National Bureau of ^f. ,

jioulder laboratories

PB 16162 9

92o. 128

BIBLIOGRAPHY ON AURORAL

RADIO WAVE PROPAGATION

^

BY

WILHELM NUPEN

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
THE NATIONAL BUREAU OF STANDARDS

Functions and Activities

The functions of the National Bureau of Standards are set forth in the Act of Congress, March 3, 1901, as amended by Congress in Public Law 619, 1950. These include the development and maintenance of the national standards of measurement and the provision of means and methods for making measurements consistent

with these standards; the determination of physical constants and properties of materials; the development of methods and instruments for testing materials, devices, and structures; advisory services to government agencies on scientific and technical problems; invention and development of devices to serve special needs of the Government; and the development of standard practices, codes, and specifications. The work includes basic

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and various consultation and information services. Research projects are also performed for other government

agencies when the work relates to and supplements the basic program of the Bureau or when the Bureau's

unique competence is required. The scope of activities is suggested by the listing of divisions and sections on the inside of the back cover.

Publications

The results of the Bureau's research are published either in the Bureau's own series of publications or

in the journals of professional and scientific societies. The Bureau itself publishes three periodicals avail- able from the Government Printing Office: The Journal of Research, published in four separate sections,

presents complete scientific and technical papers; the Technical News Bulletin presents summary and pre- liminary reports on work in progress; and Basic Radio Propagation Predictions provides data for determining

the best frequencies to use for radio communications throughout the world. There are also five series of nonperiodical publications: Monographs, Applied Mathematics Series, Handbooks, Miscellaneous Publications, and Technical Notes. A complete listing of the Bureau's publications can be found in National Bureau of Standards Circular 460, Publications of the National Bureau of Standards, 1901 to June 1947 ($1.25), and the Supplement to National Bureau of Standards Circular 460, July 1947 to June 1957 ($1.50), and Miscellaneous Publication 240,

July 1957 to June 1960 (Includes Titles of Papers Published in Outside Journals 1950 to 1959) ($2.25); avail- able from the Superintendent of Documents, Government Printing Office, Washington 25, D. C.
NATIONAL BUREAU OF STANDARDS

technical ^^ote

No. 128

January 12, 1962

BIBLIOGRAPHY ON AURORAL RADIO

WAVE PROPAGATION

by

Wilhelm. Nupen

Prepared by

American Meteorological Society

Meteorological & Geoastrophysical Abstracts

NBS Technical Notes are designed to supplement the Bureau's regular publications program. They provide a means for making available scientific data that are of transient or limited interest. Technical Notes may be

listed or referred to in the open literature. They are for sale by the Office of Technical Services, U. S. Department of Commerce, Washington 25, D. C.

DISTRIBUTED BY

UNITED STATES DEPARTMENT OF COMMERCE

OFFICE OF TECHNICAL SERVICES

WASHINGTON 25, D. C.

Price $ 2.75

TABLE OF CONTENTS

Introduction

Subject Outline iii

Geographical Outline xxiii

Chronological Index xxix

Bibliography on Auroral Radio Wave Propagation.

Author Index 105

Note:

Abstractors; Bibliography on Auroral Radio Wave Propagation

MGA Staff Members;

A. A Andrew Assur

R. B Ronald Baker

C. E. P. B. . . C. E. P. Brooks

I. L. D Isadore L. Dordick

A. K Ajmal H. Khan

A. J. M Andrew J. Meglis

N. N Nndem E. U. Nndem

W. N Wilhelm Nupen

A. M. P. . . . Alexis M. Poushkin

M. L. R. . . Mary L. Rice

M. R Malcolm Rigby

I. S Ismail Saad

N.P. S. . . Nicholas P. Setchkin

E. Z. S. . . Evelyn Z. Sinha

O. T Otto Taborsky

G. T Geza Thuronyi

A. V Andre Vandenplas

Others

;

L. A. M L. A. Manning

S. F S. Fritz

IRE, Proc Institute of Radio Engineers, Proceedings

Phys. Abstr Physics Abstracts

Sci. Abstr Science Abstracts

Library Symbols;

DBS U. S. National Bureau of Standards, Washington, D. C.

DGS U. S. Geological Survey, Washington, D. C.

DLC Library of Congress, Washington, D. C.

DWB U. S. Weather Bureau, Suitland, Maryland

DN-HO U. S. Navy Hydrographic Office, Suitland, Maryland

INTRODUCTION

The present compilation is presented as the third of a series of

bibliographies in preparation by Meteorological and Geoastrophysical

Abstracts for the Boulder Laboratories of the National Bureau of Standards.

Several such bibliographies, all on the general subject of electromagnetic (radio) wave propagation in the atmosphere or ionosphere,

are being published in the ITBS, Technical Notes Series. The first

bibliography entitled "Bibliography on Ionospheric Propagation of Radio

Waves (1923-19S0)" was published in October 1960, as NBS, Technical

Note, No. 84, and is available from United States Department of Commerce, Office of Technical Services, Washington 25, D. C.(PB 161585).

Price $7. 00. It contains 1404 references, mostly annotated. The second: " Bibliography on Meteoric Radio Wave Propagation", containing

368 items, was published in May 1961 as K^bs Technical Note No. 94

(PB 161595). Price $2. 75.

Similar bibliographies in preparation on

" Radio Astronomy^ and on

"Tropospheric Propagation of Radio Waves" will be published in 1962.

The present compilation is made up of about 300 abstracts or titles

from the literature published during the period 1893-1961. It is thus

only a portion of the international literature on radio-auroral research.

Omissions of pertinent papers are involuntary and it will be greatly

appreciated if brought to our attention so they may be included in future

supplements.

Auroral effects on radio waves were known before Oscanyan, in

1929 (C -222), actually observed the influence of visible aurora on radio

communication. International research lagged until 1938, when Harang

and Stoffregen discovered and identified auroral VHF scattering. Wliere- as at first the disturbances attending the aurora v/ere considered only

as a nuisance to radio communication, the auroral effects have now

been exploited as a new and enhanced mode of communication and a

tool for further exploration and research into the physical characteristics
11

of the atmosphere.

For the most recent systematic discussion of the * Radio Aurora*,

the reader should consult Chapter 6 of the new (1S61) book **Physics of

the Aurora and Airglov/'. by J. W. Chamberlain of Yerkes Observatory.

This excellent review of the subject was received after the present bibliography had been completed and indexed; hence it has been added as

a supplementary item (C-297).

V7e wish to express our appreciation to Mrs. Evelyn Z. Sinha for

her assistance in locating and editing much of the material in the files

of M&GA; to Mr. Otto Taborsky for preparing the geographical outline;

to Miss. Muriel Haas for checking the accuracy of the bibliographic

entries; and to Mrs. Doris Nickey for typing and correcting the manuscript. Finally, we wish to acknowledge the very considerable help

rendered by various members of the staff of the National Bureau of

Standards, Boulder Laboratories, especially Mr.. Bradford R. Bean, who

has given us guidance and has coordinated our efforts with those of the

Boulder Laboratories.

Additions and corrections should be addressed to:

Malcolm Rigby, editor

Meteorological & Geoastrophysical Absts.

P.O. Box 1736, Washington 13, D. C.
Ill

SUBJECT OUTLINE

I. GENERAL WORKS

1. Textbooks, monographs, manuals. C -7, 32, 40, 59, 126, 145,

172, 200, 202, 234, 241, 255, 259, 275, 277,

283, 297

2. General reviews and surveys. C-6, 28, 49, 76, 88, 117, 159,

160, 165, 173, 247, 275, 276, 297

3. Data publications. C-3, 4, 9, 13, 16, 18, 28, 37, 38, 47, 56, 57,

64, 66, 82, 83, 86, 87, 108, 109, 112, 118, 120,

125, 156, 165, 174, 187, 188, 192, 203, 204,

215, 216, 249, 257, 273, 277

a. Statistical data. C-66, 184, 187

b. Analyses. C -21, 22, 35, 38, 87

4. Theses. C-35, 82, 260

5. Maps and nomograms. C-3, 4, 6, 22, 47, 215

6. Bibliographies. 0-9, 11, 49, 64, 72, 105, 137, 143, 160, 163,

175, 202, 224, 255, 276

7. History. C -8, 23, 24, 57, 76, 221, 222, 251-254, 260, 266-269,

291

8. Conferences, symposia. C-38, 54, 64, 68, 111, 149, 171, 177

9. Research programs. C-5, 111, 226, 244

a. Expeditions. C -129, 221, 287

b. I. G. Y. C-54, 55, 57, 69, 104, 149, 159, 232, 245, 246, 293

10. Nomenclature. C-14, 63, 76, 95, 108, 110, 126, 168, 171, 172,

179, 209, 257, 288
IV

II. THEORIES

Alfven's C-7

Appleton'e C-161

Birkeland's C-23, 24, 71

Birkeland and Stormer's C-7, 253

Booker's / scattering C-30, 84, 86

Booker, Gartlein and Nichol's C-S4

Chamberlain's C-48

Chapman-Ferraro-Martyn's C-45, 86, 151, 247, 296

Harang and Landmark's C-84, 127, 174

Hulburt's C-71

Lindquist / Polar blackout C-172

Martyn's C-198

Meinel and Schulte C-174

Moore's / Trail analogy C-37, 84

Moore's C -207, 208

Peterson's C-149

Stormer's C.41, 71, 86, 215, 251-253

Vegard's C-71, 276

Miscellaneous

Aurora C-169

Auroral echo hypothesis C-164 , Auroral mechanism C-161

Auroral noise C-91

Electric field theory C-7

Experimental testing of theories C-52

Ionosphere C-72

List of German theories C-137

Modes of reflection C-174

Molecular diffusion C-31

Plane earth C-16

Review of current theories C-49, 275, 297

III. FORMULAS

Auroral radar C-166

Determination / propagation constant C-13

Radar C-166

Small scale eddies C-31
IV. MODELS

1. Theoretical

Atmosphere C-259

Atmosphere, upper C-209

Atmosphere, underdense ionosphere C-233

Auroral ionization C-203

Protons C-259

SC magnetic storms and aurora C-247

Other C-112, 185

2. Experimental (laboratory) models

Bennet's C-296

Birkeland 's C -23, 24, 253

Briiche's C-41

Malmfors' C-7

Torus space C-71

V. ATMOSPHERIC AND COSMIC STRUCTURE AND PHYSICS

1. Atmospheric Stratification

a. Troposphere C-31

Arctic C-9

Thunderstorms C-138

b. Ionosphere C-158

Ionospheric disturbances C-9, 11, 18, 21, 31, 95, 121,

155, 168, 196, 213, 265

Large eddies C-31

Small eddies C-31

Elongated irregularities C-213

Ionized columns C-28, 30, 38, 174, 207, 242,

271

Ionized columns diam. C-208

Spiral patterns C-121

Arctic disturbances C-33

Measurements C-19, 27

Currents C-39

SID C-65

c. Upper atmosphere C-193, 194

Electric currents C-24
VI

2. Layers

a. D-region C-11, 78, 131, 162, 223, 228, 238

Damping effect C-162

Disturbed periods C-16

b. E-region C-18, 22, 30, 60, 74, 75, 79, 94, 182, 211, 216,

213, 223, 228, 235, 256, 278, 291

Eg C-75, 79, 83, 85, 119, 127, 136, 139, 140, 156, 194,

197, 200, 219, 229, 231, 241, 285

Diurnal variation C-83, 173

Seasonal variation C-173

Classification C-227

E2s C-79

Spiral occurrence C-79

N, C-136

Gloving E c-13

c. F-region C-18, 60, 74, 107, 119, 140, 210, 229, 245, 278

Irregularities C-16, 18, 72, 131, 196, 223

Irregularities - height C-16

Overhead changes C-18

Tilt C-248

F^ reflections C-18, 79, 286

F2 C-22, 74, 79, 194, 195, 216, 288

Reflections C-18, 22, 227

d. Other

Absorbing layers C-102

Below E C-27

Structure C -225, 237

Auroral C-18, 46, 141

Layer height C-46, 124, 139, 140, 197

Inbreak layers C-168

Horizontal layers C -116, 270

3. Clouds

Cirrus C-24

Ionization clouds C-103, 119, 151, 258

Velocity C-119

Luminescent clouds C-61, 176
Vll

4. Winds C-112,211

Norwegian anticyclones

Vertical air movement C-124

5. Outer atmosphere C-92

Exosphere, fluctuations C-118

6. Miscellaneous

Temperature measurements C-65, 78

Plasma oscillations C-95

Air glow C-54, 193

Night air glow C-14

Atmospheric electricity C-9, 146

7. Stellar bodies

a. Meteors C-10, 168

Trails C-31

Influences C-72, 84, 228, 231, 291

b. Radiostars

Scintillation C-30, 31, 40, 149, 175, 280

c. Moon C-95, 147

Moonlight C-12

d. Sun

Solar activity C-9, 21, 60, 94, 142, 157, 168, 249,

257, 273, 288, 291, 294

Activity variation C-82

Solar flares C-5, 11, 133, 168, 235, 281, 289

Solar sunspots C-5, 93, 45, 50, 146, 223

Solar sunspot maximum C-5, 6

Solar streamers C-51, 60, 196

Density C-51

UV light C-56

Solar corpuscles C-58, 60, 117, 121, 172, 194, 247

Equinoxes C-19, 28

Mogel-Dellinger effects C-168
Vlll

VI. AURORAL PHENOMENA

1. Types

Artificial C-14, 23, 24

Australia C-53, 57, 129, 242

Borealis C-10, 13, 34, 37, 38, 53, 61, 94, 129, 134, 176,

231, 261, 274

Visible C.2, 34, 38, 43, 58, 84, 103, 109, 110, 115, 116,

149, 156, 174, 179, 182, 199, 219,

222, 223, 230, 243, 265, 281, 282,

234

Subvisual C-80

Invisible C-200

Low frequency type C-149

Overhead C-65, 174, 208, 287

Luminous C-58, 115

Red C - 126, 133, 236, 294

"Radio aurora" C -63, 297

2. Forms

Homogenous C-38

Rayed C-38, 67, 101, 109, 179

Pulsating 0-139, 140, 190

Nonpulsating C-139

Daytime form C-166, 233

Night time form C-166, 233

Curtain form C-138, 161

Curl form C-179

Diffuse C-174

Flaming C-190

Bright displays C-95, 156

3. Classification C-181

Generation C-10, 12, 14, 56, 97, 161, 175, 276

4. Aurora structure

Spectra C- 14, 117, 277

Monochromatic arc C-14

Reflecting light C-73

a. Streamers 0-61, 138, 176, 219

Rayed structure C-67, 179

Rays C-48, 53, 258

Rays, diameters C-48
IX

Curtains C-161

Curls C-179

Atomic rays C-14

Cosmic rays C-11, 146, 289

Hydrogen rays C-14

Oxygen rays C-14, 58

Red rays C-80, 91

Nitrogen rays C-14

X - rays C-56

Nitrogen bands C-218

Calcium C-11

b. Arcs C-138, 141, 154, 179, 199

c. Rings C-71, 296

d. Particles C-90, 110. Ill, 164

Protons C-1, 48, 56, 58, 112, 259

Proton gyrofrequency C-118

1 Mev protons C-207

CL photons C-58

Atomic ions C-11

Molecular diffusion C-31

Nitric oxide molecules C-56

Particle mass C-110

Particle flux C-133

Particle bombardment C-285

Particle radiation C-288

Particle precipitation

Precipitation, spiral C-120, 121, 161

Particle interaction C-110, 112, 113

5. Auroral aspects

Auroral activity C-9, 11

Auroral periodicity C-10

Diurnal variation C-114

Auroral aspect classification C-63

Aspect sensitivity C-39, 103, 233, 271

Auroral movements C-10, 43

Auroral movement speed C-43

Movements, horizontal C-154

Auroral depth range C-26, 46
Auroral corona discharges C-138

Brush discharges C-138

Electric discharges C-46, 48

Auroral luminosity C-58, 110, 139, 192, 212, 218, 232, 289

Auroral display intensity C-50, 97, 197

Auroral interaction C-110, 112, 113

Auroral noise C-50

Auroral audibility C-138

Auroral radiation C-209

Auroral mechanism C-86, 117, 161, 277

6. Miscellaneous

Laboratory experiments C-7, 23, 24, 41, 64, 71, 111, 117

Spectrograms C-118

7. Auroral zones, regions, layers

a. Zones C-78, 80, 84, 89, 104, 118, 154, 164, 189, 194, 246,

257, 286, 290

Absorption zone C-2, 11

Attenuation C-5

Micropulsations C-1

b. Regions C-58, 119, 149

Subauroral regions C-149

Minauroral regions C-210

c. Layers C-18, 46, 141

Layer heights C-46, 124, 139, 140, 197

Inbreak layers C-168

Vn. PHYSICO-CHEMICAL FACTORS AND PROCESSES

1. Magnetic activities C -3, 6, 9, 23, 82, 88, 91, 108, 109, 115,

211, 213

Periodicity C-56, 95

Magnetic field state C-79, 213

Magnetic field lines C-17, 25, 53, 247, 279

Magnetic pole C-157, 159

Magnetic equator C-39

Magnetic micropulsations C-1

Magnetic ground currents C-239

Magnetic light C-198

Magnetic relationships C-114, 139, 159
XI

2. Magnetic storms and disturbances

Storms C-7, 86, 93, 122, 125-127, 142, 180, 181, 200,

218, 259, 280, 288

Disturbances C-11, 17, 20, 21, 33, 65, 80, 92, 95, 118,

121-123, 151, 168, 173, 189, 198,

199, 212, 215, 232, 235, 236, 244,

258, 266-269, 278, 279, 281, 282,

284, 294

SC C-121 180

Bays C-60, 140, 151, 194, 247, 285, 289

Positive C-198

Negative C-198

Miscellaneous

Earth's declination C-131

Earth's lines of force C-150, 152, 174

Earth's rotation C-8, 154

3. Ionization C-16, 30, 45, 62, 68, 102, 104, 133, 139, 140, 141,

149, 151, 159, 166, 207, 229, 278,

291

Density C-22, 61, 212

Distribution C-148, 188, 196

Height of maximum ionization C-139, 219

Photoionization C-19

Drifts C-20, 43, 45, 148, 151, 196, 211, 212

Low level ionization C-235

Ionizing agents C-172

X-rays C-56

Clouds C-103, 119, 151, 258

Cloud velocity C-119

Columns C-207, 271

Columns diameter C-208

Horizontal layers C-116, 270

Mechanism C-56, 171, 203, 204, 218, 219

Maintenance C-259

lonograms C-210
xii

4. Electron characteristics

Density

3

per cm

3

per m

4X lO"^ C-101 3 X 10-^^

> 4 X lo"* C.141

10^ C-51 2

per cm

5 X 10^ C-211 6 X 10^^

6X 10^ C-10

10^ C-48, 51 2

per m

< 2. 6 X lo'^ C.141 10-"

2. 6 X lo"^ C-295

4 X lo"^ C-67

6. 5 X lo"^ C-295

10^ C-48, 100

1.4 X 10^ C-67, 218

loii C-98

C-204

C.48

C.147

Density, general C-30, 40, 48, 100, 107, 126, 161, 207, 211,

232, 235, 274

Maximum height C-140

Electron energies C-14, 58

Gyro power C-13, 67

Penetration C-58

Radiation C-41

Flux C-48

Flux, primary C-58

Flux, secondary C-58

Speed C-211

Collision frequency

Fast electrons C-14
Xlll

5. Reflection C-21, 43, 45, 51, 53, 61, 67, 70, 73, 76, 82, 86, 101,

107, 123, 199, 240, 256

Characteristics C-22, 107, 192, 204

Mechanism C-102, 164, 182, 185, 219, 242, 278

Diurnal variation C-28, 82

Seasonal variation C-28, 82

Oblique C-11, 16, 17, 89, 107, 114

Ground C-28

F-^ C-18, 79, 286

F2 C.18, 22,227

"Reflecting wall" C-76

6. Reflection distances

^ 100 km

8-20 km C-125, 126

17 km C-125

j> 200 km

32 km C-58

50 km C-56

75-90 km C-256

80 km C-58, 182, 219,

256

60-100 km C-125

93 km C-243

100 km C.118, 130,

213, 219

> 100 km C-172

90-160 km C-106

100-120 km C-128

110 km C-46, 270, 279

110-120 km C -272, 273

116-165

120

125

<125

150-200

200

C-243

C-136, 232

C-258

C-43

C-126

C -141, 258

> 500 km

80-300 km

100-300 km

200-400 " 300

350-500 "

C-213

C-10

C-126

C-240

C-16

> 1. 000 km

300.1,200 km C-248

500-1,100 " C-84

500-2,500 " C-126

600-1,100 " C-101

1,400 " C-260

1, 400-4, 700 km C-164

li000 km

80-1, 000 km C-117

400-730 ' C-128

400-800 • C-125, 126

500-800 • C-126

500-900 • C-184

600 C-174

900 C-284

480 miles C-61
XIV

7. Absorption C-58, 88, 96, 139, 140, 155, 171, 175, 177, 190, 191,

197, 215, 223, 235, 238, 285, 286, 289

Nighttime C-11, 155

Daytime C-11, 56

Nondeviate C-56

Height C-219

8. Radiation C-60, 78, 118, 209, 250

Cosmic C-11, 96, 146, 289

Soft C-56

Van Allen belts C-88

Particle radiation C-19, 78, 79, 146, 288

Photon C-218

Electron C-41

Lyman QC C-56, 58

Zones C-215

Maps C-215

Wave radiation C-79

UV C-78, 146, 159

X C-6, 14, 19, 56, 194, 289

Thermal radiation C-78, 250

Miscellaneous C-209

From empty sky C-65

Cerenkov radio emission C-90

VIII. RADIO COMMUNICATION

1. Propagation

Forward scattering C-2, 11, 29, 31, 235

Anomalous ionospheric propagation C-34

'Super propagation" C-257

Propagation constant C-13

Miscellaneous

Skip effect C-205
XV

2. Freauencies

< 10 Kc/s

20 - 200 Cps C-118

750 wt C-1

10 Cps-10 Kc/s C.118

1.3 IF C-118

3-5 r C-91

4.5 B C-118

8

fr C-191

10 Kc/s - 1000 Kc/s

18 Kc/s C-230

2-30 n C-91

2-40 w C-91

100 (r C-77

180 C-77

330 c C-256

770 t C-249

1 Mc/s - 10 Mc/s

2 Mc/s C-78

3

n C-258

4.6 n C-80

5 - 6

i> C-79

6

tr C-195

6.42 n C.229

3-8 * C-123

8

» C-5

3-9 1 C-126

9.44 Ml C-25

10 n C-5, 21

10 Mc/i3 - 20 Mc/s

11 Mc/s C.5

12 K C -174, 223

12.86 n C-229

7-13 » C-126

14 m C-292

15 K C-5

1-16 (t C-r72

2-16 n C-195

16.7 n C-260

19 w C-260

17.31 " C-70, 229

18 w C-96

1-20 «c C-219

20 •• C-225

20 Mc/s - 30 Mc/s

1-25 Mc/s C-17

25 n C-174

25.4 w C-36

28 •* C-264

15-30 fr C-222

30 ii C-3,235

30 Mc/s - 40 Mc/s

32 Ma/s C-85, 132

33 » C- 182, 228

35 (t C-127

36 •• C.116

40 Mc/s - 50 Mc/s

41 Ma/s C-17, 170

41.15 m C-211

43 n C-95

44.10 n C-95

46 m C -61, 295

48 n C-188

48.2 n C-178, 179

48.5 r C-187

30-50 n C-62, 204

32-50 •r C-102

43-50 w C-264

50 M C-34,81,82,83,

113, 174, 186,

265

50 Mc/s - 100 Mc/s

51.9 Ma/s C-84

53 •1 C-132

50-54 n C-265

55 It C-108, 270, 272,

273

56 « C-67, 100, 183,

264

69 > C-242

72 » C-45, 61, 295

74 M C-127

80 n C-60

82-88 •• C-262

100 m C-38, 174
XVI

100 Mc/s - 150 Mc/s

106 Mc/s C.37,67, 174,

183, 211

106.1 •1 C-240

106.5 • C.99, 100, 10]

112 n C-264

140 li C-85

28-148 II C-205

25-150 II C-38

150 Mc/s - 500 Mc/s

210 Mc/s C.166

398 C.166

400 C-167

488 C-25, 26, 166

500 C-133

500 Mc/s - 3000 Mc/s

1,306 Mc/s C-86

2,800 " C-65

3,000 " C -67, 97,99

b. Other frequencies

Audio frequency bands C-1, 118, 127, 205, 206

LF C -90, 91,1 18, 230, 256

HF C -5, 88, 199, 227, 260, 290

VHF C-11, 17, 29, 37, 38, 81-83, 132, 155, 170, 175, 188,

199, 200, 205, 211, 227, 233, 235, 271

UHF C-25, 94, 147, 175, 233

Choice of frequency C-72

3. Communication links

Telephone C-IS

Telegraph C-15

Shortwave C -122, 217, 244

Amateur communication C-34, 165, 264

FM C.95

TV C-174, 262

Networks C-63, 69, 245

Communication forecasting C-94, 165, 217

Communication geometry C-165

Communication enhanced C-237

4. Communication conditions

a. Transmission

Over auroral paths C-5, 17

VHF scattered transmissions C-29

AM speech transmissions C-34

Experimental Transmissions C-82, 174, 201, 223, 237, 257
XVll

b. Reception

TV C- 174, 262

FM C-95

5. Communication disturbances

Polar blackouts C-3, 4, 6, 66, 121, 158, 171-173, 194, 285

287, 290

Types C-6

Latitude variation C-6

Contour plots C-3, 4

Magnetic disturbances C-7, 11, 17, 20, 21, 33, 65, 80, 86,

92, 93, 95, 118, 121-123, 125-127,

142, 151, 168, 173, 180, 181, 189,

199, 200, 212, 215, 218, 232, 235,

236, 244, 258, 259, 266-269, 278-

282, 284, 288, 294

Topographical C-221, 222

Blocking C -15, 115, 142, 221, 236, 265, 292, 294

Noise C-60, 77, 80, 88, 90, 91, 96, 132, 175, 228, 242,

289

Cosmic noise C-11, 77, 235

Energy C-118

Signal origin C-118

Chorus C -209, 228

Sferics C-9, 162, 221, 222

Whistlers C-87, 207

Hiss C-1, 77, 138, 191

Flutters C-292

Clicks C.138

Grinders C-138

Miscellaneous effects C-15, 71, 122, 135, 180, 181, 222,

230, 266-269

On TV channels C-262

Nuclear e:qplosions C-168

Ice masses C-244

M5gel -Bellinger effect C-168

Faraday effect C-175

Doppler effect C-26, 28, 36, 38, 39, 95, 112, 167,

185, 219
XVlll

6. Paths

Distances

L25 Km C-93

250 ' C-243

480 ' C-295

325-500 • C.243

800 ' C-84

860 C.102

1, 000 C-29

2. 000 ' C-29

5, 200 C-220

15, 000 •

• C-244, 286

25, 000 ' C-244

Miscellaneous

Secondary paths C-33

Great circle paths C-153, 257

Dark hemisphere paths C-11, 60, 151

IX. WAVE CHARACTERISTICS

1. Scattering C-28, 29, 116, 174, 126, 200, 207

Sources C-17, 102, 210

Mechanism C-63, 200, 203, 204

Ground C-16, 223

Back scatter C-31, 127, 200, 213, 223

Forward scatter C-31, 235

2. Waves

USW C.125, 126, 160

Short C-160, 274, 286

Cosmic radio waves C-96

Gyro waves C-13

Shock waves C-13

Radio wavelengths

10 cm C-50, 98

4 m C-279

7.3 " C-125

8 " C -73, 279

10 " C-33, 136, 200

23 " C-86

37. 08 m C-257

50 m C-221

84 '• C-18

86 " C-278
3C1X

X. ECHO CHARACTERISTICS

1. Echo types

Delayed echoes C-8, 42

Diffuse echoes C-46, 134, 166, 229, 233

Discrete echoes C-17, 134, 166, 233

E echoes C-123, 126

Slant E echoes C-17, 19, 156, 168, 173

s F echoes C-123, 126

F, echoes C-16

"Life-timed" echoes C-126

Meteor echoes C-175, 182

Moon echoes C-147, 175

Radar echoes C-178, 179, 192, 199, 208, 211, 212, 219

Radio echoes C-183, 219

Scatter echoes C-182, 183

SW echoes C-274

UHF echoes C-81

World wide echoes C-76, 260

2. Echo analysis C-35, 38-40, 43, 119, 127, 164, 176, 187,

188, 200, 273

Echo geometry C -47, 53, 103, 129, 229, 271, 272, 279

Echo directions C-84, 167, 177, 178, 270, 272

Echo polarization C-34, 123, 147, 152, 184, 205, 270

Echo spectra C-167, 185, 207, 208

Echo amplitude C-11, 81, 100, 118, 127

Echo distribution C-45, 103, 105, 160

Echo ranges C-128, 211, 295

Echo angle of arrival C-8, 25, 110, 128

3. Echo fading C-30, 39, 110, 122, 126, 172, 241, 278, 288, 290

4. Miscellaneous

Echo absence C-99

"No echo periods" C-288
XX

XI. METHODS and TECHNIQUES of OBSERVATION

1. Radar methods C -21, 22, 25, 26, 38, 62, 69, 84, 97, 98, 101,

108, 134, 136, 188, 233

Simultaneous radar - photographic C-38

2. Radio methods C-10, 14, 129, 193, 203

Experimental transmissions C-38

Cross modulation C-171

Spaced transmitter-receiver technique C-25, 26, 63, 92,

123, 126, 147, 225

Monitoring techniques C-18, 37, 100, 101, 127, 147, 225

Soundings C-83, 107, 158, 245

Echo method C-72

3. Various techniques

Drifting station (SP-3) observations C-79

Rocket methods C-14, 58, 193

Satellite methods C-225

Ship observations C-180

Optical observations C-36, 201

Photographic observations C-97, 101, 144

Tape recording C-38

C W - techniques C-81, 167, 171

Pulse method C-81

Interference method C-128

Spectrographic observations C-69

Method for separating Es and auroral ionization C-83

Method for obtaining sudden absorption of cosmic noise

C-96

Method for auroral detection C-14

Method for probability of occurrence of polar blackout

C-4,6

Method for change of frequency C-72

Method for utilizing scaled data to obtain echo activity

index C-170

Visual method of influence of atmospheric conditions on

radio reception C-201

XII. INSTRUMENTS and EQUIPMENT

Antennas

Multivibratory C-22

Semivibratory C-22

Parabolic C-22

Directional C -29, 81, 97, 127
XXI

Antennas (cont'd.)

Rotary C-89, 136

Continuously rotating C-84

Receiving C-34

Transmitting C -34

YAGI C-127

Half wave C-12

Automatic equipment C-195

Balloon borne instruments C-289

Cameras C-22, 144

Experimental equipment C-291

Experimental separation system of ground wave and sky

waves C-201

Fading rate counters C-122

Ionospheric recorders C-256

lonosondes C-210

Low power radio equipment C-281

Low sensitivity equipment C-279

Magnetometers C-132

Oscillographs C-22

Panoramic recorders C-172

Photomultipliers C-132

Radars C-21, 25, 101, 106

Bistatic type C-25, 106

Equipment C-26, 62

SCR 270 C-37

50 Mc C-186

Continuous recording automatic radars C-186

VHF radars C-170, 188

400 Mc C-167

Double Doppler C-185

L-band C-86

Low power FM radars C-62

High power pulse systems C-62

Ship borne radars C-85

L band radars C-86

Mc Namara's radar system C-283

Rockets C-14

Satellites

Explorer VI C-88

Sounding equipment C-19

Spectrographs C-69

Spectrometers C-69
XXll

Miscellaneous

Description of instruments C-126, 129, 134, 152, 170,

218, 222, 232, 241

Modulation system design C-29

Design considerations / radars C-291
XXlll

GEOGRAPHICAL OUTLINE

A. HEMISPHERES AND REGIONS

1. Northern Hemisphere C -3, 53, 74, 95, 215, 273

2. Southern Hemisphere C-74, 215

3. Western Hemisphere C-69

4. Polar regions C -27, 33, 79, 119, 157, 158, 285

Arctic CIS, 33, 174, 215, 221, 222, 227, 245

North Pole C -79, 244, 245

Franz Joseph Land

Tikhaia Bay C-9

Svalbard

Spitsbergen C -245, 293

Longyearbyen C-216

North-east Land C-287

Bjornoya C-216, 293

Antarctica C-245

Byrd Station C-191

HalleyBay C -19, 129, 130

Mirny C-244

Pioneerskaya C-244

Port Lockroy C-131

Port Stanley 0-131

South Pole C-244

5. Temperate regions C-78

B. CONTINENTS

1. Africa

South Africa C-265, 292
XXIV

2. Asia

India C-57

Japan C-33, 135, 210

Hiraiso Radio Wave Observatory C-122

Kokubunji C-210

Tokyo C-257

Lebanon

Beirut C-135

Pakistan C-57

U. S. S. R. in Asia

Cape Schmidt C-22

Dickson Island C-22

Siberia C-33

Tiksi C-22

Yakutsk C.22

3. Australasia C-243

Australia

New South Wales

Camden C-SO, 82

South Australia

Adelaide C-92, 284

Tasmania C-77

Macquarie Island C-163, 190

New Zealand C-33, 288

Bluff C-270

Campbell Island C-243

Christchurch C-243, 288

Invercargill C-108, 109, 272, 273

South Island C-288

4. Europe C-260, 265

Austria C-236

British Isles C-15, 189

England C-126

Abinger C-292

Jodrell Bank C-43, 44, 47, 60, 116, 129, 134, 148,

255, 279, 280, 282, 295
XXV

Scotland

Eskdalemuir C-45, 282

Lerwick C-282

Rosshire

Fortrose C-2S2

Denmark C-238

France

Dijon C-33

Haute Provence, Observatory of C-14

Paris C-135, 257

Germany C -177, 236, 239

Beelitz C-278

Berlin C-239

Bonn C-142

Gottingen C-142

Leipzig

Collm Observatory C-115

Scharmutzelsee

Pieskow C-278

Greece C-236

Netherlands C-177

Eindhoven C-251

Norway C-115, 171, 255

Arendal C-239

Bosekop C-24

Lillestrom

Kjeller C-127, 189, 255

Nordi C-158

Oslo C-75, 216, 251

Tromso C-75, 125, 126, 189, 216, 255, 288, 293

Scandinavia C-189

Sweden C-236

Goteborg C-236

Kiruna C-89, 118, 136, 172, 173, 200, 255

Lycksele C-256

Uppsala C-256

Switzerland

Arosa C-115
XXVI

U. S. S. R. (General and European)

Moscow region

Moscow C-142, 195, 244, 294

Murmansk region C -144, 294

Tulom C-145

Leningrad region

Roshchino C-22, 192, 232

Ukraine

Sumy C-294

Yaroslavl region C-294

5. North America C-llS, 114, 265

Canada C-63, 66, 68, 104, 119, 154, 171, 196

Alberta

Meanook C-88

Manitoba

Winnipeg C-107

Northwest Territories

Resolute Bay C-107

Nova Scotia

Greenwood C-102

Ontario

Agincourt C-20

Ottawa C-20, 26, 62, 102, 132, 182, 187

Saskatchewan

Saskatoon C-67, 99, 101, 178, 179, 183-185,

197, 255

Greenland C-221, 238, 257

Mt. Evans Observatory C-222

U.S.A. C-6, 96, 260, 265

U. S. West Coast C-292
XXVI

1

Alaska C-6, 36, 169, 171, 223

Anchorage C-5

College C-5, 16, 17, 28, 36, 37, 167, 174, 211,

233, 241, 285

Point Barrow C-84, 156, 174

California

San Francisco C-257

Stanford C-88, 174, 229

District of Columbia

Anacostia

Bellevue C-260

Hawaii C-33

Honolulu C-257

Iowa

Cedar Rapids C -28, 83

Massachusetts

Cambridge C-230

Concord C-70

Newton Center C-230

S. Dartmouth C-106

Minnesota

Crow River C-20

Minneapolis C-289

New Jersey

Tuckerton C-230

New York C-135

Ithaca C-28, 83

Long Island

Riverdale C-153

Sampson Station C-96

Schenectady C-230

North Dakota

Bismarck C-174
XXVlll

Oregon

Corvallis C-174

Pennsylvania

Pittsburgh C-230

Washington C-257

Pullman C-83

6. West Indies

Puerto Rico

San Juan C-153

Antigua C-85

7. South America C-265

Argentine

Buenos Aires C-135

Brazil

Rio de Janeiro C-135

C. OCEANS

1. Indian Ocean C-180

2. Pacific Ocean

N. Pacific C-33

N. W. Pacific C-33

S. W. Pacific C-244
XXIX

CHRONOLOGICAL INDEX

1833 1935

C-137 C-117, 257

1896 1936

C-23 C -124, 217

1901 1937

C-24 C-292

1923 1938

C-138

1925

C-9, 12, 13, 18, 71, 72,

153, 155, 177, 239, 276

278, 287, 288

C.266 1939

1927 C-15,39, 115, 123

C-221 1940

1928 C-74, 94, 125, 249

C-8, 51

260,

., 201, 230

267, 274

,251, 252, 1941

C-95

1929

C-37, 222, 253,263, 268

1942

C -126, 250

1930

C-41, 135

1944

C-264

1931

C-157, 224, 254, 269

1946

C-75, 105

1932

1947 ^'^^

C-61, 141, 146, 176, 231,

1934 241, 285, 295

0-27, 161 1948

C-195
XXX

1949 1958

C . 93, 97, 291 C

1950

C 7, 10, 65, 98, 99, 258,

265

1951

C . 52, 70, 110, 172, 173,

205, 206

X959

C

1952

C 34, 42, 111, 136, 139,

196, 202, 207, 208, 259,

261

6, 19, 25, 26, 40, 49, 62,

79, 96, 121, 122, 129,

133, 142, 145, 151, 154,

158, 160, 164, 165, 171,

178, 186, 189, 192, 194,

200, 210, 232, 242-244,

248, 256, 271, 284, 289

14, 16, 58, 60, 63, 77, 80,

85, 91, 92, 107-109, 120,

128, 152, 166, 167, 170,

212, 213, 220, 225, 227,

228, 233, 235, 237, 240,

272, 273, 286

1953

C - 33, 47, 50, 53, 67, 100,

112, 140, 162, 182, 197,

234, 262

1954

C - 2-4, 35-37, 46, 54, 59,

64, 66, 68, 81, 101, 119,

127, 134, 183, 184, 190,

193, 198, 199, 216, 226,

229, 293

1960

C

1961

1, 20, 22, 39, 78, 88, 89,

103, 104, 116, 118, 130,

131, 147, 179, 181, 187,

191, 209, 279, 280, 290

17, 86, 188, 203, 204,

281, 282, 297

1955

C - 28, 38, 43, 44, 48, 82-84,

113, 114, 143, 148, 174,

185, 218, 255, 296

1956

C - 5, 29-31, 55, 69, 132, 149,

156, 163, 169, 175, 219,

223, 245, 246, 275

1957

C - 11, 21, 45, 56, 57, 90, 102,

106, 144, 150, 159, 180,

211, 214, 215, 236, 238,

247, 270, 283, 294
BIBLIOGRAPHY ON AURORAL RADIO WAVE PROPAGATION

C-1 Aarons, J. (Air Force, Cambridge Res. Cent.); Gustafsson, G. and Egeland, A. (both, Kiruna Geophys. Observ. ),

Correlation of audio-frequency electromagnetic radiation with

auroral zone micropulsations . Nature, London, 185(4707):

148-151, Jan. IS, 1960. 5 figs. , table, 6 refs. DWB--There

are excellent correlations between the auroral zone micropulsations and the radiation in the audio-frequency band. Two

distinct frequency bands have appeared on 12% of the days

for which results were obtained. This is a lower limit since

on several days when the sensitivity v/as lov/, emissions

were not detected. The upper frequency band is "hiss". It varies in frequency throughout the recording period. The

lower band at 750 C.P.S. for almost all the cases is steadier in frequency. Its spectral location indicates that it may

well be radiation from protons, but its occasional change in

frequency may make it another component of the "hiss" signals. (Item 12 A-l, Met. Abs.)"E. Z. S.

C-2 Agy, Vaughn, The location of the auroral zone. Journal of

Geophysical Research, 59(2):267-272, June 1954. 7 figs.,

2 refs. --A study of data from a chain of radio-v\rave field

strength recording stations along the 90th meridian suggests

that "the auroral absorption zone" coincided with the zone of

maximum frequency of occurrence of visible aurora. North of

this, there appears to lie a region in which absorption is ex- tremely low. Although the accuracy of location of the absorption zone is limited by use of fixed transmitters and receivers, as well as by the fact that varying modes of propagation are not taken into account, the indications are that it is somewhat

farther north and narrower than has been suggested previously.

(Item 6. 2-340, Met. Abs. ) --Author's abstract.

C-3 Agy, Vaughn (Nat. Bur. of Standards, Boulder, Colo.), Geographic and temporal distribution of Polar blackouts . Journal

of Geophysical Research, 59(4):4SS-512, Dec. 1954. 22 figs.,

2 tables, 14 refs. , eq. MH-BH--Tabulations of hourly values

of the ionospheric parameters for IS Northern Hemisphere stations have been used to derive diurnal variations in the
occurrence of "blackout" conditions. Contour plots are presented showing the diurnal average percentage of time during

which blackout conditions prevailed, the amplitude of the

diurnal variation, and the time of maximum frequency of oc- currence. Changes in the contours with season and with magnetic activity are discussed. (Item 6. 8-22, Met. Abs. )--

Author's abstract.

C-4 Agy, Vaughn, Variations in the probability of occurrence of

polar blackouts . American Geophysical Union, Transactions,

33(2), 1954. --Tabulations of hourly values of the ionospheric

parameters for 18 northern hemisphere stations have been used

to derive diurnal variations in the occurrence of "blackouiT

conditions. Geographic contour plots of the "probability" of

occurrence are presented showing the average value, the amplitude of the diurnal variation, and the time of maximum probability. Changes in the contours with season and with magnetic activity are discussed. Shortcomings in the method are emphasized and further studies are mentioned which may lead

to conclusions of greater reliability and usefulness. (Abstract

only)

.

C-5 Agy, Vaughn, Study of auroral zone attenuation of high frequency radio v>yaves . U. S. National Bureau of Standards.

Boulder Lab. , Colo., Contract IA-454, Progress Report

,

April 1-June 30, 1956. Also Progress Report, July 1-Sept.

30, 1956 (both pub. June 14, 1957. ) 2 pieces, each about

7 p. figs. , 31 refs. in first report. DWB--Correlation of

field strength for reception of 8, 10, 11 and 15 Mc waves

between Washington, D. C. , Bismarck, N. D. , and Maui,

respectively, and Anchorage and Fairbanks, respectively,

is high enough to indicate that little difference exists (at

least did in Sept. 1955-June 1956), between transmission

conditions over an auroral and a nonauroral path. Perhaps

at times of sunspot maximum or solar flares there would be

some difference in conditions over the 2 types of paths. It is concluded that amount of auroral zone attenuation is much

less than v/as previously supposed. (Item 9. 10-304, Met.

Abs.)-M.R.

C-3 Agy, Vaughn (National Bureau of Standards, Boulder, Colo.),

Polar blackout occurrence patterns . Journal of Atmospheric

and Terrestrial Physics, London, Special Suppl. , Pt. 2, 1957,

publ. 1958. p. 129-134, 4 figs. DLC-Presents maps of

maximum probability of blackout on magnetically quiet and

disturbed days, and shows the latitudinal variation in a graph.

Suggests one type of blackout as due to magnetic activity,

another to X-rays of auroral origin. (Item llE-2, Met. Abs.

)

-G.T.
C-7 Alfven, Hannes, Magnetic storms and aurorae. (In his:

Cosmical electrodynamics. Oxford, Clarendon Press, 1950.

Chap. VI. p. 175-207. 20 figs. , 26 refs. , 27 eqs. DLC--

Opens with the statement that 'The intimate connection between magnetic storms and aurorae makes it necessary to

consider them as two manifestations of the same phenomena".

Reviews the work of BIRKELAND and STORMER which he

considers the first serious attempt to interpret magnetic

storms and auroras. He next summarizes the investigations

of CHAPMAN and FERRARO. A more detailed discussion of

the electric field theory (ALFVEN) and MALMFOR's scalem.odel experiment follows. (Item 5C-140, Met. Abs. )--

M.L. R.

C-S Appleton, E. V., Note on "Short wave echoes and the aurora

borealis by Van der Pol" . Nature, London, 122(3084) :87GDec. 8, 1928. fig. --Brief comments on StiSrmer's letter on

auroral radio echoes (See ref. No. C-253) which possibly may

be due to deflection caused by the spinning earth. Delayed

signals of same nature were first observed by Taylor and

Young. (See ref. No. C-261)"W. N.

C-9 Arkhangel'skii, B. F. and Pabo, N. V., Rasprostranenie

radiovoln v vysokikh shirotakh. (Radio wave propagation

in high latitudes. ) Leningrad. Arkticheskii NauchnoIssledovatel'skii Institut, Trudy, v. 124, 1938. 88 p. 55

figs. , S tables, refs. at end of each chapter. DLC--A very

thorough treatment of all available data on Arctic troposphere and ionospheric radio propagation conditions and their

disturbance by solar, magnetic, auroral and statis (sferics)

activity. Actual recorder records, as well as derived diagrams, tables, and curves are presented. Numerous references are given to the sources (mostly 1932-1C37 in Russian

periodicals). Theoretical considerations are not neglected

but applications to study of atmosphere - especially the

upper layers - and the aurora, ionosphere, terrestrial magnetism and atmospheric electricity are emphasized. The

study is based on data obtained in 1932/33 and 1934/35 at

Tikhaia (Calm) Bay in Franz Josef Land, and other Polar Year

stations in 1932/33. (Item 51-73, Met. Abs.)"M.R.

C-10 Aspinall, A. and Hawkins, G. S. , Radio echo reflections

from the aurora borealis. British Astronomical Association,

Journal, 60(5): 130-135, April 1950. figs., plate, tables, 12

refs. DLC--This paper describes some studies of the aurora

borealis using contemporary radio techniques such as are
employed in the investigation of meteors. A number of aurora formations occurring during 1949 have been identified by the

characteristic echoes which they produce on 72 Mc/s, and

continuous observations on this frequency have disclosed periods of auroral activity. Auroral rays were found to have an

electron density of 6 x lO^ electrons/cc and height measurements confirm that these rays occur from 100 to 300 kms above

the earth's surface. Apparent radial velocities have been observed which are interpreted as random movements in the

aurora. (Item 3. 2-338, Met. Abs. ) --Authors* abstract.

C-11 Bailey, D. K. (Page Communications Eng. Inc. , Wash. , D.C.),

Disturbances in the lower ionosphere observed at VHF following the solar flare of Feb. 23. 1956 with particular reference to

auroral zone absorption. Journal of Geophysical Research,

Wash., D. C, 62(3) :431 -463, Sept. 1957. 4 figs. , 4 tables,

65 refs. , 19 eqs. DLC--Observations at the time of the great

solar flare of Feb. 23, 1956 of oblique incidence signal intensities and simultaneous observations of the background cosmic

noise were made at VHF for a number of high latitude communication links employing the ionospheric scatter mode of propagation. During the flare and for some hours afterward, all

paths lay in the dark hemisphere. Virtually synchronously

with the arrival of solar cosmic rays, a sharp signal intensity

enhancement was observed, which is tentatively explainable

if it is supposed that the first arriving solar cosmic rays were

predominantly of positive charge. The unusually stable nighttime absorption which developed in one to three hours after the

flare and the much greater following daytime absorption are ex- plained in some detail as consequences of the deposition in

the D region of moderately heavy solar atomic ions, such as calcium, having ionization potentials low compared with the

normal atmospheric constituents. The absorption effects,

which were limited to fairly high geomagnetic latitudes, gradually died away over a period of several days. The absence of

significant magnetic disturbance and unusual auroral activity

for nearly 48 hrs after the flare is shown to be in accord with

the suggested explanation of the absorption effects. Assymmetry about local noon was observed in the absorption effects

on signal intensity, for which an explanation is suggested.

(Item llF-6, Met. Abs. )--Author's abstract.

C-12 Bailey, V. A. , Generation of auroras by means of radio waves . Nature, London, 142(3596) :613-614, Oct. 1, 1938. fig., 6

refs. "Wants to take a 500 kw station at gyro frequency, and

beam of 800 half-wave antennas, and light up the 90-km atmosphere fifty times as bright as the night sky. This done, he
6

wants to use 10 kw and light the country up like full moon

light. Hopes to reduce auto accidents. --L. A. Manning.

C-13 Bailey, V. A. , On some effects caused in the ionosphere by

electric waves. Philosophical Magazine, 26(176): 425-453,

Oct. 1938. 3 figs. , table, refs. in foot notes, 68 eqs. -- Gives a series of 10 formulas through which propagation constant can be determined by successive substitution. Considers interaction caused by gyro-waves. Calculates gyro-power

necessary to cause a glowing E layer. --L. A. Manning.

C-14 Barbier, Daniel, L 'observation des aurores polaires et de la

lumiere du ciel nocturne pendant I'Annee G^ophysique Interna - tionale . (Observation of polar auroras and night airglow during

thelGY.) La Nature, Paris, No. 3294:439-443, Oct. 1959.

5 figs. DLC--The article presents a brief report on the morphology of polar auroras and night airglow, and considerations

relating to the observation of these two phenomena during the

IGY. The methods of auroral detection are described and also

the methods used at the Observatory of Haute Provence (France)

which led to discovery of a new phenomenon called "monochromatic arc". The author describes this phenomenon and treats

briefly of radioelectric exploration of auroras, artificial auroras,

exploration of auroras by rockets and of the spectrum of auroras. Auroral exploration by rockets has shown that the auroras producing radiation particles are essentially electrons with energies

less than 100 kev. Fast electrons, when decreasing speed,

cause X radiation and play an important part in aurora production. Spectral auroral observation reveals some particular spectra, formed by atomic rays of neutral and ionized oxygen and

neutral and ionized nitrogen. It shows that hydrogen rays may

occur one or two hours before the beginning of the aurora and

that there is a correlation between their extent and the presence of radioelectric echoes. (Item 11. 5-125, Met. Abs.)

"A.V.

C-15 Barlow, E. W. , Aurora and allied phenomena. Marine Observer,

16(133): 12-17, Jan. 1939. table. --A study of aurora and allied

phenomena with brief mention of radio effects. During an aurora

in 1915 radio reception in the British Isles was seriously affected, short wave reception being either completely absent or very weak and subject to fading. European stations near the

lower end of the medium waveband were also faint. Telegraphic

and telephonic communications were strongly interfered with.

--£. Z. S.
C-16 Bates, Howard F. (Geophys. Inst. Univ. Alaska, College,

Alaska), The height of F layer irregularities in the Arctic

ionosphere . Journal of Geophysical Research, Wash., D. C,

64(9): 1257-1265, Sept. 1959. 5 figs. , 10 refs. , 14 eqs.

DLC. Also issued as Alaska. Univ. Geophysical Institute,

Contract AF 19(604) -1859, Scientific Report No. 3, March

1959. 19 p. 6 figs. , 12 refs. , 17 eqs. DWB-Results and

interpretations of oblique-incidence soundings of the Arctic

ionosphere are presented. Anomalous echoes are found to be

prevalent in high latitudes in contrast to lower latitudes where

2F ground scatter predominates. One of the echoes seen re- gularly at College, Alaska, has been identified as direct F

layer (IF) back scatter propagated via the least time mode.

The observations of the IF echo provide direct evidence of

the presence of irregularities in the F layer between heights

of 350 and 500 km. The IF echoes are recorded regularly at

night and occasionally during the day in disturbed periods.

They appear to be associated with auroral ionization. The

analysis of ground scattered (2F) echoes is extended from a plane to a spherical geometry, and it is shown that a geometrical extension of the plane-earth theory is adequate. The

observed range-frequency dependence differs only slightly

from that predicted by the latter theory. (Item llF-7, Met.

Abs. )- -Author's abstract.

C-17 Bates, Howard F. , The slant Es echo. A high-frequency

auroral echo. Journal of Geophysical Research, 66(2):447-

454, Feb. 1961. 6 figs. , tables, 13 refs. -Whenever the

slant Es echo was strong on the College oblique incidence,

sweep frequency (1-25 Mc/s) sounder, the College 41 Mc/s

auroral radar recorded an echo at the same range as that at

25 Mc/s on the sweep frequency record. This range was

close to that at which the line of sight most nearly approaches

normal incidence upon the geomagnetic field lines. The highlatitude slant Es echo appears to be the result of energy that

is scattered by randomly distributed, field aligned irregularities, and is strongly enhanced by one of two focusing agents

that depend upon the frequency. The slanting portion of the

echo is produced by least-time focusing, and the constant

range VHF portion, by aspect focusing. The high latitude

slant Es echo is associated with magnetic disturbances; in

the cases examined the magnetic K index was between 3 and

7. Its extension at 41 Mc/s is occasionally observed as a discrete t-ype of auroral echo. The scatterers are diffusely distributed, however, indicating that auroral radar records must

be interpreted with care. --Author's abstract.
C-18 Beckman, B. ; Menzel, W. and Vilbig, F. , Ver^nderunqen in

der lonosph&re beim Auftreten von^ Nordlicht. (Changes in the

ionosphere during aurora borealis). Telegraphen Femsprech

Funk und Ferns eh Technik, 27(7):245-251, July 1938. 8 figs.--

Echo recordings of Sept. 30, 1937 using 84 m A are discussed

in comparison with simultaneous recordings conducted 100 km

farther north. It is concluded that the auroral layers cannot be

explained by reflexion from a northerly located slant ion-front.

Over head changes of the F region are distinct. Observed re- flexions from E, F and F 1 and F2 refute their theoretical nonexistence. --W. N.

C-19 Bellchambers, W. H. and Piggott, W. R. , Ionospheric mea- surements made at Halley Bay. Nature, London, 182(4649):

1596-1597, Dec. 6, 1958. fig. , 2 refs. -An analysis of the

initial results from the ionospheric sounding equipment at

Halley Bay is given. Absorption controlled by corpuscular

radiation during the polar winter has a maximum at 0400 L M T

(30 W). The occurrence of auroral radar echoes shows a similar diurnal maximum which peaks a few hours earlier; coincident with excessive ionospheric absorption and zenithal aurora's weak reflections from an ionized layer at about 80 km

have been obtained. The diurnal variations of foF2 show:

(1) a peak near noon in the winter in spite of the comparative

absence of photoionization; (2) a seasonal maximum near noon

at the equinoxes; and (3) a minor increase around midnight during the summer. The results demonstrate the predominating

influence of ionization transport phenomena over that of previously mentioned processes. --Phys. Abstract.

C-20 Bhattacharyya, B. K. (Natl. Res. Council, Ottawa), Correla - tion studies of radio-aurora, magnetic and earth-current disturbances . Canadian Journal of Physics, Ottawa, 38(5) :624-

637, May 1960. 7 figs. , tables, 20 refs. DWB, DLC-Correlation studies of the radar echo occurrence rate from aurora in

half-hourly intervals at Ottawa, S and S , components of the

horizontal magnetic field H at Agincourt, and the disturbance

diurnal variation of earth current at Crow River have been car- ried out. Short-time variations in auroral echo strength and

moderate perturbations in H have also been correlated. The

auroral echo occurrence rate seems to have a diurnal variation

characteristic similar to that of H. It is found that auroral

activity always precedes magnetic activity. The variation of

the delay time between the two phenomena shows a local time

dependence, being practically constant and quite small (0-15

minutes) before local midnight and increasing afterwards. This

variation of the delay time appears to have a connection with

reports of others regarding reversal of the direction of auroral

ionization drift from west to east somewhere around midnight
8

with subsequent magnetic perturbations which change from

positive to negative. No definite conclusion could be reached

regarding the relationship of earth current to other factors because of a practically random variation of cross correlation

coefficients from month to month. (Item 12A-28, Met. Abs.

)

--Author's abstract.

C-21 Birfel'd, la. G. , Radiolokatsionnye otrazheniia ot poliamykh

siiani^. (Radar reflections from auroras. ) Akademiia Nauk

SSSR, Izvestiia, Ser. Geofiz. , No. 4:543-547, 1957. 5 figs.

,

5 refs. DLC. Transl. into English by M. G.Priestley in the

English language edition of the Izvestiia, Bulletin of the Academy of Sciences of the U. S. S. R. , Geophysics Series, No. 4:

154-158, 1957, issued 1957, by American Geophysical Union.

DWB--Radar reflections from auroras were studied with radar

having a frequency of about 10 mh Hz for an impulse with

length of 10 mc/sec, a thickness of 75 kw in a frequency of

recurrence of 50 z. The type of reflections obtained on the

radar screen are reproduced and analyzed. In general, the re- flections, although complex, consist of signals having a width

of the order of 10 mc/sec corresponding to the length of the

impulse studied. The reflections are associated with solar

activity and geomagnetic and ionospheric disturbances produced in the ionosphere. Reflections were observed in all

directions. (Item 10. 8-129, Met. Abs.)"I.L.D.

C-22 Birfel'd, la. G. , Radiolokatsiia poliamykh siianii. (Radar

observation of auroras. ) Akademiia Nauk SSSR, Izvestiia,

Ser. Geofiz., No. 12:1871-1882, Dec. 1960. 7 figs. , 32

refs. DLC. Transl. into English in the corresponding number

of the Akademiia Nauk SSSR, Bulletin of the Academy of Sciences, USSR, Geophysics Series. DLC --Various recording

apparatuses (radar, oscillographs, photo cameras, etc.), re- ceiving equipments (multivibratory, semi-wave vibratory and

parabolic antennas) and method of observation and coordination of the aurora are described with details and illustrations.

The observations were made on six radar stations (Lopark,

Dickson, Shmidt, Tixy, Roshchino and Yakutsk) on various

frequencies from 5 to 74 megahertz. The character and properties of the radar single and group reflections and their typical classification are discussed with photographs, oscillograms and charts with graphic distribution of the ionization

density and brightness of image on the semi-sky maps. General process of radar reflection and density of ionization are analyzed with respect to their relation to the solar activities.

The radar group reflections of the auroras are graphically co- ordinated with (H) and (Z) components of the earth's magnetic

field and also with variation of critical frequencies of (E) and
(F2) layer of the ionosphere. Major points of the discussion

are summarized in the conclusion. --N. P.S.

C-23 Birkeland, Kristian, Sur les rayons cathodiaues sous Taction

de forces magnetiques intenses. (On cathode rays under the

action of intense magnetic forces. ) Archives des Sciences

Physiques et Naturelles, Geneva, Ser. 4, 497-512, 1896.

DLC--Laboratory experiments on cathode rays in tubes under

the influence of magnetic fields are described in detail and

the analogy to auroral manifestations suggested. The polarity

of the aurora and the source of the energy are the two aspects

that could be explained only on the basis of a hypothesis of

polar origin of energy and action of magnetic poles in concentrating the discharges. (Item 5C-6, Met. Abs.)--M. R.

C-24 Birkeland, Kristian, Expedition Norveqienne de 1899-1900

pour Tetude des aurores boreales. Resultats des recherches

maqnetiques. (Norwegian Expedition of 1899-1900 to study

the aurora borealis. Results of magnetic research.) Videnskabs-selskabet i Kristiana, Math. -Naturvidenskapelig

Klasse, Skrifter, No. 1, 1901. 80 p. 12 plates (some fold. ), port. DLC --Report contains discussion of simultaneous variations in geomagnetism at Bosekop and Potsdam and relation to aurora and upper atmospheric electric currents. Theory is developed and laboratory experiments illustrating the aurora in a cathode ray tube (artificial auroral bands) described. Finally, a discussion of possibility that cirrus clouds could be formed

by extension of auroral action into lower levels of upper atmosphere is presented in some detail. (Item 5C-9, Met. Abs.)

-M.R.

C-25 Blevis, B. C. , UHF auroral radar observations. Journal of

Geophysical Research, 63(4): 867-868, Dec. 1958. 2 figs.,

2 refs. --Brief note on measurements with a bistatic type radar,

transmitter receiver separation of about 19 km, as conducted

at Ottawa, Canada, during April 18-19, 1957 when auroral

echoes were obtained on 488 Mc/s and an off-perpendicular

angle corresponding to 3 or 4 between radar and magnetic

lines of force at 100 km level. Echo observations at 944 Mc/s

during July 8-9 indicated effective cross sections up to several

thousand m2. --W. N.

C-26 Blevis, B.C. and Cameron, E. A. , Further data on radar re- turns from aurora at 488 Mc/s. Canada. Defence Research

Telecommunications Establishment, Report 44-2-2, July 1958.

9 p. 7 figs. , ref. DWB (M(055) C212rep)"This report ex- tends the information previously presented (Chapman, J. H. etal.)

on auroral radar observations at a frequency of 488 Mc/s.
10

The present work is concerned primarily with measurements of

auroral depth in range and with observed Doppler shifts in the

signals returned from the aurora. The observations were made

with a transmitter located near Ottawa, Ont. (45 21 'N, 75

53'W) and with the receiver located near Meath, Ont. (45

44 'N, 76 59 'W). The equipment used for the measurements is

described with particular reference to modifications which

have been made since the previous report was published. Comments are made about the auroral echo geometry and the re- ceiver and transmitter sites. Representative photographs of

visual displays are included and the results of the measurements are indicated. (Item 12B-26, Met. Abs. )- -Authors'

introduction,

C-27 Bontch-Bruewitch, M. A. , Ionospheric measurements in the

polar regions. Nature, London, 133(3353): 175-176, Feb. 3,

1934. --Found evidence of an absorbing layer below the E layer.

--L. A. Manning.

C-28 Booker, H. G. ; Gartlein, C. W. and Nichols, B. (Cornell Univ.),

Interpretations of radio reflections from the aurora. Journal of

Geophysical Research, 60(l):l-22, March 1955. 17 figs. , 31

refs. , eq. DWB--The literature on radio echoes from the aurora is reviewed and results obtained at Ithaca, N. Y. , College, Alaska^and Saskatoon,and from analysis of radio signals

transmitted from Cedar Rapids, Iowa, are analyzed. Diurnal

and seasonal variations in auroral reflections correspond with

frequency of auroras; maximum before and after midnight; minimum during daylight and at midnight; and, respectively, maximum at equinoxes (especially spring equinox), and minimum at

solstices (especially winter solstice). Results of both pulse

and continuous radio transmissions at 2.4 to 144 Mc/sec show

fine structure, azimuth (always to N), fading time (proportional

to frequency), which is much faster than would be expected and

give clue to cause of above phenomena. Reflections are due to

scattering from numerous ionized columns as in meteor trail re- flections but with faster motion. Theory of ground reflection

(HARANG) rejected. (See ref. C-127). (Item 6. 11-107, Met.

Abs,)-M.R.

C-29 Booker, H. G. , Some practical aspects of auroral propagation.

Institute of Radio Engineers, Transactions on Communication

Systems, CS-4(1):5, March 1956. 9 refs. DLC -The several

aspects of the reflection or scatter mechanism which enable

VHF radio communication up to 1000 km and 2000 km, with low

and high power transmitters respectively, are explained (except Doppler shift and fading) in terms of radio scattering under

given conditions. It is advised to think of the regular VHF

scattered transmission as the normal mean for communication
11

ill the auroral zone, and to use highly directional antennas

and improved design of the modulation system. --W. N.

C-30 Booker, H. G. , A theory of scattering by nonisotropic ir - regularities v/ith application to radar reflections from the aurora. Journal of Atmospheric and Terrestrial Physics, London,

8(4/5) :204-221, May 1£56. 4 figs., 14 refs. , 48 eqs. DWB.

Also in: Cornell Univ. , School of Electrical Engineering,

Ithaca, N. Y., Technical Report 28, Oct. 30, 1955. --Radar

echoes from aurora come mainly at low elevations from north,

even at stations north of auroral visual zone. Horizontal and

vertical extent of echoes increase as frequency decreases

from 100-25 Mc/s. An explanation is given in terms of columns of ionization parallel to earth's magnetic field, but only

about 40 m long by 1 m diameter, probably too small to be as- sociated with visible rays. These irregularities are of the

same order of size as turbulence elements and it is suggested

that the magnetic field creates nonisotropic irregularities of

electron density in the E region, with maxima some 100 times

the normal, but this cannot explain fading of auroral echoes,

which must be due to other features of auroral ionization.

(Item 7. 10-297, Met. Abs. )-C. E. P. B.

C-31 Booker, H. G. (Cornell Univ. ), Turbulence in the ionosphere

with applications to meteor trails, radio star scintillation . auroral radar echoes, and other phenomena. Journal of Geophysical Research, Wash., D. C, 61(4):673.705, Dec. 1G56.

11 figs. , 43 refs. , 63 eqs. (Also in: Polar Atmosphere Symposium, Oslo, July 2-8, 1D53, Proceedings, Pt. 2, Ionosphere

Section, issued 1958. p. 52-81. 11 figs., etc.) These proceedings also issued as Journal of Atmospheric and Terrestrial

Physics, London, Special Supplement, Pt. 2 1957, pub. 1958.

p. 52-81. DLC--Two scales of turbulence are discussed, since

large eddies are responsible for forward scattering phenomena

and small eddies for back-scatter. Molecular diffusion theory

forms the basis for small scale eddy formulas; Richardson's

number is used for the large scale eddies. Large eddies have

time constants of 40 to 100 seconds; small eddies about 0.4

sec near 100 km. Large eddies have a scale of 1. 6 km, small

eddies about 1. 3 m. The coefficient of eddy diffusion in meteor trails is less than 10 for small eddies and increases to 10^

for large eddies. The large eddies responsible for radio star

scintillation are located near 200 km. The turbulence power in

watt/kg is given as 5 X 10-4 in the troposphere, 25 at the meteoric level and 1000 at the scintillation level. (Item 12B-31,

Met. Abs.)--S. Fritz.
12

C-32 Booker, Henry G. , Radar studies of the aurora. (In: Ratcliffe, J. A. "Physics of the Upper Atmosphere". N. Y.

Academic Press, 1960.) p. 355-375. 17 figs. , table, 29

refs. --A chapter devoted to discussion of radar studies of aurora under the following headings: Pulse radar experiments;

Radar observations of the aurora; Analysis of observations in

terms of azimuth; The distribution of auroral echoes with range;

Analysis of auroral echoes in terms of height; Diurnal, seasonal, and sunspot cycle variations of auroral echoes; Motion

associated with auroral echoes; Frequency dependence of auroral echoes; Polarization of auroral echoes; The importance

of approximate perpendicularity between the Earth's magnetic

field and the radius from the radar to the aurora; Theories of

auroral radio echoes; and The cause of movement in the location of auroral echoes. --E. Z. S.

C-33 Bouchard, Jean, Sur la propagation ionospherique des ondes

decametriques dans les regions polaires arctiques. (On ionospheric propagation of 10 m waves in the Arctic. ) Academie

des Sciences, Paris, Comptes Rendus, 236(2): 220-222, Jan.

12, 1953. DLC --Systematic study of the propagation of 10 m

waves over great distance shows the influence of ionic disturbances in the Arctic, connected with magnetic disturbances.

The signals received at Dijon, France, from the region of the

North Pacific (NE Siberia, Alaska, British Columbia, the Pacific Northwest and Hawaii) are distorted when passing through

the belt of maximum auroral activity during magnetic storms but

signals from other parts of the Pacific (Japan, Mariannes, New

Zealand, etc. ) are not thus distorted, except when taking sec- ondary paths traversing these disturbed zones. (Item 6D-158,

Met. Abs.)"M.R.

C-34 Bowles, K. , The fading rate of ionospheric reflections from

the aurora borealis at 50 mc/sec. Journal of Geophysical Research, 57(2): 101-196, June 1952. 3 figs. , 2 refs. MH-BHAmateur radio operators communicate from time to time by a phenomenon of anomalous ionospheric propagation associated

with the aurora borealis. Measurements have been made of

the rapid flutter-type of fading associated with this kind of

propagation at 50 Mc/sec. The power spectrum of the fading

seems to have frequency components of roughly equal strength

from zero frequency to a cut-off frequency between 100 and 200

cycles/sec. The fading frequency is thus about a power of

ten greater than might be anticipated from usual ionospheric

velocities. In most cases, both transmitting and receiving

antennas must be of the same polarization and must be pointed

more or less in the direction of the visible aurora. Amplitude

modulated speech transmission is occasionally possible at 50

Mc/sec by means of this type of propagation. (Item 4. 5-233,

Met. Abs. )- -Author's abstract.
13

C-35 Bowles, K. L. , Analysis of the fading of very high frequency

radio waves propagated by aurorally disturbed ionosphere . Cornell University, School of Electrical Engineering, Studies

on propagation in ionosphere. Technical Report, No. 15, 1954.

Master Thesis. (Unchecked).

C-36 Bowles, K. L. (Geoph. Inst. , Univ. of Alaska), Doppler

shifted radio echoes from aurora . Journal of Geophysical Research, 59(4): 553-555, Dec. 1954. fig., 5 refs. MH-BHA brief report on observations and discoveries regarding the

Doppler shift in radio echoes from the aurora using 25. 4 Mc/

sec C. W. or pulse signals from a 100 watt transmitter located

15 mi from a low-gain receiving antenna pointed N. The spectrum of the Doppler shifted auroral echo and fo signal from

transmitter obtained at College, Alaska, Oct. 24, 1954 is re- produced. Doppler shifts cannot be attributed to horizontal

movements. Upward shifts correlate with homogeneous auroral forms; (downward motion) and downward shifts with raus (upward motion). Velocities along lines of force are calculated to be about 6 km/sec which is much less than MEINEL

reports obtaining from optical methods. (Item 6.8-348, Met.

Abs.)-M.R.

C-37 Bowles, K. L. , VHF auroral and meteor echoes including

simultaneous observations . American Geophysical Union,

Transactions, 35(2) :375, 1954. --Auroral echoes have been

observed at College, Alaska, using SCR270 radar at 106 mc/

sec. The location of College close to the center of the auroral zone makes these observations unique, since visible aurora is commonly seen in all directions of azimuth, as well

as overhead. Similar to previous results, (1) echoes are found only within a sector slightly wider than one quadrant,

centered on geomagnetic north, (2) ranges between approximately 500-1000 km are found, and (3) no vertical incidence

echoes may be obtained from the various forms of aurora v/hen

seen overhead. These observations are seen to conform v/ith

the meteor trail analogy for VHF echoes as postulated by R. K.

Moore. An interesting observation, though not substantiated

by a large amount of data, is that the rate and strength of meteor echoes is considerably enhanced during periods when aurora is seen in the sky. The normal rate of three to five echoes per hour is increased to as much as 25-30 echoes per hour.

No indication of preferred azimuth is found. In the meteor

echo after the initial whistle has ceased, the fading rate fits

in with results of other workers but is an order of magnitude

slower than fading found in auroral echoes. (See ref. C-208).
14

C-38 Bowles, K. L. , Aurora borealis studies using VHF radio

echoes. IRE-URSI Meeting, Washington, D. C. , May 1955.

--Two experiments recently performed by the author are described. In the first a 100 mc/s radar set with good horizontal

antenna beamwidth was used in Alaska. Simultaneous photographs of the visible aurora and the PPI pattern were taken.

In many cases direct comparison may be made between the two.

Echoes were received from both homogeneous and rayed auroral forms. A suggested accounting is made for similar visible forms which do not correlate with echoes. In the second

experiment rf spectrograms were made of cw echoes from aurora at several carrier frequencies (between 25 and 150 mc/s)

and locations. A- 'scope presentation of pulsed echoes was

available at the same time for comparison with the spectra.

Final analysis has been made from tape recordings of the two

types of information. Whenever possible visual aurora was

correlated with the radio echoes. The results show that the

auroral echoes are generally Doppler shifted several hundred

cycles relative to the transmitted frequency. They are also

broadened over a band of several hundred cycles width. Both

quantities depend upon carrier frequency and location of the

station in the geomagnetic field. Homogeneous auroral forms

produce upward Doppler shifts (approaching motion) while

rayed forms produce downward shifts (receding motion). The

results are taken as support for the suggestion of earlier Cornell work that the radio echoes arise from thin columns of ionization aligned with the lines of force of the earth's magnetic

field. The motions implied by the Doppler shifts are downv/ard

in homogeneous forms but upward in rayed forms in the visible

aurora. With accounting taken for geometry, velocities along

the columns of the order of S km/s are implied.

C-39 Bowles, K. L. ; Cohen, R. ; Ochs, G. R. et al. (all, Natl.

Bur. of Standards, Boulder, Colo. ), Radio echoes from field

aligned ionization above the magnetic equator and their resem- blance to auroral echoes. Journal of Geophysical Research,

Wash., D. C, 65(6): 1853- 1855, June 1960. 6 refs. DLCBoth classes of echoes occur in about the same height range

and have about the same band width of fading and similar

Doppler shift characteristics. Both exhibit an aspect of sensitivity corresponding to the influence of the earth's magnetic

field. Strong currents are observed to flow horizontally to the

lines of force of the earth's magnetic field both at the magnetic

equator and in auroral forms. The authors suggest that in both

phenomena irregularities could reasonably consist of a family

of plane-v/ave disturbances constrained to lie parallel to the

local lines of force of the earth's magnetic field. The apparent

weakness of the aspect sensitivity in both cases could be produced by local distortion of the earth's magnetic field due to

the flow of strong localized ionospheric currents. (Item 12B32, Met. Abs.)-E.Z. S.
15

C-40 Brown, Robert Hanbury and Lovell, A. C.6. , Radio and the

Aurora borealis. (In their: Exploration of space by radio.

N. Y. , John Wiley, 1958. pp. 171-177. 7 figs. (incl. photos),

2 refs. ) DLC (QB475. B7)--A brief but fairly detailed discussion of radio investigations of auroras. Radio echoes and

radio noise from auroras, electron density in the auroras, interpretation of the echo structure, motion of the echo pattern,

and some associated magnetic, visual and scintillation features are the topics covered. Figures and photos illustrate

the chapter, and references to the work of specific investigators are given in the text. (Item 12A-34, Met. Abs.)--

A.J.M.

C-41 Brtiche, E. , Modelversuche mit sichtbaren Elektronstrahlen

zu St(5rmers Theorie des Polarlichtes und des Welraumechos . (Model experiments with visible electron rays to Stormer's

theory on polar aurora and worldwide echoes. ) Naturwissenschaften, 18(50): 1085-1092, Dec. 12, 1930. 9 figs. , 7 refs.

,

eqs. --An illustrated presentation of laboratory experiments

with a magnetic sphere simulating the earth exposed to electron radiation (200-250 volts) from an oxide cathode, in order

to check the trajectories of the electrons and their behavior

in a dipole field. The experiments showed good agreement

with Stormer's theory. (See ref. C-255). -W. N.

C-42 Budden, K. G. and Yates, G. G. , A search for radio echoes

of long delay. Journal of Atmospheric and Terrestrial Physics,

2(5):272-281, 1952. 23 refs. DWB-An unsuccessful search

was made for echoes delayed 3-15 sec. The cause of such

echoes is discussed and they are tentatively attributed to ''the propagation of guided waves over long curved paths formed by

belts of ions outside the earth but fixed relative to it". (Item

4.4-100, Met. Abs.)-C.E.P.B.

C-43 BuUough, K. and Kaiser, T. R. , Radio reflections from aurorae, Pt. 1. Journal of Atmospheric and Terrestrial Physics,

5(4):189-200, Sept. 1954. 9 figs. , 3 tables, 16 refs. Also:

Pt. 2, Ibid., 6(4):198-214, April 1955. 18 figs. , table, 11

refs. DWB"Pt. 1 reports that observations at Jodrell Bank

with a rotating aerial system on 4. 1 m included 3 occasions of

auroral echo. Echo is interpreted as a reflection from the most

highly ionized part of an auroral arc extending more than 1000

km along geomagnetic latitude 59 . The reflecting region was

only a few km across, at a height below 125 km, moving westward at 1-2 km/sec. The movement is attributed to movement

of the ionizing agent. Pt. 2: Observations of auroral echoes

1949-53 on a beam directed 68°W of N at Jodrell Bank are attributed to large single blobs or localized aggregates. There

was a marked fall of activity in 1952-53 with decrease of
16

sunspot activity. Echoes without discrete structure occur

mainly between 16 h and 21 h, those with discrete structure

between 18 h and 6 h. Annual variation shows a slight maximum in July-Oct. Geomagnetic locality, correlation with visual aurora and with magnetic activity are discussed; auroral

speeds and motions are described. (See ref. C-129). (Item

12B-35, Met. Abs. )"C.E. P. B.

C-44 BuUough, K. and Kaiser, T. R. , Radio reflections from au - rorae. Pt. 2. Journal of Atmospheric and Terrestrial Physics,

6(4):198-214, April 1955. 18 figs. , table, 11 refs. DWBObservations of auroral echoes 1949-53 on a beam directed

68°W of N at Jodrell Bank are attributed to large single blobs

or localized aggregates. There was a marked fall of activity

in 1952-3 with decrease of sunspot activity. Echoes without

discrete structure occur mainly between 16 and 21 h, those

with discrete structure between 18 h and 6 h. Annual variation shows a slight maximum in July-Oct. Geomagnetic locality, correlation with visual aurora and with magnetic activity

are discussed. Evening echoes (13-21 h) moved westward,

speed at 15 h being 600 m/s to west, night -morning echoes

(22-6 h) moved eastward, speed being 600 m/s to east at 5 h.

At 21 h, when echoes are at a minimum, mean speed is zero. (Item 6. 8-349, Met. Abs. )-.C. E. P. B.

C-45 Bullough, K. ; Davidson, T. W. ; Kaiser, T. R. and Watkins,

C. D. , Radio reflections from aurorae. Pt. 3, The association with geomagnetic phenomena. Journal of Atmospheric

and Terrestrial Physics, London, 11(3/4): 237-254, 1957. 15

figs. , 2 tables, 15 refs. DLC--This paper presents a further

study of the radio-echo observations of auroral ionization,made

on a frequency of 72 Mc/s between June 1949 and Oct. 1953,

described in a previous paper of this series (BULLOUGH and

KAISER, 1955). The data are compared with geomagnetic observations made at Eskdalemuir during the same period. A

good correlation is found between the daily frequency distribution of the radio echoes and the mean daily variation in magnetic disturbance. The change from a positive to negative bay

type of disturbance tends to occur between 2100 and 2200 hr

local time and coincides with a minimum in the frequency of

echo occurrence. This minimum separates the diffuse echoes

(from westward-moving ionization) of the evening sequence and

the discrete echoes (from eastward moving ionization) of the

morning sequence. There exists a close correspondence between the occurrence of radio echoes and features in the magnetic disturbance. In a number of cases there appears to be a displacement in time between echo components and peaks in

the magnetograms; it is suggested that this corresponds to the

time of transit of the ionization between the reflecting region
17

and the magnetic meridian through Eskdalemuir (some 10 in

magnetic longitude to the west). The probability of occur- rence of 72 Mc/s echoes during a positive disturbance is approximately double that for a negative one, being 50% for

A H > 100 y and a H < -200 y . The results and conclusions appear in several aspects to conflict with the ChapmanFerraro-Martyn theory of magnetic storms and aurorae. (Item

12B-36, Met. Abs. )--Authors' abstract.

C-46 Burkhart, K. , Radioechos am Nordlicht. (Auroral radio

echoes.) Umschau, 54(11):342, June 1, 1954. 2 refs. DLCBrief article on discrete and diffuse ephoes. Radar echoes

give the height of the auroral layer as 110 km with a range of

not more than 5 km. (Item 5. 8-280, Met. Abs. )--C. E. P. B.

C-47 Cain, Joseph C. (Geophysical Institute of the Univ. of

Alaska), Auroral radio-echo table and diagram for a station

in geomagnetic latitude 58 . Journal of Geophysical Research,

Wash., D. C, 58(3): 377 -380, Sept. 1953. fig., table, ref.

DWB--CHAPMAN has computed the echo geometry of radio signals reflected from auroras for the transmitter-receiver sites at

geomagnetic colatitudes, OC = 30 , 45 , 60 , and 90 . This

paper computes the echo geometry for OC = 34 , which is the

geomagnetic colatitude of the Jodrell Bank Radio Experimental

Station, of the University of Manchester, and is very close to

that of the stations in northern United States which are concerned with radio echo work. (Item 5C -235, Met. Abs.)--

Author's abstract.

C-48 Chamberlain, Joseph W. , Auroral rays as electric-discharge

phenomena. Astrophysical Journal, Chicago, 122(2) :349 -350,

Sept. 1955. 3 refs. DLC --Nearly constant luminosity of auroral rays over a large height and density range requires a compensatory mechanism which is not fully understood. Excitation could increase with height due to greater incident energy,

and the number of collisions decrease with height due to decreasing density. A current density of 6 X 10^2 electrons/

cm^ sec would be necessary for a ray 10^ cm in diameter. An

electron density of 10^ cm'^ would be postulated for the lower

part of the ray (in arcs 10^ electrons/cm^). The current density is uncertain because the diameter of rays is uncertain.

The theory advanced by author balances the electron and proton influx and penetration against the conductivity in the layers where the arcs form and leads to the conclusion that the

electron may be accelerated downward by the pull of the protons and that when arcs recede the rays are left in position

originally occupied by the latter. (Item 7. 10-298, Met. Abs.)

"M.R.
18

C-49 Chamberlain, Joseph W. , Theories of the aurora. Advances

in Geophysics, N. Y. , 4:109-215, 1958. 21 figs. , 113 refs.,

numerous eqs. DLC. Also reprinted as Chicago. Univ.

Yerkes Obs. , Williams Bay, Wise, Contract AF 19(122).480,

Technical Report, No. 40. --A major critical summary and re- view of current knowledge of auroral physics and theory. Historical and observational aspects comprise Ch. ^; Motions of

charged particles in magnetic fields, Ch. 2; STORMER's

theory, Ch. 3; Electric currents from sun to earth, 4; CHAP - MAN-FERRARO's theory and ring current, 5; ALFVEN's,

HOYLE's and LEBEDINSKII's theories, 6; VESTINE and WULF's

dynamo theory, SINGER 's shock-wave theory, PARKER 's theory of hydromagnetic displacement of lines of force, MARIS - HULBURT's UV -light and meteor theories, 7; and theories of

auroral excitation, 8. (Item 9. 9-17, Met. Abs.)--M.R.

C-50 Chapman, R. P. and Currie, B. W. (Physics Dept. , Saskatchewan Univ. , Canada), Radio noise from aurora. Journal of

Geophysical Research, Wash. , D. C. , 58(3):363-367, Sept.

1953. fig. , 13 refs. DWB-- A search for radio noise of 10 cm

wavelength from aurora during 1951 and 1952 with improved

equipment was unsuccessful. The failure to detect the auroral

radio noise, observed previously in 1949, is attributed to the

decrease of the intensity of auroral displays and of sunspot

activity. (Item 5C -236, Met. Abs. )- -Authors' abstract.

C-51 Chapman, Sydney and Eckersley, T. L. , Radio echoes and

magnetic storms . Nature, London, 122(308): 768, Nov. 17,

1928. --Brief note on Stcirmer's observation of auroral radio

echoes at A 31.4 m. (See ref. C-253). If streams of electrons emitted from the sun associated with aurora be the cause,

as Stormer suggests, then this is the first direct evidence obtained of the density of the streamers since an electron density

of 10^ to 10" per cm*^ is required for these reflected signals.

-W. N.

C-52 Chapman, Sydney, The theory of magnetic storms and aurora. Nature, London, 168(4263) :86, July 14, 1951. 5 refs. -A brief

note suggesting the need for experimental work to test the var- ious theories of magnetic storms and auroras. --W. N.

C-53 Chapman, Sydney, The geometry of radio echoes from aurorae.

Journal of Atmospheric and Terrestrial Physics, 3(l):l-29, Jan.

1953. 8 figs., 3 tables, 9 refs. , eqs. DWB--An examination

of discrete auroral echoes in which part of a radio beam is re- flected back to sending station in Northern Hemisphere from

aurora borealis, or possibly from an aurora australis stream beyond the atmosphere. The reflecting unit is taken to be an auroral ray lying along a line of force of the geomagnetic field.
19

Diagrams and tables show positions of surfaces reflecting

radio beams of different elevations at stations in different

latitudes. (Item 4. 9-34, Met. Abs. )--C. E. P. B.

C-54 Chapman, Sydney, Aurora and airglow. Report from Subject

group IV, of International Unjon of Geodesy and Geophysics,

at the 10th Assembly, Rome 1954. 7 p. refs. Mimeo. -- Objectives of aurora and airglow program suggested for IGY,

1957-8, are set forth and visual, photographic, spectroscopic,

radio-auroral, rocket auroral and airglow measurements planned, are described in some detail. (Item 9. 7-38, Met. Abs.)

-M.R.

C-55 Chapman, Sydney, The IGY auroral programme. International

Geophysical Year, 1957/1958, Comite Special, Bulletin d 'In- formation, No. 7:58-61, 1956. DWB-The objectives of auroral

observations during the IGY are: an understanding of the nature

of auroras, the solar emissions, the modes and periods of emissions from the sun, their courses to the earth and the ensuing

luminous, electromagnetic and ionospheric processes near our

earth and in the atmosphere. The immediate objective to increase our factual knowledge of the aurora. The auroral program during this IGY included the following: the synoptic picture by photographic methods and visual surveys, alerts and

special world intervals for warning information, the photometry,

spectrophotometry and spectrography, the possible transfer of

equipment during the months of Arctic daylight, the radio detection of aurora, the auroral radio emissions, radio absorption

and scattering associated with auroras, rocket studies, atmospheric electric field, auroral sounds. The principal experiments in the ionospheric program are included. (Item 10. 6-34,

Met. Abs.) -N.N.

C-56 Chapman, Sydney and Little, C. Gordon, The nondeviative

absorption of high frequency radio waves in auroral latitudes . Journal of Atmospheric and Terrestrial Physics, 10(1):20-31,

Jan. 1957. 3 tables, 21 refs. , 14 eqs. DWB--In auroral latitudes the nondeviative absorption of high frequency radio waves

is much more irregular, and often much stronger, than in subauroral latitudes. It is greater and more frequent by day than by

night; this is the converse of the daily variation of magnetic

activity. The electrons that produce the absorption in subauroral latitudes are mainly caused by solar ultraviolet light; in

auroral latitudes, often the major source is bombardment of the

atmosphere by solar gas. According to J. A. VAN ALLEN's new

interpretation of the soft radiation observed by himself and his

colleagues in auroral latitudes, down to 50 km, a small minority of the primary bombarding particles generate X-rays, which

penetrate further than the particles themselves. It is here
20

suggested that the layer ionized by these X-rays is an important factor in the daytime radio absorption. Also, as D. R.

BATES has pointed out, Lyman-alpha radiation will be generated by the auroral protons; ionization of nitric oxide molecules by this radiation may also contribute appreciably to the

absorption. The same processes of ionization will occur likewise at night, and often still more strongly; however, loss of

the electrons to form negative ions by attachment is countered

by photodetachment during the day, but not at night. Very

tentative tables are given, based on these ideas, indicating

ionospheric conditions consistent with greater daytime absorption than at night, even when the nighttime bombardment is

twenty times more intense than that by day. The corresponding absorption relaxation times, and daily variation of magnetic disturbance, will be examined in a later note. (Item

8. 6-17S, Met. Abs. ) -Authors' abstract.

C-57 Chapman, Sydney, Auroral observation in India and Pakistan. National Institute of Sciences of India, Calcutta, Bulletin,

No. 9:180-192, Nov. 2, 1957. fig., 10 refs. Abstracted

from reprint. DWB (523. 74 C719rg) --Printed records remain

of observations from at least eight places, in what is now

India and Pakistan, of the great aurora of Feb. 4, 1872; their

geographic latitudes range from 34 to 19 N (geomagnetic, 24

to 10 N). Hence this remarkable aurora may be called tropical as well as polar. These records are reproduced and discussed, and a plea is renewed for a search for further records

of observations of this aurora (and possibly also others) from

the Indian subcontinent. More important still, attention is

drawn to the need for observation of future great auroras observable therefrom, and from elsewhere in low latitudes, and

especially from high altitude observatories. The types of

desirable observations and equipment are outlined. The possibilities of successful observation (on the rare occasions

when nature provides the event) may be increased by keeping

a special watch at times when there is an enhanced probability of their occurrence. Such times may be recognized with

the aid of magnetic, radio and solar observations made on the

spot, or they may be called attention to by an international

center, as is planned during the International Geophysical

Year 1957-58. (Item 10.11-265, Met. Abs. ) -Author's abstract.

C-58 Chapman, Sydney (Geophysical Inst. , College, Alaska),

Disturbances in the lov/er auroral ionosphere . Journal of Atmospheric and Terrestrial Physics, London, 15(1/2): 29 -37,

Sept. 1959. 2 figs., table, 16 refs. DLC--The solar particles

that enter the atmosphere and produce the luminous aurora are known to include protons, which also ionize the atmosphere.
21

As suggested by BATES, their ionizing action may extend below the level of their own penetration, by the Lyman QL, - photons they emit. These can penetrate to about 75 km, and ionize nitric oxide. Recent rocket researches by VAN ALLEN and

his colleagues prove that the primary auroral particles also include electrons, with energies up to 100 keV. These penetrate to about 80 km, thus directly extending the auroral ionization well below the level of auroral luminosity. Indirectly

these electrons ionize the atmosphere down to far lower levels,

by the X-rays emitted by a small fraction of the electrons.

WINCKLER's balloon results show that such ionization ex- tends at least down to 32 km. This ionization below the level

of the visible aurora accounts for most of the absorption, in

auroral regions, of high frequency radio waves. Though the

primary electron flux at night probably exceeds that by day,

the secondary electrons are often more numerous (and absorbent) by day than by night. This is because, by day, photodetachment prolongs the free life of these electrons, despite

their ready attachment to oxygen. (Item llF-18, Met. Abs.)--

Author's abstract.

C-59 Chestnov, F. I. , Zagadka ionosfery. (Enigma of the ionosphere. ) Moscow, Gosud. Izdat. Tekhniko-Teoreticheskio

Literary, 1S54. 54 p. 24 figs. Nauchno-populiarnaia Biblioteka. No. 70. DLC--The detailed structure of the ionosphere

is described and shown in an original schematic diagram. Ionization, twilight, night sky light, aurora, diurnal effects, magnetic field, magnetic storms and ionosphere, solar effects,

radio propagation (long and short wave), ionospheric soundings

by radio impulses, sunspot effects, forecasts of radio propagation, meteor traces, radio radiation from stars and rocket ex- ploration of ionosphere are treated in condensed popular technical form. (Item 6D-235, Met. Abs.)--M.R.

C-SO Chivers, H. J. A. (Univ. of Manchester, Jodrell Bank Exper.

Sta. ) and Wells, H. W. (Carnegie Inst. , Wash. ), Observa - ti ons of unusual radiofrequencv noise emission and absorption

at SO Mc/s. Journal of Atmospheric and Terrestrial Physics,

N. Y. , 17(1/2):13-1&, Dec. 1959. 2 figs. , 2 tables, 11 refs.

DWB, DLC --Unusual radiofrequency noise emissions at SO Mc/s

have been identified during periods of solar activity. The

noise enhancements may be classified as (1) smooth, bay-like

disturbances lasting for approximately 1 hr which occur in both

dciy and night hours, and (2) abrupt increases, often of large

, but fluctuating amplitude which occur within a few hours of

local midnight. The smooth enhancements occur almost simultaneously with the absorption of radiation in a sector of the

northern sky. These effects could be caused by transit of high

velocity streams of charged particles which produce emission
22

from F region levels and absorption in the E region or below.

The abrupt noise bursts at night are from the northern sky and

seem to be associated with pronounced changes in the horizontal component of the earth's magnetic field. The noise may

be a form of "auroral" radiation or may arise from propagation

of solar noise outbursts from the sunlit to the dark hemisphere.

(Item 11. 7-164, Met. Abs. )- -Authors' abstract.

C-Sl Clegg, J. A. and EUyett, C. D. , Radio echoes from the aurora borealis . Nature, London, 160(4063): 372, Sept. 13, 1947.

6 refs. , eqs. --Radio echoes from a distance of 480 miles were

obtained on 46 Mc/s, apparently arising from a luminescent

cloud near the end of an aurora streamer. There was also general nonlocalized reflection from the same region on 46 and 72

Mc/s. The ionization density is estimated to have been r-K^

100 X the average F layer night ionization. --Authors' abstract.

C-62 Collins, C. , Some observations of aurora using a low-power

frequency modulated radar. Canadian Journal of Physics,

Ottawa, 36(7):926-934, July 1958. 5 figs. , table, 18 refs.

DWB, DLC--A frequency modulated, continuous -wave radar

seems to be particularly well suited to the observation of auroral ionization, since it provides both range information and

a Doppler indication of radial motion. An experimental equipment of this type has been operated for a few months near Ottawa. The system parameters are briefly considered and the

radar observations are compared with similar measurements

made with higher powered pulse systems. (Item 10. 5-164,

Met. Abs. ) --Author's abstract.

C-63 Collins, C. and Forsyth, P. A. (both. Defence Research

Board, Ottawa, Canada), A bistatic radio investigation of auroral ionization . Journal of Atmospheric and Terrestrial Physics, London, 13(3/4) :315-345, Feb. 1959. 13 figs. , 2 tables, 32 refs. DLC--The scattering of radio waves in the upper atmosphere during auroral disturbances has been studied

by means of a number of radio systems in which each transmitter v/as separated from its associated receiver by a distance of about 1000 km. Some twenty of these systems were

used in a network covering a large area in Canada. The frequencies were in the range 30-50 Mc/s. At least four different kinds of auroral events are distinguishable. Of these, two

appear to be associated separately with different phases of

visible aurora, the third with a later stage in the auroral process which is not observed visually, and a fourth with the re- current daytime absorption which often precedes an auroral

disturbance. The term "radio-aurora", which applies to all of

the events, is used to avoid confusion with that part of the

auroral process which is observable visually. In these four
23

events, evidence is found for three separate scattering mechanisms, each of which has been proposed previously as the

principal source of radar echoes from aurora. (Item 11. 1-315,

Met. Abs. ) --Authors' abstract.

C-64 Conference on Auroral Physics, July 23-26, 1951, London,

Ontario, Proceedings. Ed. by N. C. Gerson; T. J. Keneshea

and R. J. Donaldson, Jr. U. S. Air Force. Cambridge Research Center, Geophysical Research Papers, No. 30, July

1954. 459 p. numerous tables, diagrs. (incl. photos) and

eqs. Bibliogs. throughout. Alphabetical author and subject

indexes. MH-BH--The papers collected in this volume have

been abstracted separately. They cover the theory and physicochemical aspects of the aurora, sunlit aurora, radar or radio reflections from auroras, the airglow, laboratory investigations of upper atmospheric processes and auroral afterglow, interpretation of atmospheric emission, geomagnetic

storms and aurora, solar and magneto-hydrodynamic waves and

atmospheric absorption. Many references and a good index

are included. (Item 6. 9-3, Met. Abs.)--M. R.

C-S5 Covington, A. E. , Microwave sky noise. Journal of Geophysical Research, 55(l):33-37, March 1950. 4 figs. , 7 refs.

MH-BH--Radiation of 2800 mc was received from empty sky,

equivalent to a temperature of ca. 50 K but with short time

bursts from zenith. Examples are described, associated with

magnetic disturbances, with aurora overhead and once with a sudden ionospheric disturbance. (Item 4. 9-113, Met. Abs.)

--C £• P. B.

C-86 Cox, J. W. and Davies, K. , Statistical studies of polar radio

blackouts. Canadian Journal of Physics, 32(12): 743-756, 1954.

15 figs. , 3 refs. --A statistical study of high-frequency radio

blackouts in Canada is made from records taken at several ionosphere sounding stations. Both vertical incidence and communication data are examined to determine the geographical,

seasonal and diurnal distributions of the frequency of occur- rence of blackout. It is found that blackouts are most abundant in the morning and that the time of maximum occurrence

increases with increasing latitude. --Authors' abstract.

C-67 Currie, B. W. ; Forsyth, P. A. and Vawter, F. E. (Physics

Dept. , Saskatchewan Univ. , Canada), Radio reflections from

aurora. Journal of Geophysical Research, 59(2): 179-200, June

1953. "7 figs. , 5 tables, 19 refs. MH-BH—This paper outlines

observations and experiences associated with a continuing investigation of radio echoes from aurora at Saskatoon, Canada.

For the three frequencies investigated - 3000, 106 and 56 Mc/s

- echoes have been observed with the last two. Echoes occur
24

when the auroral forms exhibit some ray structure and, then,

only from parts of the aurora at elevations less than 15 above

the horizon. Using range-amplitude and range-azimuth displays of echoes in combination with the corresponding photographs of the aurora, it is shown that the echoes originate

from levels close to the lower edge of the aurora. Height distributions of the centers from which the echoes come agree

closely with height distributions found from parallactic photographs of aurora in other regions. Using aerial arrays for the

106- and 56-Mc/s frequencies that are mounted on a rotable

tower so that each beam scans simultaneously the same part

of the sky, the 106-Mc/s echoes are found to occur most frequently within the auroral zone and the 56 Mc/s echoes some

distance to the south. Relative frequencies and diurnal var- iations of the two groups of echoes, as well as their heights

and geographical distributions, indicate that echoes originate

from a threshold process. It is suggested that the echoes

arise by critical reflection from centers of high electron density (1.4 X 108 and 4 x 10^ electrons per cm3, respectively)

that are formed close to but above the levels where the electron collision frequency exceeds the gyrofrequency of the electrons. (Item 5C -237, Met. Abs. )- -Authors" abstract.

C-68 Currie, B. W. , Progress report of atmospheric ionization in

Canada 1948-1951. I. U. G. G. Association of Terrestrial

Magnetism and Electricity, Bulletin, No. 14, Transactions

of the Brussels Meeting, :90-91, 1954. --This report covers

primarily activities in Canada that come to the attention of

the Sub-Committee on Atmospheric Ionization of the Associate

Committee of the National Research Council of Canada on Geodesy and Geophysics. As such, it concerns itself with re- searches in atmospheric electricity, aurora and geomagnetic

phenomena in so far as they indicate the ionic conditions of

the atmosphere, ionospheric reflections of radio waves and

meteor ionization. It does not concern itself with such matters as tropospheric propagation of radar waves, reflection of

radar waves by precipitation, ozone content of the atmosphere

and cosmic rays, each one of these fields of investigation

falling more properly under the jurisdiction of other existing

committees of the National Research Council.

C-69 Currie, B. W. , IGY aurora and airqlow program. Ciencia,

Mexico City, 16(11/12):309-316, 1956. 5 tables. DWBSpecial problems and techniques to be used during IGY in the

auroral and airglow program, a list of the 100 Western Hemisphere stations from pole to pole making or intended to make

visual, photographic and photoelectric observations of auroras,

a list of 23 stations to make patrol-type spectrographic observations, 12 stations to operate high resolution spectrographs
25

and photoelectric scanning spectrometers during IGY, 13

stations to make auroral radar studies and 10 stations to

make airglow observations, and a detailed account of the

Canadian auroral program are included in this informative

article. (Item 9. 7-35, Met. Abs.)--M.R.

C-70 Davidson, D. , Reflexion of high frequencies during auroral

activity. Nature, London, 167(4242): 277-278, Feb. 17, 1S51.

2 figs. , 2 refs. DWB--Ionosphere reflection of 17.31 Mc/sec

waves observed at Concord, Mass. on Aug. 8, 1S50 during

strong aurora. (Item 2. 7-193, Met. Abs.)

C-71 De Kock, A. C. , Het Noorderlicht. (Aurora borealis.

)

Hemel en Dampkring, 33(3): 104-108, March 1938. plate (6

auroral photos). ,,DWB"The theories of HULBURT, BIRKELAND,

VEGARD and STORMER on the origin of the aurora, conclusions as to the composition of the high atmosphere obtained

from auroral spectra, laboratory models showing auroral rings

and torus space, and the disturbance to radio communication

caused by the great aurora of Jan. 25-26, 1938 are mentioned

in this review article. (Item 5C -87, Met. Abs.)--M.R.

C-72 Dieminger, Walter, Die Ionosphere und ihr Einfluss auf die

Ausbreitung elektrischer Wellen. (The ionosphere and its influence upon the propagation of radio waves.) Ergebnisse

der Exakten Naturwissenschaften, Berlin, Vol. 17:282-324,

1938. 31 figs. , 153 refs. , 20 eqs. --The purpose of this

paper is to clarify the relationships between the ionosphere

and radio wave propagation, specifically with regard to choice

of frequencies under a variety of atmospheric conditions, times

and seasons, as well as distances of path of communication.

The introduction deals with the method of change of frequency

and the echo method, followed by the discussion of (1) the

theory of the ionosphere and (2) ionospheric observations

under which subject headings the pertinent aspects are treated

individually. The behavior of radio waves as influenced by

meteors and aurorae is included. The bibliography envelopes

the period 1925-1936. -W. N.

C-73 Dieminger, Walter and Plendl, H. , Abnormale Erscheinung

in der Ionosphere wahrend des Nordlichtes vom 24. -25. Febr.

1939. (Abnormal phenomena in the ionosphere during the aurora of Feb. 24-25, 1939.) BeitrSge zur Geophysik, 55(2):189-

192, 1939. 3 figs. , ref. DLC- -Photographs of 80 m wave re- flection during an unusual aurora, presented for the surface

wave and the different F layers, show distinct disturbances

and a general increase of the reflecting light. (Item 5C-98,

Met. Abs.)"A. A.
26

C-74 Dieminger, Walter, Neue Erqebnisse der lonospharenfors - chunq. (Recent result of ionospheric research. ) Die Umschau,

44(3):37-40, Jan. 21, 1940. 8 figs. --Measured virtual height

versus frequency during times of magnetic storm and polar light

Describes normal characteristics of E and F layers. Points out

geographical study of F2 and shows it behaves as if there were

two ionizing components, one seasonal, and the other annual.

The annual component is not yet found. (Annual has maximum

simultaneously in both hemispheres, seasonal does not.) Describes abnormal E reflections, storms. --L. A. Manning.

C-75 Dieminger, Walter, Zwei Arten der abnormalen E-Schicht.

(Two kinds of E layer.) Die Naturwissenschaften, 33(5): 154,

Sept. 1946. 6 figs. , 2 refs. --Discusses the difference between the types of sporadic E ionization found at medium and

high latitudes. Compares curves showing the percentage of

time for which sporadic E appears above 4 Mc/s at Tromso,

Oslo, and Kochel. Tromsb shows a maximum frequency of oc- currence at night, the others near noon. Shows monthly distribution of occurrence. Tromso, the high latitude station,

shows little seasonal change, while Oslo and Kochel show a pronounced peak in occurrence in the summer, a minimum near

December. He suggests that tv/o causative mechanisms appear to be active in producing the two types of sporadic E.

That active in the north might be called "Nordlicht-E". --L. A. M.

C-76 Dostal, E. , Betrachtunqen zur ErklSrunq des Weltraumechos

des Polarlichtes und der maqnetischen StSrunqen. (Explanatory notes on the v/orldwide auroral echoes and the magnetic

disturbances.) Annalen der Physik, Leipzig, 5(14):S71-984,

Oct. 1932. 7 figs. , 7 refs. , 3 eqs. --The present theoretical

attempts to explain the phenomenon are summarized, followed

by a brief discussion in terms of the geometric optics and the

physical nature of the reflecting "wall". --W. N.

C-77 Dowden, R. L. (Commonv/ealth lonos. Prediction Serv. , Hobart, Tasmania), L ow frequency (100 kc/s) radio noise

from the aurora . Nature, London, 184(4689), Supp. No. 11:

803, Sept. 12, 1959. 7 refs. DWB-A report of "hiss" observations carried out at Hobart, Tasmania. Five frequency channels were operated simultaneously, covering the gap from the

normal "hiss" frequencies to the controversial 100 kc/s band.

The center frequencies of these channels were 4. 6, S. 6, 27,

70 and 180 kc/s. The observations establish that "hiss" can

sometimes occur at frequencies up to 180 kc/s, at least, suggesting that extraterrestrial noise much below a megacycle

might be a "hiss" rather than "cosmic noise". (Item 11. 10-

167, Met. Abs.)-I.S.
27

C-78 Dowden, R. L. (Ionospheric Prediction Service, Hobart, Tasmania), Ionospheric thermal radiation at radio frequencies in

the auroral zone . Journal of Atmospheric and Terrestrial Physics, N. Y. , 18(1):8-19, April 1960. 6 figs. , 2 tables, 11

refs. DLC --Measurements of the temperature of the ionospheric D-region in the auroral zone from observations of 2

Mc/s radio noise are described and compared with measurements similarly made in the temperate region. The temperatures of the undisturbed and disturbed ionospheres at the two

latitudes are found to be essentially similar, but the disturbing influence in the auroral zone is probably corpuscular

rather than ultraviolet radiation. (Item 11. 10-324, Met. Abs.

)

"Author's abstract.

C-79 Driatskii, V. M. and Besprozvannaia, A. S. , I onospheric

conditions in the circumpolar region. Annales de Geophysique, Paris, 14(4):438-455, Oct. /Dec. 1958. 13 figs. , 11

photos, 3 refs. DLC--Ionospheric observations from the drifting station SP-3 during the period May 15, 1954 to April 14,

1955, and especially observations made during the Arctic

night, are given. The authors give a short description of the

characteristics of the apparatus and of the magnetic field

state. The results of the observations are given for the normal

E layer, the E sporadic ionization, the E2 sporadic ionization, the normal Fl and F2 layers and the anomalous absorption of radio waves. Of greatest interest are the results re- ceived under the conditions of the Arctic night in connection

with the F2 layer. The critical frequency for F2 layer during

this period was unexpectedly high, reaching 5-6 mc at times.

The evident sporadic type of the layer being expressed in the

sharp change of the critical frequency in the layer from hour

to hour and from day to day, a definite connection with the

state of the magnetic field proves its corpuscular nature. At

the same time, the distinct shape of height-frequency diagrams, normal for reflections from the F2 layer, stipulated by

a wave radiation, can hardly be taken to agree with the cor- puscular conception. It is still impossible to solve the problem of the nature of observed high ionization in the F2 layer

during a Polar night. (Item 11. 1-53, Met. Abs.)"A. V.

C-80 Duncan, R. A. and Ellis, G. R. , Simultaneous occurrence

of sub-visual aurorae and radio noise bursts on 4. 6 kc/s.

Nature, London, 183(4675): 1618-1619, June 6, 1959. 3 figs.,

table, 3 refs. DLC --Observations at Camden, near Sydney

(geom. lat. 42 S) of enhanced emission toward the south of

the red oxygen (6300 A) airglow are interpreted as sub-visual

aurorae. Simultaneous radio noise at 4. 6 kc/s shows a definite correlation, both related to magnetic disturbance and tending to occur when the disturbance index (K) > 5. The one can

occur without the other and is explained. (Item 11. 10-168,

Met. Abs.)..W. N.
28

C-81 Dyce, Rolf Buchanan, Auroral echoes of fifty megacycles ob- tained at College. Alaska. American Geophysical Union,

Transactions, 35(2) :375, April 1954. --CW and pulse methods

were used to study returns from the aurora at 50 mc/sec during the summer of 1953, the equipment being located near the

center of the auroral zone. Aurora was frequently seen in all

parts of the sky but the VHF echoes were obtained only from

5<3:azimuth angles within 60 of magnetic north and with ranges

of from 200-900 km but chiefly 400-700 km. A verticallypointing antenna was used in an attempt to obtain echoes from

overhead visible aurora but results were negative. Most of

the echoes were therefore originating far north of the zone of

maximum auroral activity. These data support the view that

strongest echoes will be obtained when looking roughly perpendicular to the Earth's magnetic field. CW signal-strength

recordings with antenna directed northward yield a diurnal

variation of auroral propagation similar to results obtained at

Ithaca, N. Y.

C-82 Dyce, Rolf Buchanan, Communication aspects of V.H.F.

auroral reflections . Cornell Univ. School of Electrical Engineering, Ithaca, N. Y. , Technical Report 23, June 1, 1955.

Unchecked. Microfilm available. DLC (AC 1, Publication

No. 15, Oil) --Experiments on frequencies around 50 Mc/s in

northeastern United States and northern Alaska show the following: (1) The occurrence of auroral reflections have distinct diurnal, seasonal, and solar activity variations; (2) the

reflection condition is that the transmitted and reflected rays

should be nearly perpendicular to the magnetic field at the

position of the aurora; and (3) the fraction of incident energy

reflected is on the order of 10-4. The effects of auroral re- flections on VHF communication circuits are discussed. -- Author's abstract.

C-83 Dyce, R. B. , VHF auroral and sporadic E propagation from

Cedar Rapids. Iowa, to Ithaca. N. Y. Institute of Radio

Engineers, Transactions on Antennas and Propagation, AP3(2):

78-80, April 1955. 8 figs. , 14 refs. DLC-The results of a

total of 13, 595 hours of valid observations with a 50 Mc transmitter from April 1952 to May 1954 are presented and discussed. A simple and effective technique for separation of

sporadic E and auroral ionization is described. The diurnal

variation for each type was determined; one being a nighttime,

the other a daytime phenomenon. The seasonal variation determined for each mode of propagation showed maximum sporadic E at solstices and auroral signal minimum. Successful

correlations with (a) visual aurora occurrence and (b) ionospheric sounder data were made. --W. N.
29

C-84 Dyce, R. B. (Geophysical Inst. , College, Alaska and Cornell Univ. , Ithaca, N. Y. ), Auroral echoes observed north

of the auroral zone on 51. 9 Mc/sec . Journal of Geophysical

Research, Wash., D. C. , 60(3):317-323, Sept. 1955. 3 figs.,

9 refs. DLC--During Nov. 1954, a simple radar system designed for observation of auroral echoes at 51. 9 Mc/sec, was

operated at Point Barrow, Alaska. Because this location is

north of the accepted maximum of the auroral zone, most of

the visible aurora is seen to the south of the observing station. The radar used a continuously rotating antenna to see

with equal sensitivity in all directions, but more than 90% of

the echoes were obtained from directions north of east and

west. Echoes were obtained only from 500 to 1100 km. These

effects are explained by the theory of MOORE (See ref. C-207

208) as enlarged by BOOKER, GARTLEIN, and NICHOLS (See

ref. C-28), requiring near-perpendicularity of radio ray paths

to the lines of the earth's magnetic field. During visible aurora, propagation at 51. 7 Mc/sec was investigated over an

800 km path from College to Barrow, across the auroral zone. Bursts of signal due to meteor ionization were readily observed. Propagation associated with aurora was almost nonexistent, even v/ith visible aurora at the mid-path. If the theory of

auroral echoes of HARANG and LANDMARK (See ref. C-127)

were true, auroral propagation should have been readily detected. (Item 7. 10-70, Met. Abs. ) -Author's abstract.

C-85 Dyce, R. B. ; Dolphin, L. T. et al. (all, Stanford Res. Inst. , Calif. ), Aurora-like radar echoes observed from 17 latitude . Journal of Geophysical Research, Wash. , D. C. , 64(11):

1815-1818, Nov. 1959. 2 figs. , table, 8 refs. DLC-Anomalous echoes are regularly observed by a shipbome radar located at Antigua, British West Indies. These echoes, observed at 32 and 140 Mc/s, have many of the characteristics of

echoes from the auroras observed in the Arctic, although visible auroras should not be observable at Antigua more frequently than once in 7 yrs. Similar observations at Stanford

Univ. indicate a correlation with one kind of sporadic E ionization. (Item llF-33, Met. Abs .) -Authors ' abstract.

C-86 Eastwood, E. ; Isted, G. A. and Bell, J. D. , Radar echoes

from the aurora at 1300 Mc/s. Nature, London, 189(4759):

115-117, Jan. 14, 1961. 2 figs. , 2 tables, 8 refs. DLCExperimental results of 2 years observations with a high power

L-band radar operating at 23 cm A. . are discussed. It is

shown "that the departure from the 90 reflexion condition is

less than ±'>^ , and that the region of the ionosphere where

the auroral reflexions take place is of the order of 20 km

thick". The mechanism responsible for the aurora at 1306 Mc

can. be explained by Booker's scattering theory. —W. N.
30

C-87 Eckersley, T. L. , An investigation of short waves. Institution of Electrical Engineers, Proceedings, 67(392): 992- 1032,

Aug. 1929. 30 figs. , 4 tables, eqs. DLC—Long paper dealing mainly with scattering, etc. Computes shape of pulse

transmitted after random (like gas molecule) scattering. Analyzes effect of dispersion on pulse shape, and finds f must be

very near the critical value to produce appreciable pulse blurring. Quotes Chapman on time for diffusion: at 100 km mean

free path is 12 cm, so diffusion over 100 meters of electrons

would take less than one second, but of positive ions about

27 min. At 125 km, 11 sec. Gives much data on directions

of arrival of signals. Discusses atmospheric "whistlers"

heard when an audio amplifier is connected to an antenna.

Shows them most frequent during magnetic storms. Attributes

to dispersion of click resulting from sudden stopping of ou particles in the atmosphere. Considers mechanical analogy.

In discussion, J. E. Taylor wonders whether "whistlers"

aren't due to meteors, especially as they are heard at night.

Eckersley wondered, but could find no reason why they should

be, thinks Stormer's theories explain charged particles on

dark side of earth. --L. A. Manning.

C-88 Egan, R. D. and Peterson, A. M. , Auroral noise at H. F. Journal of Geophysical Research, 65(11): 3830-3832, Nov.

1960. 2 figs. , 13 refs. DLC--A brief review of previous

studies of auroral noise at HF is followed by a report that

riometer records during the large magnetic storm of Nov. 27-

28, 1959, recorded intense aurorally associated absorption

at Meanook, Alberta. On that night a low latitude red aurora was present. The 3-hr Kpindex reached a maximum value of

8. There is a close correlation apparent between the noise

peaks recorded at Stanford, California, and absorption peaks

at Meanook. The records taken at Pullman, Wash. , indicate

that both absorption and noise are present, and consequently,

only the net effect was measured. Possible mechanisms for

the generation of auroral noise include radiation from accelerated electrons in the Van Allen belt. Synchrotron radiation

from trapped electrons in the outer Van Allen region that are mirrored at a lower height as a result of a magnetic disturbance is regarded as the most likely mechanism for the noise

observed at Stanford. Reference is made to the work of Dyce

and Nakada (1959), Schwinger (1949), Chivers and Wells

(1959). The experiments (direct measurement of the flux density in the outer Van Allen belt as a function of energy) made

by Walt Chase, Cladis, et al (1960) are described. Arnold

Hoffman's and Winkler's (1930) work with Explorer VI data is

reported. In summary it is suggested that auroral noise does

not correlate with daily magnetic indices, although there is a general over-all storm period correlation. --E. Z. S.
31

C-89 Egeland, Alv; Hultqvist, Bengt and Ortner, Johannes (all,

Kiruna Geophys. Observ. Kiruna, Sweden), A day-time

maximum of oblique auroral reflexions observed in the auroral

zone . Nature, London, 185(4712) :519, Feb. 20, 1960. fig.,

8 refs. DWB--From four months records of aurorally propagated

very high frequency signals taken in the auroral zone at Kiruna,

a diurnal variation curve with two maxima has been found. One

of these maxima is in day time between 1200 and ISOO M.E.T.

The experimental points include all observed reflections. The

day time echoes have the same signal characteristics observed

as night echoes on the Esterline Angus records. The direction

distribution for day and night maxima is approximately the

same; this has been determined by means of rotary antennae.

(Item 12A-63, Met. Abs. )--E. Z. S.

C-90 Ellis, G. R. , Low frequency radio emission from aurorae . Journal of Atmospheric and Terrestrial Physics, 10(5/6) :302-

306, 1957. 2 figs. , table, 11 refs. , 2 eqs. DWB--This paper

discusses the possibility that Cerenkov radio emission by auroral particles approaching the earth may contribute to the level

of the continuous component of atmospheric radio noise observed at frequencies of hundreds of kilocycles per second. It is

shown that, provided the Cerenkov process is valid at radio

frequencies, the flux density of the radiation may be as high

as 10"2l W m"^(c/s)"-^ at these frequencies, well above the

minimum observable using current techniques. The frequency

range of the emission would extend from a few hundred kc/s

to low audio frequencies. (Item 8. 10-302, Met. Abs.)--Author's abstract.

C-91 Ellis, G. R.A. (Upper Atmosphere Section, CSIRO, Camden,

N. S. W. ), Low frequency electromagnetic radiation associated

with magnetic disturbances. Planetary and Space Science,

N. Y., l(4):253-258, Sept. 1959. 5 figs. , 2 tables, 13 refs.,

eqs. DWB, DLC --Continuous observations of the amplitude

and spectrum of naturally occurring radiation in the band 2-40

kc/s were made during the period June to December 1958 near

Sydney, Australia. A large number of isolated noise bursts

lasting for some hours were detected. The intensity ranged

from 6 X 10-19 to 6 X lO'l^ w m-2(c/s)-l at 4. 6 Kc/s. Three

main types of bursts were identified and classified on basis of

their spectra which usually extended from 3 to 5 Kc/s and 2 to

30 Kc/s, respectively. Major bursts, which were always of

the latter two types, were clearly associated with strong auroral and magnetic activity and some showed a reproducible

sequence of amplitude variation lasting about 36 hrs. On

three occasions, a detailed correspondence between intensity

of the noise and of simultaneously occurring red oxygen airglow was observed. Theories and origin of the noise are discussed. (Item 11. 9-134, Met. Abs. ) -Author's abstract.
32

C-92 Ellis, G. R. A. ; Cartwright, D. G. and Groves, J. R.V./

Spaced observations of radio noise from the outer atmosphere.

Nature, London, 184(4696, Supp. No. 18): 1391 -1392, Oct. 31,

1959. fig. , ref. DWB--It was suggested by G. R.A.Ellis

that- during some types of radio noise storms in the Earth's

outer atmosphere, the source of noise may remain in constant

position in right ascension. In this case the arrival of the

storm will be recorded at the same local time at places of different longitude rather than simultaneously. In a majority of

the cases noise bursts were recorded simultaneously at Camden and Adelaid. A distinct time delay was observed only

during a major geomagnetic storm and aurora. (Item 11. 12-

321, Met. Abs.)-A.H.J.

// C-93 Fanselau, Gerhard, Uber die St'6rung der Ionosphere vom 24-

26 Januar 1949. (On the disturbance of the ionosphere from

Jan. 24-26, 1949.) Zeitschrift fQr Meteorologie, 3(4): 100-110,

April 1949. 6 figs. , 5 tables. DWB--On Jan. 21st two large

spots approached central meridian of sun. A magnetic storm

began on Jan. 24th and is described in detail. Reception of

the 1, 250 m space radio wave from Kalundborg showed great

variations. 27-day recurrences are clearly shown in Potsdam

magnetic character figures from December to March. Associated auroras on Jan. 24-26 are listed and described. (Item

1.5-116, Met. Abs.)-C.E.P.B.

C-94 Fendler, Ernst, Die ionosphSrischbedingte Ubertragung ultra,

kurzer Wellen. (Ultra short wave transmission affected by

ionospheric activity. ) Hochfrequenztechnik und Elektroakustik, 55(2):41-47, 1940. 13 figs. , 12 refs. , eq. DLC-The

purpose was to determine whether, how, and at what time of

day and seasons the ionospheric propagation of <" 12 m A

would be most favorable, considering the dependency of solar

activity. Propagation through the E layer during abnormal ionization, the relationships between aurora borealis and ultra

short radio wave propagation are discussed with some remarks

on transmission power and antennas. Peculiar propagation

conditions occurred in winter during aurora borealis. --W. N.

C-95 Ferrel, Perry, Jr. , Aurora U.H.F. propagation. Radio, Santa

Barbara, Calif., No. 256:20-22, 74, Feb. 1941. fig. DLCThe so-called "Aurora-dx" signals at 43. and 44. 10 Mc as- sociated with bright aurora displays, ionospheric and magnetic disturbances are discussed. Auroral effects on FM re- ception, Doppler effect and periodicity are also considered.

The disturbances were at minimum in June and December,

maximum in March and September. More severe storms occur

in the northern hemisphere when the moon is below the earth's

equator. --W. N.
33

C-96 Fleischer, R. (Rensselaer Polytechnic Institute, Troy, N. Y.),

Auroral absorption of 18 Mc/s cosmic radio waves on Feb. 11^

1958. Nature, London, 181(4616): 1156, April 19, 1958. fig.

DWB--This preliminary report illustrates graphically the appearance of the spectacular auroral display observed widely

in the United States on the night of Feb. 11, 1958. Observation of its effect on the 18 Mc/s cosmic noise from the sky

was made at the Sampson Station (lat. 42°47'N; long. 73°27'

W). A description of the method of obtaining such sudden

absorptions of cosmic noise is recorded briefly in the Astron.

Joum. , 62:243, 1957. (Item 12B- 184, Met. Abs.)-N. N.

C-97 Forsyth, P. A. ; Petrie, W. and Currie, B. W. , Auroral radiation in the 3000 megacycle region. Nature, London, 164

(4167):453, Sept. 10, 1949. DLC- -Pulses of radiation of

duration 1-5 A sec, arriving in a random manner in bursts of

short duration ("CI sec) were observed visually on the indicator of a radar set with transmitter off. Auroral origin was

confirmed by observations of 20 aurorae, the part of the display to which the receiving aerial pointed at any time being

photographed. Some correlation between frequency of pulses

and intensity and type of aurora was found.

C-98 Forsyth, P. A. ; Petrie, W. and Currie, B. W. , On the origin

of ten centimeter radiation from the polar aurora. Canadian

Journal of Research, Sec. A, 28(3):324-335, May. 1950.

7 tables, 25 refs. , eqs. DLC --Short-lived bursts of 10 cm

radiation from auroral displays have been received by radar

equipment. The sources of continuous radiation from a partially ionized medium are briefly discussed. From a knowledge of the constants of the equipment used it is deduced

that the power density at the receiver is at least 2 X 10"^^

watts per m^ and it seems that the most likely source of this

radiation is a plasma oscillation of the ionized volume associated with the auroral display. If it is so, the electron density in at least localized regions must be of the order 10-^^

per cm^. --Authors ' abstract.

C-99 Forsyth, P. A. ; Petrie, W; Vawter, F. and Currie, B. W.

,

Radar reflexions from auroras. Nature, London, 165(4197):

561-562, April 8, 1950. 7 refs. , 2 eqs. DLC-Report of investigation at Saskatoon, Canada. Radar equipment operating at a frequency of 3000 Mc/sec detected no radio echoes

from auroras but well-defined and persistent echoes appeared

on the 106. 5 Mc/sec equipment. It could not be determined

if the reflection came from the lower, brighter regions of the

display or from higher points. Offers an explanation for absence of echoes on the 3000 Mc/sec frequency. (Item 4J187, Met. Abs.)-M.L. R.
34

C-100 Forsyth, P. A. (Physics Dept. Univ. of Saskatchewan,

Saskatoon, Canada), Radio measurements and auroral electron densities . Journal of Geophysical Research, 58(1):53-

66, March 1953. 3 figs. , table, 13 refs. , 15 eqs. DWB--

Radar echoes from aurora have been recorded simultaneously

at frequencies of 56 and 106. 5 Mc/sec. The ratio of the echo

amplitudes at the two frequencies varies between wide limits.

An attempt is made to reconcile the experimental evidence

with (i) partial reflections from the surfaces of large ionized

regions in the aurora, (ii) scattering from inhomogeneities in

the auroral ionization, and (iii) critical reflections from small

volumes of intense ionization. It is concluded that (iii) is

responsible for the typical auroral echoes which are observed

at Saskatoon, although (ii) may be responsible for echoes of

small amplitude which are often observed in the early stages

of an auroral display. If these conclusions are correct, the

occasional existence is indicated of electron densities of

10^ per cm3 in small volumes of the aurora. (Item 4J-231,

Met. Abs. )--Author's abstract.

C-101 Forsyth, P. A. (Univ. of Saskatchewan), Radio wave re- flections from aurorae. U. S. Air Force. Cambridge Research Center, Geophysical Research Papers, No. 30:117-

135, July 1954. 11 figs. , 17 refs. MH-BH-Radio wave re- flections from auroras were reported by a number of workers

including HARANG and STOFF-REGEN, PIERCE, LOWELL,

CLEGG and ELLYETT, and ASPINALL and HAWKINS. Such

reflections have been interpreted by HERLOFSON (See ref.

C-141) as being due to partial reflection of the radio waves

at the boundaries of the auroral structures. According to

this interpretation, the electron density within an auroral

structure could be as low as 4 X lO^/cm^. Radio observations of auroras have been made at Saskatoon, Saskatchewan, for the past two years, utilizing radar equipment operating at 106. 5 Mc/s. Due to the nature of the apparatus

used, the reflections were restricted to auroral forms located

from 600 to 1100 km distant and elevated less than 7. 5°

above the horizon from the observing site. The auroral forms

most frequently observed by the radar method were the rayed

arcs and rayed bands. The auroral origin of the radio wave

echoes was confirmed by comparing the radar records with

photographs of the same region of the sky, both types of

observations being made simultaneously. (Item 8. 9-332,

Met. Abs. ) --From author's abstract.
35

C-102 Forsyth, P. A. and Vogan, E. L. , The frequency dependence of radio reflections from aurora. Journal of Atmospheric

and Terrestrial Physics, 10(4):215-228, 1S57. 6 figs. , 10

refs. , 10 eqs. DWB --Auroral radio reflections on 4 frequencies (32-50 Mc/s) transmitted from Greenwood, Nova Scotia,

were received at Ottawa, 860 km to west. Periods of en- hanced signals on one or more frequencies were often associated with auroral activity. Results are compared with

those expected with various reflection mechanisms. They

point conclusively to small auroral scattering centers in

which ionization is sufficient to cause complete reflection,

but suggest that localized absorbing regions are associated

with each auroral display. (Item 8.8-126, Met. Abs.)--

C El. P. B.

C-103 Forsyth, P. A. (Univ. Saskatchewan), On the geometry of radio reflections from aurora. Canadian Journal of Physics,

Ottawa, 38(5): 593-603, May 1960. 5 figs. , 15 refs. DWB,

DLC--By assuming that auroral radio reflections are produced

by volume scattering in clouds of ionization having the same

spatial configuration as the visible auroral structures, and

by taking into account the radar pulse duration and antenna

beam width, it is possible to predict the probability of echo

occurrence as a function of range and azimuth. This echo

distribution is quite similar to that observed experimentally

even when "aspect sensitivity" of the individual scatterer is

neglected. Unfortunately, the optical evidence is not sufficiently extensive to permit precise calculations to be made,

nor the radio evidence to permit detailed comparisons, but

previous estimates of the shape of the scattering structures

that have been based on the azimuthal echo distribution

without regard to the factors discussed here are likely to be

seriously in error. (Item 11.10-170, Met. Abs. )- -Author's

abstract.

C-104 Forsyth, P. A. ; Green, F. D. and Mah, W. , The distribution

of radio-aurora in central Canada. Canadian Journal of Physics, Ottawa, 38(6): 770- 778, June 1960. 5 figs. , 2 tables,

10 refs. DWB, DLC--Five bistatic v. h. f. radio systems

were operated in central Canada during the IGY for the purpose of detecting auroral ionization. Consistent records

were obtained for a period of 5 months and these records

have now been analyzed. Two types of events were detected.

The nighttime (A) events occur most frequently in the auroral

zone and characteristically are observed simultaneously at

tv7o points separated by about 300 km. The daytime (S) events

occur simultaneously over a much larger area. The time of

maximum occurrence of A events becomes later with decreasing latitude whereas the reverse is true for S events. The
36

variation with latitude of the occurrence of A events is

similar to that of other auroral phenomena. (Item 12A-76,

Met. Abs. )- -Authors' abstract.

C-105 France. Meteorologie Nationale and Societe Meteorologique

de France, Biblioqraphie Meteorologique Internationale.

Nouvelle Series, v. 1-7, 1933-1939; (Unnumbered), 1946-.

Last issue received, 1952, Fasc. 1-2. v. 1-6, pub. 1934-

1949; V. 7, n. d. ; issues for 1946-pub. 1946-. Title varies:

V. 1-2, Bibliographie Internationale de Meteorologie Generale; v. 3-Bibliographie Meteorologique Internationale.

DLC, DWB--Classified and partially annotated (in French)

bibliographies covering periodical literature from all over

the world. The material is arranged according to the U. D. C.

scheme for meteorology (551. 5). An author index and a subject index (with corresponding U. D. C. ) are included. References to aurora will be found under 551. 594. 5, 551. 594. 51,

551. 594. 52 and 551. 594. 53. 1952 issued by WMO as its

OMM, No. 17. (Item 5C -65, Met. Abs.)"M.L. R.

C-106 Fricker, S. J. ; Ingalls, R.P.; Stone, M. L. and Wang, S. C.

(all, Lincoln Lab. , M.I.T.), UHF radar observations of aurora. Journal of Geophysical Research, Wash. , D. C.

,

62(4): 527 -546, Dec. 1957. 14 figs. , 2 tables, 6 refs. DLCRadar returns from aurora have been observed on a 412. 85

Mc/s pulsed bistatic radar, located at South Dartmouth, Mass.

Results obtained during two observational periods, Sept. 19

to Oct. 6, 1956, and Nov. 29 to Dec. 21, 1956, are given in

terms of occurrence and position data, together with typical

returns obtained on A-scope and range-time intensity modulated displays. Positions of observed returns are compared

with positions computed on the basis of requiring beam perpendicularity to the earth's magnetic field. Indications are

that returns may be obtained from regions which are 2° to 3

off perpendicular, and that returns at larger off-perpendicular

angles may be limited by a height factor. The returns appear

to be limited to the height range of 90 to 160 km approximately. (Item 9. 7-100, Met. Abs. ) -Authors' abstract.

C-107 Fulton, B.J. ;Petrie, L. E. et al. (all. Defence Res. Board,

Ottawa, Canada), Transient modes of high frequency radio

wave propagation across the auroral zone. Journal of Atmospheric and Terrestrial Physics, London, 16(1/2): 185-186,

Oct. 1959. ref. DWB, DLC--Records of sweep frequency

oblique incidence radio soundings from the observations between Winnipeg and Resolute Bay since Oct. 1958, as illustrated on photographs, and indicating extra reflections, are analyzed. Their characteristics depend on the size and electron density of the irregularity and its position to the F layer.

"O.T.
37

C-108 Gadsden, M. (D. P.L. Auroral Station, Awarua Radio, Invercargill, N. Z. ), Studies of the upper atmosphere from

Invercarqill. New Zealand. Pt. 2, Correlation of the radar

echoes and magnetic activity. Annales de Geophysique,

Paris, 15(3):395-402, July/Sept. 1959. (For Pt. 1, see ref.

C-273; for Pt. 3, see ref. 109). 4 figs. , 2.tables, 4 refs.

French and English summaries p. 395. DLC--Six months'

operation of a 55 Mc/s radar has shown echoes occurring in

545 cases out of a possible 1220 three-hour periods. Analysis of this data reveals that the probability of occurrence of

echoes increases with increasing magnetic K-index, and that

this probability is closely related to the local K-index rather

than the planetary K-index. Evidence is found for a "radar

auroral zone" whose size increases with increasing magnetic

activity. It is shown that radar echoes are observed in the

daytime to a lesser extent than suggested by the diurnal var- iation of local K-index. (Item 11.6-117, Met. Abs.)--Author's abstract.

C-109 Gadsden, M. , Studies of the upper atmosphere from Inver- carqill. New Zealand, Pt. 3. Radar echoes and visual aurorae. Annales de Geophysique, Paris, 15(3):403-411, July/

Sept. 1959. (For Pt. 1, see ref. C-273; for Pt. 2 see ref.

C-108). 3 figs., 2 plates, 2 tables, 10 refs. DLC--Evidence

is presented and discussed that leads to the conclusion that

there is no direct connection between radar echoing regions

observed at 55 Mc/s, and visible auroral forms. It is illustrated by graphs that the diurnal variation of the occurrence

of an echo observed at any range presents a broad maximum

at midnight, whereas the observed auroral probabilities show

fairly large fluctuations from hour to hour. An indirect association exists since both aurorae (all - and rayed aurorae)

and radar echoes have a greater probability of occurrence as

the K-index increases. But it is also shown, and illustrated

by comments of several authors, that for high levels of magnetic activity a one-to-one correspondence does not exist.

Finally, the analysis of series of simultaneous photographs

of rayed auroral forms and of the radar A-scope shows that

radar echoes are not to be identified with the rayed arc. (Item 11.6-118, Met. Abs.)-A.V.

C-110 Gerson, N. C. , Radio observations of the aurora on Nov. 19,

1949. Nature, London, 167(4255) :804-805, May 19, 1951.

fig. , 3 refs. DLC--The phenomenon which is termed "auroral

interaction" generally describes the reception of radio signals at a given location from a northerly direction, even

though the transmitting station may be to the east, west, or even south of the receiver. In many instances, the transmitting and receiving stations which are able to establish radio
38

communication through auroral interaction are located geographically so that they cannot communicate with each other

during normal ionospheric conditions. When visible aurora

is present, these stations may establish contact with each

other by means of auroral interaction only when the directional antennae at both locations are directed 'northwards'. It was assumed that the portion of an aurora which has the

greatest light intensity was also that portion which allowed

auroral interaction to take place. Experimental procedures

are described and it is concluded that the experimental method may be employed for the detection of the aurora when

visual observations are difficult because of bright moonlight,

scattered light or general cloudiness. The antenna beam

width employed by the amateurs is about 30-35 , making it difficult to determine accurately the azimuth of any particular radio ray received from the aurora; however, narrower

beam widths undoubtedly could be employed to provide much

greater accuracies. It would also be expected that analyses

of the rates and character of the garbling and fading of the

returned signals would provide valuable information on the

mass and velocities of the bombarding particles. --E. Z. S.

C-111 Gerson, N. C. (Air Force Cambridge Research Center),

The Colloquium on auroral physics. Franklin Institute, Philadelphia, Journal, 253(4): 331-338, April 1952. DLC--The colloquium was held at London, Ontario on July 27-28, 1951 under

the joint sponsorship of the Geophysics Research Division of

the Air Force Cambridge Research Center and the University

of Western Ontario. The author presents a concise but informative summary of the discussion of the four sessions. The

first session, with B. FRIEDMAN as chairman, was on "Electromagnetics as applied to auroral problems" and covered the

following topics: "(a) the passage of a neutral stream of ionized matter from the sun toward the earth; (b) the interaction

of this neutral plasma with the geomagnetic field to cause a ring current (and the early and late phases of magnetic storms);

and (c) the subsequent movement of charges along the magnetic

lines of force toward the terrestrial atmosphere eventuating in

the observed luminosities. " The theories of CHAPMAN and

FERRARO on auroras and magnetic storms and MARTYN's

extension of these theories were reviewed and MALFORS'

experiment on the terrella was described. R. W. B. PEARSE

was moderator of the second session which discussed "Interpretation of auroral and airglow spectra". The molecular

spectra and atomic lines possibly present in the auroral spectra were considered as they relate to the composition of the

ionosphere (80-400 km) and mesosphere (400-1000 km). Conclusions are drawn as to the positive existence of certain

bands and lines and doubtful existence of others. ""Quantum
39

mechanics as applied to auroral problems" was the subject

of the third session presided over by TA-YOU-WU. "This

meeting considered the vitally important but very much neglected field of cross sections for collision of atomic, molecular, and ionized particles found in the ionosphere and

mesosphere (a) to each other and (b) to the auroral bombarding particles." The fourth session was under the chairmanship of D. R.Bates. "Laboratory investigations of mesospheric processes" was the topic. In this session various

experiments which have been undertaken, or are planned, to

study various processes in the ionosphere and mesosphere

were explained. (Item 3. 11-278, Met. Abs. )--M.L. R.

C-112 Gerson, N. C. (U.S. A.F. Cambridge Res. Center, Geoph.

Res. Directorate), A note on auroral interaction. Journal of

Atmospheric and Terrestrial Physics, London, 4(1/2) :81-82,

1953. DWB--Several explanations are possible for the modulation of radio frequencies when reflected from auroral cur- tains. The probability is that the phenomenon is caused by

a Doppler effect. However, this effect would be 5 to 50

times as great as is actually observed, assuming ionospheric

winds of 250 km/hr. More probable results could be produced

by assuming that the reflections come from the sides, not the

ends of the approaching stream of solar protons. A few quantitative values for the models are given in tables. (Item 7. 9-

266, Met. Abs.)"M.R.

C-113 Gerson, N. C. , Radio observations of the aurora. Journal

of Atmospheric and Terrestrial Physics, 6(5):262-267, May

1955. fig. , table, 6 refs. DWB--Radio wave probings mostly on 50 Mc/s North America showing auroral interaction in

1949-51 are listed. Monthly variation shows maximum frequency in April and Sept. -Oct. (Item 6. 9-333, Met. Abs. )--

C.E.P.B.

C-114 Gerson, N. C. , Diurnal variation in auroral activity. Physical Society of London, Proceedings, Ser. B, 68(7):408-414,

July 1, 1955. 3 figs. , 19 refs. DWB-The variation deduced

from analysis of radio contacts between amateurs in North

America (50-60 geomagnetic N) in 1949-51 by waves incident

obliquely to the ionized aurora showed a strong maximum at

21 h 75th W meridian time, about the time of greatest auroral

activity; 86% of the contacts fell between 17 and 24 h. The

period of contact was longest in April, May and Oct. It does not seem to depend on geomagnetic control. (Item 7. 2-

283, Met. Abs.)"C.E.P. B.
40

C-115 G'6tz, Friedrich Wilhelm Paul and Penndorf, Rudolf, Das

Nordlicht vom 24. /25. Februar 1939 in Arosa. (Aurora of

Feb. 24-25, 1939, in Arosa. ) Naturwissenschaften, 27(15):

241-243, April 14, 1939. 3 figs. DLC--A carefully detailed

account of the conditions accompanying a brilliant auroral

display which reached its greatest intensity at 11:28 p.m.

on Feb. 24, and which reached 20 above the N horizon at

12:40 a. m. Feb. 25, just prior to the taking of the two vivid

photos which are presented. A chart shows the course of the

3 magnetic elements at Collm Observatory, Leipzig, for the

night in question, with arrows indicating times of greatest

auroral activity so they may be correlated with the evident

magnetic activity. The display was not visible in Norway

but a magnetic disturbance (150 milliamperes) prevented telegraph communication between Norway and the Continent.

(Item 5C -99, Met. Abs.)"M.R.

C-116 Greenhow, J. S. ; Neufeld, ELL. and Watkins, CD. (all,

Univ. of Manchester), The scattering of 36 Mc/s radio

waves by weak auroral ionization. Journal of Atmospheric

and Terrestrial Physics, London, 18(2/3): 174-180, June 1960.

3 figs. , 10 refs. , 2 eqs. DLC--Some observations of weak

back-scatter echoes similar in type to the echoes associated

with visual auroras are described. With an equipment of

high sensitivity at a frequency of 36 Mc/s, these echoes are present to the north of Jodrell Bank (lat. 53 N, geographic;

lat. 56 N, geomagnetic), for up to 30% of the observing time.

The irregularities in ionization, which are aligned along the

earth's magnetic field, have a length scale of 160 m and a scattering polar diagram with a width of approximately + 3 . The horizontal dimensions of the ionized regions are about

500 km along parallels of geomagnetic latitude, and 50 km

at right angles to this direction. Echoes from horizontal

layers of ionization, associated with the field aligned irregularities, are also observed. (Item 12A-91, Met. Abs. )--

Authors' abstract.

C-117 Gusev, P. I. , Poliamye siianiia i verkhnie sloi zemnoi

atmosferv. (Auroras and the upper layers of the earth's atmosphere. ) (In: Vsesoiuznaia Konferentsiia po Izucheniiu

Stratosfery, Leningrad, 1934, Trudy, p. 283-289, 1935. 6

refs., eqs.) Not trans, into English. DLC --An article re- viewing the progress in study of the height, structure and

composition of the atmosphere from 80 to 1000 km which has

resulted from studies on the physics of the aurora and auroral

spectra beginning with BIRKELAND's (See refs. C-23, 24)

famous demonstration of the analogy between the aurora and

laboratory models using cathode rays, and his conclusions

regarding the corpuscular radiations from the sun, and later
41

work of VEGARD (See refs. C-276, 277) in identifying auroral spectra lines. Theory which allows calculation of temperature in auroral layers is presented. MARIS and HULBURT's UV theory of aurora is also reviewed critically. Ionization and radiowave reflection from ionosphere also considered. (Item 5C -68, Met. Abs.)--M.R.

C-118 Gustafsson, Georg; Egeland, Alv and Aarons, Jules, Audio- frequency electromagnetic radiation in the auroral zone.

Journal of Geophysical Research, Wash., D. C. , 65(9):

2749-2758, Sept. 1960. 9 figs. , table, 18 refs. DLCDuring three one-month periods, continuous spectograms of

the electromagnetic energy in the spectral region between 10

cps and 10 kc/sec were recorded in Kiruna, Sweden. The

records were examined from the viewpoint of background

energy. Throughout the entire frequency band studied, there

is a low daytime signal level and a nighttime maximum. The

ratio of the maximum to minimum amplitude varies as a function of frequency (the higher maximum-to-minimum ratio oc- curs at the lower frequency range of 20 to 200 cps) and with

the season of the year. It is concluded that the daytime ionosphere absorbs the energy throughout the entire spectrum

studied. It was found that, although strong deviations of

the signal level from the normal were often associated with

geomagnetic disturbances, there was a general lack of cor- relation between magnetic index and low-frequency noise,

except in the 10 to 45 cps frequency range. The origin of

the background signals is probably two-fold, atmospherics

from great distances as well as magnetic and exospheric

fluctuations contributing to the lower band. On eleven oc- casions, electromagnetic radiation associated with micropulsations of the earth's magnetic field was detected. Two

frequency bands were identified: one centered at 750 cps,

which is the gyro frequency for protons at an altitude of 100

km above Kiruna; and the other ranging between 1.8 and 4. 5

kc/s, which has been identified as hiss. On all but one of

the occasions when emissions were detected the 750 cps

signals were quite stable in frequency. During four of the

longest periods when radiation was recorded, the low frequency emissions were received between two phases of a magnetic storm; micropulsations were simultaneously evident on

the Kiruna magnetograms. (Item 11. 12-324, Met. Abs.)--

Authors' abstract.

C-119 Hagg, E. L. and Hanson, G. H. , Motion of clouds of abnormal ionization in the auroral and polar regions . Canadian

Journal of Physics, 32(12): 790-798, Dec. 1954. 10 figs.

,

3 refs. DLC --Examination of records taken in rapid succession at ionospheric stations in Northern Canada has revealed
42

three distinctive types of echoes corresponding to clouds of

ionization in motion. One type is ascribed to clouds of sporadic E moving horizontally over the station. The second

type is believed to be due to clouds of ionization descending vertically from the F region to the E region, while the

third type appears to be from clouds moving at extremely

high velocities in the E region. Reflections of the second

and third types have been seen only at stations in or north

of the auroral zone. The characteristics of the echoes, the

velocities of the clouds, and other associated phenomena

are discussed. --Authors' abstract.

C-120 Hagg, E. L. ; Muldrew, D. and Warren, E. (all. Defence

Res. Board, Shirley Bay, Ottawa), Spiral occurrence of spo- radic E. Journal of Atmospheric and Terrestrial Physics,

14(3/4) :345-347, June 1959. 2 figs. , table, 5 refs. DWB,

DLC--High density sporadic E, as observed at high latitudes,

is distributed in a spiral form very much like St'6rmer's precipitation spiral for negative particles shown in comparison

with results obtained at 11 selected stations (1944-1955).

Tabulated sporadic E is here considered only in a single

variety, namely when the vertical incidence reflection of a frequency J> 5 Mc occurred (or 7 Mc for 3 stations). --W. N.

C-121 Hakura, Yukio; Takenoshita, Yugoro, and Otsuki, Toshiharu

(Hiraiso Radio Wave Obs. , Radio Research Lab.), Polar

blackouts associated with severe geomagnetic storms on

Sept. 13, 1957 and Feb. 11. 1958. Japan. Science Council.

Ionosphere Research Committee, Report of Ionosphere Research in Japan, 12(4): 459-468, 1958. 7 figs. , 18 refs.

DWB, DLC- -Examining through the world-wide ionospheric

disturbances on Sept. 13, 1957 and Feb. 11, 1958, outstanding features of polar blackouts associated with severe magnetic storms have been discovered. A distinct region of abnormal ionization (usually called polar blackouts) appears in

the polar region well before (about 20 hours) the onset of the

geomagnetic storms. Such an ionized region builds up in the

polar cap by the time of the sudden commencement (SC) of

magnetic storm, and then spreads toward lower latitudes as

the geomagnetic storm develops. A rather spiral-like pattern

of the abnormal ionizing region is formed during the main

phase of magnetic storm. Individual world-wide patterns of

abnormal ionization, which are deduced from ^^^-^ data, are shown for the respective stages of magnetic storm. It is

quite a remarkable fact that some corpuscular invasion exists in the polar cap well before the SC of magnetic storms

without inducing any appreciable world-wide geomagnetic

disturbance. Spiral precipitation of particles indicates a

rather complicated mechanism of the corpuscular intrusion
43

into the earth's upper atmosphere, suggesting the revival of

the old Birkeland-St'6rmer theory. Some discussions about

these phenomena are also given. (Item 12.3-134, Met. Abs.)

--Authors' abstract.

C-122 Hakura, Yukio and Takenoshita, Yugoro (both, Hiraiso

Radio Wave Obs. , Radio Res. Labs.), On the short wave

transmission disturbance of Feb. 11. 1958. Japan. Science

Council. Ionosphere Research Committee, Report of Ionosphere Research in Japan, 12(1):10-15, 1958. 5 figs. , 3

refs. DWB, DLC--The storm was of unusually large scale

and was accompanied with intense radio disturbance. Herein,

the data obtained at Hiraiso Radio Wave Observatory are discussed and graphically presented. A fading rate counter was

also used to investigate the detailed characteristics of propagation conditions. The present discussion is confined to

the changes of field intensity levels and fading rates of 4

circuits, WWV, SF, WWVH and JJY. Then locations are shown on a map. The main features discussed and graphically represented are: 1) a sudden change of fading rate in

WWV immediately after the onset of magnetic storm, 2) a southward shift of the fluttering fading of radio waves during

the course of a magnetic storm; 3) an unusual rise of nighttime field intensity levels and fading rates of JJY and WWVH

which coincides with the appearance of auroral echoes in the

ionospheric record of vertical incidence observations. (Item

12A-92, Met. Abs.)"I.S.

C-123 Harang, Leiv and Stoffregen, W. , Per Polarizations zustande

der Radiowellen bei der Reflexion Schichten. die wcLhrend

erdmaqnetischen St^runqen und Nordlichter qebildet werden.

(Polarization of radio waves reflected from the ionized re- gions formed during magnetic disturbances and auroras.

)

Hochfrequenztechnik und Elektroakustik, 53(6): 181-187, June

1939. 11 figs. , 16 refs. , 5 eqs. DLC --Purpose of the ex- perimental investigation discussed was to check the polarization of normal E and F echoes at vertical incidence. To

this end, a 50 kW transmitter and with the receiver at 300 m

distance were used at 3-8 MgHz. Film strip recording shows

that echoes from the E layer, ionized during magnetic disturbances and aurora, were of the two circular component type,

of which the predominant component in comparison with normal

E echoes was the lesser absorbable one. --W. N.

C-124 Harang, Leiv, Vertical movement of the air in the upper atmosphere. Journal of Geophysical Research, 41(2): 143-160,

1936. DLC --Considers auroral heights and radio echoes, and

considers among other things three-fold splitting of traces.

Shows pictures. --L. A. Manning.
44

C-125 Harang, Leiv and Stoffregen, Willi, Echoversuche auf ultrakurzwellen. (Echo experiments with USW. ) Hochfrequenztechnik und Elektroakustik, 55(4): 105-108, April 1940. 4

figs. , 4 refs. , 3 eqs. DLC- -Experiments were conducted at

Tromsft Observatory using 7L 7. 3 m with the purpose of investigating possible USW echoes from 60-100 km during a severe geomagnetic storm and aurorae. This was negative

but reflections were obtained from an auroral display in

zenith (equivalent reflection distance of 400-800 km). Other

experiments from the altitudes 8-20 km and at 17 km are also

described. --W. N.

C-126 Harang, Leiv, Experimental studies of the reflection of

radio waves from the ionized regions . Geofysiske Publikasjoner, Oslo, 13(4); 1942. 24+ p. 28 figs. , 2 tables, 23

refs. , eqs. DLC --Discusses observational results of: (1)

the state of polarization of radio waves reflected from ionized layers formed during terrestrial magnetic storms and

aurorae; (2) scattering of radio waves from great virtual distances; (3) scattered reflections from the niveau of the E

layer; and (4) reflections of ultrashort waves from the ionized regions. These studies were conducted during April,

May, June and December 1938, and January 1939, at Tromsft

where the inclination of the earth's magnetic field f -69 .7

N, A = 18 . 9 E. Gr. ) is about 77 . Instrumentation and techniques employed for each study are described in detail. (1)

E and F layer echoes were studied during (a) normal, (b) small

and (c) strong terrestrial storms. The transmitter and receiver operating at the frequency range 3-9 Mc were interspaced

by 300 m. It was found that (a) the echoes largely consisted

of the ordinary component; (b) frequently both components

were distinctly reflected even on lower frequency, indicating

steep gradient electron density at the lower E layer edge; and

(c) when the echo was about to vanish on higher frequencies,

only the extraordinary component was reflected. Hence, a quantitative estimation of maximum electron density of a layer produced during a storm is feasible. (2) A high-power

transmitter operating at 7-13 Mc enabled reflections equal to

500-2500 km virtual distances. Four different phases in

diurnal variation are tabulated. Scattering heights varied

from 500-800 km down to 150-200 1cm during stronger perturbations. (3) Since the observed "life-timed" echoes of 1/2 to

2-3 sec duration showed a frequency curve almost identical

to Appleton and Piddington's from southeast England, and

which involves the height interval at the lower boundaries of

aurorae; careful observations at 200-400 km were made when

the E region echoes were most frequent. No scattered echoes

were observed however. (4) On Dec. 16 during a violent magnetic storm associated with intense (red) aurora in zenith.
45

echoes on 7. 3 A were observed as irregular scattering from

400-800 km. Simultaneous control at 1-15 Mc gave no echoes implying a measure for upper limit of maximum value

electron density of terrestrial magnetic storm and aurorae

produced layers. Echoes from 8-20 km as received with adjusted equipment interspaced at 150, 900 and 2000 m showed

no fading indicating lateral rather than vertical deflections.

It may well be that these echoes are explainable by local

topographic scattering of the USW. --W. N.

C-127 Harang, Leiv and Landmark, B. , Radio echoes observed

during aurorae and terrestrial magnetic storms using 35 and

74 Mc/s waves simultaneously. Journal of Atmospheric and

Terrestrial Physics, N. Y. , 4(6):322.338, 1954. DLC. (See

ref. C-200 and C -284) --Observations have been made at

Kjeller, Lillestrftm and at Tromsft (near the auroral zone)

using pulse transmitters operating simultaneously on 35 and

74 Mc/s. These transmitters were supplied from common

pulse modulator and HT units and gave 25 kw output into geometrically similar, rotatable, Yagi aerial systems. The echoes received were displayed on a twin beam oscilloscope

with a common time sweep. The presence of echoes was

closely connected with geomagnetic and auroral activity but

there was no correlation between the position of the aurora

in space and the range of the echoes. Further, when the

aerials were pointed at intense auroral forms no echoes were

received. Echoes could only be observed when the aerials

were directed at a low angle of elevation toward the North.

It is concluded that these echoes are not due to direct scatter from the ionosphere or from auroral structures, as assumed previously, but can only be explained as back scatter

from land or sea after reflection at an intense Eg layer formed

along the auroral zone during aurorae and geomagnetic storms.

An analysis of the characteristics of the echoes and the differences in the echo ranges on 35 and 74 Mc/s support this

hypothesis. Different types of echoes are described and the

results of polarization measurements summarized. Correlation in time between the echo amplitudes is studied by means

of double pulse modulation, the time interval between the

pulses being variable. Possible passive radiation from the aurora in the 10 cm band could not be detected with the equipment available. --Authors' abstract.

C-128 Harang, L. and Tr?>im, J. (both, Div. Telecommunications,

Kjeller, Lillestrom, Norway), Determination of the angle of

arrival of auroral echoes. Journal of Atmospheric and Terrestrial Physics, London, 14(1/2): 107-110, April 1959. 3 figs.,

5 refs. DLC--The angle of arrival, Q , of auroral echoes is

measured by an interference method. The variation of 9 with
46

echo range R is demonstrated. & varies from 15 to 6. 5

when the range increases from 400 to 730 km. The height of

the reflection area must lie at 100-120 km. (Item 11. 9-125,

Met. Abs. ) --Authors' abstract.

C-129 Harrison, D. P. and Watkins, CD.. A comparison of radio echoes from the aurora, Australis and Aurora Borealis. Nature,

London, 182(4627) :43.44, July 5, 1958. figs., 4 refs. DLC

--The Royal Society's expedition to Halley Bay has provided

an opportunity for a simultaneous study of the aurora australis

and borealis by the radio echo technique, and a preliminary

account of the results is given in this note. Full details of

the equipment are given in the IGY Annals, 3, Pt. IV, 337

(1957) by Lovell, A. C. B. Preliminary results on the occur- rence of auroral echoes for the period May-October 1957 have

been compared with the Jodrell Bank results for the same period. Echoes from the aurora australis have been detected at

Halley Bay on 134 out of 164 days of observation, whereas

on only 13 days were echoes from the aurora borealis obtained at Jodrell Bank. A study of the echo geometry at both

locations shows that the echoes are obtained from the region

where the line of sight is normal to the local magnetic field

at a height of about 110 km rather than from along a line of

geomagnetic latitude as originally proposed by Bullough and

Kaiser (1954). (See ref. C-43). -E. Z. S.

C-130 Harrison, D. P. (Jodrell Bank Experimental Station, Univ. of

Manchester), Auroral radio echoes at Halley Bay. Royal

Society of London, Proceedings, Ser. A, 256(1285): 229-234,

June 21, 1960. 5 figs. , 9 refs. DLC--The echoes observed

are shown to fit closely the case of specular reflections from

columns of ionization aligned along the local magnetic field

at a height of about 100 km. (IRE, Proceedings, Abs. No.

570).

C-131 Harrison, V. A. W. (DSIR, Radio Res. Sta. , Slough, Bucks),

An unusual ionospheric disturbance in the Antarctic on June

30 to July 1. 1957. Journal of Atmospheric and Terrestrial

Physics, N. Y., 18(l):72-75, April 1960. 2 figs. DLCRecordings of changes in declination, D, of the earth's magnetic field were made at Port Stanley and also at the FIDS

magnetic observatory in the Argentine Islands a few miles

from Port Lockroy, and it is therefore possible to compare

the ionospheric observations obtained at the two stations

with magnetic recordings made nearby. At Port Stanley the

first phase of the storm was associated with the presence of

scattered reflections from the F region — there were no significant abnormalities in the D layer of the ionosphere during

the period. After 1900 UT on June 30 unprecedented
47

departures from typical storm behavior were observed at both

Port Stanley and Port Lockroy — the echoes showed unusually

large spread. At Port Lockroy the F layer was so disturbed

and spread echoes so intense that no estimate^ of critical

frequencies or even of the ranges in which they might lie was

possible. Conditions returned to normal by 1400 UT on July 1.

--ci. Z. S.

C.132 Hartz, T. R. ; Reid, G. C. and Vogan, E.L. (all. Radio Physics Lab. , Def. Res. Board, Shirley Bay, Ottawa, Ont. ), V.H.F. auroral noise. Canadian Journal of Physics, Ottawa,

34(7): 728-729, July 1956. fig., 6 refs. DWB, DLC-FORSYTH, PETRIE and CURRIE reported in 1949 (See ref. C-97)

noting radio frequency radiation from the aurora, though later

studies failed to support such occurrence. The present re- port shows radio frequency (32 Mc) emissions at the time of

an aurora on March 21-22, 1956. The fact that it was also

noted on 50 and 53 Mc/s rules out the possibility that it was

from a distant station. The signals might, however, originate

from the disturbed ionosphere at the time of an aurora. On

numerous other occasions similar signals or noise has been

recorded at the Radio Physics Lab. , Ottawa, at the time an

aurora was observed visually and recorded on a magnetometer,

and a photomultiplier directed at the northern sky. (Item 8. 10-

297, Met. Abs.)"M.R.

C-133 Hartz, T. R., Auroral radiation at 500 Mc. Canadian Journal

of Physics, Ottawa, 36(6): 677-682, June 1958. 2 figs. , 14

refs. DWB, DLC--An observation of radio noise emissions at

500 Mc, from a type A red auroral display which occurred on

Oct. 21-22, 1957, is reported. The circumstances surrounding this phenomenon are considered, and the unusual display

is linked to a large flare on the sun some 30 hrs earlier. It is concluded that an unusually large particle flux for the ejected solar matter would produce sufficient ionization in local re- gions of the ionosphere so that auroral radio emissions would

be possible. (Item 10. 5-256, Met. Abs. )--Author's abstract.

C-134 Hawkins, G. S. , Observations of the aurora borealis by radio

methods at the Jodrell Bank Experimental Station of the University of Manchester. I. U. G. G. Association of Terrestrial

Magnetism and Electricity, Brussels, 1951, Transactions, pub.

1954. p. 229-234. 6 refs. DWB-The auroral displays, briefly

reported in this note, were studied at Jodrell Bank by the re- flection of radio energy from the associated regions of ionization. Five sets of apparatus were used each consisting of an

aerial system, pulsed transmitter, and receiver. The apparatus

details are tabulated. Results obtained with each set are
48

discussed and graphically represented. Photographs of

echoes showing diffuse and discrete aurora on different

dates are reproduced. (Item 12A-100, Met. Abs.)--I. S.

C-135 Helbronner, Paul, Sur I'aurore polaire du 3 septembre et sur son action dans les transmissions radiot^l^qraphiques. (The

polar aurora of Sept. 3 and its effect on radio transmission.

)

Academie des Sciences, Paris, Comptes Rendus, 191(14):

536-538, Oct. 6, 1930. DLC --Brief comments are given on

the auroral influences on the radio links Paris - New York;

Japan - France; Beyruth - Paris; Rio de Janeiro and Buenos

Aires. -W. N.

C-136 Hellgren, Gftsta and Meos, Johan (Res. Lab. of Electronics,

Chalmers Univ. of Techn. , Gothenburg), Localization of au- rorae with 10 m high power radar technique, using a rotating

antenna. Tellus, 4(3):249-261, Aug. 1952. 18 figs. , 11 refs.

DLC --The paper describes the 10 m high power recorder with a

rotating antenna that is used since May 1951 for the localization of aurorae at the Radio Wave Propagation Laboratory of

the Kiruna Geophysical Observatory (67 . 8 N, 20 .5 E). Continuous observations during the time of May 1951-March 1952

have disclosed periods of auroral activity. The preliminary

results from these observations indicate that there is a good

correlation between the auroral activity, the magnetic activity,

and the appearance of the N]^ layer, a special type of sporadic

E ionization often appearing in connection with magnetic bays

and supposed to be caused by the same ionizing agent as the

aurora. The distribution in range and bearing of the recorded

aurorae agrees with the simple theory that most of the radio

wave scattering comes from those points where the radar beam

is perpendicular to the surface of the auroral discharges. The

calculated height distributions of the reflection centers have

maxima around 120 km. (Item 4. 6-247, Met. Abs. )-- Authors'

abstract.

C-137 Hellman, Gustav, Repertorium der deutschen Meteorologie.

(A repertory of German meteorology. ) Leipzig, Wilhelm Engelmann, 1883. 995 p. chart, table. DLC-Approximately 60

references to works of German authors on Aurora and Auroral

theories are listed on p. 687-688, 690. (Item 5C-255, Met.

Abs.)"M.L.R.

C-138 Henderson, J. P. , Aurora and radio. Royal Astronomical

Society of Canada, Journal, 17(8/10) :374-378, Nov. /Dec.

1923. DLC "With the sharp electrical discharges, possibly

also streamer aurorae, clicks are heard in radio receivers

and no particular relation was found to exist regarding good

or bad reception. Clicks and grinders are probably results
49

of thunder storm conditions somewhere. With corona and

brush discharges, also waving curtain aurorae, hisses are heard. It is likely that with aurorae like sounds might be

produced but of such audibility outside of its wireless manifestations or its laboratory analogues there is still question.

Good receiving conditions nearly always accompany arc and

curtain aurorae. --Author's abstract.

C-139 Heppner, J. P. ; Byrne, E.G. and Belon, A.E. (Univ. of

Alaska, GoUege, Alaska), The association of absorption

and Es ionization with aurora at high latitudes. Journal of

Geophysical Research, 57(1): 121-134, March 1952. 6 figs.,

2 tables, 8 refs. --Nocturnal Es ionization and '*no echo" oc- currences, as recorded on H'f records, have been classified

according to the absence or presence of aurora and to its

form when present in the zenith areas. The analysis supports the following generalizations: (1) Es ionization increases at successively greater heights as aurora approaches

the GoUege zenith from the north. (2) In the presence of different non-pulsating auroral forms the Es ionization varies

with changes in auroral form in a manner similar to the change

in luminosity. Likewise, variations in the height of maximum

ionization parallel variations in auroral heights. (3) Gomplete absorption is only slightly more frequent during nonpulsating aurora than during absence of aurora but prevails

in the presence of pulsating aurora. Geomagnetic relationships are discussed. (Item 4. 2-286, Met. Abs. )- -Authors'

abstract.

G-140 Heppner, James, Association of absorption and sporadic E

ionization with aurora at high latitudes . Alaskan Science

Gonference, 2nd, Mt. McKinley National Park, Sept. 4-8,

1951, Proceedings, p. 278-279, (pub. 1953?) DWB-Analysis of vertical incidence measurements of nocturnal E ionization and absorption shows that: 1) when aurora is not present

in evening, high frequency traces show F layer but no E layer.

When aurora is present E layer is always present. 2) Eg ionization increases at successively greater heights as auroral

arc approaches zenith from N. 3) Ghanges in height of maximum electron density parallel changes in auroral height.

4) Erratic radio transmission may be due to scattered reflection from non-pulsating auroras, whereas absorption is more

nearly related to pulsatory auroras. 5) Gonditions associated

with pulsatory auroras resemble those during magnetic bays.

Gorrelations may differ with changes in geomagnetic latitude

near auroral zone. (Item 5G -233, Met. Abs.)"M.R.
50

C-141 Herlofson, N. , Interpretation of radio echoes from Polar

auroras. Nature, London, 160(4077) :867-868, Dec. 30,

1947. 2 refs. , 4 eqs. DLC- -Quantitative consideration of

the strength of the echoes observed by Lovell et al, indicates that the electron density must be > 4 X 10^ and < 2 • 6 X 10^ electrons/cm . The former figure postulates a

thin reflecting layer with sharp boundaries, and even the

latter figure indicates diffuse boundaries < 3 m thick. Since

such boundaries could not persist as long as 20 min, it is

suggested that the observed echoes were reflected from the

vertical surfaces of a stationary discharge (auroral arc) at a height of 200 km above the brightest area.

C-142 Hoffmeister, C. and Kftnig, Hermann, Nordlicht-Beobachtunqen auf der Stemwarte Sonneberq der Deutschen Akademie

der Wissenschaften. (Observations of auroras at the Sonne

berg Observatory of the German Academy of Sciences. ) Die

Sterne, Leipzig, 34(5/6): 125-126, 1958. DLC -Review of

the observations of auroras during the night of March 1-2,

1957 at 23 h 40 and during the night of June 30-July 1, 1957

at 23 h. The first notice of increase of solar activity and

visibility of the auroras was given by Moscow. The GSttingen Geophysical Institute registered a magnetic storm during the night of June 30-July 1, 1957. Transatlantic radiocommunications were interrupted. The aurora was also observed at Bonn University. (Item 11. 2-297, Met. Abs.)--

A.V.

C-143 Institute of Radio Engineers, N. Y. , Proceedings, Vol. 43.

No. 11. Pt. 2, Nov. 1955, Index to abstracts and references

1946-1953. 189 p. Author Index and Subject Index for each

year, and List of Journals for years 1948-1953. DLC --Eight

separate author indexes, 8 subject indexes and 5 journal indexes for the respective years are bound together in an excellently printed, 3 column to the page publication which, unfortunately, is almost illegible without a magnifying glass. The

author indexes contain abbreviated titles and reference to abstracts. Subjects under which abstracts of interest to meteorologists may be found include absorption, anemometer,

hot wire, atmosphere, troposphere, ionosphere, microwaves,

radar, wave propagation, meteorology, atmospherics, aurora,

cosmic radiation, meteors, geomagnetic storms, geomagnetism,

astronomy and radio, refractive index, etc. (Item 7. 11-60,

Met. Abs.)-M.R.
51

C-144 Isaev, S. I. , Podgotovka k issledovaniiam poliamykh siianii

V Murmanske. (Preparations for the study of auroras at Murmansk. ) Akademiia Nauk SSSR. Mezhduvedomstvennyi Komitet po Provedeniiu Mezhdunarodnogo Geofizicheskogo Goda,

Informatsionnyi Biulleten', No. 3:86-87, 1957. fig. DLCThirty four stations situated in high geomagnetic latitudes of

Antarctica, Arctic, Murmansk, Yakutsk, Cape Chelyuskin,

etc. , have been equipped with special (large) wide-angle

photo cameras (C-180) for photographing auroras. One of

these cameras installed at the Murmansk branch of the Scientific Research Institute of Terrestrial Magnetism, Ionosphere

and Radio Wave Propagation of the Ministry of Communication U. S. S. R. (M. O. . NIZMIR) was tested in March 1957 at

Murmansk. More than 3000 photographs of auroras of var- ious intensity, cloud conditions and of other weather peculiarities were made. Films of auroras taken every minute

and ionograms were obtained (latter was carried out at the

automatic panoramic ionospheric station). A two month

course for the training of observers for polar stations of the

Northern Sea Route, attended by 20 students, took place in

February - March 1957. (Item 11.2-298, Met. Abs.)--

A.M.P.

C-145 Isaev, Sergei Ivanovich and Pushkov, N. V. , Poliamye

siianiia. (Auroras.) Illus. by G. N. Gamon-Gamon. Moscow, Akademiia Nauk SSSR, 1958. Ill p. 50 figs. , 14

plates, 5 tables. At head of t-p. : Akademiia Nauk SSSR,

Nauchno-Populiarnaia Seriia. DLC (QC971. 178) --A popular

(25, 000 copies) scientific, but very substantial and scholarly,

monograph on the aurora in all of its geographic, esthetic and

physicochemical aspects. The 12 separate chapters discuss

in concise form, with effective illustrations or graphs (taken

mainly from original Soviet sources), the history of study of

the aurora, auroral charts, forms and classification, geographic distribution, relation to magnetic storms, to solar

phenomena, knowledge of composition and temperature of

upper atmosphere from auroral data, radar location of auroras,

spectroscopic and photometric studies, theories, effect on

radio propagation and, finally, a chapter by G. N. GAMONGAMON entitled Moi zarisovki poliaenykh siianii (My auroral sketches), gives the history of the excellent sketches

of 14 auroral displays which are appended. These were made

in 1937-38 at Tulom near Murmansk. The present work is

mainly devoted to Russian investigations and workers from

LOMONOSOV to IGY. (Item 11. 5-9, Met. Abs. )"M. R.
52

C-146 Isra'^1, Hans, Extraterrestrische Einflttsse auf das luftelektrische Feld. (Extraterrestrial influence on the atmospheric

field. ) Germany. Deutscher Meteorologischer Dienst im

Franz'6sischen Besatzungsgebiet, Wissenschaftliche Arbeiten,

1:62-37, 1947. 2 figs. , table, 17 refs. In German; German

and French summaries p. 67. DLC--The four extraterrestrial

causes of the atmospheric electric charges which vary from

day to day are: 1) cosmic rays; 2) corpuscular radiation

from the sun; 3) UV discharges from the sun; and 4) sunspot

and related activity. Numerous attempts have been made

since 1872 to show a quantitative relation between aurora and electric charge in the atmosphere. A chart (after J. SCHOLZ, 1935) shows a rise in the electric field, increase

in current and conductivity about 15-20 min before an aurora and a sharp drop at onset to a minimum about 10 min after

the onset of the aurora. Other authors' theoretical explanations of positive charge without aurora and negative or <

positive during aurora are presented. (Item 5. 11-220, Met.

Abs.)"M.R.

C-147 James, J. C; Bird, L. E. ; Ingalls, R.P. et al. , Observed

characteristics of an ultra-high frequency signal traversing

an auroral disturbance. Nature, London, 185(4712) :510-512,

Feb. 20, 1960. 3 figs. DWB--An experimental study was

made to determine the characteristics of ultra-high-frequency

signals propagated through auroral type disturbances. The

experiment was performed by illuminating the moon from a site in the auroral zone and receiving the reflected signals

from the moon at two sites in mid-latitudes. Each site used

an antenna having two orthogonal polarizations. It was

found that an auroral disturbance in the path of propagation

causes a rapid fluctuation in the polarization angle of the

signal received, and an increase in the rate of fading of the

signal received, but no measurable absorption of the signal

itself. The observed rapid changes in polarization angle are probably due to changes of electron content of the ionosphere of the order of lO'l-' electrons in a vertical column of

1 sq m cross section. (Item 12A-113, Met. Abs. )--E. Z. S.

C-14S Kaiser, T. R. and Bull ough, K. (Jodrell Bank Exper. Stat.,

Univ. of Manchester Lr. Withington, Macclesfield, Cheshire, Eng. ), Radio echoes from aurorae . Annales de Geophysique, Paris, 11(3):279-2S3, July/Sept. 1955. 5 figs. , 9

refs. DLC--Radio echo auroral observations made at Jodrell

Bank from 1950 to 1953 are analyzed. A systematic picture

is obtained of the special distribution and motion of the re- flective ionization. A close correlation of the results is

found with visual auroral and magnetic data„ (Item 12A-113,

Met. Abs. )- -Authors' abstract.
53

C-149 Kaiser, T. R. (Dept. of Physics, Univ. of Reading, Berks),

Radio investigations of aurorae and related phenomena. (In:

The airglow and the aurorae: a symposium, London, Pergamon, 1956. p. 153-173. 8 figs. , table, 41 refs. , eqs.

)

DWB--The paper discusses in some detail the characteristics

of auroral ionization as revealed by metre v/avelength radioecho observations in the auroral and subauroral regions. A

close association between the radio echoes, visual auroras,

magnetic activity, and radio star scintillations is revealed.

A similar correspondence appears to exist between low frequency auroral type echoes and scintillations in the minauroral region, although these show some marked differences

from the high-latitude phenomena. Some suggestions are made for the future lines of work, particularly during the

International Geophysical Year, 1957-58. (Item 3. 7-341,

Met. Abs. )-- Author's abstract.

C-150 Kaiser, T. R. (Dept. of Physics, Univ. of Sheffield 10,

Eng. ), The geometry of auroral ionization. Journal of Geophysical Research, Wash., D. C. , 32(2):2£7-298, June

1957. 2 figs. , 5 refs. DLC--A note comparing the interpretation of results obtained by the author at Jodrell Bank in

1954, with the interpretations of PETERSON (1955) at Stanford. It is explained that the pattern of radio echoes from

auroral and auroral-type ionization agrees with the hypothesis that it is distributed along an arc v.'hich follows a parallel of magnetic latitude, rather than with the assumption of

extreme specular reflection from narrov/ columns of ionization aligned with the earth's magnetic lines of force. (Item

12A-11S, Met. Abs.)-E. Z. S.

C-151 Kaiser, T. R. , Relationships betv/een auroral ionization

and magnetic disturbance . Annales de Geophysique, Paris,

14(1) :76-79, Jan. /March 1C5G. 3 figs. , 7 refs. DLC--This

report presents results from a detailed analysis of the cor- relation between characteristics of auroral ionization and

geomagnetic disturbances. The magnetic disturbance is as- sociated with spatially localized regions of intense ionization moving horizontally along a magnetic parallel of latitude. It suggests that, while the ionized clouds must presorve nearly electrical neutrality, there is a net drift of

negative charge in the direction of motion of the ionization.

This is from the dark to the sunlight hemisphere and is thus

opposite to that predicted by MARTYN in his extension of

the CHAPMAN-FERRARO corpuscular stream theory. It also

appears that, for a given m.agnitude of magnetic disturbance,

the ionization during positive bays is more intense than during negative ones. This supports the viev/ that the morning

maximum may become relatively less pronounced at higher

radio frequencies. (Item 10. 1-359, Met. Abs. )--A. V.
54

C-152 Kavadas, A. and Glass, D. G. , Polarization of radar echoes

from aurora. Canadian Journal of Physiqs, Ottawa, 37(6):

690-397, June 1G59. 6 figs. , 5 refs. DWB, DLC- -Auroral

radar echoes at very high frequency received at antennas

sensitive to linearly polarized components in directions symmetrical to the plane of polarization of the vertically polarized transmitted wave and the ground plane indicate that the

received wave, in addition to an unpolarized component, contains a linear component of polarization tilted in the general

direction of the earth's magnetic field lines. (Item 11.4-113,

Met. Abs. )--Authors' abstract.

C-153 Kenrick, G. V/. ; Braaten, A. M. and General, J. , The rela - tion between radio transmission path and magnetic storm effects. Institute of Radio Engineers, Proceedings, 26(7):

331-o47, July 193S. 12 figs. DLC--This paper presents the

results of a quantitative study of the relationship between

the proximity of great circle transmission paths to the magnetic pole and of signal stability during terrestrial magnetic

disturbances. Reception from Europe, as observed at Riverhead, Long Island, and San Juan, Puerto Rico, is compared

during normal and disturbed periods. A brief description of

t'le duplicate equipment and antenna systems employed at

the two locations is included. --E. Z. 3.

C-154 Kim, J. S. and Currie, B. W. , Horizontal movements of aurora. Canadian Journal of Physics, 36(2): 180-170, Feb.

195o. 2 figs. , 4 tables, 18 refs. DLC --Measurements on

t'le drifts of auroral fonns at three stations to the south of

the auroral zone in west-central Canada failed to show evidence of a motion due to the earth's rotation relative to fixed

excitation pattern in space. The distribution and the magnitude of the speed of auroral structures parallel and normal to

the geomagnetic meridians are substantially the same as for

non-luminous ionic irregularities observed by radio methods.

The speed of an auroral arc or band parallel to the geomagnetic m.eridian is apparently constant. Speed increases v/ith

geomagnetic activity, particularly in an east-west direction.

There is no indication of a reversal of the east-west motions

close to local midnight. Speeds and directions show no

characteristic variations v/ith the time of night. --Authors'

abstract. (See ref. C- 137).

C-135 Kirby, S. S. ; Smith, N. and Gilliland, T. R. , The effects of

ionospheric storms on radio transmission. International

Scientific Radio Union, 5th Assembly, Venice and Rome,

Sept. 1C3S, Proceedings, 5(l):2S6-28£. ref. DLC-Describe

ionosphere storm. In first, a turbulent phase, the ionosphere

in auroral regions is literally torn to pieces. Then there is
expansion and diffusion away from auroral zone. Effects

are failure of high frequency communication, v/eakening of

night-time broadcast sky v/ave, increase of daytime broadcast sky wave during first phase. During the second, decreased MUF, increased absorption at high frequency, increased night time broadcast absorption. --L. A. Manning.

C-156 Knecht, R. W. (Nat'l. Bur. of Standards, Boulder, Colo.),

Relationships between aurora and sporadic E echoes at Barr ow, Alaska. Journal of Geophysical Research, Wash. , D.

C, 61(l):59-69, March 1955. 8 figs. , 13 refs. DLC-During March 1951, a series of visual auroral observations was

made simultaneously with ionospheric soundings at Barrow

Alaska (71 N, 156 W). Auroras were visible during 32%

of the 379 observations, made at least every 15 min during

the dark hours of 10 successive clear nights. Three nights

are described in detail. Statistical results include (1) a strong tendency for sporadic E (Es) echoes at frequencies ^

7 Mc to be recorded v/hen aurora was near the zenith;

(2) a direct relationship between brightness of (inactive) aurora and the top frequency of Es echoes; (3) evidence for

the correspondence of (oblique) Es echo ranges with estimated slant ranges of visible auroral forms. The observations lend support to the view that ionization in the imme"-

diate vicinity of visible auroral forms gives rise to ionospheric type reflections at high frequencies. (Item 7.9-237,

Met. Abs. )--Author's abstract.

C-157 Kruger, K. , Die drahtlose Nachrichtenubermittlunq in den

Polargebieten. (Radio transmission in polar regions.

)

Arktis, Gotha, 4(3/4):52-34, 1931. 4 figs. , 10 refs. , 13

eqs. DLC--The discussion is mainly concerned v/ith the influence of the low sun and the neighboring magnetic pole

on Arctic short wave communication. --W. N,

C-158 Landmark, Bjorn (Norv/egian Defence Res. Establishment,

Kjeller, Norway), Echoes from the lower ionosphere during

Polar blackouts. Journal of Atmospheric and Terrestrial

Physics, London, 12(l):79-80, 1958. 2 figs. DLC-This is a short summary report on the special pulse soundings car- ried out near the mid-point of a path in the period June 15 to

July 31, 1957 at Nordi (65°N, 14°E). The note presents

some results obtained at this station. They may have some

bearings in connection with conditions of radio fade-outs in

the Polar region. (Item 11E-S3, Met. Abs. )"N. N.
C-159 Lange-Kesse, G. , Das Internationale Geophysikalische

Jahr. XII: Polarlicht und Naclithimmelsleuchten. (The I.G.Y.

Pt. 7, Aurora and night sky light, ) Umschau, 57(23):707-

70G, Dec. 1, 1G57. 4 figs. , footnote refs. DLC- -There is a permanent weak light source round the earth, and a much

stronger occasional ring of light 22-24 from the magnetic

pole. This is the aurora. The cause of the night sky light

is the ionization and dissociation of gases by UV sunlight

at great heights, that of aurora corpuscular rays from the

sun focused by the geomagnetic field. The I, G. Y. program

for world-v/ide study of aurora is set out, including tropics

and radio v/aves, and especially German contributions to

observation of aurora and night sky light. (Item 9.4-276,

Met. Abs.)-C.E.P. B.

C-160 Lange-Hesse, Gunther (Max-Planck Inst. f. Physik der

Stratosphare, Lindau u. Northeim, Hann. ), Ruckstrahlunq

kurzer und ultrakurzer Wellen an Polarlichtern . (Reflection

of short and ultrashort waves from polar auroras. ) Archiv

dor Elektrischen Ubertragung, Stuttgart, 11(G) :253-231, June

1G57. Pt. 2, Ibid., 11(7):203-2G3, July 1CG3. figs., G2

rafs, English summary p. 253. DLC--Recent progress

achieved in different countries in observing and interpreting

auroral echoes is reviev/ed. Sample radar scope photographs,

and diagrams of echo distribution are presented. Applications to radio communication, navigation,and auroral observation are discussed. Of various interpretations proposed so

far concerning different characteristics of auroral echoes, the

author favors those of BOOKER^ (See ref. 0-23). -G.T.

C-131 L armor, Joseph, Aurorae. electric echoes, magnetic storms.

Nature, London, 133(3354) :221-223, Feb. 10, 1G34. 7 refs.,

eqs. DLC--Reference is made to the results obtained by

APPLETON and others regarding the complex connections bet-veen the optical and magnetic phenomena of the upper at- mosphere, and consideration is given to electron densities

required in the reflecting layer to provide reflection by rays

following vertical or oblique paths. A scheme is next introduced in v/hich it is assumed that the aurora is due to lasting local pulsations on a large scale, of long period, excited by a local cause, large enough and of abrupt type, produced conceivably by arrest high up of an ionized torrent

from outside sufficiently concentrated to require relief by

propagation in waves. This could give the banded auroral

curtains v/ith spiralling transmission along the magnetic

field. The splitting by the earth's magnetic field of the

ridiation into two cyclic components is examined for magnetic fields along and transverse to the waves and the methods by which these components could be verified. Finally,
57

tlie effects of riarTiltonian group velocity and transition bet yeen energy levels are discussed. (Item 4J-G0, Met. Abs. ) --Science Abstracts, No. 1E3C, April 1934.

C-1S2 L^-iter, E, A., Variationen der D-Schichtdampfung auf 245

kHz. (Variations of D layer damping on 245 kHz.) Zeitschrift fur Meteorologie, 7(ll):321-330, Nov. 1£53. IG figs.,

13 refs. MH-BH--Results of the measurement of reflection

coefficient on 245 kHz during midday and in the evening are communicated. The diurnal and auroral course of the damping is shown, and the data v/ith other frequencies compared.

The damping values of the D layer have a close relationship

to atmospherics and a weak one to geom.agnetic activity. A

24-day recurrence tendency is clearly indicated. The midday

values of the damping are 2 nepers in the winter and almost

7 nepers in the summ.er. (Item 3.1-121, Met. Abs.)--A.A.

C-lo3 Law, Po G. and Burstall, T. , Macguarie Island. Australian

National Antarctic Research Expeditions, Interim Reports,

No. 14, Sept. 1956. 48 p. 11 plates, 5 tables, 70 refs.

DWB (M03. 5 A£38i)--The general climatic features of the

inland are covered on p. 28-35 of this monograph. Observation and research work in geomagnetism., cosmic rays, aurora and radiophysics is covered on p. 33-43. Activities

are illustrated and many references to works on the region

appended. The history of the island, of the station on the

i-sland^and of work in each field of endeavor is outlined in

detail in each separate chapter. (Item 12A-128, Met. Abs.

)

-M.R.

C-1S4 Leadabrand, R.L. and Peterson, A.M., Radio echoes from

auroral ionization detected at relatively low geomagnetic

latitudes. Institute of Radio Engineers, Transactions,

AP-3(l):35-7&, Jan. 1S58. 21 figs. , 28 refs. , IB eqs. DLCThis is an extension of an earlier paper (See ref. C-229),

describing the characteristics of auroral zone echoes at distance ranges between 1400 km and 4700 km. The reflection

m.echanism is discussed in terms of a partially reflecting,

sem.i-infinite ionized sheet. The identification of these highfrequency echoes at Stanford favors the hypothesis that they

are reflections from the primary auroral particles. Curved

ecirth - curved ionosphere ray path derivations are appended.

-W. N.

C-lo5 Loadabrand, R.L. and Yabroff, I., The geometry of auroral

communications. IRE Transactions on Antennas and Propagation, AP S(l):80-87, Jan= 1£5S. DLC-The scientific knowledge and results obtained since 1&3£ when the radio amateurs discovered how to exploit auroral ionization for
58

communication under otherwise difficult conditions are summed up here. Based upon analysis of accomplished geometrical studies and available material on radio amateur communication report, a geometrical study is presented which

implies the feasibility of selected communication and forecast of the same. --W. N.

C-166 Leadabrand, R.L. ; Dolphin, L. and Peterson, A.M., Preliminary results of auroral echoes at College. Alaska. IRE

Transactions on Antennas and Propagation, AP 7(2): 127-136,

April 1959. 35 figs., table, 12 refs. , eq. DLC-Auroral

ionization at 398 Mc was investigated with a SRI 400 Mc

radar located 100 km south of the maximum of the auroral zone. The two types of echoes observed, discrete and diffuse, are generally night and daytime auroral forms, the

former visible. Using the auroral radar equation

Ptj ^ "PtT, /\, ^°^ comparison with earlier (negative) re- sults at 210 Mc and Canadian results at 488 Mc the A de5 pendence law for the reflection deduced = P^ </" Pm

-W.N. R*^ T

C-167 Leadabrand, R.L. ; Presnell, R.I. ; Berg, M. R. and Dyee, R.B. (all, Stanford Res. Inst., Menlo Park, Calif.),

Doppler investigations of the radar aurora at 400 Mc. Journal

of Geophysical Research, Wash., D. C. , 64(9): 1197-1203,

Sept. 1959. 9 figs. , 11 refs. DLC--By means of a relatively

sensitive 400 Mc radar located at College, Alaska, the var- iation of Doppler shift of auroral echoes has been determined

as a function of the following parameters: (1) azimuth angle

of the radar ray; (2) off-perpendicular intersection angle of

the radar ray and the earth's magnetic field; (3) elevation

angle of the radar ray; (4) range of the echoes; (5) altitude

of the reflection centers; (6) time of day; (7) number of oc- currences; (8) strength of the echoes. These data have been

further delineated in terms of the type of echo seen (discrete

or diffuse) and whether the data were taken before or after

magnetic midnight. An estimate of the spectrum spread of

auroral echoes has also been determined by pulse and by CW

techniques. A consistent trend in these data has been found

which would indicate an east-west motion of the ionospheric

irregularities. There is no appreciable variation in the direction of motion with time of day or with respect to magnetic

midnight. The mean velocity of the east-west motion appears

to be 500 m/sec. These conclusions agree with those of KIM

and CURRIE (1958) (See ref. C-154), but disagree with those

of LYON and KAVADAS (1958) (See ref. C-178), NICHOLS

(1957) (See ref. C-211), and BULLOUGH et al (1957) (See

refs. C-43,44,45). (Item llH-83, Met. Abs. )-Authors'

abstract.
59

C-168 Leithauser, G., Uber ionospharische Storunqen und irdische

Auswirkunqen. (On ionospheric disturbances and their terrestrial effects. ) Funk und Ton, Berlin, 3(3):127-143, 1949.

9 figs. , 14 refs. --Describes normal daily variation of wireless echoes and its disturbances by Mogel-Dellinger solar

effect, auroras and meteors, with illustrations. Most important are the new reflection levels due to "inbreak layers"

associated with auroras and magnetic disturbances. These

have marked effects on wireless transmission. There is also

a relation between development of inbreak layers and of low

pressure areas at the surface in the auroral region, illustrated by charts Feb. 13-17, 1948 and meteorological observations Feb. 1-March 19. Association of Norwegian anticyclones and cold European winters with solar eruptions is

also discussed, including possible ameliorating effect of

atom bombs. (Item 3. 8-5, Met. Abs. )"C. E. P. B.

C-169 Leonard, Robert S. , Radar echoes from the aurora. (In:

Conference on Arctic Radio Wave Propagation, Alaska Univ.,

Jan. 1953, Papers. Issued May 1956. p. 58-71. 8 figs.

)

DWB--Auroral radar work at Geophysical Institute is described. The major difference between the ordinary and the

auroral radar is that the latter uses pulse lengths on the

order of 100 microseconds to one millisecond and has much

lower operative frequencies. Some auroral radar experiments obtain no echoes from aurora overhead despite visual

aurora in the sky. Three different theories explaining auroral echoes are given. (Item 12A-131, Met. Abs. )--A. H. K.

C-170 Leonard, Robert S. , A low power VHF radar for auroral re - search. Institute of Radio Engineers, N. Y. , Proceedings,

43(2):320-322, Feb. 1959. 3 figs. (incl. photos), 2 refs.

DLC--A 5 kw, 41 Mc radar which was designed for use in

the U. S. IGY program is described. The standard operating

procedures are outlined and a sample of the records is shown.

The design of a scaling machine is discussed and a method

of utilizing the scaled data to produce an auroral echo activity index is described. (Item llH-88, Met. Abs. )- -Author's

summary.

C-171 Lied, F. (Norwegian Defence Res. Establishment), Quantitative measurements of absorption in the auroral zone. (In:

Polar Atmosphere Symposium, Oslo, July 2-8, 1956, Proceedings, Pt. 2, Ionospheric Section. N. Y. , Pergamon Press,

1958. p. 135-146. 14 figs. , 11 refs. ) Also issued in Journal of Atmospheric and Terrestrial Physics, London, Special

Supplement, Pt. 2, 1957, pub. 1958? p. 135-146. DLCIn the study of "normal" auroral absorption as well as the

disturbances, we need the application of different techniques with overlapping sensitivity since the observational
60

phase in connection with ionospheric absorption is not terminated. The statistical distribution in time and space of

the more catastrophic blackouts, a little of the real nature

and cause of the general and excessive high absorption due

to some ionizing mechanism, and the techniques for locating where in the ionosphere the excessive absorption takes

place, as well as the magnitude of the extra ionization,

have been covered in this paper. Techniques include the

CW oblique measuring, the pulse amplitude, the Galactic,

the cross modulation techniques, all of which must be used

contemporaneously and forced to overlap as in the ionospheric recordings made in Canada, Alaska and Norway.

(Item 10. 9-316, Met. Abs. )-N. N.

Lindquist, Rune, Polar blackouts recorded at the Kiruna

Observatory. Gothenburg, Sweden. Chalmers Tekniska

Hogskola, Handlingar, No. 103, 1951. 24 p. photos. , graphs, refs. Price: kroner 3. DWB--"Polar blackout" is

the name H. W. WELLS gave the phenomenon of fadeout that

shows no connection with solar flares, contrary to the ordinary ones occurring in the lower latitudes. The phenomenon was studied by E. V. APPLETON (1932-1933) and by

BRAMHOLT and SEATON (1941). In the present study at

Kiruna (67 50'N, 20 14. 5'E geomagnetic coordinates

63 19 'N, 115 30' E) a panoramic recorder (frequency

range 1-16 Mc/s in 30 sec) and a recording magnetometer

were used. The preliminary results indicate that an abnormally high absorption, caused by the impact of some

ionizing agent (maximum probably occurs below the 100 km

level); some sort of corpuscular bombardment --is the cause.

(Item 3. 9-88, Met. Abs. )..W. N.

Lindquist, Rune A. , A survey of recent ionospheric measurements at the Ionospheric and Radio Wave Propagation

Observatory at Kiruna . Arkiv for Geofysik, Stockholm,

1(2-4) :247-266, 1951. 28 figs. , 10 refs. MH-BH-Ionospheric research started at the Ionospheric and Radio Wave

Propagation Observatory at Kiruna on Oct. 1, 1948. This

report gives some preliminary results obtained from the re- cordings during the period October 1948-August 1949. Different types of sporadic E echoes are classified and the

diurnal and seasonal behavior of Es is shown and discussed.

The relation between E s and magnetic disturbances is further discussed. A few typical polar blackouts are described

and studied. The diurnal and seasonal behavior of the ordinary layers is also shown as a final bi -product. (Item 4. 3-

103, Met. Abs. )"Author's abstract.
61

C-174 Little, C. G. (Asst. Dir. , Geophysical Inst. , Alaska),

Radio wave propagation in the Arctic. Alaska. Univ. Geophysical Institute, Contract AF 19(604) -1089, Interim Scientific Report No. 1, Aug. 15, 1955. 74 p. 23 figs. (incl.

photos), 3 tables, 23 refs. --An extensive study of radar

echoes from auroras (on 12, 25, 50 and 100 mc), involving

correlation with visual aurora (as shown by panoramic photographs made simultaneously at College, Alaska), shows

that radio echoes probably come from ionized columns in

the immediate vicinity of visible auroral forms, contrary to

theory of HARANG and LANDMARK (1954) (See ref. C-127).

Sixteen pairs of photographs presented in this report show

good agreement as to direction and distance, and the few

exceptions are explained as due to abnormally high visible

or faint diffuse forms. Three theories concerning the mode

of reflection from ionized auroral layers are examined and

the one of R.K.MOORE (1952) (See ref. C-207, 208), involving right angle reflection from ionized columns oriented

along magnetic lines of force,is shown to agree with actual

observations of 311 auroral forms from Aug. -Oct. 1954.

Greatest concentration is to be N by NE (geomagnetic) and

about 600 km distant. None occur overhead and few to the

S.. Theoretical distribution chart gives nearly same pattern.

Attempts at using longer waves (than 106 mc) have thus far

been unsuccessful. Experiments on a microwave link 25 mi

long failed to show any meteorological influence (ducts).

Most winter time ducts are too close to ground to be of any

use with normal equipment which sticks up above the duct.

An all -sky camera has been used for a year at College and

for a shorter time at Pt. Barrow; analysis of the 180 bands

show that these are very frequent (105 cases), with openings to W just before midnight and to E at 0300 being most

frequent. Movements of bands to E or W were more random

than theorized by MEINEL and SCHULTE (1953) who reported

only westward drifts during evening and eastward during

morning hours. A good correlation was found between intensity of auroral light and Eg ionization. Whistlers were studied with special equipment and comparison will be made with

those at lower latitudes (Corvallis, Ore. and Stanford) to

see if dispersion is much greater in high latitudes as predicted. Between July 1 and 10, 1955, 38 whistlers were re- corded. Abnormal TV signal reception and scatter was observed over high peaks of Alaska Range. (Items 9. 8-29;

12A-132, Met. Abs. )-M. R.
62

C-175 Little, C.G. ;Rayton, W. M. and Roof, R.B. , Review of

ionospheric effects at VHF and UHF. Institute of Radio

Engineers, Proceedings, 44(8):992-1018, Aug. 1956. 2

tables, 182 refs. , eqs. --This paper summarizes the present

day knowledge of ionospheric effects at VHF and UHF, with

the exception of forward scattering of VHF radio waves by

the ionosphere. The seven effects covered in the paper are: radar echoes from aurora; radar echoes from meteors; the

Faraday effect and radar echoes from the moon; radio noise

of auroral origin; absorption of radio waves by the ionosphere; refraction of radio waves by the ionosphere; and the

scintillation of the radio stars. A bibliography of 182 items

is included. --E. Z. S.

C-176 Lovell, A. C.B. , Clegg, J. A. and EUyett, G. E. , Radio

echoes from the aurora borealis. Nature, London, 160(4063):

372, Sept. 13, 1947. 6 refs. Herlofson, N. , Interpretation

of radio echoes from polar auroras. Ibid. , 160(4077) :S67-

868, Dec. 20, 1947. (See ref. C-141). DLC- Echoes obtained during the night of Aug. 15-16, 1947 apparently originated in a luminescent cloud which appeared near the end

of an aurora streamer. HERLOFSON's article is a discussion

of above cited paper. (Item 4J-169, Met. Abs. )--M. R.

C-177 Lugeon, J. , Les perturbations radiophoniques pendant

I'aurore polaire du 25 Janvier, 1933. en Suisse . (Radiophonic perturbations during the polar aurora of Jan. 25, 1938,

in Sv/itzerland. ) International Scientific Radio Union, 5th

Assembly, Venice and Rome, Sept. 1938, Proceedings, 5(1):

326-327, DLC --Describes effects during the aurora. Great

absorption v/as observed on signals from Holland and Germany. However, signals from the west remained audible,

though weak. --L. A. Manning.

C-178 Lyon, G. F. and Kavadas, A., Horizontal motions in radar

echoes from aurora. Canadian Journal of Physics, Ottawa,

36(12): 1661-1671, Dec. 1958. 8 figs. (incl. photo), 18 refs.

DWB, DLC- -A systematic motion of 48. 2 Mc/sec echoes as- sociated with aurora is found at Saskatoon. The motion is

toward the west before midnight and toward the east after midnight, the mean velocity in either direction showing a statistical relation to variations in the earth's magnetic field.

No correlation is found between individual echo velocity and

magnetic disturbance, and no period of zero velocity is observed. There is also evidence of an ordered relation between motion in the north-south direction and disturbances

in the earth's magnetic field. (See ref. C-167). (Item IIH101, Met. Abs.) "Authors' abstract.
63

C-179 Lyon, G. F. (Univ. Saskatchewan), The association of

visible auroral forms with radar echoes . Canadian Journal of

Pnysics, Ottawa, 38(3):385-38£, March l&SO. 2 figs. , table,

9 refs. DWB, DLC--A peak in 48. 2 Mc/sec echo occurrence

is observed at Saskatoon corresponding in time to the period

of breakup of quiet arcs into active rayed structures. This

is also the time of most frequent occurrence of characteristic "curl" forms in the aurora. If, as GARTLEIN suggests,

the "curl" forms are formed by instabilities in a sheet beam

then the primary particles are positively charged. (Item 12A134, Met. Abs. ) -Author's abstract.

C-180 Mclnnes, B. , Auroral display observed from unusually low

geomagnetic latitudes . Meteorological Magazine, London,

83(1018): 114-117, April 1957. fig. , 2 refs. DWB-Observations of aurora from ships in S. Indian Ocean (geomagnetic

coordinates 43°S 184°E and 37°S 129°E) on Sept. 8, 1956,

are described. There was a world-wide magnetic storm,

radio effects, etc. (Item 8. 8-314, Met. Abs. )"C. E. P. B.

C-181 Mclnnes, B. and Robertson, K. A. , Aurora. Marine Observer, London, 30(189): 135-139, July 1960. fig., tables.

DWB, DLC--A log is given listing auroral observations for

the period July-Sept. 195G and some comments on the outstanding auroral displays. The auroras are classified and

their geomagnetic latitudes and longitudes and inclinations

are given. The most outstanding display was observed during July 15-13. This geomagnetic storm had a significant

effect on some ships' compasses and also affected radio

reception. (Item 12A-137, Met. Abs.)"R.B.

C-182 McKinley, D. W. R. and Millman, Peter M. , Long duration

echoes from aurora, meteors, and ionospheric back-scatter.

Canadian Journal of Physics, 31(2):171-181, Feb. 1953. 2

figs. , 6 tables, 10 refs. DLC--In the course of the Ottawa

meteor program some unusual echoes have been detected on

33 Mc. Echoes from the aurora are discussed and correlated

with visual observations. Two mechanisms of radio reflections from the aurora have been proposed but the data here

presented are insufficient to favor one or the other. On Aug.

4, 1G48 six extremely long duration meteor echoes were observed. Since Aug. 1948, a weak semipermanent echo has

been recorded, usually appearing at a range of about 80 km,

and enduring up to an hour. It is suggested that this echo

is due to backscatter from the same sources in the lower Eregion that are presumed to be responsible for long range

very high frequency propagation. (Item 4. 10-33, Met. Abs.

)

--Authors' abstract.
64

C-183 McNamara, A. G. and Currie, B. Wc (Physics Dept. , Univ.

of Saskatchewan, Saskatoon), Radio echoes during aurora. Journal of Geophysical Research, 59(2):27G-285, June 1954.

4 figs. , 6 refs. DLC--A reassessment of all the Saskatoon

data on 56- and 106-Mc/sec echoes from aurora suggested

that some of the 56 Mc/sec echoes might have occurred

through back.vard scatter from the land via the lower part of

the ionosphere. These could have originated only through

the second lobe transmission of the radar equipment. Two

antennae placed at heights to give the maximum resolution

between echoes arising in directions corresponding to the

first- and second-lobe signals were used to examine this

possibility. The results show that practically all (if not

all) the echoes were due to direct reflection from aurora. (Item 6. 2-39, Met. Abs. ) --Authors' abstract.

C-184 McNamara, A. G. and Currie, B. W. , Polarization of radio

echoes from aurorae. Nature, London, 174(4442): 1153-

1154, Dec. 18, 1954. 3 figs. , 6 refs. DWB--Observations

at Saskatoon on 56 Mc/s are analyzed statistically for ratio

(horizontal/vertical polarization) frequency variation as a function of range, showing a significant increase at 500-SOO

km, and echo occurrence against radar range. Some observations on 106. 5 Mc/s are included; these showed only plane

polarization in sense of transmitted signals. (Item 6. 6-330,

Met. Abs.)-C.E.P. B.

C-185 McNamara, A. G. (Saskatchewan Univ. , Saskatoon, Canada),

Double Doppler radar investigations of aurora. Journal of

Geophysical Research, Wash., D. C. , 60(3): 257-269, Sept.

1955. 7 figs. (incl. photos), 11 refs. DLC--A pulsed double

Doppler radar technique has been employed to study the 90. 7

Mc/sec signals reflected from auroral ionization. A spectrum

analyzer was used in conjunction with the radar to measure

the power spectra of the auroral echoes. The Doppler data are compared with observations of the visible aurora and with simultaneous echoes on 56 and 106 Mc/sec non-coherent high - resolution radar equipment. An interpretation of the Doppler

data is given, and several theoretical models of the reflection mechanism are examined in terms of their effect on the

observed spectra. (Item 7. 10-71, Met. Abs. )- -Author's

abstract.

C-186 McNamara, A. G. , A continuously recording automatic auroral radar. Canadian Journal of Physics, Ottawa, 36(l):l-8,

Jan. 1958. 6 figs. , 6 refs. DWB, DLC--A simple, low power

50 Mc/s radar is described vvhich has been designed for automatic recording of radio reflections from auroral ionization.

The system features high sensitivity with good reliability.
65

Photographic records are taken in the form of a continuous

film strip displaying range and time. A complementary re- cording system employs circuitry which cancels interference

and noise signals but produces an output signal proportional

to the integrated echo intensity. The display in this latter

case is in the form of a chart record from which data are immediately available. (Item 9. 7-102, Met. Abs. )- -Author's

abstract.

C-187 McNamara, A. G. (Natl. Res. Council, Ottawa), An analysis of some statistical properties of auroral radar reflections

and their relationships to the detection capabilities of the

radar. Canadian Journal of Physics, Ottawa, 38(3):425-438,

March 1960. 5 figs. , 2 tables, 6 refs. , 22 figs. DWB, DLC

--A statistical model of auroral echo occurrence has been

made from an analysis of observations at 4S. 5 Mc/s obtained

over a number of years of continuous operation. The probability density distribution of auroral target cross sections (cr)

has been examined experimentally, and the resulting curve

fitted by simple mathematical relations. Both an inverse

power law and an exponential law have been derived, of the

forms p(a)dcr = kcr~ i.CJ da andp(o-)dcr =/?^^) «"

^y^^^icr

These models have been interpreted in terms of distributed

and localized targets, and used to analyze the echo occur- rence indices and the effect which variation of radar parameters will have upon them. Both forms of the target law are useful although it is considered that the exponential form

yields better agreement with observations over a wider range

of the variables. (Item 12.4-356, Met. Abs. )--Author's abstract.

C-18S McNamara, A. G. , Auroral radar observations at 48 Mc/s

during the period of the Nov. 12, 1960, solar event . Canadian Journal of Physics, Ottawa, 3G(4):625-627, April

1961. fig. DWB, DLC --Simultaneous records from three auroral radars of similar characteristics have been analyzed for

the period Nov. 11, to Nov. 16, 1960. The combined results

show interesting patterns of activity. Short bursts of echoes

are sometimes associated in time with sudden commencements.

These echoes are not intense which may account for the fact

that only the more favorably situated radars detect them. Evidence cited for a large PC A event suggests that at such times

the strong low-level absorption significantly alters the detection capabilities of a VHF auroral radar, and may distort the

apparent geographical distribution of the reflecting ionization.

--£i. Z. S.
63

C-189 Maehlum, Bemt (Norwegian Defence Res. Estab. ), The

diurnal variation of foF2 near the auroral zone during magnetic disturbances . Journal of Atmospheric and Terrestrial

Physics, London, 13(1/2): 187-190, Dec. 1958. 3 figs. , 7

refs. DLC --During magnetic storms the critical frequency

of the F2 layer usually decreases and this well known effect

(APPLETON and INGRAM, 1935) has been the subject of numerous statistical studies. Distinguishing between disturbed

and quiet days, the departure in the critical frequency, A

foF2, due to magnetic storms can be studied more closely.

It has been shown that the variation in A foF2 can be separated into two components, a Sj) component which depends

on local time and a Dg^ component which depends on storm

time (FUKUSHIMA, 1949). The aim of this note is to study

the Sj) component for some stations in Scandinavia and Great

Britain. It will be shown that the Sj) variation observed at

Longyearbyen (80 N) is similar to that observed at middle

latitude stations, but the Sj) variation at Troms'4 (70 N) is

reversed. There is thus an analogy with the latitude effect

of the geomagnetic storms, where the Sj^ current systems

are reversed within the auroral zone (FtHKUSHIMA, 1953).

Item 10. 10-208, Met. Abs. ) --Author's introduction.

C-190 Major, G. , The association of pulsating and flaming auroras with complete ionospheric absorption at Macquarie Island.

Australian Journal of Physics, Melbourne, 7(3):471-476,

1054. 3 figs. , 5 refs. DLC --Simultaneous records show

that pulsating or flaming auroras are frequently accompanied

by complete absorption of waves incident vertically on the

ionosphere, but the nocturnal variations of frequency of oc- currence of the two phenomena are markedly different in form.

--Author's abstract.

C-191 Martin, L. H. ; Helliwell, R.A. (both, Radioscience Lab.

,

Stanford Univ. , Calif. ) and Marks, K. R. (U.S.Antarctic

Res. Program, Wash. 25, D. C), Association between au- roras and very low frequency hiss observed at Byrd station.

Antarctica . Nature, London, 187(4739) :751-753, Aug. 27,

1S60. 5 figs. , 6 refs. DWB, DLC--Observations during

1959 show a close association to exist between auroras and

certain very low frequency hiss. The hiss usually occurs in a broad band with a center frequency of about 8 kc/s. The

intensity and band-width vary with ionospheric absorption

and may also vary with the intensity of the auroras. The hiss

drops to undetectable levels under conditions of extreme

ionic absorption even in the presence of intense and active

auroras. The center frequency of the hiss may be associated

or related to the type of aurora. (Item 12A-151, Met. Abs.

)

-R.B.
67

C-192 Martvel', F. E. and Pogorelov, V. I. , O sviazi svetimosti

poliamykh siianii s radiolokatsionnymi otrazheniiami ot nikh. (The relation between the brightness of auroras and their

radar reflections. ) Akademiia Nauk SSSR, Izvestiia, Ser.

Geofiz. , No. 8:1052-1053, 1958. 7 figs. DLC. Transl. into English in the corresponding issue of the English language

ed. of the Izvestiia, Bulletin of the Academy of Science of

the USSR, Geophysics Ser. DWB--In order to determine the

relationship between auroras and auroral radar reflections,

the authors compare motion picture frames coinciding in time

with radar signals. The material used was that obtained at

Roshchino^( f

= 60°12'N; A = 29°34'E; ^ = 56°35';

A = 116 47 'E). An analysis of the material indicates the

following: (1) although it is impossible to determine the

form of auroral illumination that is most effective from the

point of view of radar reflection, many of the most intense

reflections are close to the most pronounced radiation forms;

(2) reflections with large amplitude correspond to the brightest reflection regions of the auroras in the supposed zones

of reflection of the auroras, and no radar reflections v/ere

observed when the auroras were completely lacking; (3) during weak illumination radar reflections were rarely observed;

(4) there were no instances in Roshchino when radar reflections preceded auroras; (5) there exist small differences

(about 5-10 ) between the azimuths of the most intense parts

of the auroras in the supposed zones of reflection and the

azimuths of the most intense radar reflections which, hov/-

ever, do not go beyond the limits of possible errors of observation and which may be explained by distortion of the

trajectories of automagnetic waves in a medium of electronic

inhomogeneities, which are considerable in the auroral re- gions; (6) the dimensions of the supposed zones of radar

reflections are slight in comparison with the region of the

heavens occupied by the auroras, (item llH-106, Met. Abs.)

--I.L.D.

C-193 Massey, H. S. W. , The nature of the upper atmosphere.

Endeavour, London, 13(50) :81 -85, April 1954. 4 figs. , 3

refs. DLC--General but semi-technical treatment of structure

and composition of the high atmosphere, the ionosphere, aurora and airglow according to latest results of rocket and

radio research. (Item 6. 4-117, Met. Abs.)--M, R.

C-194 Matsushita, S. (High Altitude Obs. of the Univ. of Colorado,

Boulder), Some studies of the upper atmosphere in the auroral zone. Annales de Geophysique, Paris, 14(4):483-4G1, Oct./

Dec. 1958. 3 figs. , 28 refs. French and English summaries

p. 483. DLC--Relations between ionospheric and geomagnetic

phenomena in the auroral zone were studied from magnetograms

both made at the same station by correlating striking features
68

in each. When a bay disturbance of moderate range occurred

at night, complete blanketing of F2 by sporadic E always

happened at the time. When the range of bays was larger,

blackouts usually occurred after the incidence of complete

blanketing of F2. Slant Eg occasionally appeared during

bays, and it never occurred except during bays or bay-type

variations during magnetic storms. Blackouts which occurred

during daylight hours had no remarkable correlations with geomagnetic variations except during magnetic storms. In other

words, there were two different types of the polar blackout;

nighttime and daytime types. The height of the absorbing

region responsible for the polar blackout during daylight hours

seemed to be lower than that at night. In order to explain

these results, the effect on the ionosphere of X-rays generated by the primary particles from the sun are discussed. The

cause of magnetic bay disturbances is also considered.

(Item 10. 8-360, Met. Abs. ) -Author's abstract.

Mednikova, N. V. , lonosfemye vozmushcheniia osobogo

tipa. (Particular types of ionospheric disturbances. ) Akademiia Nauk, SSSR, Doklady, 5£(3):475-478, Jan. 21, 1948.

3 figs. , ref. DLC --Observations of an aurora on Feb. 16,

1947 carried out at the meteorological stations of the Institute of Terrestrial Magnetism near Moscow with the aid of

automatic equipment with a frequency range from 2 to 16 MHz

led to the discovery of a particular type of ionospheric disturbance — an additional layer located above the normal F2

layer v/ith critical frequencies much smaller than the ones of

the F2 layer. The diffusivity of this layer increased with the

grov/th of the disturbance but instead of rising as does the F2

layer it descended gradually. A subsequent careful examination of earlier records of ionospheric disturbance showed that

from March 1946 to April 1947, 27 disturbances accompanied

by appearances of this additional layer above F2 were recorded. It has been noted that this layer does not appear in all

c<ises of high activity of auroras, but is always accompanied

by auroras and at the time when the critical frequencies of

F2 layer do not exceed 6 MHz. Photographs and graphs showing results of height and critical frequency measurement are included. (Item 6D-24, Met. Abs. )..A. M. P.

Meek, J. H. , Ionospheric disturbances in Canada. Journal

of Geophysical Research, Wash., D. C, 57(2): 177-190,

June 1932. 11 figs. , 4 refs. DLC--Analysis of variations of

F region ionization and of abnormally high absorption of radio

y/aves in northern latitudes indicates that disturbances appear first in one part of the auroral zone and then move round

the earth with the sun for several days. The effect of a disturbance is enhanced and extend farther south near certain
69

geographic latitudes. Diurnal and seasonal characteristics

of the disturbances are described. It is suggested that disturbances are connected with similar geomagnetic disturbances and are due to a narrow stream of solar particles moving into the earth's path. --Author's abstract.

C-1G7 Meek, J. H. (Defence Research Telecommunications Establishment, Defence Research Board, Ottawa, Ontario, Canada),

Correlation of magnetic, auroral, and ionospheric variations

at Saskatoon. Journal of Geophysical Research, 58(4) :445-

456, Dec. 1953. 7 figs. , 6 refs. DLC -An analysis has

been made for the five-month period from Dec. 1951 to April

1952 of the variations at Saskatoon of the horizontal component (H) of the earth's magnetic field, the position in the sky

and intensity of auroral light, and of critical frequencies and

heights of the ionospheric reflecting regions. There is a re- lationship between the maximum elevation above the northern

horizon of auroral light and the maximum amplitude of variation of H. Some types of sporadic E reflecting layers appear

more frequently during disturbances. Detailed analysis of

magnetically disturbed nights shows that magnetic bays and

certain other phenomena are correlated. An increase in the

, intensity of aurora is related to the rate of decrease of H in

tlie bay. Radio wave absorption or weak reflections at levels

below 100 km correspond to the periods v/hen H is of the order

of 500 gammas or more from its normal value. (For Pt. 2,

see ref. C-198). (Item 5C -260, Met. Abs. )-- Author's abstract.

C-198 Meek, J. H. (Physics Dept, Saskatchewan Univ. , Saskatoon,

Canada), Correlation of magnetic, auroral, and ionospheric

variations at Saskatoon, Pt. 2. Journal of Geophysical Research, Wash., D. C, 59(l):87-92, March 1954. fig., 8

refs. MH-BH--The relations between magnetic, auroral, and

ionospheric observations are summarized v/ith reference to

the occurrence of positive and negative magnetic bays. Auroral light associated with positive bays occurs at a higher

geomagnetic latitude than that associated with negative bays.

The magnetic and auroral light variations are compared to

MARTYN's theory of the aurora. If the latter is accepted,

the conclusion is reached (1) that most auroras are caused

by positively charged particles, and (2) that the conditions

described for the early phase actually exist throughout most

of a disturbance. (For Pt. 1, see ref. C-197). (Item 6. 10-

238, Met. Abs. )"Author's abstract.
70

C-199 Meek, J. H. and McNamara, A. G. , Magnetic disturbances,

sporadic E. and radio echoes associated with the aurora . Canadian Journal of Physics, Ottawa, 32(5): 326 -329, May

1954. fig. , 6 refs. DLC--A comparison of simultaneous

data on the visible aurora, the earth's magnetic field variation, vertical and oblique ionosonde echoes, and very high

frequency radar echoes has been made. Long range highfrequency and very high frequency radio echoes do not appear to correlate individually. Reflections are observed,

however, on both frequency ranges coincident with the appearance of low elevation auroral arcs, which are associated

with magnetic bays. --Authors' abstract.

C-200 Meos, Johan and Olving, Sven, On the origin of radar echoes associated with auroral activity. GSteborg, Sweden.

Chalmers Tekniska Hogskola, Handlingar, No. 196, 1958.

20 p. 14 figs. , table, 21 refs. DLC--Until very recently

it has been accepted that most of the VHF radio echoes obtained near the polar regions during geomagnetic storms

were due to direct scatter from auroral displays. HARANG

and LANDMARK (1954) (See ref. C-127), however, have

published a paper where they explain the echoes as backscatter from land or sea via intense sporadic ionospheric

layers in the E region. An analysis of the echoes at 10 m

wavelength, recorded at the Kiruna Radio Wave Propagation Observatory during the first quarter of 1953, indicates

that the echoes cannot be disconnected from aurora borealis.

It is concluded that the predominant mechanism is closely

connected to ionized and often invisible auroral forms.

(Item 9H-129, Met. Abs.)--From authors' summary.

C-201 Merritt, Ernest and Bostwick, William E. , A visual method

of observing the influence of atmospheric conditions on radio

reception. National Academy of Sciences, Wash. , D. C. , Proceedings, 14(11): 884-888, Nov. 1928. DLC-The experiment described is that of a partial separation of the ground

waves and the sky wave in radio communication. Two balanced coils were used (A and B). The A coil mounted with

its plane vertical and directed toward the sending station,

the B coil in vertical plane at right angles to this direction.

The latter coil responds only to that component of the sky

wave y/hich is polarized with its electric vector horizontal

and is not affected by the ground wave. Suitable amplification to one pair of plates of a cathode ray oscilloscope

featuring respectively horizontal and vertical movements,

combination of which results in a Lissajous figure on the screen. An example of the method as used during the presence of aurora is described. Further studies especially

during sunset are contemplated, (item 6D-10, Met. Abs. )--

W.N.
71

C-202 Mitra, Sisir K. (Prof, of Physics, Calcutta Univ. ), The

upper atmosphere. 2nd ed. Calcutta, The Asiatic Society,

(Preface 1952). 713 p. figs. , tables, bibliog. p. 644-668,

eqs. DLC, MH-BH--The first edition of this valuable work,

published in 1947, contained 616 pages. About 100 pages

of new material have been added, including the results of

the latest research in almost every field covered by the 13

chapters. These additions include work on escape of atmospheric gases (Chap. I), atmospheric tides (Chap. II),

radar studies of meteors (Chap. Ill), variations in ozone

content with latitude and air masses (Chap. IV), dissociation of N2 (Chap. V), ionospheric sounding by radio waves,

estimation of recombination coefficients, tides and traveling disturbances in the ionosphere (Chap. VI), Sq and L - variations near the geomagnetic equator (Chap. VII, up-todate bands and lines in auroral spectrum (Chap. VIII), new

theories of magnetic storms and aurora by ALFVEN and

MARTYN (extension of Chapman-Ferraro theory) (Chap. IX),

Russian work on zodiacal light and afterglow or airglow,

height measurements of luminescent layers, hydrogen and

sodium in the upper atmosphere, etc. (Chap. X), revised

model of temperature distribution in upper atmosphere (GERSON) (Chap. XI), a new chapter on rocket exploration of

upper atmosphere (V-2 and aerobee flights) (Chap. XII), and

new unsolved problems of the upper atmosphere (Chap. XIII).

Brief discussion of winds at high levels from indirect methods (Chap. XIII). No attempt at listing all of the important

siibjects covered in this work would do justice to its comprehensiveness. The amount of carefully prepared illustrative material - charts, graphs, tables, schematic diagrams,

etc. - both borrowed and original, is amazing. In most

cases the sources are carefully cited and a class bibliography of nearly 1000 references is a further aid in locating

source material on all fields of upper air research by physical methods. (Item 4. 8-15, Met. Abs. )--M. R.

C-203 Moorcroft, D. R. , Models of auroral ionization. Pt. I: Auroral ionization models and their radio reflection charac - teristics. Canadian Journal of Physics, Ottawa, 39(5) :677-

695, May 1961. 9 figs. , 18 refs. , 45 eqs. DLC-Although

radio observations of aurora contain information about the

nature of the reflecting ionization, the use of dissimilar

models of auroral ionization has led different workers to

widely differing conclusions. In this paper several general

models of auroral ionization are developed. By considering

the ionization as an assembly of individual scatters, it has

been possible to include a unified treatment of both weak

scattering and critical reflections. This treatment should
72

provide a basis for resolving some of the difficulties in the

interpretation of auroral radio observations. In a second

paper the available experimental evidence is examined in

the light of this theoretical treatment. --Author's abstract.

C-204 Moorcroft, D. R. , Models of auroral ionization. Pt. 2;

Applications to radio observations of aurora. Canadian

Journal of Physics, Ottawa, 39(5):695-715, May 1961. 8

figs. , 30 refs. , 13 eqs. DLC--In this paper the available

experimental evidence concerning radio reflections from aurora is examined in relation to the reflection characteristics

of the models of auroral ionization discussed in Pt. I. The

existence of critical reflection from auroral ionization at

frequencies between 30 and 50 Mc/s appears to be established. This iinplies electron densities as great as 3 X 10^^

electrons per m^. It is shown that the observations are consistent with a model consisting of irregularities of ionization elongated parallel to the earth's magnetic field in a

ratio of between 5 and 10 times, and having sizes transverse to the field lines of the order of a few meters. Some

of the observations require the irregularities to be distributed in size. It is clear that there is a need for more relevant measurements on radio reflections from aurora to specify the characteristics of the ionization more precisely. -- Author's abstract.

C-205 Moore, R. K. , A VHF propagation phenomenon associated

with aurora. Journal of Geophysical Research, 56(1):97-106,

March 1951. 3 figs. , 3 tables, 6 refs. --Discusses auroral

propagation as observed by radio amateurs operating at 28

to 148 Mc. Findings include: lack of skip effect, extremely

high fading rate and insignificant change in polarization.

North directed antenna gave better results. Number of days

and hours with auroral propagation at geomagnetic latitudes

< 52° to > 60° for the periods 1931 to 1941 and 1946 - 1950 are shown in tables and graphs. --W. N.

C-206 Moore, R.K. , Aurora and magnetic storms . QST, West

Hartford, Conn., 35(6):14-19+, June 1951. 9 figs. , 13 refs.

DLC--A general discussion of the nature of ionospheric interferences with radio communication, particularly on the VHF

bands used by radio amateurs. --W. N.

C-207 Moore, R. K. , Theory of radio scattering from the aurora.

Institute of Radio Engineers, Proceedings, 40(6) :747, June

1952. DLC "Abstract of a paper presented at the I. R. E.

Meeting, Washington, D. C, April 1952. Details of a theory,

with mathematical appendix, that signals observed are scattered from the leading edges of rapidly advancing columns of
73

ionization (of diameter ^^ 50 cm) created by bundles of incoming, 1 MeV, auroral protons. The theory explains the

observed fading spectra (akin to meteor "whistle") and the

minimum range effect (no returns at ranges less than 400 km

have been reported). The rate of advance of the ionized columns is of the same order of magnitude as that found by spectrographic observation. Calculations of electron densities

are attempted but depend on the size of the columns. --Author's abstract.

C-208 Moore, R. K. (Sandia Corp. ), Theory of radio scattering

from the aurora. Institute of Radio Engineers, Transactions

on Antennas and Propagation, AP 3:217-230, Aug. 1952.

DLC--It is postulated that radio signals returned from the aurora may be scattered by columns of ionization created

by incoming auroral protons. The scattering from each column may be treated in the same manner as the "whistles"

from meteor ionization, but because of the large number of

columns created in a short time the "whistles" blend into a fading spectrum. Experimental determination of the fading

spectra of such signals leads to curves which correlate

well with those calculated by the theory. The velocities

indicated agree in order of magnitude with that found by

Gartlein's spectrographic observations. The calculated

distances at which radar echoes should be observed agree

with experiment and bear out the observations that signals

are not heard or seen from overhead auroras. Density calculations cannot be complete because columnar size is not

known, but indications are that this size may possibly be

of the order of l''i meters in diameter. --Author's abstract.

C-209 Murcray, W. B. and Pope, J. H. (both, Geophys. Inst. Univ.

Alaska, College, Alaska), Radiation from protons of auroral energy in the vicinity of the earth. Journal of Geophysical Research, Wash. ,D.C., 65(11): 3569-3574, Nov. 1960.

3 figs. , 10 refs. , eq. DWB, DLC--Some considerations re- garding the way in which auroral protons might be expected

to radiate as they approach the earth are discussed. The

form of the frequency-time curves which might result at the

earth's surface from the radiation by such particles are deduced by assuming a reasonable model of the upper ionosphere. It is concluded, at least so far as the frequency-time

curves are concerned, that auroral protons are capable of

producing the low-frequency electromagnetic phenomenon

known as "Chorus". (Item 12B-122, Met. Abs. )- -Authors'

abstract.
74

C-210 Nakata, Yoshiaki (Radio Res. Lab. Kokubunji), Auroral

echoes in the ionoqrams obtained in the minauroral region.

Japan. Science Council. Ionosphere Research Committee,

Report of Ionosphere Research in Japan, 12(l):l-5, 1958.

6 figs. (incl. photos), 6 refs. DWB, DLC-A report of the

radio echoes believed to be from auroral ionization obtained

at a minauroral region (Japan) 3 times since the beginning of

IGY by a continuously operated newly designed ionosonde.

The instrumental details of the ionosonde are presented.

These auroral echoes occurred on the magnetically disturbed

days of Sept. 13 and 21, 1957 and of Feb. 11, 1958. The

details of these echoes are discussed and their photographic

representations shown. In order to indicate the source of

these echoes, the relation between the calculated slant

range and ionospheric height is considered and graphically

represented. In this regard, evidence obtained at Kokubunji

indicates that the echoes from auroral ionization have been

obtained in fact from scattering source located at F layer

heights. (Item 12A-169, Met. Abs.)-I. S.

C-211 Nichols, Benjamin (Geophys. Inst., Univ. of Alaska, College, Alaska), Drift motions of auroral ionization. Journal

of Atmospheric and Terrestrial Physics, London, 11(3/4):

292-293, 1957. fig. , 3 refs. DLC -Drifts 400-900 km N of

College, Alaska were measured in VHF ranges (106 and

41. 15 Mc/s) from transmitters located 40 km E of College.

Movement of echoes from auroral ionization in the E region

are probably due more to the speed of electrons in the disturbance current system than to ionospheric winds. Recent

ionization data would indicate a total current of 10^ A/100

km of lat, in accordance with currents calculated from magnetic observations by SILSBEE and VESTIl'TE (1942) and

others. Radar echoes, spread over a range of 100 km are also consistent with electron density, drift velocity and magnetic observations. (See ref. C-167) (Item 10. 3-332, Met.

Abs.)-M.R.

C-212 Nichols, Benjamin, Auroral ionization and magnetic disturbances . Institute of Radio Engineers, N. Y. , Proceedings,

47(2):245.254, Feb. 1959. 3 figs. , 56 refs. DLC --An ex- amination of radio studies of auroral ionization shows that

an average ionization density of about 5 X 10^ electrons per

cm3 is sufficient to explain the normal radar echo. The magnetic disturbances produced by current systems in the ionosphere are closely related both to the ionization and the luminosity of the aurora. The magnetic variations are also associated with increases in the speeds of motion of the ionization. The increased ionization manifest in the aurora, together with its increased speed of motion, brings about the
75

magnetic changes observed at the ground. The rapid speeds

of auroral motions observed both visually and by radio means

are at the upper end of a continuous curve of drift motions

that increase with increasing magnetic disturbance. (Item

11.8-96, Met. Abs. )--Author's abstract.

C-213 Nichols, B. (Cornell Univ. , N. Y. ), Evidence of elongated

i rregularities in the ionosphere. Journal of Geophysical Research, Wash., D. C, 64(12): 2200-2202, Dec. 1959. 11

refs. DLC --Radio observations of backscatter from ionospheric irregularities under both auroral and nonauroral conditions indicate the presence of small-scale irregularities,

elongated along the earth's magnetic field. These elongated

irregularities have been found at heights from 80 to 300 km.

The most precise measurements available are related to echoes from auroral ionization at a height of about 100 km. These

indicate scales of tens of meters along the earth's magnetic

field and tens of centimeters normal to the field. (Item IIF95, Met. Abs. ) --Author's abstract.

C-214 Nikol'skii, A. P. , K voprosu o geograficheskom raspredelenii v vysokikh shirotakh anomal'nogo pogloshcheniia radiovoln V ionosfere . (Geographical distribution in high latitudes

of radio blackouts in the ionosphere. ) Akademiia Nauk SSSR,

Doklady, 112(4):628-631, Feb. 1957. 2 figs., table, 6 refs.

Transl. into English available Special Libraries Association,

Transl. Center (John Crerar Library, Chicago) as its R-1179

(6 p. ). DLC--Frequency, diurnal amplitude and phase of

radio blackouts based upon analysis of foreign sources are discussed. The author uses the actual maximum instead of

harmonic analysis. Evidence points toward a second maximum zone of blackouts near the poles in addition to the ring

of maximum frequency in the zone of auroral activity. (Item

10.3-203, Met. Abs. ) -A. A.

C-215 Nikolskif, A. P. , O planetarnom raspredelenii magnitno

i onosfernykh nozmushchenii i poliarnykh siianii. (World-wide

distribution of magneto-ionospheric disturbance and aurora.

)

Akademiia Nauk SSSR, Doklady, 115(l):84-87, 1957. 3 figs.,

9 refs. DLC . English transl. by E. R. Hope issued as

Canada. Defence Research Board, Translation, T-266-R, Oct.

1957. DWB--World-wide data on anomalous ionospheric absorption are interpreted according to Stormer's spiral model

of solar corpuscular radiation distribution in the Arctic. Four

zones of maximum incidence of corpuscular radiation are derived (extending into equatorial latitudes) and traced on a Northern Hemisphere chart. The existence of similar zones

in the Southern Hemisphere is assumed and it is suggested

that the intensification of magnetic activity at the equator
76

might be explained by the overlapping of the tv/o hemispheric

distributions. (Item 12B-130, Met. Abs.)--G.T.

C-216 Norsk Institutt for Kosmisk Fysikk, The Auroral Observatorv at Tromso ( f = 6S°3C'. S N. A ^ 18"5S'. £ E Gr. )7

Observations 1952. Its Publikasjoner, No. 35, pub. 1£54.

31 p. graphs, 4 figs. , numerous tables. DWB--A brief description of the auroral and twilight sodium research (spectrograph observation) at Tromso and Oslo, and ozone observations at Tromso (9 months) and Longyear, Spitsbergen (7

months) with a Dobson spectrophotometer. The Longyear

observations were started in Sept. 1S50 by S.H. II.LARSEN.

The results of the first 2 years of observation there v/ill be

published in a separate paper. Following the 1-page discussion are tables of 03 values for each day of the observation

period in 1952. Geomagnetic observations at Tromso and

Bear Island, radio echo observations and hourly ionospheric

values of critical E, FoE, and Fl, F2 and vertical height,

storminess horizontal and vertical intensity and storminess

values for each hour of the year are tabulated and shov/n in

graphs. (Item 8. 1-114, Met. Abs. )--M. R.

C-217 Ohno, K. and Endo, K. , The propagation of commercial

s hort waves through high latitudes. Japan. Radio Research

Laboratories, Tokyo, Journal, S(2):13, 193S. Unchecked. -- Consider Nds to represent an index of the difficulty of commercial communications, if s is the path length, and N the

auroral frequency. --L. A. Manning.

0-218 Omholt, A. , The auroral E layer ionization and the auroral

luminosity. Journal of Atmospheric and Terrestrial Physics,

7(l/2):73-79, Aug. 1955. 2 figs. , table, 10 refs. , 10 eqs.

DWB--The processes causing increase in E layer ionization

during magnetic storms and auroras are discussed. It is

shov/n that the recombination coefficient can be derived from

simultaneous measurements of the photon emission v/ithin

the first negative nitrogen band and the maximum electron

density in the E region. Equipment and observations are described. The recombination coefficient during auroras is >

10-7 cm 3 sec-1. In medium to strong auroras the mean electron density is 2-10 X 10^ cm^^. VHF radio echoes require

localized electron densities of about 1. 4 X lO^cm^, virhich

though high may not be impossible. The variations of some

parameters v/ith height are discussed. (Item 7. 1-230, Met.

Abs.)-C.E.P.B.
77

C-21£ Oinholt, A, , R adio observations of aurorae . (In: Chicago

Univ. Yerkes Observatory, Williams Bay, WisCo , Contract

AF l&(122)-480. Technical Report, No. 22 (Syraposium on auroral observations during the IGY, Sept. 17-23, l£o3), pub.

1£55. p. 5-12. IC refs. . ) DW3--The possible altitudes and

ionization processes which might account for radar ani radio

raflections from auroral streamers (associated v/ith Ej, reflection) are discussed. The absorption of 1-20 Mc/sec v/aves

is supposed to take place at GO km, v/hereas the visible aurora is 100 km or higher. Explanation is only tentative, radio

echoes occur only ',.rith strong auroras lov/ in NW and ME and

usually vvith active rays. A strong fading rate and Doppler

broadening indicate speeds of reflecting points up to 1000

m/sec. (Item 11.4-120, Met. Abs. )"M. R.

C-220 Ortner, Johannes (Kiruna Geophysical Obs. , Kiruna, Sweden),

Around-the-v/orld echoes observed on a transpolar transmission path. Journal of Geophysical Research, Wash., D. C,

64(12): 2434-2467, Dec. 1G59. 3 figs. , table, 4 refs. DLCAuroral influence on the 5200 km long communication path,

17. £00 and 24. 025 Mc/s respectively, of the three backscatter sounders used, is discussed here. Multipath studies v/ere

made Dec. 23, 1958 - Feb. 24, 1C5£. The results are presented in table and graph. It was found that the field strength

of the v/orld travelling signal at times v/as not more attenuated

as a direct propagated pulse. --W„ N.

C-221 Oscanyan, P.C., Jr., Radio phenomena recorded by the Univ- ersity of Michigan Greenland Expedition 1C26. Institute of

Radio Engineers, Proceedings, 15(5):425-430, May 1£27. 5

figs„ DLC--J. L. Reinhartz's statement "v/hen a radio receiving station which plan to work on wavelengths of 50 m or below is placed at the foot of a hill or mountain which is of a height greater than 17 from the horizontal of the station, then

signals will be screened off from the receiver" was so v/ell

verified that the radio station of the expedition had to move;

since signals coming from north were completely blocked = An audibility graph disproves the popular belief that there is

no static in the Arctic. --W. N.

C-222 Oscanyan, Paul Co , Jr. , Arctic auroral radio interference . QST, West Hartford, Conn, 13(12):1G.20+, Dec. 1£2£. 5

figs. , refs. DLC--An account of auroral effects upon radio

waves as observed by the author, in charge of the radio station of the Mt, Evans Observatory (Greenland 1200 f. a. s. ) of the Univ. of Michigan Expedition to Greenland 1&27-1&28.

The receiving equipment described covered the frequency

range 15-30, 000 Kc. Apparently, this is the first report on

direct observation of visible aurorae affecting radio wave
propagation. The auroral effects are classified A 1, B 1, B2

and B4 according to interference on the various frequencies.

It is note.vorthy to quote: "What really offers the most interest is the fact that there seems to be a point which can be

calculated. When the corona formation is nearest to 17 (or

more) above the horizon, and between the receiving and transmitting stations, the signal is most greatly influenced". Directional movement of the radio disturbances are also considered. --W. N.

C-223 Owren, Leif; Leinbach, Harold and Nichols, B. , Auroral ab- sorption of radio waves transmitted via the ionosphere.

Alaska. Univ. Geophysical Institute, Contract DA-33-039-sc5373G, Final Report (on Task A and B), March 1, 1955 to

Feb. 2e., 1953. 79 p. 28 figs. , IG tables. DWB-Give a detailed account of experimental data collected under Experim^ent Aurora. The monthly percentage of signal-in-time is

tabulated for all frequencies and paths employed, and compared vvith East-West and South-North propagation at each

frequency. The seasonal variation in signal-in-time over

short and long paths is shov/n in diagrams. There is a significant difference statistically in signal-in-tirae for the EastWest and North-South Paths for 12 mc short paths. A study

ol the critical frequencies for E and F layers shov/s the difference in daytime variation of median signal strength between the years 1949-50 and 1954-55 due to changes in F layer ionization and D layer absorption in the course of a sunspot cycle. With a 12 mc radar, both direct backscatter and

ground-scatter echoes v/ere observed over a period of many

months. Tv/o types of echoes v/ere recorded, one of which

fades very rapidly. The data obtained about visual aurora at

five stations in Alaska are analyzed. (Item 12A-180, Met.

A:os.)-A.H. K.

C-224 Parkinson, T. ; Kirby, S. S. ; Arnold, P„ N. and others. Bibliography on radio wave phenomena and measurem.ent of radio

field intensity. Institute of Radio Engineers, Proceedings,

19(6): 1034-1084, June 1931. DLC-The bibliography contains

630 annotated entries classified under subject and related

subdivisions in chronological order: radiation, radio v/ave

phenomena, fading, daily and seasonal variations, direction variations; meteorological, geophysical and cosmic effects; eclipses, reflection, refraction, diffraction, absorption, polarization, K-H layer, wave front angle, transmission

formulas, atmospheric disturbances, strays, directional properties, etc. (Item 3B-13, Met. Abs.)-W. N.
79

C-225 Parthasarathy, R. ; Easier, R.P. and de Witt, R. N. , A nev/

method for studying the auroral ionosphere using earth satellites . Institute of Radio Engineers, Proceedings, 47(9):1SS0,

Septo 1959. DLC--Simultaneous recordings are taken at tivo

stations, 19 km apart, of the field strength of the 20 mc

transmissions from Sputnik III as it passes directly overhead.

The results are used to study the structure of the absorption

region. --IRE, Proceedings, Abstract No. 4032.

C-226 Paton, James, The observation of aurora . International Council of Scientific Unions, Brussels, Eighth Report of the Commission for the Study of Solar and Terrestrial Relationships.

Paris, 1G54. p. 157-137. 33 refs. DWB-.Early maps of isochasms are based on inadequate data and close net^-vorks of

observing stations have been recently established, supplemented by observations on transatlantic stratocruisers. Aids

to observing, analysis and classification are described; use

of punched cards is suggested. Use of radio echoes is discussed. The paper ends with a list of outstanding probleras.

(Item. 7. 4.2G9, Met. Abs. )-C. S. P. B.

C-227 Penndorf, R. and Coroniti, Samuel C. , Propagation of HF and

VHF in the Arctic region. Institute of Radio Engineers, Transactions on Communication systems, CS-7(2): 121-125, June 1C5S,

5 figs. , 9 refs. DLC--Auroras can be used as reflectors or scatterers particularly in the afternoon and night, depending

on local time. Critical analysis of all recordings by stations

north of 30 lat is reported on here. T-.vo types of F2 propagation are discussed along with the three sporadic E-types:

1. Thule, 2. auroral belts, and 3. mixed. --W. N.

C-22C Pawsey, J. L,, The question of radio emission by the ionos - phere. Journal of Atmospheric and Terrestrial Physics, London, 15(l/2):51-53, Sept. 1959. 10 refs. DLC -The importance of non-thermal emission of radio waves of the ionosphere

as a probable source of "radio noise from the aurora" in ionospheric and astronomical studies is examined. The thermal

emission from the D region does not preclude occasional

bursts nor intense emission from the E layer. Intense noise

from all over the sky reported on meter v/avelengths, and

other sim.ilar reports, until reliably reproduced, present clues

rather than evidence. Brief increases of noise level on a frequency of 33 Mc/s coinciding with meteors might originate

from a source other than the meteor. GALLET's report giving

reasons for supposing the "dawn chorus" is generated in the

outer reaches of the ionosphere is v/orthy of further examination. (Item 11. 12-323, Met. Abs.)"O.T.

C-229 Peterson, A.M. and Leadabrand, R.L. (Radio Propagation

Lab. , Stanford Univ. , Calif. ), Long-range radio echoes from

auroral ionization. Journal of Geophysical Research, 50(2):

306-309, June 1954. 2 figs. DLC-
Radio echoes were observed at 1300 to 4700 km from Stanford

Univ, (43, 7G°N) on frequencies of o„ 42, 12, 8S and 17.31 Mc

at greater heights than heretofore reported, and with intensities exceeding strongest F layer propagated ground-scatter

echoes occurring simultaneously. These echoes were first

detected in Oct. 1C52 during sporadic E layer studies. They

are found in the F layer, not E layer zone as was presumed.

Discrete and diffuse echo records are reproduced. Several

layers may be present at varying distances. Diurnal and sea- sonal frequencies agree v/ith auroral frequency data. (See ref,

C-1S4). (Item 3D-257, Met, Abs, )--M. R,

C-230 Pickard, Greenleaf W, , Aurora and lov^-frequency radio recep - tion, July 7 to 8, 1£2G, Terrestrial Magnetism and Atmospheric Electricity, 33(3) :1G8, 1C2B. DLC--The aurora observed

at Nev/ton Center, Mass. began at 20 h 15m EST, July 7 as a bright arch in the northeast. An hour later an auroral crown

doveloped near the zenith, v/ith descending rays %/hich at one

time nearly filled the hemisphere, and v/hich were at times

strongly colored v/ith pink and yellow -green. Broadcast reception from WGY at Schenectady, and KDKA at Pittsburgh v/as

greatly depressed during the entire evening and did not rise

appreciably above its normal lo / daytime level. Although

the Flarvard Astronomical Laboratory at Cambridge has not yet

r3iuced its record of WB3M for this period. Stetson reports

very low field values. My own record of field strength from

station Vv'CI at Tuckerton, Nev/ Jersey, operating at IG Kc,

sho /s a striking change from the normal diurnal curve for the

past month, which had peaks at or near sunrise and sunset,

'.vith low field during the night. On July 7 the sunset peak

7/as absent with high values during the greater part of the

night, and instead of a peak at sunset a deep depression appears in the early -noming record of July G, and a low and

irregular field during the day. As there has been nothing like

t.iis in the previous daily records of this station, it is as- sumed that the change is associated v/ith the aurora. --E. Z, S.

C-231 Pierce, J, A, , Ionization by meteoric bombardment . Physical

Review, 71(2):33--2, Jan, 15, 1£47, fig,, 12 refs, , 7 eqs.

DLC --Although the discussion centers on ionization by meteors there is a brief reference to patterns reflected by aurora borealis and sporadic E region ionization. --E. Z, S.

C-232 Pogorelov, V.L. , Radiolokatsionnve otrazheniia ot poliarnykh

s iianii. (Radar reflections from auroras.) Akademiia Nauk

S3SR, I^zvestiia, Ser, Geofiz, , No. 5:1048-1051, 1C3C, 4

figs., 3 refs, DLC. Transl, into English in the corresponding issue of the English language ed, of the Izvestiia, Bulletin of the Academy of Sciences of the USSR, Geophysics Ser.

DWB-
81

In connection with the IGY program radar studies on the aurora are being carried out at Roshchino ( 4^ = SO 12'; A = 29°34'E; 4' = Go°33'; A = 115°47'E). The radar installation

is described brieflya Tv/o types of signals 7/ere observed on

the screen of the electron tube indicator during an aurora; one

type (a) was either stationary or moving very slov/ly and the

other type (b) moved rapidly, both with increasing and diminishing distance. An examination of the distribution of both

types of signals, at hourly intervals according to local time,

shows that the time of maximum number of reflections and

their maximum intensity coincide, and that weak signals were

found to occur only at the time corresponding to that of maximum occurrence. With rare exceptions the variations in intensity with time of day is similar in both types of signals.

The maximum reflection of both types of signals occurs along

the azimuth at and 20 . It is possible that the sm.all minimum along the azimuth near 10 is a result of random deviation

and it may disappear when more extensive material is analyzed.

The mean position of azimuths, from v/hich signals of different

type issue, are often similar. Signals of type "b" are some - times either similar to or are mirror images of type "a" signals.

The coincidence of azim.uths indicates that sometimes both

types of radar reflections originate in similar regions v/ith increased electron density. It is shown by means of a graph

that the areas of reflection of signals are not located upon a narrow arc along a magnetic parallel, although fundam.entally

they are concentrated close to it. The arc-like distribution

coincides with the magnetic but not geomagnetic parallel. The

measurement of the height of the radar reflection at Roshchino

in 1957 indicates that the maxim.umi number of reflections was

at a height of 120 km., i. e. , primarily at the zone of distribution of the most intense regions of auroral illumination. When

the magnetic field is replaced by a geomagnetic field another

distribution is obtained. But the maximum number of reflections does not come from the azimuth coinciding with the plane

of the geom.agnetic meridian. (Item llH-121, Met. Abs. )--

LLoD.

C-233 Presnell, R. I. ; Leadabrand, R. L. ; Peterson, A.M. et al.

(all, Stanford Res. Inst., Menlo Park, Calif.), VHF and UHF

radar observations of the aurora at College, Alaska . Journal

of Geophysical Research, Wash., D, C. , G4(S):117£-1190,

Sept. 195£. 13 figs.. Stables, 14 refs. DLC --During routine

UHF auroral radar investigations an unusual daytime auroral effect has been discovered. It apparently occurs most frequently

-when: (1) the reflecting region is sunlit; (2) the atmosphere is

undergoing its greatest change ( earl^i morning and late afternoon). There is a minimum of echo occurrence at noon when

atmiospheric conditions are stable. Daytime aurora is
82

distributed over a larger region of space than the more commonly observed nighttime aurora. The nighttime and daytime echoes are labeled discrete and diffuse, respectively.

They can be differentiated in several ways. Discrete echoes

are identified by their relatively short duration, their occur- rence only at night, and their orientation in the E layer along

a plane at right angles to radar beam; hence, the echo does

not shift in range with change in elevation angle of the radar

antenna. Diffuse echoes last longer, occur only during the

day, and are apparently oriented in the E layer along a plane

almost parallel to the surface of the earth; hence, the echo

does shift in range when the radar-antenna elevation angle is

changed. The primary effects of increasing the observation

frequency are decreasing echo amplitudes and decreasing

maximum off-perpendicular angle. The observed aspect sensitivity and the wave length dependence are interpreted in

terms of the scattering approach of BOOKER. Using the ex- perimental UHF results, a model of the underdense ionosphere has been developed consisting of irregularities v/hich

have dimensions of 0. 1 m across and 3. 5 m along the magnetic field lines. The echo results are compared with auroral

zone effects and described, together with measurements of

the frequency spectra (Doppler shift and spread) of an aurorally reflected continuous wave signal. (Item 12B-145, Met.

Ahst. ) (*See ref. C-30)--Authors' abstract.

C-234 Rawer, Karl, Die lonosphare. Ihre Bedeutung fur Geophysik

und Radioverkehr. (The ionosphere. Its importance in geophysics and radio communication. ) Groningen, P. Noordhoff,

1953. 179 p. 67 figs., 143 refs. , 68 eqs. DLC--A complete

text on the use of radio in ionospheric research. Ch. I takes

up methods of observation by echoes, spectroscopic methods

for aurora and airglow, magnetic, meteor and luminous night

clouds, and soundings; Ch. II gives results of observations

by echo methods, magnetic data, composition, pressure, density and temperature. Ch. Ill discusses theories of ionospheric stratification (origin and disappearance of ionization

and explanation of different layers. Ch. IV takes up normal

and irregular changes of the ionosphere (D, E, F2, F, E2, G

and Eg and influence of magnetic storms, eclipses, polar

summer and night, commencements). Ch. V discusses influence of ionosphere on propagation of radiowaves and forec ---sting propagation. (Item 6D-2G7, Met. Abs. )--M. R.

C-235 Reid, G. C. and Collins, C. (both. Defence Res. Board,

Ottav/a, Canada), Observations of abnormal VHF radio wave

absorption at medium high latitudes . Journal of Atmospheric

and Terrestrial Physics, London, 14(l/2):63-81, April 1959.

7 figs. , table, 23 refs. , eq. DLC--
83

A study of cosmic noise absorption at a frequency of 30 Mc/s

at Ottawa and Churchill has revealed the existence of two apparently distinct types of abnormal absorption event. One of

these is predominantly a night-time phenomenon and is closely associated with auroral and geomagnetic disturbance. It is suggested that this absorption may be caused by an increase

in electron collisional frequency at E region heights rather than

by a large increase in electron density at lov/er levels. The

second type of absorption is confined to the auroral zone and

is predominantly a daytime phenomenon, recurring for several

days after a large solar flare. Evidence is presented to shov/

that this absorption is due to an increase in ionization at very

low levels in the ionosphere. The cosmic noise measurements

are supported by evidence from a number of VHF forv/ard scatter circuits in Canada, and this is used to obtain information

about the geographical extent and frequency of occurrence of

these abnormal absorption events. (Item llE-133, Met. Abs.

)

--Authors' abstract.

C-236 Rodewald, M. and Breitkreutz, Egon, Das grosse Nordlicht

vom 21. Januar 1957. (The great aurora borealis of Jan. 21,

1957.) Wetterlotse. No. 113:43-54, Feb. 1G57. 4 figs.

DLC-In 36°17'N, 3 46'W a red aurora penetrated by v/hite

rays. It was also seen in Portugal, Greece, Austria, Germany, etc. In Sv/eden strong magnetic disturbances caused

traffic interruptions. Radio signals were inaudible. An aurora of Nov. 9, 1956 in 33 N 60 W is also referred to. (Item 8. 6-337, Met. Abs. )--C. E. P. B.

C-237 Rumi, G.C. , Experiment Luxembourg. Alaska. Univ. Geophysical Institute, Contract AF 19(304) -3SS0, Scientific Report, No. 2, May 1959. 32 p. 12 figs. , 13 refs. DWB

(M(051) A323ex) --Auroral disturbances and the absorption of

radio v/aves in the ionosphere have been investigated. The

study shows that the absorption region is in two parts. In

one of these layers the effective electron collision frequency

increases during disturbed periods at auroral latitudes. This

is attributed to auroral activity. The report concludes that

at these auroral latitudes an auroral storm can even improve

communications. (Item 12A-202, Met. Abs. )--N. N.

C-238 Rybner, Jorgen and Ungstrup, Emil, L 'influence de la zone

d'aurores boreales sur les liaisons radio^lectriques . (Effect

of the auroral zone on radio communication. ) Annales des

Telecommunications, Paris, 12(5):172-173, May 1£:57. fig.,

3 refs. DLC--Studies of high frequency propagation between

Denmark and western Greenland are reported. Considering

all possible modes of propagation, it is found that the un- u«ually weak field intensities observed may be attributed to

D layer absorption in the auroral zone. (Item 9. 5-27S, Met.

Abs.)-G.T,
S4

C-23S Schallerer, W. , Erdstrome in Teleqraphenleitungen ini Zusamm^nhanQ mit der Nordlichterscheinung am 25. 1. 1C3G. (Terrestrial currents in telegraph wires in correlation v/ith aurora boreilis January 1, l£3o. ) Telegraphen, Fernsprech, Funk und

Fernsehtechnik, 27(2):63-69, Feb. 1£3G. DLC- -Extremely

heavy oscillations of currents v/ere observed in the ground

cribles at the UT/WT station in Berlin and elsewhere in Germany. With a periodicity of min 1 sec, m.aximum 2 minutes,

t'le phenomenon lasted from 2010 to 2200 and v/as stronger in

the north-south oriented cables than in the east-v/est ones.

In Arendal, Norway, the earth currents v/ere more distinct in

the aerial cables than in the ground cables. --W. N.

C-240 Schlobohm, J. C. ; Leadabrand, R.L. and Dyce, R.B. et al.

(all, Stanford Res. Inst. , Menlo Park, Calif. ), High altitude 103. 1 Mc radio echoes from auroral ionization detected

at a geomagnetic latitude of 43 . Journal of Geophysical Research, Wash., D. C, S4(S):1101-1196, Sept. 1S59. 11

figs. , table, 10 refs. DLC--Auroral echoes have been detected using a radar at 106. 1 Mc located at 43 geomagnetic

latitude. The geometry of reflection for ionization aligned

v/ith the earth's magnetic field lines is such that, for a geom.i.gnetic latitude of 43 , reflection can occur as high as

300 kin. The results of these observations are presented,

vrith an interpretation of the height of reflections and a discussion of the advisability of making lov/ latitude auroral

echo investigations. (Item 11. 7-144, Met. Abs. )- -Authors ' abstract.

C-241 S-jaton, S.L. and Malich, C. V/. , Auroral research at College. Alaska. 1C'41-1C44. in Researches of the Department

of Terrestrial Magnetism. Washington, D. C, Vol. 12,

Part 11. of Carnegie Institution of Washington, Publication

No. 175, 1C47. p. 373-307. 2 figs. , 2 tables. DLC--

Description of buildings, personnel, instruments and method^

difficulties, calibrations, accuracy, discussion of data. All

complete nighttime radio fade-outs occurring after midnight

v/ere accompanied by high intensity zenith aurora. Cameras

and accessories illustrated. Tables giving zenith auroral intensities in equivalent photometer values, and corresponding

values of upper frequency limits of blanketing type sporadic

E reflections, Oct. 1943-March 1944 for 15 minute intervals.

(Item 1.7-134, Met. Abs. )-M. R.

C-242 Seed, T.J. (Univ. of Canterbury, New Zealand), V.H.F. obs-jrvations on the aurora austral is. Journal of Geophysical

Research, Wash., D. C. , 33(3):517-323, Sept. 1C5G. 3 figs.,

20 refs. DLC --Investigation of the aurora australis at a radio

frequency of 39 Mc/s is reported. A value for the range
85

exponent in the radar equation has been determined and

values of the reflection coefficient deduced. Mechanisms

of auroral reflection of radio v/aves are discussed, and only

those involving column models are found to be substantiated.

Noise emission from auroral ionization has been observed

and measured at 69 Mc/s. (Item 10. 5-342, Met. Abs. )--

Author's abstract.

C-243 Seed, T.J. and Ellyett, CD. (both, Canterbury Univ. College, Christchurch, New Zealand), Lov7 latitude reflections

from the aurora australis. Australian Journal of Physics,

Melbourne, 11(1):123-12&, March 1958. 2 figs. , table, 5

refs. DLC--A search for auroral reflections within a radar

(or pulse radio transmitter) v/as begun in March 1957 at the

Canterbury Univ. College Radio Observatory, 14 mi from

Christchurch, New Zealand (lat 43. 6°S, long. 172. 6°E and

47. 8°S geomagnetic lat). Echoes were obtained at Christchurch on March 10, 1957 for 3 hrs (13-13 h) at 325-500 km

ringe and 113-135 km height. The aurora was observed

visually over S. New Zealand, Campbell Island and Australia

earlier, and over all of New Zealand from 13-14 h, and in Australia 13-1630 h. Another radar display was observed on

April 10. It is correlated with visual and magnetic data on a graph and v/as calculated to come to within a distance of 250

km and 93 km height. The beginning of the radar return coincided v/ith a steep gradient on the magnetogram. A total of

10 auroras were thus observed in 31 days (April 10-June 10)

and the data are tabulated. (Item 10. 2-341, Met. Abs. )--

M.R.

C-244 Sen'ko, P. K. , Geofizicheskie issledovaniia v Antarktide.

(Geophysical explorations in Antarctica. ) Priroda, Moscov/,

7:59-82, July 1958. 2 figs. DLC--Some of the results of

seismological, terrestrial magnetic and ionospheric observations carried out in 1953 at Mirny, Antarctica, are summarized. The seismographs were capable of recording elastic

oscillation of the ground with periods of 1-10 sec. In the

first seven months some 200 earthquakes were recorded but

only in about 1/5 could the coordinates of the epicenters be

established and for only half of these could the epicenter

distances be computed. The centers of the earthquakes were

in the southwest Pacific, The relationship between microseisms and synoptic conditions was investigated. In the

winter-spring period, v/hen the surface of the sea was covered

with ice for hundreds of kilometers, microseisms v/ith oscillation periods of 6-10 sec were observed; in summer-fall,

when ice fields are close to the shore, the microseisms have

a smaller period but with an amplitude up to 7 /6 . Short

wave communication between Mirny and Moscow was best at
S3

night when radio waves were propagated along the shortest

distance (15, 000 km); in the afternoon a more intense signal

passed through the regions of the South and North Poles

(25, 000 km). Owing to the absorption effect of the thick ice

layer, radar communications in the heart of Antarctica could

be carried on with medium length v/aves for short distances.

The absolute and variable values of the elements of the

earth's magnetic field vv^ere measured along the line MirnyPioneerskaia. At Mirny the magnetic field disturbance shov/-

ed a maximum at noon or in the afternoon hours of mean local

time. During the v/inter (May-Aug. ) there was a second nocturnal maximum disturbance near local midnight in addition to

daily maximum disturbance. In summer (Nov. -Jan. ) there was

a general increase in magnetic disturbances associated >vith

an increased intensity of diurnal disturbances. At Mirny the aurora v/as observed primarily in the northern part of the sky.

The magnetic variations as shov/n by the curve of the vertical

component displayed considerable local differences .;ithin

short distances (10 and 13 km). The cause of the local variations is attributed to an electrical current of abnormally large

density flov/ing along the sea coast. The instrumentation and

aims of studies on cosmic rays and auroras of the second continental expedition in 1G57 are outlined. (Item 11. 7-34, Met.

Abs.)--I.L.D.

C-245 Shapley, Allan H. , Clues to ionospheric conditions in the

southern auroral zone. American Geophysical Union, Geophysical Monograph, No. l:Go-C0, 1£G3„ 4 figs. , ref„ DLC--

While there is a considerable amount of experience ^7ith short

wave radio comm.unication via the ionosphere from the many

Antarctic expeditions beginning in l£li-12, quantitative determinations of ionospheric parameters exist for only a fev; places

and for relatively short periods of time. From sv/eep frequency

vortical sounding observations at these fev,' points on the Antarctic Continent and on surrounding islands, there is evidence

of at least a rough north-south correspondence of F region critical frequencies. The operation of a rather dense nct,/ork oi

stations during IGY ',vill be needed for any real description or understanding of these plienomena. The objectives of a number of analyses with data from the IGY period are mentioned.

(Item G. 4-336, Met. Abs. )--Author's abstract.

C-246 Shapley, Allan H. , The ionosphere IGY programme in the

Arctic. International Geophysical Year, lC57/lCCCi, Comite

Special, Bulletin d 'Information, No. 7:30-32, 1C53. DWB--

lonosphere program is closely linked with the auroral and geomagnetic and even the cosmic ray program.s. Behavior of the

ionosphere in auroral regions and features at or near the North

Pole during polar day and polar night will be investigated.
Hemispheric symmetry will be studied by comparing Arctic

and Antarctic data. Vertical soundings, studies of absorption, drifts, atmospheric noise (G stations in Arctic) and

sierics (1 station in Spitzbergen), whistlers, and other phases

of Arctic ionospheric program are discussed. (Item 10. 3-3C,

Met. Abs.)--N. N.

C-247 Singer, S. Fred (Dept. of Physics, Maryland Univ. ), A ne?/

model of magnetic storms and aurorae. American Geophysical

Union, Transactions, 3S(2):175-1C0, April 1057. 14 figs. , 3

tables, 30 refs. , eqs. DW3, DLC. Also issued as Maryland

Univ. Physics Dept. , Contract AF 1C(600).103S, Technical Report No. 43, July 1G53. 20 p. 14 figs. , 3 tables in appendices. DWB--A new model for explaining S.C. 's (sudden commencements), magnetic storms^and the aurora is developed

and presented in a lucid manner. Other models are reviev/ed

(CHAPMAN, FERRARO and ALFVEN), observational evidence

liscussed^and the pre-3. C. bays attributed to high velocity

particles preceding the shock v/aves foUovv^ing 22-34 hrs after a solar eruption. The shock v/ave is retarded by the geomagn'Btic field, but accelerates as it enters the auroral zone and

produces polar S. C. 's. The decrease in the storm is due to

high velocity particles foUov/ing up to £ hrs after the shock

v/ave. The shock v/ave may help accelerate auroral particles.

(Item C. 4-27C, Met. Abs. )-M. R.

C-243 Stein, Sidney (Radio Propagation Lab. , Stanford, Univ. , Stanford, Calif. ), The role of F layer tilts in detection of

auroral ionization. Journal of Geophysical Research, Wash. , D. C, 33(2):3Cl-40^x, June 1953. 3 figs. , 15 refs. DLCAn important ionospheric mode for detection of pov/erful longrange auroral reflections at Stanford depends upon appropriate

tilts in the F layer to the north. Auroral reflections received

via this mode have been reported as originating from prevalent strongly reflecting ionized structures at great heights, bet Teen 300 km and 1200 km above the surface of the earth.

This interpretation is rejected as a plausible explanation of

the radio data. An explicit distinction is m.ade betv/een

these auroral reflections and newer classes of radio reflections observed at high and middle latitudes arising from field

aligned ionization in the S and F regions. (Item 10. 5-213,

Met. Abso ) --Author's abstract.

C-240 Stetson, Idarlan True, Auroras, radio field strengths, and

racent solar activity. Terrestrial Magnetism and Atmospheric

Electricity, 45(1):77-S3, March 1C40. 2 tables, 11 refs. , 4

figs. DLC--A record of recent results of studies of changes

i:i conditions for radio transmission before and after the occurr-inces of auroral phenomena. Data of field strengths of
83

WBBM's carrier wave at a frequency of 770 Kc comprise over

100, 000 measurements, covering ten minute intervals of night

to night continuous readings. A table giving data from 1C30

through 1G39 is included. --E. Z. S.

C-250 Stetson, Harlan True, A note on occurrences of auroras,

temperature changes and radio reception . American Meteorological Society, Bulletin, 23(l):21-23, Jan. K42. DLC--

Deals primarily with temperature relationships but refers to

ridio field strength during aurora. It is noted that abnormally

high field strengths persist in advance of the aurora. Subnormal field strengths persist for several days following the

auroral date. --E. Z. S.

C-251 Stormer, Carl, Sur un echo d'ondes electromagnetiques

c ourtes arrivant plusieurs secondes apres le signa emis; et

son explication d'apres la theorie des aurores boreales . (On

an echo of electromagnetic short v/aves arriving several sec- onds after emission of signals and its explanation by the

theory of aurora borealis. ) Academie des Sciences, Paris,

Comptes Rendus, 187(1G):S11-312, Nov. 5, 1C2G. DLCAn explanation of the phenom-enon observed by Jorgen Hals

at Bygdoy near Oslo, in the autumn of 1C27 is attempted,

based on simultaneous observations by Hals and the author,

of echoes arriving at various intervals of 3 to 15 seconds

and verified by van der Pol at the emitting station Philips

Radio Eindhoven. Referring to author's research on aurora borealis in 1G04 the echoes could have been originated in

tlie cosmic space beyond the moon's orbit. Matheiciatical

analysis proved, as early as 1C04, that electrical corpuscles coming from very far (from the sun for example) could

be deviated by an immense protrusion of the earth's magnetic field and unable to penetrate it, they could be reflected

again under more favorable conditions and being still strong

enough to cross the atmosphere they appear as echoes. Calculations ascertain the experimental results. --0. T.

C-252 Siormer, Carl, Short wave echoes and aurora borealis.

Nature, London, 122(3070:331, Nov. 3, 1C2C, DLC -.Describes the reception of delayed echoes and attributes the delay to solar stream of particles. The study of these delays

may throw light on electric currents in space outside the

e.irth and on their connection v/ith the aurora borealis and

magnetic storms. --E. Z. S.
C-253 Stormer, Carl, Kurzv/ellenechos, die mehrere Sekunden nach

dem Hauptsignal eintreffen, und wie sie sich aus der Theorie

dos Polarlichtes erklargn lasseri o (Short wave echoes arriving

several seconds after the transmitted signal, and how they

may be explained according to the theory on polar aurora. ) Naturwissenschaften, Berlin, 17(33) :643-351, Aug. 1£2&.

S figso , 3 refs. , eqs. DLC--An account of the auroral radio

echoes first observed by Jorgen Hals, Oslo, when listening

in on the short v/ave station PCJJ, Eindhoven, Holland. The

observations were subsequently verified by the author, van

der Pol, E. V. Appleton and others. The tentative explanation

o£ the phenomenon involves Birkeland's historical experiment

with the magnetic sphere. --W. N,

C-254 Stormer, Carl, tjber die Probleme des Polarlichtes. (On the

problem of auroras. ) Ergebnisse der Kosmischen Physik,

Leipzig, 1:1-86, 1931. 70 figs. , refs,, eqs. DLC--One of

the important contributions to our knov/ledge on auroras. A

series of photographs shows different auroral forms. Photographic equipment is briefly described. Determination of auroral heights shov/s frequency maxima for 101 and 106 km,

explained by atmospheric tides. A lengthy discussion is

devoted to the phenomenon of auroral rays illuminated by the

sun, and to other unusual form.s. Problems connected with

the auroral spectrum are only briefly mentioned, but a detailed summary is given of author's mathematical theory of

auroras, based on the equation of motion for charged corpuscles in the magnetic field of an elementary magnet, shov/ing

that there are certain parts of the space around the magnetic

earth (the ring form "torus space"), prohibited for electrical

corpuscles. An experimental verification was found by the

discovery of echoes of radio waves, reflected from the border

surfaces of the "torus space", which had been already produced in a laboratory experiment by BIRKELAND (ICOl). The

picture gets more complicated if gravitational forces are also

considered in the theory. (Item 4J-7G, Met. Abs. )--A. A.

C-255 Stonner, Carl, The polar aurora . Oxford, Clarendon Press,

1£55. 403 p. 213 figs. (incl. photos), numerous refs.

throughout, tables, additional refs. p. 400-403. (International Monographs on Radio, ed, by Sir Edv/ard Appleton and

R.L.Sm.ith-Rose). DLC (AC971. 377). Review in Royal Met.

Soc, Quarterly Journal, C2(3£l):115, Jan. 1956. --This is the

first substantial textbook on the aurora to be published in the

English language by the man who has become v/orld famous

for his life's v/ork of photographing the aurora and studying

its nature. The book could v/ell have consisted entirely of

t'le author's own findings v/hich resulted mainly from over 50

years of study of parallactic photographs which he himself
£0

made by a method which he devised and many others have

adopted. Hov/ever, there is an abundance of reference to

work of others in this field, as can be seen in the numerous

foot-references and the added references to recent literature

not cited in the text. The book is divided into two major

parts which deal with: I. the descriptive aspects and II. the

parely physical (atomic or molecular) and theoretical aspects:

The 32 chapters cover, among other subjects: Pt. 1: 1) forms,

2) geographical description and periodicity, 3) methods of observation and photography, 4) height determinations by visual

and 3) by photographic methods, 6) measurem.ents near the

auroral belt and 7) outside the auroral belt, 8) measurements

and observations in S. Norv/ay 1911-52, C) sunlit auroras,

10) intensity, 11) color, 12) auroral spectra, 13) spectra of

sunlit aurora, 14) radio waves (10 cm) from aurora, and brief

review of notable work Forsyth, Petrie and Currie), 15) cor- pi^scular currents outside atm.osphere, IS) radio echoes from

aurora observed at Jodrell Bank, Saskatoon, Canada; Kiruna,

S 'Teden and from Kjeller and Tromso, Norv/ay, 17) Doppler

studies of corpuscular stream, IS) absorption of corpuscular

rays by atmosphere, IS) emission of corpuscular rays from

s:in. Pt. II: 1) differential equations, 2) results from study

of differential equations, 3) families of orbits, 4) numerical

integration, 5) intuitive method of control, 6) results of numerical integration (ALFVEN's method), 7) application of

theory to laboratory experiments, 8) application of theory to

polar aurora, 0) limitations of theory, 10) approach of theory

to actual conditions, 11) other theories (CHAPMAN-FERRARO,

MARTYN and ALFVEN), 12) other applications, allowed and

forbidden regions, solar, magnetic and coronal relations, etc.

A good author and subject index and scores of excellent original photographs are included. This is a most satisfying

book — one that has been awaited 25 years. (Item llA-19,

Met. Abs. )--M. R.

C-256 Stoffregen, W. (Uppsala lonos. Obs. , Res. Inst, of Natl,

Defence), Radio reflections on lov7 frequencies from 75-CO

km height during intense aurora activity. Journal of Atmospheric and Terrestrial Physics, London, 13(1/2):187.16C, Dec.

lt5G. 2 figs. , 4 refs. DLC--Observations with a nevv type

of ionosphere recorder constructed at the Uppsala Ionospheric

Observatory and installed at Uppsala and at the ne\7 Ionospheric station at Lycksele (34 37 'N and 18°45'E) are presentei. The occurrence of low frequency reflections ND from

about SO km level during strong auroral activity is illustrated on a diagram. Photos of ionosphere records show aurora E

reflections as well as reflections from about SO km level on

frequencies down to 0.33 Mc/s. (Item 12A-232, Met. Abs.)

--O.T.
C-257 Stoyko, Nicolas and Jouaust, Raymond, Sur la propagation

des ondes radio^lectricrues courtes dans la region des aurores

polaires , (On the propagation of radio electric short waves in

the region of polar auroras. ) Acadeniie des Sciences, Paris,

Comptes Rendus, 201(2): 133-134, July 8, 1935. DLC--An

analysis of measurements at Paris Observatory of short wave

signals of a length of 37. 08 m emitted from the station Honolulu is presented on the verification of the hypothesis whether anom.alies observed on short v/ave propagation received at

Tokyo from Washington were due to interference of auroral

activity of the great circle betv/een them. The signals received at Paris cross Greenland due to the magnetic north pole.

Nevertheless they were observed as being of the same length

as those of San Francisco which are a retransmission. Calculating a velocity of 270, 200 km/s for the speed of propagation between Honolulu and Paris, it is proved that the emissions of daytime related to those of nighttime received at

Paris showed a systematic delay of 0. 0518. The direct wave

transmission is completely explainable by the Sun. It is probable that the v/aves received at Paris did take the great circle Paris—Honolulu, which v/ould be a so-called super -propagcition. --O.T.

C-258 Stranz, Dietrich, Eng begrenzte lonisationswolken in 125 1cm

Hohe wahrend einer Nordlichtstbrung . (Isolated ionization

clouds at height of 125 km during an auroral disturbance. ) Archiv der elektrischen Ubertragung, 4:213-213, (1C50). 3 figs.,

table. --From 22h on Sept. 15, 194S to 1 h on loth at Go'teborg

3 MHz waves showed isolated ionization clouds beginning at

200 km and descending to 125 km. Attributed to a bundle of

deflected corpuscular rays. There were pulsations of 3-5 sec

in intensity of echo= This observation raises a number of problems = The magnetic disturbance vector is analyzed^ (Item

2.7-38, Met. Abs. )-C. E. P. B.

C-259 Sugiura, Masahisa; Tazima, Minoru and Nagata, Takesi,

Anomalous ionization in the upper atmosphere over the auroral

z one during magnetic storms. Japan, Science Council. Ionosphere Research Committee, Report of Ionosphere and Space

Research in Japan, Vol. 3, 1952, Unchecked. --The depth of

penetration and the rate of ionization of protons of extra terrestrial origin v/ere determined on the basis of the model atmosphere proposed by N. C. Gerson, It was found that the

energy of protons, which play an important part during magnetic storms, is several hundreds KeV, or 1 x 10^' crnVsec in

velocity. The rate of ionization of protons of this energy has

a pronounced maximum near the bottom edge of the range of

penetration. The life time of the ionized state vras found to

be of the order of a few minutes, ten seconds. The density of
precipitating protons required to maintain the ionized state

v/as roughly estimated at 1 proton/cm^ or less, which can be

consiiered as reasonable values. An explanation was proposed for the violent and rapid variations in magnetic field

observed in and near the auroral zone,

C-260 Taylor, Koyt A. and Young, L.C., Studies of high- frequency

radio wave propagation. Institute of Radio Engineers, Procoedings, 13(5):561-578, May 1L28. 7 figs. , Stables, refs.

DLC --Quantitative measurements of "round-the-v/orld" echoes

at IS, 700 and 19, 000 kcs rr.ade at the Naval Research Laboratory, Bellevue, Anacostia since 1£27 are discussed. Tabulated data from stations in the U. S. A. and Europe showed ';-.o- c-iUed direct signals "v/hich appear to violate the skip distance law". A possible explanation is given, however, v/ith

reluctance "to entertain the idea of an additional layer V7ith

extremely high electron concentration and of so great a height,

namely 1, 400 km., which would be necessary to explain the

path retardations on these nearby echoes by reflections and

multiple reflections from, such a layer". --W, N,

C-231 Thayer, Roger E. , Radar echoes from the aurora borealis . Cornell University, Electrical Engineering Dept. , June 1£52.

Thesis. Unchecked.

C-232 Thayer, Roger E. , Auroral effects on television . Institute

of Radio Engineers, Proceedings, 41(1):1S1, Jan. 1&53. 3

figs., 3 refs. DLC --During aurora displays, horizontal, indistinct, black bands appear on television screens in Ithaca,

N. Y. They have been noticed on TV channels up through No.

S(S2-C8 m.c/s). These appear on channels carrying no picture

signals as well as those that do. Antenna rotation indicates

that these disturbances are com.ing from, the auroral zone. C-233 Thomas, L. K. , Short wave echoes and the aurora borealis.

Nature, London, 123{30G2):16S, Feb. 2, 1929. DLC -The ex- planations for delayed echoes given by APPLETON and VAN

DER POL are briefly reviev/ed. The suggested explanation

would seem to be untenable unless it is assumed that 2>- is

much longer than believed. If 7^ v/ere 30 tim.es as large the

m.inimum- reduction for a 10 sec delay v/ould be to e"^- *^ of its

initial value, --E. Z. S.

C-234 Tilton, Edward P. , On the very highs. QST, West Hartford,

Conn., 23(3):41-43^, 1944. DLC--Auroral effects on radio

v7dves at 28, 43-50, 5S and 112 Mc are discussed in relation

to radio amateur communication. --W. N.
93

C-265 Tilton, Edward P. , Long distance communication over northsouth paths on 50 Mc/s. International Council of Scientific

Unions. Mixed Commission on Ionosphere, 2nd Meeting,

Brussels, Sept. 1950. Proceedings p. 119-120, publ. 1951.

ref. DWB--During sunspot cycle peak of 1947-48, radio amateurs made discoveries regarding 50-54 Mc/s communication

fiDm Europe to South Africa and from. North America to South

America, Daily records made in Feb. , March, Oct. and Nov.

1G49 and Feb. -March 1S50, shov/ed that no communication

WviS possible between U. S. A. north of 40 N and South America

except on the day following a visible aurora or ionospheric disturbance. (Item 5C -137, Met. Abs. ).-M. R.

C-266 Ulrich, Franklin P. , Auroral magnetic storms and difficulties

in radio reception, 1924-1925. Terrestrial Magnetism and

Atmospheric Electricity, Wash., D. C, 30(3): 150-151, 1925.

DLC--The results of observations at the Sitka Magnetic Observatory, U. S. Coast and Geodetic Survey are discussed.

The appearance of aurora was reported ten times from radio

s':ations during the reception of messages. On these ten oc- casions difficulty in reception was experienced only three

times, once when the aurora v/as bright, once when the aurora V'/as faint and once when the aurora was brilliant. On the

seven occasions ,/hen no difficulty was experienced the aurora was faint on two occasions, bright on three occasions,

and brilliant on tv/o occasions. From the observations for

1C23-1G24 no definite conclusion can be drawn as to difficulty

of radio reception during aurora. The evidence from the 1024-

1925 observations would indicate that the aurora does not in

t'le majority of cases cause any static. Kov/ever, it is stated

that a great number of observations should be made before any

conclusion can be attempted. --E. Z. S.

C-237 Ulrich, Franklin P. , Auroral observations, radio reception

and magnetic conditions at the Sitka Magnetic Observatory,

Ajigust 1927 to June 1C23 . Terrestrial Magnetism and Atmospheric Electricity, Wash., D. C, 33(3): 132-164, 1928. table.

DLC--This report is a continuation of the investigation begun

in 1923, of the relation between aurora and the earth's magnetic field and of the effect of the aurora and magnetic conditions upon radio reception. The effects of aurora on radio re- ception are noted. Aurora was reported 58 times as follov7s:

34 faint; 21 bright; 3 brilliant. On the 34 times that faint aurora was reported reception was poor 9 times, fair 10 times,

and good 15 times. On the 21 times that bright aurora was

reported radio reception was none one time, poor 2 times,

fair 6 times, and good 12 times. Three brilliant auroras oc- curred and at those times reception v/as poor, fair and good

once each. The observations for this year seem to indicate
S4

that good reception is very much more apt to occur than poor

reception during a bright or faint aurora. In former years the

results show that during a faint or bright aurora there was difficulty in radio reception about the same number of times as

there were no difficulties. In former years the results were

based on reports of cables and radio combined, v/hile this year

or.ly reports of radio y/ere considered. These results show that aurora causes poor reception in cable transmission, while in

radio reception no difficulties are experienced in the majority

oi cases. The relation between earth's magnetic field and

radio reception is also discussed. --E. Z. S.

C-268 Ulrich, Franklin P. , Auroral observations, radio reception,

and magnetic conditions at the Sitka Magnetic Observatory,

July lC28-June 1C2G . Terrestrial Magnetism and Atmospheric

Electricity, Wash., D. C, 34(4) :301 -302, Dec. K2£. table.

DLC--This report is a continuation of the reports begun in

1G23 at Sitka Magnetic Observatory. It is noted that radio re- ception during the past year v/as much poorer than during the

previous year. --Ec Z. S.

C-2o2 Ulrich, Franklin P. , Auroral observations and magnetic conditions at the Sitka Magnetic Observatory. Alaska, July 192C

t o June 1C30. Terrestrial Magnetism and Atmospheric Electricity, Wash., D.C., 36(3):23G-240, 1&31. DLC -This paper

is a continuation of the reports begun in 1£23, of the investigation concerning the relation betv/een aurora, the earth's

magnetic field and radio reception. The investigation of the

earth's magnetic field and its relation to radio reception v/as

discontinued with the report last year because of the lack of

proper sensitive instruments and because this investigation is

being taken up elsewhere in a more detailed manner than -v/as

possible at this observatory. --E, Z. S.

C-270 Unwin, R, S. and Gadsden, M. (both, IGY Station, Dept, of

Sci. and Ind. Res. , Awarua Radio, Invercargill, New Zealand),

Determination of auroral height by radar. Nature, London,

130(4300) :143C- 1470, Dec. 2S, 1S5'7. 2 figs. , 3 refs. DWB,

DLC --Auroral radio echoes observed by radar operating at 53

Mc/s at Bluff in the South Island of Nev/ Zealand. A v/ell defined aerial lobe pattern is obtained by interference of the direct and sea-reflected rays up to an angle of elevation of about

10 . The polarization is horizontal resulting in deep minima

betv/een lobes. A range-time record of auroral echoes and a graph of observed heights of auroral echoing regions versus observed ranges are presented. The region producing the echoes

occurs as an approximately horizontal sheet at an average

height of 110 km. (Item CPI-101, Met. Abs.)-I.L.D.
C-271 Unwin, R. S. (IGY Station of Dominion Physical Lab. , Dept.

of Sci. & Indus. Res. , New Zealand), The geometry of auroral ionization. Journal of Geophysical Research, Wash. , D.C., 33(3):501-506, Sept. 1958. 5 figs. , 7 refs. DLC--

New evidence is presented which shows that VHF radio echoes

from auroral ionization are reflections from aspect-sensitive

columns aligned with the earth's magnetic field. Previous ex- perimental data, interpreted in terms of a distribution of ionization along a line of magnetic latitude, are shown to be consistent v/ith this hypothesis. (Item 10.5-343, Met. Abs. )--

Author's abstract.

C-272 Urmin, R. S. (D. P.L. Auroral Station, Dept. of Sci. & Indus.

Res. , Av/arua Radio, Invercargill, N. Z. ), Movement of auroral echoes and the magnetic disturbance current system. Nature, London, 183(4637): 1044-1045, April 11, 1C5£. 2 figs.,

11 refs. DWB--This preliminary report on radar investigations

since 1958 at Invercargill is part of a research program of the

Dominion Physical Laboratory of the New Zealand Dept. of

Scientific and Industrial Research. The radar operating at 55

Mc/s has its antenna beam orientated alternately on geographical bearings of 175 for six min and 240 for four min to avoid

possible 210 centered echoes. A histogram of all absolute

directions observed in the period May-August features movement of echoes in terms of number of occurrences vs. direction, those with an E or W component in direction vs. universal time, and average velocities in the 800-1200 km range vs. Macquarie Island K-index. The echoes came from a layer

varying in thickness up to 25 km, and in the altitude between

110 and > 120 km. (Item 11. 6-121, Met. Abs. )-W. N.

C-273 Unwin, R. S. (D. P.L. Auroral Station, Awarua Radio, Invercargill, N, Z. ), Studies of the upper atmosphere from. Invercargill. Nev/ Zealand. Pt. 1, Characteristics of auroral radar

echoes at 55 Mc/sec. Annales de Geophysique, Paris, 15(3):

377-3G4, July/Sept. 195C. (For Pts. 2 and 3, see refs. C-IOS,

lOS). 13 figs, , 2 tables, 13 refs. French and English summaries p. 377. DLC --Observations v/ith a 55 Mc/sec radar

e iuipment in the south of New Zealand are discussedo Echoes

associated with magnetic activity are recognized as being

similar to the auroral echoes that have been observed in the

Northern Hemisphere over the past ten years. They may be

divided into four major types v/ith distinct differences in appearance and times of occurrence. The height and thickness

of the region producing the echoes is significantly different

for each type, though most originate from, the 110-120 km level.

Although recorded during the second half of 1957 at a time of

high solar activity, the frequency of occurrence appears to be

much greater than at comparable geomagnetic latitudes in the
c/-o

Northern Hemisphere, though diurnal variations are similar.

Systematic motions of the ionized regions are indicated, with

a pronounced northward component before local magnetic midnight, and southward after. (Item 11. 6-116, Met. Abs. )--

Author's abstract.

C-274 Van der Pol, Balth, Short wave echoes and the aurora borealis.

Ndture, London, 122(3084) :G78-87£., Dec. 8, ]£28. DLC--

Various explanations for the delay of short wave echoes are considered. The length of the delay may be governed by the

gr-idient of the electron density. Our view is that the "group"

is compressed and 'bottled' for some time in those regions

where the group velocity approaches zero. --E. Z. S.

C-275 Vassy, Etienne (Prof. Faculty of Science, Paris), Physique

de 1 'atmosphere. Tome I . (Physics of the atmosphere. Vol. 1.

)

Paris, Gauthier-Villars, 1956. Ch. 1. Les aurores polaires.

(Ch. 1, Polar auroras. ) pp. 61-167. 75 figs. , C tables, eqs.

DLC (QCS30. V3)--The chapter on auroras occupies a major

portion of this excellent text, giving perhaps the most complete survey of existing knowledge in this field. The material

is treated in five sections. In Sec. A, descriptive phenomena,

such as auroral forms, brightness, color, distribution in space

and time, etc. , are discussed, and relations to solar activity

and atmospheric tides are considered. Sec. B contains a detailed summary of the results of auroral spectroscopy. Sec. C

deals with radio emission and reflection from auroras. Sec. D

is a review of various auroral theories, namely, the theory of

corpuscul^jr radiation of atmospheric origin, theories of BIRKELA.ND, STORMER, DAUVILLIER, CHAPMAN-FERRARO, ALFV£N, and others. Finally, in Sec. E, applications of results

of auroral research to investigations of upper atmospheric composition, temperature, density and pressure are described. The

chapter is illustrated throughout with representative data obtained by various authors. (Item 12B-164, Met. Abs.)--G.T.

C-276 Vegard, Lars, Die Deutunq der Nordlichterscheinunqen und

die Struktur der lonosphare. (Explanation of auroral phenomena

and the structure of the ionosphere. ) Ergebnisse der Exakten

Naturwissenschaften, 17:229-231, 1938. 10 figs. , 9 tables,

109 refs. , 14 eqs. DWB--This is a major treatise on all phases

of auroral physics and theory bringing the author's 25 years of

work up to date and summarizing critically over a hundred v/orks

hy other authors. The research embraced by this reviev/ falls

into t'.Yo categories: 1) the form, geographic distribution, time

variations, relation to magnetic storm.s, earth currents and cos- mia phenomena outside the earth's sphere of influence. These

problems are kept uppermost in the author's presentation and

are integrated by a single theory; 2) the physics of the aurora
97

as determined mainly from^ recent research on the spectra of

the aurora, radio reflections from the ionosphere and the night

airglow. The scores of auroral lines identified at the time of

this v/ork are tabulated and their m.eaning in terms of the composition and ionization of the atmosphere are specified. Resulting theory as to origin of aurora is treated in detail. The

bibliography covers the period 1896-1S37. (Item 5C-91, Met=

Abs.)-M.R.

C-277 Vegard, Lars, Vorqanqe und Zustande in der Nordlichtregion.

(Processes and conditions in the auroral region. ) Geofysiske

Publikasjoner, Oslo, 12(5), 1938. 23+ p. 4 figs. , 4 tables,

2 plates, 34 refs. , 5 eqs. DLC--A fundamental monograph

giving the solution, or attempted solution, to a large num.ber

of problems concerning the physical properties of the aurora and the chemistry and physics of the ionosphere, from evidence gained through analysis of numerous auroral spectrograms in connection with magnetic, sunspot and radio propagation data. A few of the main points treated are: 1) the ex- planation of the types of the red (relative to green) bands

(colors) at the lovirer and upper portions of rays, 2) the temperature (and density) distribution at 25-150 km, and 3) the

intensity distribution and changes therein (relative and absolute). Over 100 spectral bands %vere obtained by the author

and his colleagues, and over SO of these identified. Nev/

bands recently discovered are listed and discussed. (Item

5C-33, Met. Abs.)-M.R.

C-270 Vilbig, F. ; Beckmann, V. and Menzel, W. , Uber Vorgcinge

in der lonosphare, wahrend des Nordlichtausbruches am 25

Januar 193G in mittleren Breiten (52 ) festgestellt wurden.

(Ionospheric processes as established during the aurora of

Jan. 25, 1938 in the middle latitudes (52 ). ) TelegraphenFernsprech-Funk und Fernseh-Technik, 27(3):73-81, March

1938. 4 figs. , table, 3 refs. , eq. DLC--The results of echo

recordings as obtained in Pieskovv at Scharmlitzelsee from

18. 00 Jan. 25 to 0800 Jan. 27, 1938 on 86 m wavelength are presented and discussed. It was found that aurora at this

latitude has tv/o different reflecting layers, one of VkJ-hich

penetrated the F layer, reduced the ionization present, caused

a powerful sudden increase of the magnetic disturbance foUov/-

ed by penetration of the radiation into the E layer with subsequent ionization. The short v/ave reception at Station Beelitz

was characterized by the nightly after effect propagated from

the pole. The latitudinal effect on fading of these waves,

mainly propagated via the F layer, was distinct. --W. N.
C-279 Watkins, C. D. (Jodrell Bank, Univ, Manchester), The height

and geometry of auroral radio echoes . Journal of Atmospheric

and Terrestrial Physics, N. Y. , 1G(1):1-C, 3ept„ 1G30. 7 figs.,

10 refs. DLC--The geometry of auroral radio echoes detected

at Jodrell Bank with low sensitivity equipments (wave length

4 m) is discussed. It has been found that echoes are only obtained from regions where the line of sight is -./ithin 1 of perpendicularity to the lines of force of the local magnetic field

at a height of about 110 km, •vith a spread in height of the echo

regions of not more than 5 kni. This conclusion is in disagreement with the original interpretation of BULLOUGII and KAISER

(1954) (See ref„ C-43), who proposed that the range azimuth

characteristics of the echoes arose from the alignment of the

reflecting regions along geomagnetic latitudes. The nevT re- sult agrees -veil with other observations carried out at Jodrell

Bank on a -wave length of S m and with observations of the aurora australis carried out in Antarctica and New Zealand on

shorter wave lengths. It is suggested that small differences

in the location of the echo-regions arise from changes in the

height of the regions and distortions of the lines of force during magnetic disturbances. (Item 12A-243, Met. Abs. )--

Author's abstract.

C-230 Watkins, CD. (Nuffield Radio Astronomy Lab, , Jodrell Bank,

Manchester Univ. ), The magnetic storm-time variation of radio

s^.ar scintillations and auroral radio echoes. Journal of Atmospheric and Terrestrial Physics, London, lC(3/4):23C-2£2, Dec.

IQSO. 3 figs. , 3 refs. DVirB--An examination of the observations made at Jodrell Bank during 1C55-1?5C sho.7s that about

oO percent of all the series of radio echoes recorded v/ere preceded by a sudden commencement. This suggests that echo

activity is m.ainly related to s„ c. type magnetic storms. The

srorm-time variations of echo incidence and mean scintillation

rate are graphically presented. The variation of echo incidence is also plotted for the periods Jan. 1C55 - June 1C57 and

July 1C57 - Dec. 1C53 separately and combined, and the associated features are discussed. --I. S.

C-201 Watkins, CD. (Royal Radar Estab. , Malvern, Worcs. ), Temporal variations of auroral radio-echo activity in sub-auroral

latitudes. Journal of Atmospheric and Terrestrial Physics, London, 20(2/3): 140-140, March 1931. 6 figs. , 16 refs, DLCLov7 po'/er radio-echo equipments have been continuously operated for several years recording observations of auroral ionization. The results have been examined for the follov/ing temporal variations of activity: diurnal, 27 day, seasonal, and

11 year. The timiC delay betv/een the occurrence of class 3

solar flares and subsequent echo activity has also been investigated. It is suggested that the bimodal diurnal distribution
possibly arises from the condition of specular reflection v/hich

controls the detection of echoes and from the north-south motions of visual auroral forms. The general features of the other

periodicities are found to be little different from the well known

ones of geomagnetic disturbance. --Author's abstract.

C-282 Watkins, CD. (Royal Radar Estab. , Malvern, Worcs. ), Auroral radio echoes and magnetic disturbances. Journal of

Atmospheric and Terrestrial Physics, London, 20(2/3); 131 -139,

March 1961. 6 figs. , S refs. DLC--It is shown that the probability of detecting auroral radio echoes with a low sensitivity

equipment at Jodrell Bank increases with the value of the magnetic K index, being 100 percent for local K indices of 8 and S

There is a close correlation betv/een east-west moving echo re- gions crossing the meridian of Eskdalemuir, Scotland, and magnetic disturbances recorded there. A comparison of magnetograms obtained at Lerwick and Eskdalemuir (north and south of

the echo regions respectively) show that, in general, during

the occurrence of echoes, the current systems giving rise to

the magnetic disturbance are situated south of Lerwick and

north of Eskdalemuir and thus near the echo regions. An in- ' vestigation of the location of visual auroral forms during the

occurrence of echoes shov/s that they also are mainly situated

in this region. The results confirm the suggestion of BULLOUGH et al.*'(1957) that magnetic disturbances are closely

related to regions of ionization which move approximately

along magnetic parallels of latitude and v/hich can be detected

with radio echo equipments. (* See ref. C -43) --Author's abstract.

C-2S3 Wax, Nelson, A note on design consideration for a proposed

auroral radar. Goteborg, Sv/eden. Chalmers Tekniska Kogskola, Handlingar, No. 182, 1957. 13 p. 10 refs. , 3 eqs.

DLC --Examines the uses of a range-gated pulsed Doppler radar

with filters and narrow beam widths. To that effect, the pertinent results of auroral studies are summarized, followed by

some objectives and recommendations involved in the radar

design discussed in comparison with MC NAMARA's system.

Author's system, based on the significance of the fine struct- ure of auroral echoes, pursues the fine azimuthal resolution

and V7ide scanning ability. The principle outlined fundamentally exploits tested techniques and appears practical. --W. N.

C-284 V/eiss, A. A. and Smith, J. W. (both, Dept. Phys. U. of

Adelaide), Radar record of an aurora at Adelaide. Journal of

Atmospheric and Terrestrial Physics, London, 12(2/3) :217. 210,

195C. 2 refs. DLC-The aurora of Sept. 13, 1G57 was visible

throughout Australia and was observed from Adelaide. Facts

gathered were similar to those observed by HARANG and LANDMARK in 1954 (See ref. C-127). The auroral echoes were first
100

heard from 1655 to 1927 LT and the aurora was first seen at

the limiting slant range of 900 km. The echoes varied con- siderably during the course of the aurora. They first appeared

with small amplitude at maximum range. The amplitude then

increased until the range reaches a minimum value and thereafter decreased again as the range increased. (Item 10. 6-127,

Met. Abs.)"N. N.

C-285 Wells, H. W. , Polar radio disturbances during magnetic bays . Terrestrial Magnetism and Atmospheric Electricity, Wash. , D.C., 52(3):315-320, Sept. 1G47. 4 figs. , 4 refs. DLC--A

comparison of ionospheric and magnetic records at College,

Alaska, shows that marked increases in ionospheric absorption, producing partial to complete radio blackouts, occur during magnetic bays. The period of the absorption is limited to

the duration of the magnetic bay. Particle bombardment is suggested as the cause of polar region radio blackouts and sporadic E ionization. The observations indicate that these absorption effects occur simultaneously over wide areas of

^

500 miles diameter.

C-286 Whale, H. A. , The effects of ionosphere irregularities and the

auroral zone on the bearings of short wave radio signals . Journal of Atmospheric and Terrestrial Physics, London, 13-

(3/4):258-270, 1959. 8 figs. , 12 refs. --The nature of the observed variations in the received bearing of the signals from

short wave radio stations at various distances is discussed

and the origins of some of the effects are suggested. The

major part of the daily variation of bearing of stations up to

about 15000 km distant arises from the refraction of the ray in

the F 1 region when it is reflected from the F2 region. A discussion of the curving of the ray path by successive small

changes of direction at each reflection point leads to the concept of an antipodal area replacing the geometrical antipodal

point. The large changes in direction associated with the passage of a ray through the auroral regions suggest a method of

plotting the shape of the absorbing parts of the auroral zone

by observations at a place remote from this zone. A sample

plot obtained by this method is presented. (Item 12.4-357,

Met. Abs. ) --Author's abstract.

C-2S7 Whatman, A. B. and Flamilton, R. A. , High latitude radio observations . Physical Society of London, Proceedings, 50(278):

217-232, March 1938. DLC-The Oxford Univ. Arctic Expedition, 1935-1936 to North-East Land (80°23'N, 19°31' ) observed no special conditions in the ionosphere during overhead

auroras, nor any significant change of absorption. --W. N.
101

C-288 White, F. W. G. ; Skey, H. F. and Geddes, M. , Radio fadeouts, auroras and magnetic storms . Nature, London, 142-

(35SC):289, Aug. 13, 1938. 3 refs. DLC- A brief letter suggesting that it would appear in high latitudes a radio fadeout

may be due to ultraviolet radiation emitted during an erruption

or may also be due to ionization by the particle radiation causing the auroras. Observations made in South Island, New Zealand Jan. 20-22 and Jan. 24-26, 1937, are discussed. The first

of these periods began with solar activity and poor reflection

from wireless waves from the ionosphere. On beginning observations of the reflection of waves from the F2 region on Jan.

20 no reflected wave could be observed. Magnetic conditions

were moderately stormy and an aurora was observed over New

Zealand. Similar events occurred during the second period.

Ionospheric conditions in Christchurch appear to be similar to

those observed at Tromso by APPLETON (1G37) during a magnetic storm and auroral display. It is found that "no echo"

periods often occur in the morning following a night of magnetic and auroral activity. --E. Z. S.

C-289 Winckler, J. R. ; Peterson, L. ; Hoffman, R. et al. (all. School

of Physics, Univ. of Minnesota), Auroral storm of Feb. 10-11,

1958. American Geophysical Union, Transactions, 39(6): 1225-

1230, Dec. 1958. 3 figs. DWB, DLC--During the night of

Feb. 10-11, 1958, a very large auroral storm occurred. The

storm and other related phenomena were especially well observed and reported, both visually and by a number of instrumental techniques. Balloon-borne instruments at Minneapolis

detected two groups of strong X-ray bursts during the storm.

These coincided v/ith two large magnetic bays (increases or decreases in the intensity of magnetic-field components, re- presented by bay-like indentations on graphs showing variations of magnetic intensity with time); with strong absorption

of radio noise; and with the passage across the zenith of a very large amount of auroral luminosity. A cosmic ray decrease also accompanied the storm. The University of Minnesota workers believe that these terrestrial disturbances

were associated with the earth's entry into a large cloud of

solar gases that may have originated in a solar flare occurring about a day earlier. (Item 11. 1-314, Met. Abs. ) --Authors' abstract.

C-290 Yeh, K.C. (Univ. of Illinois) and Villard, O. G. , Jr. (Stanford Univ. ), Fading and attenuation of high-frequency radio

waves propagated over long paths crossinq the auroral, temperate and equatorial zones . Journal of Atmospheric and Terrestrial Physics, N. Y. 17(4): 255-270, Feb. 1960. 12 figs. , table, 22 refs, DLC--This investigation is primarily concerned

with the fading and attenuation of high frequency radio signals
102

propagated over a long path crossing the auroral zone. The

fading of high frequency signals propagated over non-auroral

paths of comparable length has also been studied, and some

new results are obtained. The principal fading and attenuation measurements on which these conclusions are based were

carried out in Aug. 1957. For the auroral paths, there is no

diurnal variation in fading speed except for a distinct minimum

in time interval 1330-1900 PST, during which time the fading

speed has little apparent dependence on magnetic activity

along the path. In other time periods a positive correlation

between magnetic activity and fading speed is found. It is

suggested that the period of minimum fading speed is a conseqlience of the existence at that time of the kind of propagation mode made possible by ionospheric tilts. Attenuation

over the long auroral-zone path is found to be associated with

'polar blackouts' as indicated by the absence of returned echo

in vertical sounders located along the path. The percentage

association varies with the location of the station relative to

the path. This variation is consistent with the inferred propagation modes. It is found that during the hours 1330-1900 PST

tlie attenuation cannot be attributed to the absorption that

gives rise to blackouts as it can in the other hours. This is

also explainable on the basis of the postulated tilt-mode propagation. Similar observations for temperate latitude and

transequatorial paths of comparable length indicate that there

is strong diurnal variation in fading speed. Some plausible

explanations are offered. (Item 11.10-188, Met. Abs. )--

Author's abstract.

C-291 Zennek, J., lonosphare III . (Ionosphere III. ) Ergebnisse der

Exakten Naturwissenschaften, Berlin, 22:263-321, 1949. 47

figs. , table, 125 refs. , 23 eqs. DLC--This comprehensive

discussion is devoted to the propagation of radio waves in the

ionosphere including the influences on radio waves of the sun,

meteors and aurorae. The discussion is arranged under the

following main topics properly subdivided: (A) Experimental

equipment; (B) Theories of electro-magnetic wave propagation

in the ionosphere; (C) Normal state of ionization; (D) Abnormal E layer; and (E) Ionospheric disturbances. A good bibliography containing 125 pertinent references arranged alphabetically by authors is included. --W. N.
103

ANONYMOUS

C-292 Auroral display and radio disturbance. Nature, London,

139(3512) :318, Feb. 20, 1937. DLC--A brief note under the

heading "News and Views". The occurrence of an aurora on

Jan. 7 is confirmed by Mr. W. N. Craig of The Manse, Fortrose, Ross-shire. Mr Craig, who was listening on the 14 Mc

amateurs band, found that reception from long distance stations in South Africa and on the west coast of America, which

was good at first, suddenly deteriorated so as to render the

signals practically unintelligible by a very rapid flutter. He

found that a conspicuous auroral display was in progress at

the time. Magnetic traces recorded at the Greenwich magnetic station at Abinger show distinctive movements at the

same time. --E. Z. S.

C-293 Exploring the ionosphere. News of Norv/ay, Wash., D. C. , 11(41):162, Nov. 18, 1954. DLC- -Brief news report outlining

the plans for Norwegian participation in the International Geophysical Year, 1957-58. The Aurora Borealis Institute at

Tromso will be the center of investigations mainly concerned

with ionospheric soundings and auroral research. Other institutes will participate and new facilities v/ill be added to

those available at Spitsbergen and Bjomoya (Bear Island).

(Item 6. 9-22, Met. Abs.)..G.T.

C-294 Poliamoe siianie 21-22 ianvaria 1957 goda . (Aurora of Jan.

21-22, 1957.) Priroda, Moscow, 46(12):S3-85, Dec. 1957.

photo. DLC --This is a review of information on the aurora described by a number of eye witnesses from the Moscow, Sumy

(Ukraine), Yaroslavl and Murmansk Oblasts and mailed to the

Murmansk branch of NIZMIR (Scientific Research Institute of

Terrestrial Magnetism, Ionosphere and Radio-wave Propagation).

The aurora was an outstanding geophysical phenomenon. Its

origin was linked with an increase of solar activity. Its characteristic feature was the pre-eminently red color in more southem regions, which indicates its great height and its increased

intensity. The aurora was accompanied by a very intensive ionospheric-magnetic disturbance and an interruption of radio communication on almost all lines. (Item 10. 5-341, Met. Abs.)--

A. M.P.
1'34

C-2G5 Radio echoes from aurora . British Astronomical Association,

Journal, 57(3):23£, Dec. 1947. DLC--Brief note on echoes observed //ith 46 Mc/s and 72 Mc/s equipm.ent, Aug. 15-13, at

Jodrell Bank Experimental Station. The measured range of the

echoes -vas 480 km. The electron density apparently betv/een

2. 6 X 10-^ and 3. 5 X 10^^ per c. c. is some 100 times greater

than the normal local electron density during night. --"W. N.

C-2G6 Sho.v model aurora . Science Newsletter, V/ash. , D. C,

67(20) :308, May 14, 1955. DLC --Describes an experim,ental

arrangement developed by WILLARD H. BENNETT of the Naval

Research Laboratory in Washington. A small model earth is

bombarded by electrons inside a vacuum tube. The existence

of a ring current as first postulated by CHAPMAN, FERRARO

and MARTYN is demonstrated in this experiment. It also

shows a simultaneous appearance of auroras in both hemispheres. (Item 7. 8-271, Met. Abs. )--G. T.

ADDENDUM

C-297 Chamberlain, Joseph W. (Yerkes Obs. , Univ. of Chicago),

Physics of the aurora and airqlo v . N. Y. , Academic Press, 1G31.

704 p. Numerous figs. , tables and eqs. Bibliog. p. EGC-370.

(International Geophysics Series, ed. by J. Van Mieghem, Vol.

2) DLC, DV7B (M21C443ph) -Chapter 3 (p. 217-243) of this ne,y

and exceedingly thorough reviev^ of the entire field of the physics of the aurora, airglo/7 and t//ilight emissions, gives a two part summary of recently derived kno /ledge of the radio

aurora: 1) the observed characteristics: distinction between auroras and radio auroras; types of echoes, location of radio auroras, periodic variations, motions of ionization areas, polarization, sensitivity and echo strength, and relationships with

geomagnetic storms, fields, etc. , and 2) theory of auroral re- flections, geometry, critical and partial reflections from a large surface, scattering by small variations in ionization, and

various mechanisms. The radio aurora (Collins and Forsyth

1959) designates ionization associated with auroras permitting

radio reflections at VHF and UHF (30-3, 000 Mc/sec) bands.

The aurora, //hich is visual (emitted), is an associate phenomenon with the same basic origin, but not always occurring

simultaneously. Radio auroras go to greater heights and depths

in the atmosphere than do auroras, and occur in day as well as

night tim.e, v/hereas certain forms of auroras can be seen at

times and at aspects .vhich do not correspond to radio auroral

observation. R good number of references to literature on radio

and radar auroral studies are cited. Other chapters give basic

information up to 1960 on spectroscopy, photochemistry, etc.

"M.R.
105

AUTHOR INDEX

Aarons, Jules C-1, 118

Agy, Vaughn C-2-S

Alfven, Hannes C-7

Appleton, E.V. C-0

Arkhangel'skii, B. F. C-9

Arnold, P.N. C-224

Aspinall, A. C-10

Bailey, D. K. C-11

Bailey, V. A. C-12, 13

Barbier, Daniel C-14

Barlov/, E. W. C-15

Basler, R.P. C-225

Bates, Howard F. C-16, 17

Beckmann, V. C-278

Bell, J. D. C-8S

BcUcharabers, Y/.H. C-19

Belon, A.E. C-139

Berg, R.I. C-167

Besprozvannaia, A. S. C-79

Bhattacharyya, B. K. C-20

Bird, L.E. C-147

Birfel'd, la. G. C-21, 22

Birkeland, Kristian C-24

Blevis, B.C. C-25, 23

Bontch-Brue vitch, M. A. 0-27

Booker, Henry G. C -28-32

Bost..7ick, Vailiam E. C-2C1

Bouchard, Jean C-33

Bowles, K.L. C -34-39

Braaten, A.M. C-153

Breitkreutz, Egon C-236

Brov/n, Robert Hanbury C-40

Bruche, E. C-41

Budden, K. G. C-42

Bullough, K. 0-43-45,148

Burkhart, K. 0-46

Burstall, T. 0-163

Byrne, E.O. 0-139

Oain, Joseph O. 0-47

Oaraeron, E. A. 0-26

Oartwright, D. G. 0-92

Ohamberlain, Joseph W. 0-48,

43, 297

Ohapman, R.P. 0-50

Ohapman, Sydney 0-51-58

Ohestnov, F.I. 0-59

Ohivers, H. J. A. 0-60

Olegg, J. A. 0-61, 176

Oohen, R. 0-39

Oollins, O. 0-32,63,235

Oonference on Auroral Physics,

July 23-26, 1951 0-64

Ooroniti, Samuel O. 0-227

Oovington, A.E. 0-65

Oox, J. W. 0-66

Ourrie, B. W. 0-50,67-69,97-

99, 154, 183, 184

Davidson, D. 0-70

Davidson, T. W. 0-45

Davies, K. 0-66

De Kock, A. O. 0-71

de Witt, R.N. 0-225

Dieminger, Walter 0-72-75

Dolphin, L.T. 0-85,166

Dostal, E. 0-76

Do-^den, R.L. 0-77,78

Driatskii, V. M. 0-79

Duncan, R. A. 0-80

Dyce, Rolf Buchanan 0-81-85,

167, 240

Eastwood, E. 0-86

Eckersley, T.L. 0-51,87

Egah, R. D. 0-88

Egeland, Alv 0-89, 118

Ellis, G. R.A. 0-80,90-92

Ellyett, O.D. 0-61,243

EUyett, G. E. 0-173

Endo, K. 0-217
106

Fanselau, Gerhard C-93

Fendler, Ernst C-94

Ferrel, Perry, Jr. C-95

Fleischer, R. C-96

Forsyth, P. A. C -63, 67, 97-99,

100-104

France. Meteorologie Nationale

& Societe Meteorologique

de France C-105

Fricker, S.J. C-106

Fulton, B.J. C-107

Ingalls, R.P. C-106, 147

Institute of Radio Engineers

C-143

Isaev, Sergei Ivanovich C-144,

145

Israel, Hans C-146

Isted, G.A. C-86

James, J. C. C-147

Jouaust, Raymond C-257

Gadsden, M. C- 109, 270

Gartlein, C. W. C-28

General, J. C-153

Gerson, N. C. C-110-114

Gilliland, T. R. C-155

Glass, D. G. C-152

Gotz, Friedrich Wilhelm Paul

C-115

Green, F. D. C-104

Greenhow, J. S. 0-116

Groves, J. R.V. C-92

Gusev, P.I. C-117

Gustafsson, Georg C-118

Hagg, E.L. C-119, 120

Hakura, Yukio C-121, 122

Hamilton, R.A. C-287

Hanson, G.H. C-llG

Harang, Leiv C -123-128

Harrison, D. P. C -129, 130

Harrison, V. A. W. C-131

Hartz, T. R. 0-132, 133

Hawkins, G. S. 0-10, 134

Helbronner, Paul 0-135

Hellgren, Gosta 0-136

Ilelliwell, R.A. 0-191

Hellman, Gustav 0-137

Henderson, J. P. 0-133

Keppner, J. B. 0-139

Heppner, James 0-140

Herlofson, N. 0-141

Hoffman, R. 0-289

Hoffmeister, O. 0-142

Hultqvist, Bengt 0-89

Kaiser, T. R. 0-43-45,148-151

Kavadas, A. 0-152, 178

Kenrick, G. W. 0-153

Kim, J.S. 0-154

Kirby, S. S. 0-155,224

Knecht, R. W. 0-156

Konig, Hermann 0-142

Kriiger, K. 0-157

Landmark, Bjom 0-127, 158

Lange-Hesse, Giinther 0-160

Larmor, Joseph 0-161

Lauter, E. A. 0-162

Law, P.G. 0-163

Leadabrand, R.L. 0-164-167,

229, 233, 240

Leinbach, Harold 0-223

Leithauser, G. 0-168

Leonard, Robert S. 0-169, 170

Lied, F. 0-171

Lindquist, Rune A. 0-172, 173

Little, O. Gordon 0-56, 174, 175

Lovell, A.O.B. 0-40,176

Lugeon, J. 0-177

Lyon, G.F. 0-178,179

Mc Innes, B. 0-180,181

Mc Kinley, D. W. R. 0-182

Mc Namara, A. G. 0-183-188,

139

Maehlum, Bernt 0-189

Mah, W. 0-104

Major, G. 0-190
107

Malich, C. W. C-241

Martin, L.H. C-191

Martvel', F. E. 0-192

Massey, H. S. W. C-193

Matsushita, S. C-194

Mednikova, N.V. C-195

Meek, J. H. C-196-199

Menzel, W. C-278

Meos, Johan C- 136, 200

Merritt, Ernest C-201

Millman, Peter M. C-182

Mitra, Sisir K. C-202

Moorcroft, D. R. C -203, 204

Moore, R.K. C-205-208

Muldrew, D. C-120

Murcray, W. B. C-209

Nagata, Takesi C-259

Nakata, Yoshiaki C-210

Neufeld, E.L. C-116

Nichols, Benjamin C-28, 211-

213, 223

Nikol'skii, A. P. C-214, 215

Norsk Institutt for Kosmisk

Fysikk C-216

Ochs, G. R. C-39

Ohno, K. C-217

Olving, Sven C-200

Omholt, A. C-21S, 219

Ortner, Johannes C-89, 220

Oscanyan, Paul C, Jr. C-221,

222

Otsuki, Toshiharu C-121

Owren, Leif C-223

Petrie, W. C -97-99

Pickard, Greenleaf W. C-230

Pierce, J. A. C-231

Piggott, W. R. C-19

Plendl, H. C-73

Pogorelov, V.I. C- 192, 232

Pope, J.H. C-209

Presnell, R.I. C- 167, 233

Pushkov, N.V. C-143

Rawer, Karl C-234

Rayton, W. M. C-175

Reid, G. C. C-132, 235

Robertson, K. A. C-181

Rodewald, M. C-236

Roof, R.B. C-175

Rumi, G. C. C-237

Rybner, Jorgen C-238

Schallerer, W. C-239

Schlobohm, J. C. C-240

Seaton, S.L. C-241

Seed, T.J. C -242, 243

Sen'ko, P. K. C-244

Shapley, Allan H. C -245, 245

Singer, S.Fred C-247

Smith, J. W. C-284

Stein, Sidney C-248

Stetson, Harlan True C-249, 250

Stoffregen, Willi C -123, 125, 256

Stone, M.L. C-106

Stormer, Carl C-251-255

Stoyko, Nicolas C-257

Stranz, Dietrich C-258

Sugiura, Masahisa C-259

Pabo, N.V. C-9

Parkinson, T. C-224

Parthasarathy, R. C-225

Paton, James C-226

Pawsey, J.L. C-228

Penndorf, Rudolf C-115, 227

Peterson, A. M. C-88, 164, 166,

229, 233

Peterson, L. C-289

Petrie, L.E. C-107

Takenoshita, Yugoro C-121, 122

Taylor, Hoyt A. C-260

Tazima, Minoru C-259

Thayer, Roger E. C-262

Thomas, L.H. C-263

Tilton, Edward D. C-264, 265

Troim, J. C-128
108

Ulrich, Franklin P. C-26S269

Ungstrup, Emil C-23S

Unv/in, R.S. C-270-273

Van derPol, Balth C-274

Vassy, Etienne C-275

Vawter, F. E. C-67, 99

Vegard, Lars C-276, 277

Vilbig, F. C-27S

Vogan, E.L. C -102, 132

Wang, S.C. C-106

Warren, E. C-120

Watkins, CD. C -45, 116,

129, 279-282

Wax, Nelson 0-283

Weiss, A. A. C-2S4

Wells, H. W. C -SO, 285

Whale, H. A. C-286

Whatman, A. B. C-287

White, F. W. G. C-283

V/inckler, J. R. C-2S9

Yabroff, I. C-165

Yates, G. G. C-42

Yeh, K.C. C-290

Young, L. C. C-260

Zennek, J. C-291

ANONYMOUS

C -292-296
I!. S. UKPAHTMEN r OF COMMERCE

Luther H. Hodges, Secretary

NATIONAL BUREAU OF STANDARDS

A. V. Astin, Director

THE NATIONAL BUREAU OF STANDARDS

riie scope of activities of the National Bureau of Standards at its major laboratories in Washington, D.C., and

IJoulder, Colorado, is suggested in the following listing of the divisions and sections engaged in technical work.

In general, each section carries out specialized research, development, and engineering in the field indicated by

its title. A brief description of tlie activities, and of the resultant publications, appears on the inside of the

front cover.

WASHINGTON, D.C.

Electricity. Resistance and Reactance. Electrochemistry. Electrical Instruments. Magnetic Measurements,

Dielectrics. High Voltage.

Metrology. Photometry and Colorimetry. Refractometry. Photographic Research. Length. Engineering Metrology.

Mass and Scale. Volumetry and Densimetry.

Heat. Temperature Physics. Heat Measurements. Cryogenic Physics. Equation of State. Statistical Physics.

Radiation Physics. X-ray. Radioactivity. Radiation Theory. High Energy Radiation. Radiological Equipment.

Nucleonic Instrumentation. Neutron Physics.

Analytical and Inorganic Chemistry. Pure Substances. Spectrochemistry. Solution Chemistry. Standard Refer- ence Materials. Applied Analytical Research.

Mechanics. Sound. Pressure and Vacuum. Fluid Mechanics. Engineering Mechanics. Rheology. Combustion

Controls. Organic and Fibrous Materials. Rubber. Textiles. Paper. Leather. Testing and Specifications. Polymer Structure. Plastics. Dental Research.

Metallurgy. Thermal Metallurgy. Chemical Metallurgy. Mechanical Metallurgy. Corrosion. Metal Physics. Electrolysis and Metal Deposition.

Mineral Products. Engineering Ceramics. Glass. Refractories. Enameled Metals. Crystal Growth. Physical

Properties. Constitution and Microstructure. Building Research. Structural Engineering. Fire Research. Mechanical Systems, Organic Building Materials. Codes and Safety Standards. Heat Transfer. Inorganic Building Materials. Applied Mathematics. Numerical Analysis. Computation. Statistical Engineering. Mathematical Physics, Operations Research. Data Processing Systems. Components and Techniques. Computer Technology. Measurements Automation.

Engineering Applications. Systems Analysis.

Atomic Physics. Spectroscopy. Infrared Spectroscopy. Solid State Physics. Electron Physics. Atomic Physics.

Instrumentation. Engineering Electronics. Electron Devices. Electronic Instrumentation. Mechanical Instru- ments. Basic Instrumentation. Physical Chemistry. Thermochemistry. Surface Chemistry. Organic Chemistry. Molecular Spectroscopy. Molecular Kinetics. Mass Spectrometry.

Office of Weights and Measures. BOULDER, COLO.

Cryogenic Engineering. Cryogenic Equipment. Cryogenic Processes. Properties of Materials. Cryogenic Technical Services. Ionosphere Research and Propagation. Low Frequency and Very Low Frequencv Research. Ionosphere Research.

Prediction Services. Sun-Earth Relationships. Field Engineering. Radio Warning Services. Vertical Soundings Research. Radio Propagation Engineering. Data Reduction Instrumentation. Radio Noise. Tropospheric Measurements.

Tropospheric Analysis. Propagation-Terrain Effects. Radio-Meteorology. Lower Atmosphere Physics.

Radio Standards. High Frequency Electrical Standards. Radio Broadcast Service. Radio and Microwave Materials. Atomic Frequency ana Time Interval Standards. Electronic Calibration Center. Millimeter-Wave Research.

Microwave Circuit Standards. Radio Systems. Applied Electromagnetic Theory. High Frequency and Very High Frequency Research. Modulation

Research. Antenna Research. Navigation Systems.

Upper Atmosphere and Space Physics. Upper Atmosphere and Plasma Physics. Ionosphere and Exosphere

Scatter. Airglow and Aurora. Ionospheric Radio Astronomy.

U3C0MU-NBS.eL