31:
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164:. As the Sun heads toward solar maximum, the coronal holes move closer and closer to the Sun's poles. During solar maxima, the number of coronal holes decreases until the magnetic fields on the Sun reverse. Afterwards, new coronal holes appear near the new poles. The coronal holes then increase in size and number, extending farther from the poles as the Sun moves toward a solar minimum again.
209:(CMEs), which usually have a sudden onset. Because coronal holes and associated CIRs can last for several solar rotations (i.e., several months), predicting the recurrence of this type of disturbance is often possible significantly farther in advance than for CME-related disturbances.
190:. The latter originates in coronal holes and has radial flow speeds of 450–800 km/s compared to speeds of 250–450 km/s for the slow solar wind. Interactions between fast and slow solar wind streams produce stream interaction regions which, if present after a
496:
Tsurutani, Bruce T.; Gonzalez, Walter D.; Gonzalez, Alicia L. C.; Guarnieri, Fernando L.; Gopalswamy, Nat; Grande, Manuel; Kamide, Yohsuke; Kasahara, Yoshiya; Lu, Gang; Mann, Ian; McPherron, Robert; Soraas, Finn; Vasyliunas, Vytenis (July 2006).
73:
to escape into space at a much quicker rate. This results in decreased temperature and density of the plasma at the site of a coronal hole, as well as an increased speed in the average solar wind measured in interplanetary space.
205:. The majority of moderate-intensity geomagnetic storms originate from CIRs. Typically, geomagnetic storms originating from CIRs have a gradual commencement (over hours) and are not as severe as storms caused by
77:
Streams of fast solar wind originating from coronal holes can interact with slow solar wind streams to produce co-rotating interaction regions. These regions can interact with
69:. Compared to the corona's usual closed magnetic field that arches between regions of opposite magnetic polarity, the open magnetic field of a coronal hole allows
352:
383:
627:
Jiang, Y., Chen, H., Shen, Y., Yang, L., & Li, K. (2007, January). Hα dimming associated with the eruption of a coronal sigmoid in the quiet Sun.
448:
Cranmer, Steven R.; Gibson, Sarah E.; Riley, Pete (November 2017). "Origins of the
Ambient Solar Wind: Implications for Space Weather".
38:, coronal holes appear as relatively dark patches in the Sun's corona. Here, there is a large coronal hole in the northern hemisphere.
251:
Freedman, Roger A., and
William J. Kaufmann III. "Our Star, the Sun." Universe. 8th ed. New York: W.H. Freeman, 2008. 419–420. Print.
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Geiss, J.; Gloeckler, G.; Von
Steiger, R. (April 1995). "Origin of the solar wind from composition data".
952:
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Temmer, Manuela (December 2021). "Space weather: the solar perspective: An update to
Schwenn (2006)".
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of minor to moderate intensity. During solar minima, CIRs are the main cause of geomagnetic storms.
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124:. At the time, what they were was unclear. Their true nature was recognized in the 1970s, when
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mission were flown above the Earth's atmosphere to reveal the structure of the corona.
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101:(pictured), coronal structures not otherwise visible can be observed above the limb.
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compared to their surroundings. They are composed of relatively cool and tenuous
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The solar wind exists primarily in two alternating states referred to as the
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499:"Corotating solar wind streams and recurrent geomagnetic activity: A review"
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When the Sun's disk is obscured during a total solar eclipse or by a
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In the 1960s, coronal holes appeared in X-ray images taken by
270:. Australian Government Bureau of Meteorology. Archived from
194:, are referred to as co-rotating interaction regions (CIRs).
125:
109:. They appeared as dark regions surrounded by much brighter
1109:
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688:
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221:– includes coronal dimmings, sometimes referred to as
160:
Coronal hole size and population correspond with the
153:A coronal hole at the Sun's north pole observed in
447:
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120:and in observations at radio wavelengths by the
219:Coronal mass ejection § Coronal signatures
503:Journal of Geophysical Research: Space Physics
384:"Large Coronal Hole Near the Sun's North Pole"
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491:
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577:"Fast Solar Wind Causes Aurora Light Shows"
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201:, producing minor- to moderate-intensity
105:Coronal holes were first observed during
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27:Cool, tenuous region of the Sun's corona
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230:– dark spots on the Sun's photosphere
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266:Kennewell, John; McDonald, Andrew.
24:
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122:Sydney Chris Cross radio telescope
25:
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353:"Massive Coronal Hole on the Sun"
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607:Physics of the Space Environment
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541:Living Reviews in Solar Physics
296:Living Reviews in Solar Physics
359:. 24 June 2013. Archived from
138:
13:
1:
1150:List of heliophysics missions
239:
167:
1155:Category:Missions to the Sun
7:
687:
382:Fox, Karen (19 July 2013).
290:Cranmer, Steven R. (2009).
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10:
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611:Cambridge University Press
563:10.1007/s41116-021-00030-3
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1131:G-type main-sequence star
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480:10.1007/s11214-017-0416-y
268:"What is a Coronal Hole?"
994:In mythology and culture
49:that emit low levels of
605:Gombosi, Tamas (1998).
223:transient coronal holes
197:CIRs can interact with
861:Supra-arcade downflows
207:coronal mass ejections
157:
113:above the Sun's limb.
102:
39:
841:Coronal mass ejection
450:Space Science Reviews
415:Space Science Reviews
199:Earth's magnetosphere
172:Further information:
152:
143:Further information:
96:
79:Earth's magnetosphere
33:
1105:Standard solar model
1075:Solar radio emission
893:List of solar cycles
654:at Wikimedia Commons
523:10.1029/2005JA011273
327:10.12942/lrsp-2009-3
234:List of solar storms
107:total solar eclipses
67:interplanetary space
925:Magnetic switchback
515:2006JGRA..111.7S01T
472:2017SSRv..212.1345C
427:1995SSRv...72...49G
394:on 12 November 2020
363:on 19 December 2020
318:2009LRSP....6....3C
45:are regions of the
36:extreme ultraviolet
1115:Sunlight radiation
710:Internal structure
456:(3–4): 1345–1384.
435:10.1007/BF00768753
274:on 11 August 2015.
203:geomagnetic storms
158:
103:
83:geomagnetic storms
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1180:
1145:Solar observatory
1060:Solar observation
958:Termination shock
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826:Transition region
650:Media related to
65:that are open to
34:When observed in
16:(Redirected from
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184:slow solar wind
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18:Coronal holes
1080:Solar System
1050:Solar energy
1045:Solar dynamo
1006:Heliophysics
836:Coronal loop
831:Coronal hole
830:
808:Moreton wave
790:Chromosphere
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609:. New York:
606:
585:. Retrieved
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396:. Retrieved
392:the original
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361:the original
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47:Sun's corona
42:
41:
1138:Exploration
1016:Solar deity
963:Heliosheath
945:Heliosphere
915:Wolf number
888:Solar cycle
752:Photosphere
635:(1), 77–87.
162:solar cycle
145:Solar cycle
139:Solar cycle
99:coronagraph
81:to produce
51:ultraviolet
1090:Solar time
1011:In culture
968:Heliopause
920:Solar wind
851:Prominence
743:Atmosphere
728:Tachocline
554:2104.04261
463:1708.07169
398:31 October
367:31 October
240:References
174:Solar wind
168:Solar wind
155:soft X-ray
129:telescopes
71:solar wind
973:Bow shock
880:Variation
846:Nanoflare
309:0909.2847
1188:Category
1173:Category
587:11 April
336:27194961
302:(1): 3.
213:See also
186:and the
989:Eclipse
982:Related
803:Spicule
775:Sunspot
770:Faculae
765:Granule
689:The Sun
511:Bibcode
468:Bibcode
423:Bibcode
314:Bibcode
228:Sunspot
131:in the
89:History
818:Corona
617:
509:(A7).
334:
133:Skylab
59:plasma
930:Flare
798:Plage
549:arXiv
547:(1).
458:arXiv
304:arXiv
126:X-ray
1110:Star
1021:List
718:Core
700:List
615:ISBN
589:2022
581:NASA
400:2014
388:NASA
369:2014
357:NASA
332:PMID
176:and
53:and
633:240
559:doi
519:doi
507:111
476:doi
454:212
431:doi
322:doi
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