Atmospheric Electricity (eBook)

Front Cover 1
Atmospheric Electricity 4
Copyright Page 5
Table of Contents 6
PREFACE 8
ACKNOWLEDGEMENTS 9
CHAPTER 1. Historical Survey 10
1. Primitive Notions 10
2. Identification of Lightning with Electricity 10
3. Electricity from Thunder Clouds 10
4. The Lightning Conductor 11
5. Electricity of Fine Weather 13
6. The Movable Conductor 14
7. Early Theories 16
8. The Flame Collector 16
9. Theory of the Charge on the Earth 17
10. Kelvin's Contributions 17
11. Absolute Values of Potential Gradient 19
12. Relation with Humidity 19
13. The Fine-Weather Potential Gradient 20
14. Conductivity of the Air 20
15. The Origin of Atmospheric Ionization 21
16. Stormy-Weather Phenomena 22
17. Early Theories involving Ice 22
18. The Thunder Cloud 22
19. War-Time Advances 23
CHAPTER 2. General Principles and Results 24
20. Scope of the Chapter 24
21. MKS Units 24
22. Electrostatic Formulae 25
23. Potential 26
24. Potential Gradients and Fields 27
25. Lines of Force, Space Charges, and Surface Charges 28
26. Location of Charges 29
27. Numerical values 29
28. Ionic Conductivity 30
29. Mobility 30
30. Diffusion Coefficient 31
31. Ionic Current 31
32. Saturation Current 32
33. Relaxation Time 33
34. Quasistatic State 33
35. The Electrode Effect 34
36. Electrical Images 35
37. Effect of Conductor in Potential Gradient 36
38. The Ionosphere 37
39. Potential of the Ionosphere 38
40. Variation of Potential Gradient and Conductivity with Height 39
4L Fundamental Formulae for Fine Weather 40
42. Disturbed-Weather Phenomena 40
43. Electrification of Clouds 41
44. Relation between Space Charge and Change of Conductivity 42
45. Cloud Types 43
46. The Initiation of Precipitation from Ice 44
47. The Initiation of Precipitation by Coalescence 44
48. Contamination in Clouds and Precipitation 44
49. Cloud Physics 45
50. Development of Thunder Clouds 46
51. Radar Study of Clouds 47
52. The Capture of Ions by Water-Drops 47
53. Electrical Phenomena Associated with Changes of State of Water 50
54. Electrical Effects of Ice Impact 51
55. Austausch 52
56. Correlation of Meteorological and Physiological Phenomena 53
57. Relation between Atmospheric Electricity and Phenomena in the Upper Atmosphere 53
58. Measurements of Atmospheric Electricity 53
59. Relation between Atmospheric Electricity and Meteorology 54
60. Variability of Results 55
61. Application of Statistical Methods 56
62. Insulation 56
63. Earth Connections 57
64. Contact Potentials 58
65. Measuring Instruments 59
66. Use of Cathode Follower 60
67. Direct Current Amplification 60
68. Use of Negative Feedback 61
69. Continuous Recording 61
70. Cylindrical Condenser Measurements 62
CHAPTER 3. The Ions in the Atmosphere 64
71. Small Ions 64
72. Nature of Small Ions 65
73. Large Ions 65
74. Intermediate Ions 66
75. Distinction between Large and Small Ions 66
76. Condensation Nuclei 67
77. Original Method for Counting Nuclei 67
78. Photoelectric Counting of Nuclei 68
79. Continuous Nucleus Counter 69
80. Charged and Uncharged Nuclei 69
81. The Ion Counter 70
82. Results of Ion Counting 72
83. Ion Counting in Aircraft 73
84. Measurements in a Large Enclosed Sphere 74
85. The Production of Ionization 74
86. Ionization due to Radioactive Substances 75
87. Ionization due to Cosmic Rays 76
88. The Total Ionization of the Air 77
89. Surface Effects 77
90. Equilibrium of Ionization 78
91. Destruction of Ions 78
92. Discussion of Equilibrium 79
93. Nolan and de Sachy's Assumption 80
94. Whipple's Theory 80
95. Values of Combination Coefficients 82
96. Multiply Charged Nuclei 83
97. Rate of Approach to Equilibrium 83
98. Ratio of Charged and Uncharged Nuclei 85
99. Decay of Nuclei 86
100. Sizes of Nuclei 86
101. The Dissipation Coefficient 87
102. The Life of an Ion 88
103. Radioactivity of the Atmosphere 88
CHAPTER 4. The Earth's Vertical Potential Gradient 90
104. Types of Measurement 90
105. Potential Equalizers 90
106. The Water-Dropper 91
107. Speed of Response of Water-Dropper 92
108. Effective Resistance of Collector 93
109. Effects of Leaks 93
110. The Use of the Water-Dropper 93
111. Electronic Method with a Water-Dropper 94
112. The Radioactive Collector 94
113. Leak-Free Method with Radioactive Collector 95
114. Electronic Method with a Radioactive Collector 96
115. Current from a Radioactive Collector 97
116. Limitations of Radioactive Collector 98
117. The Flame and Fuse 99
118. The Reduction Factor 99
119. Collection by Point Discharge 100
120. Measurement of the Bound Charge 101
121. The Universal Portable Electrometer 101
122. The Capillary Electrometer 103
123. Electronic Method for Bound Charge 103
124. Field Machines 104
125. The Field Mill 105
126. The Electrostatic Fluxmeter 107
127. Determination of Sign of Potential Gradient 108
128. The Agrimeter 109
129. Theory of the Agrimeter 110
130. Double Field Machine 113
131. Measurements of Changes of Potential Gradients 113
132. The Raised Sphere 114
133. Measurement of Time Intervals 114
134. Measurements in Balloons 115
135. Measurements in Aeroplanes 116
136. Measurements in Gliders 116
137. Measurements at Sea 117
138. Measurement of Potential Gradient on Mountains 117
139. Choice of Periods for Analysis 118
140. Diurnal Variation of Potential Gradient 118
141. Diurnal Variation in Undisturbed Conditions 120
142. Local-Time Effects 121
143. Origin of Diurnal Variation 122
144. Annual Variation 124
145. Local Effects on Mean Value 124
146. Space Charge 125
147. Space Charges and Potential Gradients 126
148. Effect of Relaxation Time 127
149. Effects during Eclipses of the Sun 128
150. Effect of Volcanic Eruptions on Potential Gradient 128
151. Potential-Gradient Fluctuations due to Space Charges 129
152. Horizontal Potential Gradients 130
153. Potential-Gradient Effects from High-Tension Cables 130
154. Potential-Gradient Variations in Fine Weather 131
155. Potential-Gradient Variations under Cloud 131
156. Effect of Dust Storms on Potential Gradient 131
157. Potential Gradients in Disturbed Weather 132
158. Potential Gradients in Quiet Rain 132
159. Potential Gradients in Snow 133
160. Effect of Point-Discharge Ions on Potential Gradient 133
161. Potential-Gradient Patterns 134
162. Jet Stream and Potential Gradient 135
CHAPTER 5. The Conductivity of the Air 137
163. Ionic Conductivity 137
164. Gerdien's Method 137
165. Leakage from Conductor 139
166. The Nolans' Method 140
167. Hogg's Measurements 140
168. Indirect Determination of Conductivity 141
169. Measurements under Trees 141
170. Cause of Variation of Conductivity with Height Close to the Surface 141
171. Variations of Conductivity 142
172. Conductivity of Fogs and Clouds 143
173. Balloon Measurements 144
174. Measurements in Aircraft 145
175. The Columnar Resistance 146
176. Measurements in a Large Enclosed Sphere 147
177. Calculations of Conductivity and Potential Gradient 147
178. Conductivity in Clouds 148
179. Conductivity Measurements on Mountains 148
180. Effect of Nuclear Explosions on Conductivity 149
181. Conductivity inside Buildings 149
182. Conductivity and Physiological Phenomena 149
CHAPTER 6. The Air-Earth Conduction Current 151
183. The Fair-Weather Conduction Current 151
184. Methods of Measurement 152
185. Displacement Currents 152
186. Direct Method of Measurement 152
187. Wilson's Measurements 153
188. Simpson's Measurements 153
189. Scrase's Measurements 154
190. Kasemir's Methods 155
191. Indirect Method of Measurement 157
192. The Electrode Effect 157
193. The Idea of Convection Currents 158
194. Comparison of Two Methods 158
195. Variation of Ionization 159
196. Diurnal Variation 159
197. Annual Variation of the Air-Earth Current 160
198. Relation between Air-Earth Current and Conductivity 161
199. Synoptic Use of Measurements 162
200. Measurements on Mountains 163
201. Measurements over Oceans 163
202. Air-Earth Current and Terrestrial Magnetism 163
CHAPTER 7. Point-Discharge Currents 165
203. Point Discharge 165
204. Ionization by Collision 165
205. Simplified Theory 166
206. Pulsed Nature of Discharge 166
207. General Effect of Space Charge 167
208. Laboratory and Atmospheric Conditions 167
209· Early Measurements 168
210. Wormell's Microvoltameter 168
211. Schonland's Measurements 169
212. Point-Discharge Ratio 171
213. Relation between Point-Discharge Current and Potential Gradient 171
214. Discharge from Points attached to Kites and Balloons 172
215. Point Discharge from Isolated Point 173
216. Multiple Points 173
217. Time Lags 174
218. General Space-Charge Theory 174
219. Application to Widespread Point Discharge 176
220. Application to Point in Rectangular Array 176
221. Application to Single Point 177
2 2 2 . Chapman's formula 179
223. The Altielectrograph 179
224. Width of Altielectrograph Traces 182
225. Radiosonde Method 183
226. Potential Gradients below Clouds 183
227. Effective Separation of Discharging Points 184
228. Total Current below Cloud 185
CHAPTER 8. Precipitation Currents 187
229. Importance of Rain Electricity 187
230. Measurements of Rain Charge by Electrometer 187
231. Direct Measurement of Current 189
232. Completely Exposed Receiver 189
233. Single Drops 191
234. Need for Continuous Observations 192
235. General Considerations 193
236. Ratio of Positive to Negative Charge 193
237. Times of Rainfall and Quantities of Water 194
238. Numbers of Single Drops 195
239. Vertical Rain Currents 195
240. Single-Drop Charges 196
241. Relation between Precipitation Charge and Potential Gradient 196
242. General Interpretation of Relation between Charge and Potential Gradient 197
243. Space Charge of Rain 198
244. Relation between Rain Current and Point Discharge 198
245. Smith's Single-Drop Observations 199
247. Precipitation Charges at Zugspitze 201
248. Explanation of Relation with Point Discharge 202
249. Rain Current with Low Potential Gradients 203
250. Total Current with Low Potential Gradient 203
251. Charges on Snow, Sleet, and Hail 204
252. Total Current in Continuous Snow 205
253. Origin of Charges on Continuous Rain and Snow 205
254. Splashing at the Ground 206
255. The Mirror-Image Effect 206
256. Charges from Blizzards 208
257. Charges in Mist and Fog 208
258. Charges on Droplets in Nonraining Clouds 209
259. Precipitation Static 210
CHAPTER 9. The Transfer of Charge 211
260. The Maintenance of the Earth's Charge 211
26L The Potential of the Ionosphere 212
262. The Charge on the Ionosphere 212
263. Correlation with Thunderstorm Activity 213
264. Correlation between Potential Gradient and Storms 214
265. Correlation between Current and Storms 215
266. The Electrical Balance Sheet 216
267. Conduction Current 216
268. Point Discharge 216
269. Precipitation Currents 217
270. Lightning Discharges 217
271. Total Transfer 218
272. Currents above Clouds 219
273. Horizontal Currents 219
274. Number of Storms 220
275. Charge Transfer in Nonstormy Rain and Snow 221
CHAPTER 10. The Thunder Cloud 222
276. Polarity of Cloud 222
277. Methods of Investigation 222
278. Potential Gradient due to Thunder Cloud 224
279. Measurements of Potential Gradients due to Thunder Clouds 226
280. Measurements by Point Discharge 228
282. Measurements of Potential-Gradient Changes 230
283. Multiple-Station Recording of Potential-Gradient Changes 231
284. Electric Moment Destroyed 232
285. Predischarge Potential Gradients 232
286. Recovery of Potential Gradient after Lightning 232
287. Recovery after Close Flashes 233
288. Relaxation and Regeneration Times 234
289. The Altielectrograph Results 234
290. Zugspitze Measurements 237
291. Double Dipole Theory 238
292. Potential Gradients inside Clouds 239
293. Breakdown Potential Gradients 240
294. Quantities of Free Charge 240
295. Distribution of Conduction Currents 241
296. Radar Observations of Thunderstorms 241
297. The Physical Storm 243
298. Distinction between Storms and Showers 243
299. Mountain Thunderstorms 244
300. Thunderstorms and Penetrating Radiation 244
CHAPTER 11. The Lightning Discharge 246
301. Investigation of Lightning 246
302. The Moving Camera 246
303. General Results 247
304. The Pilot Streamer 250
305. The Stepped Leader 251
306. The Dart Leader 252
307. The Main Stroke or Return Stroke 252
308. Multiple Strokes 253
309. Theories of Stepped Leaders 253
310. Potential-Gradient Change Measurements 254
311. Effects of Close Discharges 255
312. Junction Leaders 256
313. Heights of Charge Centres 256
314. Slow Potential-Gradient Changes 257
315. Slow Final Potential-Gradient Change 258
316. Discharges bringing Positive Discharge to Earth 258
317. Changes of Electric Moment 258
318. Potentials and Energies 259
319. Cloud and Earth Flashes 259
320. Minor Discharges 260
321. Counting of Lightning Flashes 260
322. Discharges from Cloud to Ionosphere 260
323. Discharges to Skyscraper 261
324. Discharges to Balloons 262
325. The Branching of Lightning Flashes 263
326. Initiation of Lightning Discharge 264
327. The Klydonograph 264
328. The Magnetic Link 264
329. Use of Cathode-Ray Oscillograph 265
330. General Results for Lightning Currents 265
331. Atmospherics 266
332. Low-Frequency Atmospherics ("Whistlers") 266
333. Radar Echoes from Lightning 266
334. Aircraft and Lightning 267
335. Discharges to Power Lines 267
336. Ball Lightning 268
CHAPTER 12. The Separation of Charge 269
337. The Main Thunder-Cloud Charges 269
338. Subsidiary Charges 269
339. Charges in Nonstormy Clouds 269
340. Connection with Precipitation 270
341. Requirements of Theory 271
342. Quantities of Charge Required 272
343. Classification of Theories 273
344. Gerdien's Theory 274
345. Elster and Geitel's Influence Theory 274
346. Wilson's Theory 275
347. Wall's Theory 276
348. Electrical Cell Theories 277
349. Diffusion Theory 278
350. Convection Theory 278
351. The Breaking-Drop Theory 279
352. Ice-Impact Theory 279
353. Ice-Splinter Theory 280
354. Glazing Theories 281
355. Other Theories 282
356. Discussion of Theories 283
357. The Lower Positive Charge 284
358. Water Theories 285
359. Secondary Theories 286
360. Subsidiary Charge Centres 287
361. Charge Separation in Clouds giving Continuous Rain and Snow 287
362. Charge Separation near the Ground in Continuous Rain and Snow 288
363. Charge Separation in Nonraining Cumulus Clouds 288
364. Charge Separation in Stratus Clouds 288
365. Control of Thunderstorm Electrification 289
CHAPTER 13. Conclusion 290
366. Outstanding Problems 290
367. The Maintenance of the Earth's Charge 290
368. Thunderstorm Problems 290
369. The Origin of Thunderstorm Charges 291
370. Instrumented-Bomb Method 291
371. Intermediate Ions 292
372. Equilibrium of Ionization 292
373. Potential-Gradient Measurements 293
374. Conductivity of the Air 293
375. Air-Earth Current 293
376. Point Discharge 294
377. Precipitation Currents 295
378. The Continuous-Rain Cloud 295
379. The Lightning Discharge 296
380. Instrumentation 297
381. Theoretical Considerations 297
382. The Future 298
APPENDIX I 299
APPENDIX II 299
REFERENCES 300
INDEX 332