193:, where both the central main axis of the prism and the top and bottom prism side faces are oriented horizontally. This orientation is responsible for several rare haloes. Parry arcs are the result of light passing through two side faces forming a 60° angle. The shape of Parry arcs changes with the elevation of the sun and are subsequently called upper or lower arcs to indicate they are found above or under the sun, and sunvex or suncave depending on their orientation.
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The mechanism by which column crystals adopt this special Parry orientation has been subject to much speculation – recent laboratory experiments have shown that it is the presence of crystals with a
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slightly wrong. On the other hand, he added two arcs extending laterally from the bases of the 46° halo, for long interpreted as incorrectly drawn
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174:(both produced by the same crystal orientation but with light passing through different faces of the crystals).
130:. On April 8, under harsh conditions while his two ships were trapped by ice forcing him to winter over at
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138:, he made a drawing of the phenomenon. The drawing accurately renders the
126:(1790–1855) in 1820 during one of his Arctic expeditions in search for the
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397:– Photo by Joe MacGregor of a rare lower Parry sunvex arc in Antarctica (
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350:(Including a computer simulation recreating the halo observed by Parry.)
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31:. Several distinct halo phenomena are featured in the photo: Two
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hexagonal cross-section which are likely to be the cause.
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Quarterly
Journal of the Royal Meteorological Society
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23:A halo display photo documented by Cindy McFee,
211:, and any of the odd radius halos produced by
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182:Parry arcs are generated by double-oriented
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203:Parry arcs can be confused with either
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122:The halo was first described by Sir
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106:which occasionally appears over a
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59:Complex Moon halo. Visible are:
86:and sunvex Parry arc seen over
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415:Atmospheric optical phenomena
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162:. He did, however, get the
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136:Canadian Arctic Archipelago
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376:. Arbeitskreis Meteore e.V
282:"Origin of the Parry arc"
280:Westbrook, C. D. (2011).
88:Santa Rosa Beach, Florida
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27:, December 1980 at the
267:Arbeitskreis Meteore,
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39:(horizontal line), a
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361:. Atmospheric Optics
341:. Atmospheric Optics
124:William Edward Parry
301:2011QJRMS.137..538W
189:, i.e. a so-called
213:pyramidal crystals
205:upper tangent arcs
160:circumzenithal arc
104:optical phenomenon
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35:(bright spots), a
29:South Pole Station
16:Optical phenomenon
191:Parry orientation
168:infralateral arcs
164:upper tangent arc
152:lower tangent arc
128:Northwest Passage
112:upper tangent arc
110:together with an
84:Upper tangent arc
69:upper tangent arc
45:upper tangent arc
43:(circle), and an
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134:in the northern
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187:column crystals
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140:parhelic circle
132:Melville Island
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37:parhelic circle
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389:External links
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395:Halo Reports
378:. Retrieved
363:. Retrieved
359:"Parry Arcs"
343:. Retrieved
339:"Parry 1820"
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146:, a pair of
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374:"Parry Arc"
355:Cowley, Les
335:Cowley, Les
209:Lowitz arcs
380:2007-04-23
365:2007-04-23
345:2007-04-23
328:References
257:Parry Arcs
245:Parry 1820
225:Lowitz arc
98:is a rare
317:119944725
269:Parry Arc
184:hexagonal
178:Formation
118:Discovery
96:Parry arc
71:and Moon
65:Parry arc
49:Parry arc
409:Category
255:Cowley,
243:Cowley,
219:See also
158:, and a
156:46° halo
148:sun dogs
144:22° halo
108:22° halo
41:22° halo
33:sun dogs
297:Bibcode
198:scalene
315:
51:(top).
47:and a
399:Blogg
313:S2CID
285:(PDF)
231:Notes
102:, an
154:, a
150:, a
142:, a
100:halo
73:dogs
61:halo
25:NOAA
305:doi
293:137
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94:A
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