.1 PRECIPITATION 5-15.1.1 C Surface Rates of Precipitation 5-1

5.1.1.1 Clock Hourly Rates 5-15.1.1.2 Instantaneous Rates of Precipitation 5-25.1.1.3 Separation of Rainfall and Snowfall 5-45.1.1.4 Extreme Rates of Rainfall 5-4

5.1.2 Hail 5-55.1.2.1 Horizontal Extent 5-55.1.2.2 Vertical Extent 5-65.1.2.3 Size of Hail 5-6

5.2 MODEL ATMOSPHERES FOR PRECIPITATION 5-65.2.1 Widespread Precipitation 5-6

5.2.1.1 Water Content of Clouds 5-95.2.1.2 Particle Size Distribution 5-105.2.1.3 Integrals of Diameter over the Size Distribution 5-10

5.2.2 Thunderstorm Rainfall 5-105.2.3 Real Precipitation Distributions 5-115.3 CLOUDS 5-115.3.1 Data Available from Surface Observations 5-11

5.3.1.1 Summaries of Surface Observations 5-125.3.1.2 Limitations in the Use of Summaries for a Particular Station 5-12

5.3.2 Data Available from Aircraft and Radar 5-145.3.3 Vertical Extent of Cirrus Clouds 5-145.3.4 Frequency of Occurrence of Cloud Formations Above 20,000 Ft. . . . 5-145.3.5 Horizontal Extent of Cirrus Clouds 5-155.3.6 Maximum Water Content of Clouds 5-155.4 NOCTILUCENT CLOUDS 5-205.5 AEROSOLS 5-225.5.1 Size Range and Field of Importance 5-225.5.2 Size Distribution 5-235.5.3 Characteristics of Aerosols at Various Altitudes 5-245.5.4 Interaction with Radioactive Material 5-255.5.5 Impaction of Aerosol Particles on Aircraft 5-255.6 REFERENCES 5-25

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CHAPTER 6. ATMOSPHERIC COMPOSITION

6.1 PRINCIPAL CONSTITUENTS 6-16.2 OZONE 6-26.2.1 Regions of Ozone Formation 6-36.2.2 Distribution of Total Ozone 6-36.2.3 Vertical Ozone Distribution 6-36.3 ABSORPTION AND IONIZATION IN THE UPPER

ATMOSPHERE 6-76.3.1 Molecular Nitrogen 6-96.3.2 Molecular Oxygen 6-126.3.3 Nitric Oxide 6-136.3.4 Atomic Oxygen and Nitrogen 6-136.3.5 Minor Constituents 6-146.3.6 Absorption Cross Sections, 100 to 1 A 6-146.3.7 Average Absorption Coefficients 6-156.4 RECOMBINATION 6-156.4.1 Radiative Recombination 6-156.4.2 Dissociative Recombination 6-166.4.3 Three-Body Recombination 6-176.4.4 Ion-Ion Recombination 6-176.5 ELECTRON ATTACHMENT 6-186.6 ELECTRON DETACHMENT FROM NEGATIVE IONS :. 6-186.6.1 Photodetachment 6-196.6.2 Collisional Detachment 6-196.7 NON-DETACHMENT REACTIONS OF NEGATIVE IONS

WITH NEUTRALS 6-206.8 REACTIONS OF POSITIVE IONS WITH NEUTRALS 6-206.9 REFERENCES 6-23

CHAPTER 7. ATMOSPHERIC OPTICS

7.1 ATMOSPHERIC ATTENUATION MODEL 7-17.1.1 Parameters of Atmospheric Attenuation 7-17.1.2 Applications 7-2

7.1.2.1 Turbid Atmosphere 7-27.1.2.2 Rayleigh Atmosphere 7-2

7.2 REFLECTANCE 7-37.2.1 Ground Reflectance 7-3

7.2.1.1 Water Surfaces 7-37.2.1.2 Snow, Bare Areas, and Soils 7-47.2.1.3 Vegetative Formations 7-4

7.2.2 Polarization 7-47.2.3 Observations at High Altitudes 7-47.2.4 Cloud Reflectance 7-57.3 FLUX EMERGING FROM THE ATMOSPHERE 7-67.4 OPTICAL RADIATION IN THE ATMOSPHERE 7-67.4.1 Rayleigh Scattering (Molecular) and Polarization 7-77.4.2 Aerosol (Mie) Scattering 7-87.4.3 Atmospheric Scattering 7-87.4.4 Absorption Coefficients for Ozone 7-97.5 MEASUREMENTS OF SKYLIGHT 7-97.6 REFERENCES 7-36

CHAPTER 8. ATMOSPHERIC ELECTRICITY

8.1 FAIR WEATHER ELECTRICITY 8-18.1.1 Electrical Conductivity 8-18.1.2 Electric Field 8-18.1.3 Currents and Space Charge 8-28.1.4 Atmospheric Ions 8-2

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8.1.5 Equilibrium Conditions 8-48.1.6 Variations in the Exchange Layer 8-58.1.7 Variations in the Free Atmosphere 8-58.1.8 Worldwide Current System and Maintenance of Earth's Charge . . . . 8-68.2 THUNDERSTORM ELECTRICITY 8-68.2.1 Electrostatic Field Patterns 8-78.2.2 - Precipitation Static 8-88.2.3 Power Line and Building Strikes 8-88.2.4 Possible Strike Patterns 8-108.2.5 Charge and Field Variations 8-108.2.6 Frequency Characteristics of Radiation 8-118.3 REFERENCES 8-23

CHAPTER 9. SOME ASPECTS OF ELECTROMAGNETIC WAVEPROPAGATION

9.1 REFRACTIVE MODULUS IN THE TROPOSPHERE 9-19.1.1 Optical Wavelengths 9-19.1.2 Radio Wavelengths 9-19.1.3 Standard Profiles of Refractive Modulus 9-29.1.4 Variations of Refractive Moduli 9-29.2 ATTENUATION A N D BACKSCATTERING IN THE

TROPOSPHERE 9-29.2.1 Dielectric Properties 9-39.2.2 Backscattering and Attenuation Cross Sections 9-39.2.3 Total Reflectivity 9-99.2.4 Total Attenuation 9-149.3 IONOSPHERIC INTERACTIONS 9-149.3.1 Some Magneto-Ionic Formulas 9-169.3.2 Ionsondes and Ionograms 9-179.4 RADIO REFLECTIONS FROM METEOR TRAILS 9-179.4.1 Characteristics of a Meteor Trail 9-17

9.4.1.1 The Underdense Trail 9-199.4.1.2 The Overdense Trail 9-19

9.5 WHISTLERS, IONOSPHERICS, AND HYDROMAGNETICWAVES 9-19

9.5.1 Definitions 9-209.5.2 Theory of Whistlers and Ionospherics 9-22

9.5.2.1 Phase Refractive Index, Neglecting Collision Effects 9-229.5.2.2 Eckersley Dispersion Law 9-229.5.2.3 Nose Frequency 9-229.5.2.4 Effect of Ions, Neglecting Collisions 9-22

9.5.3 Theory of Hydromagnetic Waves : 9-239.5.4 Whistlers, Observations 9-239.5.5 Occurrence Statistics of Ionospherics 9-249.6 REFERENCES 9-26

CHAPTER 10. TRANSMISSION AND DETECTION OFINFRARED RADIATION

10.1 SOURCES AND DETECTORS 10-110.1.1 Infrared Radiation Sources 10-110.1.2 Infrared Detectors 10-110.1.3 Infrared Window Materials 10-210.2 ATMOSPHERIC ABSORPTION 10-210.3 ATMOSPHERIC EMISSION 10-610.3.1 Measurements from the Ground 10-710.3.2 Balloon Measurements 10-1510.3.3 Clouds 10-1510.3.4 Horizon Gradient (Limb Darkening) 10-1710.3.5 Satellite Measurements 10-1710.4 INFRARED CELESTIAL BACKGROUNDS 10-20

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10.4.1 Stellar Backgrounds 10-2510.4.2 IR Backgrounds Originating in the Solar System 10-2810.5 REFERENCES 10-36

CHAPTER 11. THE GEOMAGNETIC FIELD

11.1 UNITS, DEFINITIONS, AND MEASUREMENTS 11-111.1.1 Elements of the Geomagnetic Field 11-111.1.2 Magnetic Coordinates 11-211.1.3 Geomagnetic Measurements 11-211.2 THE MAIN FIELD OF THE EARTH . 11-711.2.1 Magnetic Charts 11-711.2.2 Analysis of the Main Field 11-7

11.2.2.1 Spherical Harmonic Analysis and Magnetic Dipoles . . . . 11-1711.2.2.2 Taylor Series Analysis 11-18

11.3 THE MAIN FIELD AT HIGH ALTITUDES 11-1811.3.1 Spherical Harmonic Extrapolation 11-1911.3.2 Taylor Series Extrapolation 11-1911.3.3 Comparison of Predicted and Observed Values 11-1911.4 TIME VARIATIONS OF THE GEOMAGNETIC FIELD 11-2811.4.1 Diurnal Variations and Direct Solar Flare Effect 11-2811.4.2 Magnetic Disturbances and Storms 11-2811.4.3 Magnetic Activity Indices 11-30

11.4.3.1 Indices K, a, and A 11-3211.4.3.2 Polar Range Index Q 11-3711.4.3.3 Variability Indices C, Cj, and Cp 11-3711.4.3.4 Difference Indices U, u, Uj and A 11-3911.4.3.5 Examples of the Activity Indices 11-39

11.4.4 Rapid Geomagnetic Variations 11-3911.5 THE DISTANT GEOMAGNETIC FIELD 11-4111.6 REFERENCES •. 11-61

CHAPTER 12. IONOSPHERIC PHYSICS

12.1 IONOSPHERIC REGIONS AND DISTURBANCES 12-112.1.1 Sudden Ionospheric Disturbance 12-112.1.2 High Latitude Absorption Events 12-212.1.3 F-Region Effects 12-212.2 ELECTRON AND ION DENSITY AND TEMPERATURE 12-212.2.1 Densities 12-212.2.2 Electron and Ion Temperatures 12-612.3 TOTAL ELECTRON CONTENT 12-612.3.1 Lunar Reflections, Cross Section, and Libration 12-612.3.2 Faraday Rotation of Plane of Polarization 12-1512.3.3 Variations in Electron Content 12-1512.4 NON-DEVIATIVE ABSORPTION 12-1512.4.1 Absorption in an Isotropic Medium : 12-1712.4.2 Effect of the Geomagnetic Field 12-2112.4.3 Effect of Electron Collisions With Ions 12-2512.4.4 Absorption Due to Collisions of Ions With Neutral Particles 12-2512.5 IONOSPHERIC WINDS 12-2812.5.1 Drift Directions 12-2812.5.2 Drift Velocities 12-3412.5.3 Characteristic Velocity 12-3512.5.4 Orientation of the Correlation Ellipse 12-3512.5.5 Axial Ratio of Correlation Ellipses 12-3512.5.6 Area of the 0.5-Correlation Ellipse 12-3612.6 SPORADIC E 12-3612.6.1 Worldwide Occurrence of Es 12-3712.6.2 Results of Analysis of Radio Amateur Data 12-3712.7 REFERENCES 12-53

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CHAPTER 13. AIRGLOW AND AURORAE

13.1 AIRFLOW 13-113.1.1 Spectrum 13-113.1.2 Intensity 13-113.1.3 Altitudes 13-113.1.4 Latitude Variation 13-113.1.5 Diurnal, Annual, and Secular Variations 13-2

13.1.5.1 Diurnal Variation 13-313.1.5.2 Annual Variation 13-313.1.5.3 Secular Variation 13-4

13.2 AURORA 13-413.2.1 Forms, Brightness, and Color 13-4

13.2.1.1 Form, Condition, and Structure 13-513.2.1.2 Brightness Index 13-513.2.1.3 Color Class 13-6

13.2.2 Spectrum 13-613.2.3 Altitudes 13-613.2.4 Occurrences and Variations 13-613.3 REFERENCES 13-29

CHAPTER 14. METEORITIC PHENOMENA

14.1 DEFINITIONS 14-114.2 METEOROID COMPOSITION AND DENSITY 14-114.3 METEOROID MAGNITUDE 14-114.4 INTERACTION WITH ATMOSPHERE 14-214.5 SPEED 14-414.6 METEOROID MASS AND FLUX 14-514.7 TEMPORAL VARIATIONS AND SHOWERS 14-714.8 METEOROID DAMAGE . . 14-814.9 REFERENCES 14-8

CHAPTER 15. THE SUN

15.1 BASIC CHARACTERISTICS OF THE SUN 15-115.2 STEADY-STATE FEATURES OF THE SOLAR ATMOSPHERE . . 15-115.2.1 The Photosphere and the Line Absorbing Layer 15-115.2.2 The Chromosphere 15-315.2.3 The Corona 15-515.3 ENERGY OF THE SUN 15-615.4 TRANSIENT SOLAR PHENOMENA 15-715.4.1 Prominences 15-715.4.2 Active Centers 15-1015.4.3 Flares 15-1115.5 PROTON SHOWERS IN SPACE NEAR EARTH 15-1215.6 TERRESTRIAL EFFECTS OF SOLAR EMISSIONS 15-1215.7 SOLAR TRANSIENTS AND WEATHER 15-13

CHAPTER 16. SOLAR ELECTROMAGNETIC RADIATION

16.1 SOLAR IRRADIANCE 16-116.1.1 Irradiance Outside the Earth's Atmosphere 16-116.1.2 Irradiance Within the Earth's Atmosphere 16-716.2 SOLAR ULTRAVIOLET AND X-RAYS 16-1016.2.1 Solar Spectrum, 3000 to 1800 A 16-1016.2.2 Solar Emission Lines, 1900 to 60 A 16-1016.2.3 Solar X Ray Emission 16-1216.2.4 Intensity of Radiation Below 3000 A 16-1216.3 SOLAR RADIO EMISSION 16-1816.3.1 Quiet Sun Temperature and Flux 16-18

16.3.2 Calculation of Solar Temperature and Flux from AntennaTemperature 16-21

16.3.3 Flux of the Slowly Varying Component 16-2316.3.4 Description of the Rapidly Varying Component 16-24

16.3.4.1 Meter-Wave Range (25 to 580 Mcps) 16-2416.3.4.2 Decimeter-Wave Range (500 to 950 Mcps) 16-2516.3.4.3 Centimeter-Wave Range (3000 to 30,000 Mcps) 16-25

16.3.5 The Disturbed Sun as a Radio Source 16-2616.4 REFERENCES 16-38

CHAPTER 17. CORPUSCULAR RADIATION

17.1 BASIC RELATIONS 17-117.1.1 Nomenclature and Definitions 17-117.1.2 Trapped Particle Motion in a Magnetic Field 17-217.2 TRAPPED RADIATION 17-317.2.1 Spatial Parameters of Trapped Particles 17-317.2.2 Injection and Loss of Particles 17-617.2.3 Measurements of Naturally Occurring Trapped Radiation 17-717.2.4 Protons 17-717.2.5 Electrons 17-1017.2.6 Man-Made Trapped Radiation 17-1017.3 , COSMIC RADIATION 17-1117.3.1 Composition and Energy 17-1217.3.2 Charged Particle Flux Within the Atmosphere 17-14

17.3.2.1 Latitude and Longitude Dependence 17-1417.3.2.2 Minimum Momentum 17-14

173.3 Flux Modulations 17-1417.4 HIGH ENERGY PARTICLES FROM SOLAR FLARES 17-1917.4.1 Composition, Rigidity, and Flux of Solar Cosmic Rays 17-1917.4.2 Variations in Time and Direction of Solar Cosmic Rays 17-2117.5 REFERENCES 17-31

CHAPTER 18. INTERPLANETARY SPACE AND THE SOLARATMOSPHERE

18.1 OBSERVATIONAL DATA FOR INTERPLANETARY SPACE . 18-118.1.1 Electron Densities 18-118.1.2 Interplanetary Magnetic Fields 18-218.1.3 Solar Wind ; 18-218.2 MODELS OF THE CORONAL ATMOSPHERE 18-218.2.1 Inverse Square and Semi-Empirical Models 18-218.2.2 Chapman's Model 18-318.2.3 Chamberlain's Models 18-418.2.4 Sen's Electric Field Models 18-518.2.5 Parker's Models 18-518.2.6 Alternate Interpretations of Parker's Equations 18-518.2.7 Scale Heights for the Solar Atmosphere 18-718.3 SOLAR AND INTERPLANETARY MAGNETIC FIELDS 18*718.3.1 Solar Magnetic Cycle and Sunspots 18-818.3.2 Interplanetary Magnetic Field and Distortion of Solar Dipole Field 18-918.3.3 Effects of Rotation on Magnetic Lines of Force 18-1118.4 SOLAR METEOROLOGY AND ENERGY TRANSPORT 18-1118.4.1 Solar Rotation 18-1118.4.2 Reynolds and Prandtl Numbers 18-1318.4.3 Transport Coefficients from Gas Kinetics 18-1318.4.4 Solar-Wide Atmospheric Motions 18-1418.4.5 Energy Transport Processes 18-1618.5 TENTATIVE MORPHOLOGY OF THE SOLAR CYCLE 18-1718.6 REFERENCES 18-19

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CHAPTER 19. THE LUNAR ENVIRONMENT\

19.1 ATMOSPHERE 19-119.2 THERMAL ENVIRONMENT 19-119.3 MAGNETIC FIELD 19-119.4 COMPOSITION 19-619.5 SURFACE AND SUBSURFACE STRUCTURE 19-619.5.1 Lunar Surface Roughness 19-919.6 LUNAR RESOURCES 19-1319.7 LUNAR MOTION 19-1319.7.1 Rotation and Librations 19-1319.7.2 Librations and the Lunar Mechanical Figure 19-1419.8 LUNAR GRAVITY FIELD 19-1419.9 SUGGESTED VALUES OF LUNAR CONSTANTS 19-1519.10 REFERENCES 19-16

CHAPTER 20. PLANETARY ENVIRONMENTS

20.120.1.120.1.220.220.2.1

20.2.220.2.320.2.420.2.520.2.620.320.3.120.3.220.3.320.3.420.3.520.3.620.3.720.3.820.3.920.420.4.120.4.220.520.5.120.5.220.620.6.120.6.220.720.7.120.7.220.820.8.120.8.220.9

MERCURYGeneralTabular Data for MercuryVENUSAtmosphere20.2.1.1 Clouds20.2.1.2 Pressure and Temperature20.2.1.3 CirculationThermal EnvironmentMagnetic Field

20-120-120-120-120-120-220-220-220-320-320-320-320-520-5

Surface FeaturesSatellitesTabular Data for VenusMARSAtmospheric Composition 20-5Atmospheric Structure 20-5Atmospheric Circulation 20-7Yellow and White Clouds 20-10Blue Haze 20-10Magnetic Field '. 20-11Surface Temperatures and Features 20-11Satellites 20-13Tabular Data for Mars . .' 20-13JUPITER 20-13Satellites 20-15Tabular Data for Jupiter 20-15SATURN 20-15Satellites 20-15Tabular Data for Saturn 20-16URANUS 20-16Satellites 20-16Tabular Data for Uranus .' 20-16NEPTUNE 20-16Satellites 20-16Tabular Data for Neptune 20-16PLUTO 20-17General 20-17Tabular Data for Pluto 20-17REFERENCES 20-19

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CHAPTER 21. ASTROPHYSICS AND ASTRONOMY

21.1 GENERAL SURVEY 21-121.2 DEFINITIONS, UNITS, AND BASIC RELATIONS 21-121.2.1 Time, Distance and Motion; Solar Values as Units 21-121.2.2 Celestial Coordinate Systems 21-4

21.2.2.1 Horizon System (Azimuth and Altitude) 21-421.2.2.2 Equatorial Systems 21-421.2.2.3 Conversion Between Horizon and Equatorial Systems . . . . 21-721.2.2.4 Ecliptic System 21-721.2.2.5 Galactic Systems 21-7

21.2.3 Names and Categories of Stars 21-721.2.3.1 Supergiants, Giants, Dwarfs, and White Dwarfs 21-721.2.3.2 Binary and Multiple Stars 21-7

21.2.4 Stellar Magnitudes 21-921.2.5 Color Index and Photometric Color Systems 21-1021.2.6 Spectroscopic Terminology 21-1021.2.7 Curve of Growth '. ". 21-1021.2.8 Spectral Type and Temperature 21-1121.2.9 Saha Theory of Ionization 21-1221.2.10 Luminosity, Temperature, and H-R Diagrams 21-1221.3 STELLAR MASSES AND LUMINOSITIES 21-1421.3.1 Direct Measurement of Mass 21-1421.4 CLASSIFICATION OF STARS 21-1421.4.1 Luminosity Criteria 21-14

21.4.1.1 MK (Luminosity Class) System 21-1421.4.1.2 Two-Color Diagram (U — B vs B — V) 21-15

21.4.2 Quantitative Methods of Spectral Classification 21-1721.4.2.1 Barbier-Chalonge Classification 21-1721.4.2.2 Stromgren's Narrow-Band Photometry 21-18

21.5 INTERSTELLAR GAS AND DUST 21-1821.5.1 Interstellar Absorption Lines 21-1821.5.2 Interstellar Gas Clouds 21-1921.5.3 Interstellar Reddening and Color Excess 21-19

21.5.3.1 Interstellar Dust and Polarization 21-1921.5.3.2 Statistically Corrected Distance of a Star 21-19

21.5.4 Relation of Dust Clouds to Gas Clouds 21-1921.6 STELLAR EVOLUTION 21-2021.6.1 Nuclear Reactions, Stellar Interiors, and H-R Diagrams 21-2021.6.2 Loss of Mass During Evolution 21-2121.6.3 Populations I and II 21-2121.6.4 Clusters and Associations 21-21

21.6.4.1 0 and T Associations 21-2121.6.4.2 Galactic (Open) Clusters 21-2221.6.4.3 Globular Clusters 21-22

21.6.5 H-R Diagrams of Clusters 21-2221.7 INTRINSICALLY VARIABLE STARS 21-2321.7.1 Dwarf Irregular Variable Stars 21-23

21.7.1.1 T Tauri Stars : 21-2321.7.1.2 Flare or UV Ceti Stars 21-2321.7.1.3 U Geminorum (SS Cygni) Stars 21-24

21.7.2 Pulsating Stars . 21-2421.7.2.1 RR Lyrae Stars 21-2621.7.2.2 Cepheids 21-26

21.7.3 Novae and Supernovae 21-2721.8 DETERMINATION OF STELLAR DISTANCES 21-2721.8.1 Parallax and Proper Motion 21-2721.8.2 Spectroscopic Methods 21-2821.8.3 The Period-Luminosity Relation 21-2821.8.4 The Distance Scale 21-2821.9 GALAXIES 21-2821.10 REFERENCES 21-29

CHAPTER 22. RADIO ASTRONOMY

22.1 ' FUNDAMENTAL CONCEPTS AND DEFINITIONS 22-122.2 EFFECTS OF THE EARTH'S ATMOSPHERE 22-222.2.1 Refraction 22-222.2.2 Scintillation 22-322.2.3 Absorption 22-322.3 RADIO EMISSION FROM THE MOON AND PLANETS 22-322.3.1 The Moon 22-322.3.2 The Planets 22-5

22.3.2.1 Mercury , 22-522.3.2.2 Venus 22-522.3.2.3 Mars 22-522.3.2.4 Jupiter 22-522.3.2.5 Saturn 22-5

22.4 SOURCES OF RADIO EMISSIONS 22-522.4.1 Maps of Background Radiation 22-522.4.2 Discrete Sources v 22-722.5 HYDROGEN 21-CM LINE 22-722.6 OH LINE AT 18 CM 22-922.7 REFERENCES 22-15

APPENDIX A —UNITS, CONSTANTS, AND CONVERSIONFACTORS

APPENDIX B —BLACKBODY RADIATION

INDEX

xix