264:
60:
33:
41:
49:
351:
335:
343:
358:
In dry air, the color of produced light (e.g. by lightning) is dominated by the emission lines of nitrogen, yielding the spectrum with primarily blue emission lines. The lines of neutral nitrogen (NI), neutral oxygen (OI), singly ionized nitrogen (NII) and singly ionized oxygen (OII) are the most
164:
The excited state of oxygen is somewhat more stable than nitrogen. While deexcitation can occur by emission of photons, the more probable mechanism at atmospheric pressure is a chemical reaction with other oxygen molecules, forming ozone:
125:, when present, may also play a role; its presence is characterized by the hydrogen emission lines. The reactive species present in the plasma can readily react with other chemicals present in the air or on nearby surfaces.
359:
prominent features of a lightning emission spectrum. Neutral nitrogen radiates primarily at one line in the red part of the spectrum. Ionized nitrogen radiates primarily as a set of lines in the blue part of the spectrum.
412:
of these species. At higher temperatures, atomic emission lines of N and O, and (in presence of water) H, are present. Other molecular lines, e.g. CO and CN, mark the presence of contaminants in the air.
362:
A violet hue can occur when the spectrum contains emission lines of atomic hydrogen. This may happen when the air contains high amount of water, e.g. with lightnings in low altitudes passing through
433:
in that medium. Despite the production of similarity-colored light and an association with high-energy particles, Cherenkov radiation is generated by a fundamentally different mechanism.
384:, generated by low-frequency lightnings, emit at red to orange color and can give the lightning a yellowish to greenish tint. Generally, the radiant species present in atmospheric
657:
156:
The blue light observed is produced primarily by this process. The spectrum is dominated by lines of single-ionized nitrogen, with presence of neutral nitrogen lines.
666:'For several minutes after the blast, you could see this eerie ultraviolet glow high up in the sky. And I thought that was so spectacular, so meaningful.'
682:
279:
at 01:23 local time, employees at the power station went outside to get a clearer view of the extent of the damage. One such survivor,
369:. Water vapor and small water droplets ionize and dissociate easier than large droplets, therefore have higher impact on color.
929:
515:
817:
788:
759:
498:
17:
859:
834:
203:
is the cause of blue glow surrounding sufficient quantities of strongly radioactive materials in air, e.g. some
547:
934:
720:
300:
283:, recounts that once he stopped outside and looked up towards the reactor hall he saw a "very beautiful"
701:
570:"Christy, Robert F. Interview by Sara Lippincott. Pasadena, California, June 15, 17, 21, and 22, 1994"
944:
534:
373:
97:
When energy is deposited in air, the air molecules become excited. As air is composed primarily of
875:
598:
542:
409:
236:
806:
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78:
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846:
777:
405:
224:
220:
52:
8:
939:
592:
422:
280:
894:
850:
461:
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light, caused by the ionization of air, that appeared to be "flooding up into infinity".
906:
747:
658:"Mushroom Clouds and Everpresent Danger: Surviving Cameramen Recall Nuclear Test Shots"
316:
276:
248:
200:
118:
569:
910:
902:
813:
784:
755:
729:
693:
638:
597:(Video). Web of Stories - Life Stories of Remarkable People. Event occurs at 1'47".
572:. Oral History Project, California Institute of Technology Archives. 1998. p. 55
494:
425:. Cherenkov radiation is produced by charged particles which are traveling through a
256:
232:
184:
This reaction is responsible for the production of ozone in the vicinity of strongly
898:
854:
401:
385:
325:, the sometimes observable blue-violet hues emitted by nitrogen at lower altitudes.
312:
86:
612:
235:
near sea level. This post-explosion effect has been observed only at night from
430:
304:
239:
owing to its low brightness, with observers noticing it following the pre-dawn
228:
196:
Excitation energy can be deposited in air by a number of different mechanisms:
642:
59:
923:
733:
697:
216:
113:
molecules are produced. These can react with other molecules, forming mainly
77:
emission of characteristic blue–purple–violet light, often of a color called
263:
835:"Daylight Spectra of Individual Lightning Flashes in the 370–690 nm Region"
381:
366:
204:
185:
32:
493:(1st English ed.). San Diego, Calif.: Academic Press. p. 1655.
294:
122:
74:
627:
625:
40:
426:
380:
line) and at 486.1 nm (H-beta) are characteristic for lightnings.
288:
635:
The swords of
Armageddon: U.S. nuclear weapons development since 1945
622:
308:
64:
227:, and the eerie/low brightness "purple" to "blue" glow enveloping a
350:
334:
212:
98:
48:
137:, with emission lines in ultraviolet, visible, and infrared band:
442:
377:
354:
Emission spectrum of hydrogen (water vapor is similar but dimmer)
342:
523:. Biographical Memoirs. National Academy of Sciences. p. 7.
874:
Laux, C. O.; Spence, T. G.; Kruger, C. H.; Zare, R. N. (2003).
489:
Wiberg, Egon; Wiberg, Nils; Holleman, Arnold
Frederick (2001).
322:
208:
134:
102:
85:
subjected to an energy flux either directly or indirectly from
284:
114:
631:
Cherokee Field Report Bikini
Operations, page 10, quoted in
860:
10.1175/1520-0450(1980)019<0470:DSOILF>2.0.CO;2
363:
601:
from the original on 15 December 2021 – via YouTube.
400:, NO (in dry air) and OH (in humid air). The temperature,
133:
The excited nitrogen deexcites primarily by emission of a
876:"Optical diagnostics of atmospheric pressure air plasmas"
618:(Report). Defense Nuclear Agency. p. 247. DNA 6040F.
275:
Within minutes after the steam explosion that caused the
82:
408:
of the plasma can be inferred from the distribution of
873:
594:
The
Trinity Test: 'An eery and awesome sight' (9/20)
488:
805:
776:
719:
637:. Sunnyvale, Calif.: Chukelea Publications. 1307.
514:Goodstein, David L.; Goodstein, Judith R. (2013).
513:
421:The emission of blue light is often attributed to
754:. Mineola, N.Y.: Dover Publications. p. 20.
921:
752:The Becquerel rays and the properties of radium
839:Journal of Applied Meteorology and Climatology
231:during the first several dozen seconds after
826:
728:. Vol. 183, no. 2461. p. 46.
535:"A Backward Glance: Eyewitnesses to Trinity"
128:
692:. Muldersdrift, South Africa. p. 41.
858:
797:
768:
159:
507:
484:
482:
349:
341:
333:
262:
58:
47:
39:
31:
832:
590:
527:
14:
922:
746:
740:
655:
632:
605:
429:substance at a speed greater than the
416:
303:is the cause of blue light emitted by
883:Plasma Sources Science and Technology
680:
674:
479:
867:
803:
774:
717:
711:
783:. Dover Publications. p. 139.
683:"Chernobyl: what happened and why?"
656:Bethge, Philip (25 November 2010).
584:
24:
812:. Dover Publications. p. 96.
223:) in air, the blue flashes during
25:
961:
718:Bond, Michael (21 August 2004).
591:Christy, Robert (6 July 2017).
550:. 2005. p. 45. LALP-05-067
649:
562:
548:Los Alamos National Laboratory
454:
297:in air produce this blue glow.
13:
1:
930:Atmospheric optical phenomena
448:
376:at 656.3 nm (the strong
338:Emission spectrum of nitrogen
191:
833:Orville, Richard E. (1980).
517:Robert F. Christy: 1916–2012
92:
7:
681:Meyer, C. M. (March 2007).
436:
346:Emission spectrum of oxygen
301:Electrical discharge in air
188:and electrical discharges.
10:
966:
903:10.1088/0963-0252/12/2/301
613:Operation Dominic I: 1962
329:
237:atmospheric nuclear tests
804:Uman, Martin A. (1986).
775:Uman, Martin A. (1984).
129:Deexcitation of nitrogen
543:Nuclear Weapons Journal
374:hydrogen emission lines
633:Hansen, Chuck (1995).
355:
347:
339:
271:
160:Deexcitation of oxygen
67:
56:
45:
37:
353:
345:
337:
268:Upshot-Knothole Annie
266:
245:Upshot-Knothole Annie
225:criticality accidents
221:particle accelerators
186:radioactive materials
63:Particle beam from a
62:
51:
43:
35:
935:Electrical breakdown
721:"Cheating Chernobyl"
707:on 11 December 2013.
406:electron temperature
53:Electrical discharge
895:2003PSST...12..125L
851:1980JApMe..19..470O
808:All about lightning
491:Inorganic chemistry
423:Cherenkov radiation
417:Cherenkov radiation
281:Alexander Yuvchenko
356:
348:
340:
277:Chernobyl accident
272:
249:Operation Fishbowl
233:nuclear explosions
201:Ionizing radiation
119:nitrogen(II) oxide
68:
57:
46:
38:
27:Optical phenomenon
313:corona discharges
270:nuclear bomb test
257:Operation Redwing
16:(Redirected from
957:
945:Plasma phenomena
915:
914:
880:
871:
865:
864:
862:
830:
824:
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811:
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795:
794:
782:
772:
766:
765:
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738:
737:
723:
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709:
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700:. Archived from
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486:
477:
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458:
410:rotational lines
402:electron density
207:specimens (e.g.
71:Ionized-air glow
21:
18:Ionized air glow
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317:St. Elmo's fire
305:electric sparks
194:
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148:
144:
131:
112:
108:
95:
87:solar radiation
28:
23:
22:
15:
12:
11:
5:
963:
953:
952:
947:
942:
937:
932:
917:
916:
866:
845:(4): 470–473.
825:
818:
796:
789:
767:
760:
739:
710:
673:
648:
621:
604:
583:
561:
546:. No. 2.
526:
506:
499:
478:
466:www.albany.edu
452:
450:
447:
446:
445:
438:
435:
431:speed of light
418:
415:
397:
393:
389:
331:
328:
327:
326:
320:
298:
292:
287:-like beam of
261:
260:
229:mushroom cloud
217:particle beams
193:
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146:
142:
130:
127:
110:
106:
94:
91:
26:
9:
6:
4:
3:
2:
962:
951:
950:Radioactivity
948:
946:
943:
941:
938:
936:
933:
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928:
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840:
836:
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821:
819:0-486-25237-X
815:
810:
809:
800:
792:
790:0-486-64575-4
786:
781:
780:
771:
763:
761:0-486-43875-9
757:
753:
749:
748:Strutt, R. J.
743:
735:
731:
727:
726:New Scientist
722:
714:
703:
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500:0-12-352651-5
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453:
444:
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428:
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407:
403:
387:
383:
382:Rydberg atoms
379:
375:
370:
368:
367:thunderstorms
365:
360:
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344:
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243:, as well as
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140:
139:
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126:
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104:
100:
90:
88:
84:
80:
79:electric blue
76:
72:
66:
61:
54:
50:
42:
36:Nitrogen glow
34:
30:
19:
886:
882:
869:
842:
838:
828:
807:
799:
778:
770:
751:
742:
725:
713:
702:the original
689:
676:
665:
661:
651:
634:
607:
593:
586:
574:. Retrieved
564:
552:. Retrieved
541:
529:
516:
509:
490:
469:. Retrieved
465:
456:
420:
371:
361:
357:
295:Cathode rays
289:light bluish
252:
241:Trinity test
205:radioisotope
195:
183:
163:
155:
150:
132:
96:
70:
69:
29:
662:Der Spiegel
554:18 February
471:13 December
219:(e.g. from
123:Water vapor
105:, excited N
75:luminescent
44:Oxygen glow
940:Ionosphere
924:Categories
889:(2): 125.
643:1109685186
449:References
427:dielectric
251:, and the
192:Occurrence
911:250824737
779:Lightning
750:(2004) .
734:0262-4079
698:1818-2127
462:"Airglow"
309:lightning
93:Processes
65:cyclotron
690:Energize
599:Archived
576:5 August
437:See also
255:shot of
253:Cherokee
213:polonium
99:nitrogen
891:Bibcode
847:Bibcode
668:
443:Airglow
378:H-alpha
323:Auroras
173:* + 2 O
73:is the
909:
816:
787:
758:
732:
696:
641:
497:
404:, and
386:plasma
330:Colors
315:(e.g.
311:, and
209:radium
135:photon
103:oxygen
55:in air
907:S2CID
879:(PDF)
705:(PDF)
686:(PDF)
616:(PDF)
538:(PDF)
521:(PDF)
388:are N
285:laser
177:→ 2 O
115:ozone
109:and O
81:, by
814:ISBN
785:ISBN
756:ISBN
730:ISSN
694:ISSN
639:OCLC
578:2021
556:2014
495:ISBN
473:2021
372:The
364:rain
117:and
101:and
899:doi
855:doi
396:, O
392:, N
215:),
211:or
145:→ N
89:.
83:air
926::
905:.
897:.
887:12
885:.
881:.
853:.
843:19
841:.
837:.
724:.
688:.
664:.
660:.
624:^
540:.
481:^
464:.
319:).
307:,
247:,
151:hν
149:+
121:.
913:.
901::
893::
863:.
857::
849::
822:.
793:.
764:.
736:.
645:.
580:.
558:.
503:.
475:.
398:2
394:2
390:2
259:.
179:3
175:2
171:2
169:O
147:2
143:2
141:N
111:2
107:2
20:)
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