© Irene Ho

Hexigten, Chifeng, Inner Mongolia, China

Latitude: 43° 15' 54'' N

Longitude: 117° 32' 45'' E

06 January 2011 1421 (Local Time)

Image P/S code: P.13.1.6.1

Image I.D.: 4948

• Images & related info Other Images Images of 1987 edition
• 

  22° halo with parhelia

  The main features in this picture are the 22° halo and the parhelia flanking it on each side at 2 and 3. The parhelia (commonly known as sundogs or mock suns) are bright spots, often brightly coloured, that occur on the parhelic circle and on or just a little outside of the 22° halo.

  The parhelic circle at 4 and 5 is a white halo at the same angular elevation as the Sun that, if complete, runs as a circle around the horizon. Here, only the parts of the parhelic circle outside of the parhelia are visible. Inside the 22° halo, any parts of the circle that may have been seen are obscured in the photograph by flare from the camera lens.

  At the top of the 22° halo is a faint upper tangent arc. Also in the photograph, diamond dust ice crystals responsible for generating these halo phenomena can be seen as white specks sparkling in the sunlight against the blue, cloudless sky.

  Links in the image description will highlight features on the image. Mouse over the features for more detail.

  © Irene Ho
  Hexigten, Chifeng, Inner Mongolia, China
  Latitude: 43° 15' 54'' N
  Longitude: 117° 32' 45'' E
  06 January 2011 1421 (Local Time)
  
  
  Image P/S code: P.13.1.6.1
  Image I.D.: 4948
• 

  Sub-horizon halos

  The high vantage point of a flight from Munich, Germany to Paris, France allowed this view of parhelia together with subparhelia and a subsun.

  The arc surrounding the Sun with a radius of 22° is the small halo. The small halo is one of the most frequently observed halo phenomena. On the right and left sides of the small halo, at the same elevation as the Sun, are bright coloured spots known as parhelia, or mock suns. Extending horizontally away from each parhelion are parts of the parhelic circle. The parhelic circle is a white circle that stands parallel to the horizon and passes through the Sun.

  Vertically below the Sun is the bright reflection halo that is the subsun, or undersun. The subsun is below the horizon and so is only seen from high vantage points, such as from aircraft or mountains. To the right and left of the subsun and vertically below the parhelia are corresponding subparhelia. Extending away from these are very faint parts of the subparhelic circle.

  Links in the image description will highlight features on the image. Mouse over the features for more detail.

  © Mark McCaughrean
  Germany
  Latitude: 48° 18' 36'' N
  Longitude: 9° 29' 24'' E
  24 October 2012 1642 (Local Time)
  
  
  Camera direction: towards WSW
  Image P/S code: S.13.1.1 7
  Image I.D.: 4128
• 

  A complex halo display

  This magnificent halo display was formed by the refraction and reflection of sunlight through diamond dust at an altitude of 1 100 m in Neklid, Klinovec, Ore Mountains, Czech Republic.

  Such complex displays are usually observed only in polar regions, although they may occasionally occur in mountains when there are ice crystals in the air, as in this case. The dust-like specks in this photograph are in fact the diamond dust ice crystals sparkling in the sunlight.

  The halos visible in this picture are: a 22° halo; a parhelic circle and parhelia; a lower tangent arc; infralateral arcs; an upper tangent arc with a suncave Parry arc; a heliac arc; a supralateral arc that touches a circumzenithal arc; and four Tape arcs (also known as 46° Parry arcs). 

  Some of these halo types are quite common, such as the 22° halo and the parhelia. Others, however, are less frequently seen, and some, such as the heliac arc and Tape arcs, are rarely witnessed.  

  Links in the image description will highlight features on the image. Mouse over the features for more detail.

  © Claudia Hinz
  Neklid, Klinovec, Czech Republic
  Latitude: 50° 24' 12'' N
  Longitude: 12° 56' 19'' E
  30 January 2014 1056 (Local Time)
  
  
  Camera direction: towards SSE
  Image P/S code: P.13.1
  Image I.D.: 4204
• 

  Parhelic circle and 120° parhelion

  This picture shows Cirrostratus fibratus and Cirrus spissatus clouds, together with some aircraft condensation trails (Cirrus homogenitus) at 3 and 4. However, there are also two photometeors of particular interest.

  The first is the bright spot near the centre of the photograph; this is a 120° parhelion, caused by at least two internal ice crystal reflections of sunlight. Rays entering the top face of  plate crystals reflect internally off two adjacent side faces and then exit through the lower face. The second 120° parhelion was not visible on this occasion. At the time of the photograph, the Sun’s azimuth was 274° and the azimuth of the parhelion was 034° (an azimuthal distance of 120° from the Sun).

  The second photometeor is a white band which passes through the 120° parhelion; this is a parhelic circle. The parhelic circle is a white horizontal band circling the sky at the same angular elevation above the horizon as the Sun. The vertical faces of many ice crystals each mirror the Sun around the sky to form the circle. Only part of the circle was visible on this day. The elevation of the horizontal band was 020° above the horizon. At the time of these phenomena, a bright circumhorizontal arc was also visible but is not shown in this photograph. 

  Links in the image description will highlight features on the image. Mouse over the features for more detail.

  © Frank Le Blancq
  Jersey Airport, Jersey
  Latitude: 49° 12' 27'' N
  Longitude: 2° 11' 43'' W
  02 August 2010 1836 (Local Time)
  
  
  Camera direction: towards NNE
  C_L = 0, C_M = 0, C_H = 6
  Image P/S code: S.13.1.6
  Image I.D.: 4702
• 

  Halo display

  This extreme wide-angle photograph from Antarctica shows a 22° halo with two parhelia, or sun dogs, at 2 and 3 on either side. Circling the horizon and lying horizontally through the parhelia and the Sun is the parhelic circle at 4 and 5. At the top and bottom of the 22° halo are an upper tangent arc and a lower tangent arc, which extend around the 22° halo as a faint luminous curve to meet each other and form a circumscribed halo.   

  Links in the image description will highlight features on the image. Mouse over the features for more detail.

  © Tatsuru Fujita
  1-1 Ichibachō, Chūō-ku, Chiba-shi, Chiba-ken 260-0855, Japan
  Latitude: 77° 19' 12'' S
  Longitude: 39° 42' 0'' E
  24 December 2004 1328 (Local Time)
  
  
  Camera direction: towards NE
  C_L = 0, C_M = 0, C_H = 6
  Image P/S code: S.13.1.1 6
  Image I.D.: 4796
• 

  Halo phenomena in Cirrostratus nebulosus

  Several halo phenomena have formed here in a featureless veil of Cirrostratus nebulosus. Surrounding the Sun is a 22° halo. Lying horizontally through the Sun is a parhelic circle at 3 and 4. On the parhelic circle (5, 6) and just outside of the 22° halo are two bright parhelia (commonly known as sun dogs or mock suns), seen at 7 and 8. At the top of the 22° halo is an upper tangent arc and a Parry arc.

  Links in the image description will highlight features on the image. Mouse over the features for more detail.

  © Usynina Luybov
  g. Uray, Khanty-Mansiyskiy avtonomnyy okrug, Russian Federation
  Latitude: 60° 7' 25'' N
  Longitude: 64° 46' 58'' E
  22 May 2015 0821 (Local Time)
  
  
  Camera direction: towards E
  C_L = 0, C_M = 0, C_H = 7
  Image P/S code: P.3.0
  Image I.D.: 4805
• 

  Altocumulus stratiformis translucidus cavum and a parhelion

  The cloud is Altocumulus stratiformis translucidus. It is identified as the species stratiformis by its extensive coverage of the sky. The cloud layer is thin and translucent and the position of the Sun can be seen, hence it is the variety translucidus. There are gaps between the cloud elements in places, which also identify it in these areas as perlucidus. An aircraft dissipation trail, or distrail, can be seen forming a clear trail through the cloud. This either has not widened appreciably or has largely filled in again with cloud over time. Above this is what appears to be a wider distrail; this is the linear variant of the supplementary feature cavum. The hole in the Altocumulus has filled with fallstreaks of ice cystals, resulting from the glaciation of the supercooled water droplets that form the Altocumulus. A parhelion (commonly known as a mock sun or sun dog) has formed by the refraction of sunlight through the ice crystals.

  Links in the image description will highlight features on the image. Mouse over the features for more detail.

  © Peter Ineson
  Lowmead QLD 4676, Australia
  Latitude: 24° 40' 43'' S
  Longitude: 151° 41' 55'' E
  27 July 2015 1549 (Local Time)
  
  
  Camera direction: towards NW
  C_L = 0, C_M = 3, C_H = /
  Image P/S code: S.4.16
  Image I.D.: 4962
• 

  Parhelion (sun dog or mock sun)

  This picture shows a close-up view of a parhelion, commonly known as a sun dog or mock sun. It is one of the bright, coloured spots (parhelia) that appear to the right and left of the Sun, and at the same elevation above the horizon.

  Parhelia are one of the most common halo phenomena. Sometimes only one parhelion may be visible (depending on the position of cirriform cloud), but typically both may be seen on either side of the Sun. When the Sun is low they lie on the 22° halo, if visible, but at higher elevations they appear at slightly greater angles from the Sun.

  Parhelia form by the refraction of light through hexagonal plate ice crystals where the large, flat surfaces are lying horizontally. They may appear intensely bright (hence the reference to “mock sun”) and are red-coloured on the side nearest the Sun.

  Links in the image description will highlight features on the image. Mouse over the features for more detail.

  © Amber Liggett
  Beaver, Pennsylvania, United States of America
  Latitude: 40° 42' 0'' N
  Longitude: 80° 18' 0'' E
  06 January 2016 1520 (Local Time)
  
  
  C_L = 0, C_M = 3, C_H = /
  Image P/S code: S.13.1.6.1
  Image I.D.: 5130
• 

  Halo display

  This halo display was formed by the refraction and reflection of sunlight through diamond dust on Mt. Zugspitze, Bavarian Alps, Germany (altitude 2 963 m). Diamond dust is a precipitation that falls from a clear sky in very small ice crystals, often so tiny that they appear suspended in the air. These ice crystals are visible mainly when they sparkle in the sunlight.

  The halo types visible in the picture are: 22° halo; parhelic circle; parhelia, seen at 1 and 2; upper tangent arc; upper Sun pillar; lower Sun pillar; 46°halo; infralateral arc; and supralateral arc.

  Some of these halo types are quite common, such as the 22° halo and parhelia, while others are less frequently seen. Some appear as relatively bright spots or arcs, while others are faint and difficult to identify.

  Links in the image description will highlight features on the image. Mouse over the features for more detail.

  © Claudia Hinz
  Mt. Zugspitze, Bavarian Alps, Germany
  Latitude: 47° 25' 16'' N
  Longitude: 10° 59' 11'' E
  14 January 2013 1050 (Local Time)
  
  
  Camera direction: towards SSE
  C_L = 0, C_M = 3, C_H = /
  Image P/S code: P.13.1.2
  Image I.D.: 5621
• 

  Cirrostratus fibratus with impressive halo phenomena

  The slow northward movement of a warm front produced a shield of high cloud over southern England, UK on the morning of 7 October 2010. The first Cirrus appeared before dawn, followed by variable and beautiful Cirrus and Cirrostratus during the morning – at one point a large shield of Cirrostratus with a sharp edge spread in quickly from the south-east. Later in the morning and into the afternoon, with more general Cirrus/ Cirrostratus, there was a fine and prolonged halo display, including two very bright 22° parhelia, segments of the parhelic circle, an upper tangent arc to the 22° halo (suncave with the Sun at 33° elevation at noon) with pronounced Parry arc and, for part of the afternoon, a very bright circumzenithal arc as well (not shown in the picture). Altocumulus spread in very rapidly from the south after 1500 UTC and the rest of the day and evening remained cloudy, with rain commencing at 1730 UTC.

  Links in the image description will highlight features on the image. Mouse over the features for more detail.

  © Stephen Burt
  Stratfield Mortimer, near Reading, Berkshire RG7, United Kingdom of Great Britain and Northern Ireland
  Latitude: 51° 22' 12'' N
  Longitude: 1° 2' 24'' W
  07 October 2010 1211 (Local Time)
  
  
  Camera direction: towards S
  C_L = 0, C_M = 3, C_H = /
  Image P/S code: S.3.2
  Image I.D.: 5684